socket: Free poll handle when resetting socket state

Since 07cb0be12 we are not closing the user provided FDs,
but the above change also resulted in memory leak during
ssh_disconnect that left the poll_handle allocated during
reset.

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

.clang-format

@@ -26,3 +26,4 @@ BreakAfterReturnType: ExceptShortType
 AlwaysBreakAfterReturnType: AllDefinitions
 AlignEscapedNewlines: Left
 ForEachMacros: ['ssh_callbacks_iterate']
+AlignConsecutiveMacros: 'Consecutive'

.gitignore

@@ -10,3 +10,4 @@ tags
 /build
 /obj*
 doc/tags.xml
+.DS_Store

.gitlab-ci.yml

@@ -27,13 +27,17 @@ workflow:
       when: never
     - if: '$CI_COMMIT_BRANCH'
 
-.build:
-  stage: build
+.build_options:
   variables:
     CMAKE_DEFAULT_OPTIONS: "-DCMAKE_BUILD_TYPE=RelWithDebInfo -DPICKY_DEVELOPER=ON"
+    CMAKE_DEFAULT_DEBUG_OPTIONS: "-DCMAKE_C_FLAGS='-O0 -g -ggdb' -DPICKY_DEVELOPER=ON"
     CMAKE_BUILD_OPTIONS: "-DWITH_BLOWFISH_CIPHER=ON -DWITH_SFTP=ON -DWITH_SERVER=ON -DWITH_ZLIB=ON -DWITH_PCAP=ON -DWITH_DEBUG_CRYPTO=ON -DWITH_DEBUG_PACKET=ON -DWITH_DEBUG_CALLTRACE=ON"
     CMAKE_TEST_OPTIONS: "-DUNIT_TESTING=ON -DCLIENT_TESTING=ON -DSERVER_TESTING=ON -DGSSAPI_TESTING=ON -DWITH_BENCHMARKS=ON -DFUZZ_TESTING=ON"
     CMAKE_OPTIONS: $CMAKE_DEFAULT_OPTIONS $CMAKE_BUILD_OPTIONS $CMAKE_TEST_OPTIONS
+
+.build:
+  extends: .build_options
+  stage: build
   before_script: &build
     - uname -a
     - cat /etc/os-release
@@ -121,7 +125,7 @@ review:
 ###############################################################################
 #                               CentOS builds                                 #
 ###############################################################################
-centos10s/openssl_3.2.x/x86_64:
+centos10s/openssl_3.5.x/x86_64:
   image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$CENTOS10_BUILD
   extends: .tests
   variables:
@@ -132,7 +136,7 @@ centos10s/openssl_3.2.x/x86_64:
       make -j$(nproc) &&
       ctest --output-on-failure
 
-centos10s/openssl_3.2.x/x86_64/fips:
+centos10s/openssl_3.5.x/x86_64/fips:
   extends: .fips
   image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$CENTOS10_BUILD
   variables:
@@ -143,7 +147,7 @@ centos10s/openssl_3.2.x/x86_64/fips:
       make -j$(nproc) &&
       OPENSSL_FORCE_FIPS_MODE=1 ctest --output-on-failure
 
-centos9s/openssl_3.0.x/x86_64:
+centos9s/openssl_3.5.x/x86_64:
   image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$CENTOS9_BUILD
   extends: .tests
   variables:
@@ -160,7 +164,7 @@ centos9s/mbedtls_2.x/x86_64:
   variables:
     CMAKE_ADDITIONAL_OPTIONS: "-DWITH_MBEDTLS=ON -DWITH_DEBUG_CRYPTO=ON -DWITH_BLOWFISH_CIPHER=OFF"
 
-centos9s/openssl_3.0.x/x86_64/fips:
+centos9s/openssl_3.5.x/x86_64/fips:
   extends: .fips
   image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$CENTOS9_BUILD
   script:
@@ -225,15 +229,15 @@ fedora/coverage:
         coverage_format: cobertura
         path: obj/coverage_xml.xml
 
-fedora/openssl_3.0.x/x86_64:
+fedora/openssl_3.x/x86_64:
   extends: .fedora
 
-fedora/openssl_3.0.x/x86_64/pkcs11-provider:
+fedora/openssl_3.x/x86_64/pkcs11-provider:
   variables:
     CMAKE_ADDITIONAL_OPTIONS: -DWITH_PKCS11_URI=ON -DWITH_PKCS11_PROVIDER=ON
   extends: .fedora
 
-fedora/openssl_3.0.x/x86_64/minimal:
+fedora/openssl_3.x/x86_64/minimal:
   extends: .fedora
   variables:
   script:
@@ -405,7 +409,7 @@ fedora/mingw32:
     paths:
       - obj-csbuild/
 
-fedora/csbuild/openssl_3.0.x:
+fedora/csbuild/openssl_3.x:
   extends: .csbuild
   script:
     - csbuild
@@ -435,6 +439,62 @@ fedora/csbuild/mbedtls:
       --color
       --print-current --print-fixed
 
+###############################################################################
+#                               Fedora abidiff                                #
+###############################################################################
+
+fedora/abidiff:
+  stage: analysis
+  variables:
+    GIT_DEPTH: "100"
+    CMAKE_OPTIONS: $CMAKE_DEFAULT_DEBUG_OPTIONS $CMAKE_BUILD_OPTIONS
+  image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$FEDORA_BUILD
+  before_script:
+    - uname -a
+    - cat /etc/os-release
+    - mount
+    - df -h
+    - cat /proc/swaps
+    - free -h
+    - |
+      # for merge requests
+      if [[ -n "$CI_MERGE_REQUEST_DIFF_BASE_SHA" ]]; then
+          export CI_COMMIT_BEFORE_SHA="$CI_MERGE_REQUEST_DIFF_BASE_SHA"
+      fi
+      # for branches run
+      if [[ -z "$CI_COMMIT_BEFORE_SHA" ]]; then
+          export CI_COMMIT_BEFORE_SHA=$(git rev-parse "${CI_COMMIT_SHA}~20")
+      fi
+
+      # Check if the commit exists in this branch
+      # This is not the case for a force push
+      git branch --contains $CI_COMMIT_BEFORE_SHA 2>/dev/null || export CI_COMMIT_BEFORE_SHA=$(git rev-parse "${CI_COMMIT_SHA}~20")
+
+    - mkdir -p obj-${CI_COMMIT_BEFORE_SHA}
+    - mkdir -p obj-${CI_COMMIT_SHA}
+
+    - export INSTALL_DIR1=$(pwd)/install/${CI_COMMIT_BEFORE_SHA}
+    - export INSTALL_DIR2=$(pwd)/install/${CI_COMMIT_SHA}
+  script:
+    - git checkout ${CI_COMMIT_BEFORE_SHA}
+    - pushd obj-${CI_COMMIT_BEFORE_SHA}
+    - cmake ${CMAKE_OPTIONS} -DCMAKE_INSTALL_PREFIX=${INSTALL_DIR1} .. &&
+      make -j$(nproc) && make -j$(nproc) install
+    - popd
+    - ls -l ${INSTALL_DIR1}/lib*/
+    - git checkout ${CI_COMMIT_SHA}
+    - pushd obj-${CI_COMMIT_SHA}
+    - cmake ${CMAKE_OPTIONS} -DCMAKE_INSTALL_PREFIX=${INSTALL_DIR2} .. &&
+      make -j$(nproc) && make -j$(nproc) install
+    - popd
+    - ls -l ${INSTALL_DIR2}/lib*/
+    - ./.gitlab-ci/checkabi.sh ${INSTALL_DIR1} ${INSTALL_DIR2}
+  tags:
+    - saas-linux-small-amd64
+  except:
+    - tags
+  only:
+    - merge_requests
 
 ###############################################################################
 #                               Ubuntu builds                                 #
@@ -447,7 +507,7 @@ ubuntu/openssl_3.0.x/x86_64:
 ###############################################################################
 #                               Alpine builds                                 #
 ###############################################################################
-alpine/openssl_3.0.x/musl:
+alpine/openssl_3.x/musl:
   image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$ALPINE_BUILD
   extends: .tests
   script:
@@ -464,10 +524,10 @@ alpine/openssl_3.0.x/musl:
 ###############################################################################
 #                             Tumbleweed builds                               #
 ###############################################################################
-tumbleweed/openssl_3.0.x/x86_64/gcc:
+tumbleweed/openssl_3.x/x86_64/gcc:
   extends: .tumbleweed
 
-tumbleweed/openssl_3.0.x/x86/gcc:
+tumbleweed/openssl_3.x/x86/gcc:
   extends: .tumbleweed
   script:
     - cmake
@@ -480,12 +540,12 @@ tumbleweed/openssl_3.0.x/x86/gcc:
       -DUNIT_TESTING=ON .. &&
       make -j$(nproc)
 
-tumbleweed/openssl_3.0.x/x86_64/gcc7:
+tumbleweed/openssl_3.x/x86_64/gcc7:
   extends: .tumbleweed
   variables:
     CMAKE_ADDITIONAL_OPTIONS: "-DCMAKE_C_COMPILER=gcc-7 -DCMAKE_CXX_COMPILER=g++-7"
 
-tumbleweed/openssl_3.0.x/x86/gcc7:
+tumbleweed/openssl_3.x/x86/gcc7:
   extends: .tumbleweed
   script:
     - cmake
@@ -497,7 +557,7 @@ tumbleweed/openssl_3.0.x/x86/gcc7:
       make -j$(nproc) &&
       ctest --output-on-failure
 
-tumbleweed/openssl_3.0.x/x86_64/clang:
+tumbleweed/openssl_3.x/x86_64/clang:
   extends: .tumbleweed
   variables:
     CMAKE_ADDITIONAL_OPTIONS: "-DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++"
@@ -507,6 +567,11 @@ tumbleweed/mbedtls-3.6.x/x86_64/gcc:
   variables:
     CMAKE_ADDITIONAL_OPTIONS: "-DKRB5_CONFIG=/usr/lib/mit/bin/krb5-config -DWITH_MBEDTLS=ON -DWITH_DEBUG_CRYPTO=ON -DWITH_BLOWFISH_CIPHER=OFF "
 
+tumbleweed/mbedtls-3.6.x/x86_64/clang:
+  extends: .tumbleweed
+  variables:
+    CMAKE_ADDITIONAL_OPTIONS: "-DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DKRB5_CONFIG=/usr/lib/mit/bin/krb5-config -DWITH_MBEDTLS=ON -DWITH_DEBUG_CRYPTO=ON -DWITH_BLOWFISH_CIPHER=OFF "
+
 tumbleweed/static-analysis:
   extends: .tests
   stage: analysis
@@ -568,9 +633,7 @@ freebsd/openssl_1.1.1/x86_64:
 # 2024-05-13: These jobs run out of the stages as they take extremely long and
 # usually timeout with the update to Gitlab 17.0
 .vs:
-  stage: analysis
-  needs: []
-  allow_failure: true
+  stage: test
   cache:
     key: vcpkg.${CI_JOB_NAME}
     paths:
@@ -662,3 +725,41 @@ coverity:
     when: on_failure
     paths:
       - obj/cov-int/*.txt
+
+###############################################################################
+#                                  MacOS                                      #
+###############################################################################
+.macos:
+  tags:
+    - saas-macos-medium-m1
+  image: macos-14-xcode-15
+  before_script:
+    - echo "MacOS runner started"
+    - brew update
+    - brew install cmake openssl cmocka doxygen
+    - mkdir obj && cd obj
+  only:
+    - branches@libssh/libssh-mirror
+    - branches@cryptomilk/libssh-mirror
+    - branches@jjelen/libssh-mirror
+    - branches@marco.fortina/libssh-mirror
+
+# TODO add -DFUZZ_TESTING=ON clang cant find _LLVMFuzzerInitialize on arm64
+macos-m1:
+  extends: .macos
+  variables:
+    HOMEBREW_NO_AUTO_UPDATE: 1
+    CMAKE_DEFAULT_OPTIONS: "-DCMAKE_BUILD_TYPE=RelWithDebInfo -DPICKY_DEVELOPER=ON"
+    CMAKE_BUILD_OPTIONS: "-DWITH_BLOWFISH_CIPHER=ON -DWITH_SFTP=ON -DWITH_SERVER=ON -DWITH_ZLIB=ON -DWITH_PCAP=ON -DWITH_DEBUG_CRYPTO=ON -DWITH_DEBUG_PACKET=ON -DWITH_DEBUG_CALLTRACE=ON"
+    CMAKE_TEST_OPTIONS: "-DUNIT_TESTING=ON"
+    CMAKE_OPTIONS: $CMAKE_DEFAULT_OPTIONS $CMAKE_BUILD_OPTIONS $CMAKE_TEST_OPTIONS
+  stage: test
+  script:
+    - cmake $CMAKE_OPTIONS .. &&
+      make -j$(sysctl -n hw.logicalcpu) &&
+      ctest --output-on-failure
+  artifacts:
+    expire_in: 1 week
+    when: on_failure
+    paths:
+      - obj/

.gitlab-ci/checkabi.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+
+INSTALL_DIR1=${1}
+INSTALL_DIR2=${2}
+
+abidiff \
+    --headers-dir1 "${INSTALL_DIR1}/include/libssh/" \
+    --headers-dir2 "${INSTALL_DIR2}/include/libssh/" \
+    "${INSTALL_DIR1}/lib64/libssh.so" \
+    "${INSTALL_DIR2}/lib64/libssh.so" \
+    --fail-no-debug-info
+abiret=$?
+
+ABIDIFF_ERROR=$(((abiret & 0x01) != 0))
+ABIDIFF_USAGE_ERROR=$(((abiret & 0x02) != 0))
+ABIDIFF_ABI_CHANGE=$(((abiret & 0x04) != 0))
+ABIDIFF_ABI_INCOMPATIBLE_CHANGE=$(((abiret & 0x08) != 0))
+ABIDIFF_UNKNOWN_BIT_SET=$(((abiret & 0xf0) != 0))
+
+if [ $ABIDIFF_ERROR -ne 0 ]; then
+    echo "abidiff reported ABIDIFF_ERROR."
+    exit 1
+fi
+if [ $ABIDIFF_USAGE_ERROR -ne 0 ]; then
+    echo "abidiff reported ABIDIFF_USAGE_ERROR."
+    exit 1
+fi
+if [ $ABIDIFF_UNKNOWN_BIT_SET -ne 0 ]; then
+    echo "abidiff reported ABIDIFF_UNKNOWN_BIT_SET."
+    exit 1
+fi
+
+if [ $ABIDIFF_ABI_INCOMPATIBLE_CHANGE -ne 0 ]; then
+    echo "abidiff result ABIDIFF_ABI_INCOMPATIBLE_CHANGE, this breaks the API!"
+    exit 1
+fi
+
+if [ $ABIDIFF_ABI_CHANGE -ne 0 ]; then
+  echo "Ignoring abidiff result ABI_CHANGE"
+fi
+
+exit 0

.gitlab/merge_request_templates/default.md

@@ -0,0 +1,16 @@
+Add a description of the new feature/bug fix. Reference any relevant bugs.
+
+## Checklist
+ * [ ] Commits have `Signed-off-by:` with name/author being identical to the commit author
+ * [ ] Code modified for feature
+ * [ ] Test suite updated with functionality tests
+ * [ ] Test suite updated with negative tests
+ * [ ] Documentation updated
+ * [ ] The project pipelines timeout is [extended](https://docs.gitlab.com/ee/ci/pipelines/settings.html#set-a-limit-for-how-long-jobs-can-run) at least to 2 hours.
+
+## Reviewer's checklist:
+ * [ ] Any issues marked for closing are addressed
+ * [ ] There is a test suite reasonably covering new functionality or modifications
+ * [ ] Function naming, parameters, return values, types, etc., are consistent and according to [CONTRIBUTING.md](https://gitlab.com/libssh/libssh-mirror/-/blob/master/CONTRIBUTING.md)
+ * [ ] This feature/change has adequate documentation added
+ * [ ] No obvious mistakes in the code

CHANGELOG

@@ -1,35 +1,6 @@
 CHANGELOG
 =========
 
-version 0.11.2 (released 2025-06-24)
- * Security:
-   * CVE-2025-4877 - Write beyond bounds in binary to base64 conversion
-   * CVE-2025-4878 - Use of uninitialized variable in privatekey_from_file()
-   * CVE-2025-5318 - Likely read beyond bounds in sftp server handle management
-   * CVE-2025-5351 - Double free in functions exporting keys
-   * CVE-2025-5372 - ssh_kdf() returns a success code on certain failures
-   * CVE-2025-5449 - Likely read beyond bounds in sftp server message decoding
-   * CVE-2025-5987 - Invalid return code for chacha20 poly1305 with OpenSSL
- * Compatibility
-   * Fixed compatibility with CPM.cmake
-   * Compatibility with OpenSSH 10.0
-   * Tests compatibility with new Dropbear releases
-   * Removed p11-kit remoting from the pkcs11 testsuite
- * Bugfixes
-   * Implement missing packet filter for DH GEX
-   * Properly process the SSH2_MSG_DEBUG message
-   * Allow escaping quotes in quoted arguments to ssh configuration
-   * Do not fail with unknown match keywords in ssh configuration
-   * Process packets before selecting signature algorithm during authentication
-   * Do not fail hard when the SFTP status message is not sent by noncompliant
-     servers
-
-version 0.11.1 (released 2024-08-30)
- * Fixed default TTY modes that are set when stdin is not connected to tty (#270)
- * Fixed zlib cleanup procedure, which could crash on i386
- * Various test fixes improving their stability
- * Fixed cygwin build
-
 version 0.11.0 (released 2024-07-31)
   * Deprecations and Removals:
     * Dropped support for DSA

CMakeLists.txt

@@ -9,7 +9,7 @@ list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules")
 include(DefineCMakeDefaults)
 include(DefineCompilerFlags)
 
-project(libssh VERSION 0.11.2 LANGUAGES C)
+project(libssh VERSION 0.11.00 LANGUAGES C)
 
 # global needed variable
 set(APPLICATION_NAME ${PROJECT_NAME})
@@ -21,7 +21,7 @@ set(APPLICATION_NAME ${PROJECT_NAME})
 #     Increment AGE. Set REVISION to 0
 #   If the source code was changed, but there were no interface changes:
 #     Increment REVISION.
-set(LIBRARY_VERSION "4.10.2")
+set(LIBRARY_VERSION "4.10.0")
 set(LIBRARY_SOVERSION "4")
 
 # where to look first for cmake modules, before ${CMAKE_ROOT}/Modules/ is checked
@@ -41,6 +41,8 @@ macro_ensure_out_of_source_build("${PROJECT_NAME} requires an out of source buil
 # Copy library files to a lib sub-directory
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib")
 
+set(LIBSSSH_PC_REQUIRES_PRIVATE "")
+
 # search for libraries
 if (WITH_ZLIB)
     find_package(ZLIB REQUIRED)
@@ -66,6 +68,7 @@ find_package(Threads)
 
 if (WITH_GSSAPI)
     find_package(GSSAPI)
+    list(APPEND LIBSSH_PC_REQUIRES_PRIVATE ${GSSAPI_PC_REQUIRES})
 endif (WITH_GSSAPI)
 
 if (WITH_NACL)
@@ -249,9 +252,15 @@ message(STATUS "Benchmarks: ${WITH_BENCHMARKS}")
 message(STATUS "Symbol versioning: ${WITH_SYMBOL_VERSIONING}")
 message(STATUS "Allow ABI break: ${WITH_ABI_BREAK}")
 message(STATUS "Release is final: ${WITH_FINAL}")
+if (WITH_HERMETIC_USR)
+    message(STATUS "User global client config: ${USR_GLOBAL_CLIENT_CONFIG}")
+endif ()
 message(STATUS "Global client config: ${GLOBAL_CLIENT_CONFIG}")
 if (WITH_SERVER)
-message(STATUS "Global bind config: ${GLOBAL_BIND_CONFIG}")
+    if (WITH_HERMETIC_USR)
+        message(STATUS "User global bind config: ${USR_GLOBAL_BIND_CONFIG}")
+    endif ()
+    message(STATUS "Global bind config: ${GLOBAL_BIND_CONFIG}")
 endif()
 message(STATUS "********************************************")
 

CONTRIBUTING.md

@@ -117,6 +117,25 @@ libssh Developer's Certificate of Origin for each patch, or inside each
 patch. Just the sign-off message is all that is required once we've
 received the initial email.
 
+## Continuous Integration
+
+Contributing patches through Merge Request workflow on Gitlab allows us to run
+various checks on various configuration as part of Gitlab CI. Unfortunately,
+some pipelines are slower (as they involve building dependencies) so the default
+timeout of 1 hour needs to be extended at least to 2 hours. This can be done in
+project settings of your libssh fork:
+
+https://docs.gitlab.com/ee/ci/pipelines/settings.html#set-a-limit-for-how-long-jobs-can-run
+
+Otherwise you will encounter errors like these, usually on visualstudio builds:
+
+```
+ERROR: Job failed: execution took longer than 1h0m0s seconds
+The script exceeded the maximum execution time set for the job
+```
+
+Note, that the built dependencies are cached so after successful build in your
+namespace, the rebuilds should be much faster.
 
 # Coding conventions in the libssh tree
 
@@ -517,6 +536,37 @@ Bad example:
             break;
     }
 
+## ABI Versioning and Symbol Management
+
+To maintain [ABI](https://en.wikipedia.org/wiki/Application_binary_interface) stability
+and ensure backward compatibility, libssh uses **symbol versioning** to track and manage
+exported functions and variables. This allows libssh to introduce new symbols or modify
+existing functions in an ABI-compatible way.
+
+When introducing a new symbol:
+
+1. Use the `LIBSSH_API` macro to mark the symbol as part of the public API.
+2. If you have [abimap](https://github.com/ansasaki/abimap) installed, the new symbols are
+automatically generated in the `src/libssh_dev.map` file in the **build** directory and used automatically for building the updated library. But, depending on the version of `abimap` under use, you may face linker errors like: `unable to find version dependency LIBSSH_4_9_0`. In this case, you need to manually replace the existing `src/libssh.map` file with the generated `libssh_dev.map` file to update the symbol versioning.
+3. If you do not have abimap installed, the modified/added symbols must manually be added to the
+`src/libssh.map` file. The symbols must be added in the following format (assuming that 4_10_0 is the latest released version):
+
+```
+LIBSSH_AFTER_4_10_0
+{
+    global:
+        new_function;
+        new_variable;
+} LIBSSH_4_10_0;
+```
+4. After following either of the above steps, the library can be successfully built and
+tested without any linker errors.
+
+5. When submitting the patch, make sure that any new symbols have been added to `libssh.map` as described in step 3, so that the new additions may not be excluded from the next release due to human error.
+
+Also, to maintain ABI compatibility, existing symbols must not be removed. Instead, they can
+be marked as deprecated using the `LIBSSH_DEPRECATED` macro. This allows the symbol to be
+removed in a future release without breaking the ABI.
 
 Have fun and happy libssh hacking!
 

ConfigureChecks.cmake

@@ -226,6 +226,7 @@ if (GCRYPT_FOUND)
     endif (GCRYPT_VERSION VERSION_GREATER "1.4.6")
     if (NOT GCRYPT_VERSION VERSION_LESS "1.7.0")
         set(HAVE_GCRYPT_CHACHA_POLY 1)
+        set(HAVE_GCRYPT_CURVE25519 1)
     endif (NOT GCRYPT_VERSION VERSION_LESS "1.7.0")
 endif (GCRYPT_FOUND)
 
@@ -236,6 +237,13 @@ if (MBEDTLS_FOUND)
     set(CMAKE_REQUIRED_INCLUDES "${MBEDTLS_INCLUDE_DIR}/mbedtls")
     check_include_file(chacha20.h HAVE_MBEDTLS_CHACHA20_H)
     check_include_file(poly1305.h HAVE_MBEDTLS_POLY1305_H)
+    if (MBEDTLS_VERSION VERSION_LESS "3.0.0")
+        check_symbol_exists(MBEDTLS_ECP_DP_CURVE25519_ENABLED "config.h" HAVE_MBEDTLS_CURVE25519)
+    else()
+        check_symbol_exists(MBEDTLS_ECP_DP_CURVE25519_ENABLED "mbedtls_config.h" HAVE_MBEDTLS_CURVE25519)
+    endif()
+
+
     if (WITH_BLOWFISH_CIPHER)
         check_include_file(blowfish.h HAVE_BLOWFISH)
     endif()

DefineOptions.cmake

@@ -27,6 +27,7 @@ option(WITH_INSECURE_NONE "Enable insecure none cipher and MAC algorithms (not s
 option(WITH_EXEC "Enable libssh to execute arbitrary commands from configuration files or options (match exec, proxy commands and OpenSSH-based proxy-jumps)." ON)
 option(FUZZ_TESTING "Build with fuzzer for the server and client (automatically enables none cipher!)" OFF)
 option(PICKY_DEVELOPER "Build with picky developer flags" OFF)
+option(WITH_HERMETIC_USR "Build with support for hermetic /usr/" OFF)
 
 if (WITH_ZLIB)
     set(WITH_LIBZ ON)
@@ -59,6 +60,11 @@ if (NOT GLOBAL_CLIENT_CONFIG)
   set(GLOBAL_CLIENT_CONFIG "/etc/ssh/ssh_config")
 endif (NOT GLOBAL_CLIENT_CONFIG)
 
+if (WITH_HERMETIC_USR)
+  set(USR_GLOBAL_BIND_CONFIG "/usr${GLOBAL_BIND_CONFIG}")
+  set(USR_GLOBAL_CLIENT_CONFIG "/usr${GLOBAL_CLIENT_CONFIG}")
+endif (WITH_HERMETIC_USR)
+
 if (FUZZ_TESTING)
   set(WITH_INSECURE_NONE ON)
 endif (FUZZ_TESTING)

INSTALL

@@ -38,14 +38,16 @@ First, you need to configure the compilation, using CMake. Go inside the
 `build` dir. Create it if it doesn't exist.
 
 GNU/Linux, MacOS X, MSYS/MinGW:
-
-    cmake -DUNIT_TESTING=ON -DCMAKE_INSTALL_PREFIX=/usr -DCMAKE_BUILD_TYPE=Debug ..
+    cmake -DCMAKE_INSTALL_PREFIX=/usr -DCMAKE_BUILD_TYPE=Debug ..
     make
 
 On Windows you should choose a makefile generator with -G or use
 
     cmake-gui.exe ..
 
+To enable building tests use -DUNIT_TESTING=ON. For this, the
+[cmocka](https://cmocka.org) dependency is required.
+
 To enable additional client tests against a local OpenSSH server, add the
 compile option -DCLIENT_TESTING=ON. These tests require an OpenSSH
 server package and some wrapper libraries (see optional requirements) to

cmake/Modules/FindGSSAPI.cmake

@@ -11,6 +11,8 @@
 #  GSSAPI_INCLUDE_DIR - the GSSAPI include directory
 #  GSSAPI_LIBRARIES - Link these to use GSSAPI
 #  GSSAPI_DEFINITIONS - Compiler switches required for using GSSAPI
+#  GSSAPI_PC_REQUIRES - pkg-config module name if found, needed for
+#                       Requires.private for static linking
 #
 #=============================================================================
 #  Copyright (c) 2013 Andreas Schneider <asn@cryptomilk.org>
@@ -24,12 +26,23 @@
 #=============================================================================
 #
 
+set(_mit_modname "mit-krb5-gssapi")
+set(_heimdal_modname "heimdal-gssapi")
+
+if(NOT _GSSAPI_ROOT_HINTS AND NOT _GSSAPI_ROOT_PATHS)
+    find_package(PkgConfig QUIET)
+    if (PKG_CONFIG_FOUND)
+        pkg_search_module(_GSSAPI ${_mit_modname} ${_heimdal_modname})
+    endif()
+endif()
+
 find_path(GSSAPI_ROOT_DIR
     NAMES
         include/gssapi.h
         include/gssapi/gssapi.h
     HINTS
         ${_GSSAPI_ROOT_HINTS}
+        "${_GSSAPI_INCLUDEDIR}"
     PATHS
         ${_GSSAPI_ROOT_PATHS}
 )
@@ -317,9 +330,15 @@ endif (GSSAPI_FLAVOR_HEIMDAL)
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(GSSAPI DEFAULT_MSG GSSAPI_LIBRARIES GSSAPI_INCLUDE_DIR)
 
-if (GSSAPI_INCLUDE_DIRS AND GSSAPI_LIBRARIES)
-    set(GSSAPI_FOUND TRUE)
-endif (GSSAPI_INCLUDE_DIRS AND GSSAPI_LIBRARIES)
+if(GSSAPI_FOUND)
+    if(_GSSAPI_FOUND) # via pkg-config
+        if (GSSAPI_FLAVOR_MIT)
+            set(GSSAPI_PC_REQUIRES ${_mit_modname})
+        elseif (GSSAPI_FLAVOR_HEIMDAL)
+            set(GSSAPI_PC_REQUIRES ${_heimdal_modname})
+        endif()
+    endif()
+endif()
 
-# show the GSSAPI_INCLUDE_DIRS and GSSAPI_LIBRARIES variables only in the advanced view
-mark_as_advanced(GSSAPI_INCLUDE_DIRS GSSAPI_LIBRARIES)
+# show the GSSAPI_INCLUDE_DIR and GSSAPI_LIBRARIES variables only in the advanced view
+mark_as_advanced(GSSAPI_INCLUDE_DIR GSSAPI_LIBRARIES)

cmake/Modules/FindMbedTLS.cmake

@@ -72,21 +72,23 @@ find_library(MBEDTLS_X509_LIBRARY
 set(MBEDTLS_LIBRARIES ${MBEDTLS_SSL_LIBRARY} ${MBEDTLS_CRYPTO_LIBRARY}
         ${MBEDTLS_X509_LIBRARY})
 
+# mbedtls 2.8
 if (MBEDTLS_INCLUDE_DIR AND EXISTS "${MBEDTLS_INCLUDE_DIR}/mbedtls/version.h")
-    # mbedtls 2.8
     file(STRINGS "${MBEDTLS_INCLUDE_DIR}/mbedtls/version.h" _mbedtls_version_str REGEX
             "^#[\t ]*define[\t ]+MBEDTLS_VERSION_STRING[\t ]+\"[0-9]+.[0-9]+.[0-9]+\"")
 
-    string(REGEX REPLACE "^.*MBEDTLS_VERSION_STRING.*([0-9]+.[0-9]+.[0-9]+).*"
+    string(REGEX REPLACE "^.*MBEDTLS_VERSION_STRING.*([0-9]+\\.[0-9]+\\.[0-9]+).*$"
             "\\1" MBEDTLS_VERSION "${_mbedtls_version_str}")
-elseif (MBEDTLS_INCLUDE_DIR AND EXISTS "${MBEDTLS_INCLUDE_DIR}/mbedtls/build_info.h")
-    # mbedtls 3.6
-    file(STRINGS "${MBEDTLS_INCLUDE_DIR}/mbedtls/version.h" _mbedtls_version_str REGEX
+endif()
+
+# mbedtls 3.6
+if (NOT MBEDTLS_VERSION AND MBEDTLS_INCLUDE_DIR AND EXISTS "${MBEDTLS_INCLUDE_DIR}/mbedtls/build_info.h")
+    file(STRINGS "${MBEDTLS_INCLUDE_DIR}/mbedtls/build_info.h" _mbedtls_version_str REGEX
             "^#[\t ]*define[\t ]+MBEDTLS_VERSION_STRING[\t ]+\"[0-9]+.[0-9]+.[0-9]+\"")
 
-    string(REGEX REPLACE "^.*MBEDTLS_VERSION_STRING.*([0-9]+.[0-9]+.[0-9]+).*"
+    string(REGEX REPLACE "^.*MBEDTLS_VERSION_STRING.*([0-9]+\\.[0-9]+\\.[0-9]+).*$"
             "\\1" MBEDTLS_VERSION "${_mbedtls_version_str}")
-endif ()
+endif()
 
 include(FindPackageHandleStandardArgs)
 if (MBEDTLS_VERSION)

config.h.cmake

@@ -9,9 +9,11 @@
 #cmakedefine SOURCEDIR "${SOURCEDIR}"
 
 /* Global bind configuration file path */
+#cmakedefine USR_GLOBAL_BIND_CONFIG "${USR_GLOBAL_BIND_CONFIG}"
 #cmakedefine GLOBAL_BIND_CONFIG "${GLOBAL_BIND_CONFIG}"
 
 /* Global client configuration file path */
+#cmakedefine USR_GLOBAL_CLIENT_CONFIG "${USR_GLOBAL_CLIENT_CONFIG}"
 #cmakedefine GLOBAL_CLIENT_CONFIG "${GLOBAL_CLIENT_CONFIG}"
 
 /************************** HEADER FILES *************************/
@@ -85,6 +87,9 @@
 /* Define to 1 if you have elliptic curve cryptography in openssl */
 #cmakedefine HAVE_OPENSSL_ECC 1
 
+/* Define to 1 if mbedTLS supports curve25519 */
+#cmakedefine HAVE_MBEDTLS_CURVE25519 1
+
 /* Define to 1 if you have elliptic curve cryptography in gcrypt */
 #cmakedefine HAVE_GCRYPT_ECC 1
 
@@ -97,6 +102,9 @@
 /* Define to 1 if you have gcrypt with ChaCha20/Poly1305 support */
 #cmakedefine HAVE_GCRYPT_CHACHA_POLY 1
 
+/* Define to 1 if you have gcrypt with curve25519 support */
+#cmakedefine HAVE_GCRYPT_CURVE25519
+
 /*************************** FUNCTIONS ***************************/
 
 /* Define to 1 if you have the `EVP_chacha20' function. */

doc/command.dox

@@ -91,4 +91,10 @@ that it used:
 }
 @endcode
 
+Warning: In a single channel, only ONE command can be executed!
+If you want to executed multiple commands, allocate separate channels for
+them or consider opening interactive shell.
+Attempting to run multiple consecutive commands in one channel will fail.
+
+
 */

doc/mainpage.dox

@@ -19,7 +19,7 @@ the interesting functions as you go.
 
 The libssh library provides:
 
- - <strong>Key Exchange Methods</strong>: <i>curve25519-sha256, curve25519-sha256@libssh.org, ecdh-sha2-nistp256, ecdh-sha2-nistp384, ecdh-sha2-nistp521</i>, diffie-hellman-group1-sha1, diffie-hellman-group14-sha1
+ - <strong>Key Exchange Methods</strong>: <i>sntrup761x25519-sha512@openssh.com, curve25519-sha256, curve25519-sha256@libssh.org, ecdh-sha2-nistp256, ecdh-sha2-nistp384, ecdh-sha2-nistp521</i>, diffie-hellman-group1-sha1, diffie-hellman-group14-sha1
  - <strong>Public Key Algorithms</strong>: ssh-ed25519, ecdsa-sha2-nistp256, ecdsa-sha2-nistp384, ecdsa-sha2-nistp521, ssh-rsa, rsa-sha2-512, rsa-sha2-256
  - <strong>Ciphers</strong>: <i>aes256-ctr, aes192-ctr, aes128-ctr</i>, aes256-cbc (rijndael-cbc@lysator.liu.se), aes192-cbc, aes128-cbc, 3des-cbc, blowfish-cbc
  - <strong>Compression Schemes</strong>: zlib, <i>zlib@openssh.com</i>, none

doc/that_style/that_style.css

@@ -303,7 +303,6 @@ span.lineno {
   padding-right: 4px;
   text-align: right;
   color: black;
-  height: 100px;
   white-space: pre;
   border-right: 3px solid #1d7567;
   background-color: #323232; }

examples/authentication.c

@@ -66,7 +66,6 @@ int authenticate_kbdint(ssh_session session, const char *password)
                     return SSH_AUTH_ERROR;
                 }
 
-                buffer[sizeof(buffer) - 1] = '\0';
                 if ((p = strchr(buffer, '\n'))) {
                     *p = '\0';
                 }
@@ -75,7 +74,7 @@ int authenticate_kbdint(ssh_session session, const char *password)
                     return SSH_AUTH_ERROR;
                 }
 
-                memset(buffer, 0, strlen(buffer));
+                memset(buffer, 0, sizeof(buffer));
             } else {
                 if (password && strstr(prompt, "Password:")) {
                     answer = password;
@@ -147,7 +146,7 @@ int authenticate_console(ssh_session session)
 
     // Try to authenticate
     rc = ssh_userauth_none(session, NULL);
-    if (rc == SSH_AUTH_ERROR) {
+    if (rc == SSH_AUTH_ERROR || !ssh_is_connected(session)) {
         error(session);
         return rc;
     }
@@ -156,7 +155,7 @@ int authenticate_console(ssh_session session)
     while (rc != SSH_AUTH_SUCCESS) {
         if (method & SSH_AUTH_METHOD_GSSAPI_MIC){
             rc = ssh_userauth_gssapi(session);
-            if(rc == SSH_AUTH_ERROR) {
+            if (rc == SSH_AUTH_ERROR || !ssh_is_connected(session)) {
                 error(session);
                 return rc;
             } else if (rc == SSH_AUTH_SUCCESS) {
@@ -166,7 +165,7 @@ int authenticate_console(ssh_session session)
         // Try to authenticate with public key first
         if (method & SSH_AUTH_METHOD_PUBLICKEY) {
             rc = ssh_userauth_publickey_auto(session, NULL, NULL);
-            if (rc == SSH_AUTH_ERROR) {
+            if (rc == SSH_AUTH_ERROR || !ssh_is_connected(session)) {
                 error(session);
                 return rc;
             } else if (rc == SSH_AUTH_SUCCESS) {
@@ -206,7 +205,7 @@ int authenticate_console(ssh_session session)
         // Try to authenticate with keyboard interactive";
         if (method & SSH_AUTH_METHOD_INTERACTIVE) {
             rc = authenticate_kbdint(session, NULL);
-            if (rc == SSH_AUTH_ERROR) {
+            if (rc == SSH_AUTH_ERROR || !ssh_is_connected(session)) {
                 error(session);
                 return rc;
             } else if (rc == SSH_AUTH_SUCCESS) {
@@ -221,7 +220,7 @@ int authenticate_console(ssh_session session)
         // Try to authenticate with password
         if (method & SSH_AUTH_METHOD_PASSWORD) {
             rc = ssh_userauth_password(session, NULL, password);
-            if (rc == SSH_AUTH_ERROR) {
+            if (rc == SSH_AUTH_ERROR || !ssh_is_connected(session)) {
                 error(session);
                 return rc;
             } else if (rc == SSH_AUTH_SUCCESS) {

examples/connect_ssh.c

@@ -21,47 +21,50 @@ clients must be made or how a client should react.
 #include "examples_common.h"
 #include <stdio.h>
 
-ssh_session connect_ssh(const char *host, const char *user,int verbosity){
-  ssh_session session = NULL;
-  int auth=0;
+ssh_session connect_ssh(const char *host, const char *user, int verbosity)
+{
+    ssh_session session = NULL;
+    int auth = 0;
 
-  session=ssh_new();
-  if (session == NULL) {
-    return NULL;
-  }
-
-  if(user != NULL){
-    if (ssh_options_set(session, SSH_OPTIONS_USER, user) < 0) {
-      ssh_free(session);
-      return NULL;
+    session = ssh_new();
+    if (session == NULL) {
+        return NULL;
     }
-  }
 
-  if (ssh_options_set(session, SSH_OPTIONS_HOST, host) < 0) {
-    ssh_free(session);
-    return NULL;
-  }
-  ssh_options_set(session, SSH_OPTIONS_LOG_VERBOSITY, &verbosity);
-  if(ssh_connect(session)){
-    fprintf(stderr,"Connection failed : %s\n",ssh_get_error(session));
+    if (user != NULL) {
+        if (ssh_options_set(session, SSH_OPTIONS_USER, user) < 0) {
+            ssh_free(session);
+            return NULL;
+        }
+    }
+
+    if (ssh_options_set(session, SSH_OPTIONS_HOST, host) < 0) {
+        ssh_free(session);
+        return NULL;
+    }
+    ssh_options_set(session, SSH_OPTIONS_LOG_VERBOSITY, &verbosity);
+    if (ssh_connect(session)) {
+        fprintf(stderr, "Connection failed : %s\n", ssh_get_error(session));
+        ssh_disconnect(session);
+        ssh_free(session);
+        return NULL;
+    }
+    if (verify_knownhost(session) < 0) {
+        ssh_disconnect(session);
+        ssh_free(session);
+        return NULL;
+    }
+    auth = authenticate_console(session);
+    if (auth == SSH_AUTH_SUCCESS) {
+        return session;
+    } else if (auth == SSH_AUTH_DENIED) {
+        fprintf(stderr, "Authentication failed\n");
+    } else {
+        fprintf(stderr,
+                "Error while authenticating : %s\n",
+                ssh_get_error(session));
+    }
     ssh_disconnect(session);
     ssh_free(session);
     return NULL;
-  }
-  if(verify_knownhost(session)<0){
-    ssh_disconnect(session);
-    ssh_free(session);
-    return NULL;
-  }
-  auth=authenticate_console(session);
-  if(auth==SSH_AUTH_SUCCESS){
-    return session;
-  } else if(auth==SSH_AUTH_DENIED){
-    fprintf(stderr,"Authentication failed\n");
-  } else {
-    fprintf(stderr,"Error while authenticating : %s\n",ssh_get_error(session));
-  }
-  ssh_disconnect(session);
-  ssh_free(session);
-  return NULL;
 }

examples/examples_common.h

@@ -16,7 +16,7 @@ clients must be made or how a client should react.
 #include <libssh/libssh.h>
 
 /** Zero a structure */
-#define ZERO_STRUCT(x) memset((char *)&(x), 0, sizeof(x))
+#define ZERO_STRUCT(x) memset(&(x), 0, sizeof(x))
 
 int authenticate_console(ssh_session session);
 int authenticate_kbdint(ssh_session session, const char *password);

examples/keygen2.c

@@ -350,7 +350,12 @@ int main(int argc, char *argv[])
         goto end;
     }
 
-    if (arguments.action_list && arguments.file) {
+    if (arguments.file == NULL) {
+        fprintf(stderr, "Error: Missing argument file\n");
+        goto end;
+    }
+
+    if (arguments.action_list) {
         list_fingerprint(arguments.file);
         goto end;
     }

examples/libssh_scp.c

@@ -119,6 +119,10 @@ static struct location *parse_location(char *loc)
     struct location *location = NULL;
     char *ptr = NULL;
 
+    if (loc == NULL) {
+        return NULL;
+    }
+
     location = malloc(sizeof(struct location));
     if (location == NULL) {
         return NULL;

examples/scp_download.c

@@ -32,151 +32,163 @@ static const char *createcommand =
     "cd /tmp/libssh_tests && date > a && date > b && mkdir c && date > d";
 static char *host = NULL;
 
-static void usage(const char *argv0){
-  fprintf(stderr,"Usage : %s [options] host\n"
-      "sample tiny scp downloader client - libssh-%s\n"
-	  "This program will create files in /tmp and try to fetch them\n",
-//      "Options :\n",
-//      "  -r : use RSA to verify host public key\n",
-      argv0,
-      ssh_version(0));
-  exit(0);
+static void usage(const char *argv0)
+{
+    fprintf(stderr,
+            "Usage : %s [options] host\n"
+            "sample tiny scp downloader client - libssh-%s\n"
+            "This program will create files in /tmp and try to fetch them\n",
+            argv0,
+            ssh_version(0));
+    exit(0);
 }
 
-static int opts(int argc, char **argv){
-  int i;
-  while((i=getopt(argc,argv,"v"))!=-1){
-    switch(i){
-      case 'v':
-        verbosity++;
-        break;
-      default:
-        fprintf(stderr,"unknown option %c\n",optopt);
+static int opts(int argc, char **argv)
+{
+    int i;
+
+    while ((i = getopt(argc, argv, "v")) != -1) {
+        switch (i) {
+        case 'v':
+            verbosity++;
+            break;
+        default:
+            fprintf(stderr, "unknown option %c\n", optopt);
+            usage(argv[0]);
+            return -1;
+        }
+    }
+    host = argv[optind];
+    if (host == NULL)
         usage(argv[0]);
+    return 0;
+}
+
+static void create_files(ssh_session session)
+{
+    ssh_channel channel = ssh_channel_new(session);
+    char buffer[1];
+    int rc;
+
+    if (channel == NULL) {
+        fprintf(stderr, "Error creating channel: %s\n", ssh_get_error(session));
+        exit(EXIT_FAILURE);
+    }
+    if (ssh_channel_open_session(channel) != SSH_OK) {
+        fprintf(stderr, "Error creating channel: %s\n", ssh_get_error(session));
+        ssh_channel_free(channel);
+        exit(EXIT_FAILURE);
+    }
+    if (ssh_channel_request_exec(channel, createcommand) != SSH_OK) {
+        fprintf(stderr,
+                "Error executing command: %s\n",
+                ssh_get_error(session));
+        ssh_channel_close(channel);
+        ssh_channel_free(channel);
+        exit(EXIT_FAILURE);
+    }
+    while (!ssh_channel_is_eof(channel)) {
+        rc = ssh_channel_read(channel, buffer, 1, 1);
+        if (rc != 1) {
+            fprintf(stderr, "Error reading from channel\n");
+            ssh_channel_close(channel);
+            ssh_channel_free(channel);
+            return;
+        }
+
+        rc = write(1, buffer, 1);
+        if (rc < 0) {
+            fprintf(stderr, "Error writing to buffer\n");
+            ssh_channel_close(channel);
+            ssh_channel_free(channel);
+            return;
+        }
+    }
+    ssh_channel_close(channel);
+    ssh_channel_free(channel);
+}
+
+static int fetch_files(ssh_session session)
+{
+    int size;
+    char buffer[BUF_SIZE];
+    int mode;
+    char *filename = NULL;
+    int r;
+    ssh_scp scp = ssh_scp_new(session,
+                              SSH_SCP_READ | SSH_SCP_RECURSIVE,
+                              "/tmp/libssh_tests/*");
+    if (ssh_scp_init(scp) != SSH_OK) {
+        fprintf(stderr, "error initializing scp: %s\n", ssh_get_error(session));
+        ssh_scp_free(scp);
         return -1;
     }
-  }
-  host = argv[optind];
-  if(host == NULL)
-	  usage(argv[0]);
-  return 0;
+    printf("Trying to download 3 files (a,b,d) and 1 directory (c)\n");
+    do {
+        r = ssh_scp_pull_request(scp);
+        switch (r) {
+        case SSH_SCP_REQUEST_NEWFILE:
+            size = ssh_scp_request_get_size(scp);
+            filename = strdup(ssh_scp_request_get_filename(scp));
+            mode = ssh_scp_request_get_permissions(scp);
+            printf("downloading file %s, size %d, perms 0%o\n",
+                   filename,
+                   size,
+                   mode);
+            free(filename);
+            ssh_scp_accept_request(scp);
+            r = ssh_scp_read(scp, buffer, sizeof(buffer));
+            if (r == SSH_ERROR) {
+                fprintf(stderr,
+                        "Error reading scp: %s\n",
+                        ssh_get_error(session));
+                ssh_scp_close(scp);
+                ssh_scp_free(scp);
+                return -1;
+            }
+            printf("done\n");
+            break;
+        case SSH_ERROR:
+            fprintf(stderr, "Error: %s\n", ssh_get_error(session));
+            ssh_scp_close(scp);
+            ssh_scp_free(scp);
+            return -1;
+        case SSH_SCP_REQUEST_WARNING:
+            fprintf(stderr, "Warning: %s\n", ssh_scp_request_get_warning(scp));
+            break;
+        case SSH_SCP_REQUEST_NEWDIR:
+            filename = strdup(ssh_scp_request_get_filename(scp));
+            mode = ssh_scp_request_get_permissions(scp);
+            printf("downloading directory %s, perms 0%o\n", filename, mode);
+            free(filename);
+            ssh_scp_accept_request(scp);
+            break;
+        case SSH_SCP_REQUEST_ENDDIR:
+            printf("End of directory\n");
+            break;
+        case SSH_SCP_REQUEST_EOF:
+            printf("End of requests\n");
+            goto end;
+        }
+    } while (1);
+end:
+    ssh_scp_close(scp);
+    ssh_scp_free(scp);
+    return 0;
 }
 
-static void create_files(ssh_session session){
-	ssh_channel channel=ssh_channel_new(session);
-	char buffer[1];
-        int rc;
-
-	if(channel == NULL){
-		fprintf(stderr,"Error creating channel: %s\n",ssh_get_error(session));
-		exit(EXIT_FAILURE);
-	}
-	if(ssh_channel_open_session(channel) != SSH_OK){
-		fprintf(stderr,"Error creating channel: %s\n",ssh_get_error(session));
-		ssh_channel_free(channel);
-		exit(EXIT_FAILURE);
-	}
-	if(ssh_channel_request_exec(channel,createcommand) != SSH_OK){
-		fprintf(stderr,"Error executing command: %s\n",ssh_get_error(session));
-		ssh_channel_close(channel);
-		ssh_channel_free(channel);
-		exit(EXIT_FAILURE);
-	}
-	while(!ssh_channel_is_eof(channel)){
-		rc = ssh_channel_read(channel,buffer,1,1);
-                if (rc != 1) {
-                    fprintf(stderr, "Error reading from channel\n");
-                    ssh_channel_close(channel);
-                    ssh_channel_free(channel);
-                    return;
-                }
-
-                rc = write(1, buffer, 1);
-                if (rc < 0) {
-                    fprintf(stderr, "Error writing to buffer\n");
-                    ssh_channel_close(channel);
-                    ssh_channel_free(channel);
-                    return;
-                }
-	}
-	ssh_channel_close(channel);
-	ssh_channel_free(channel);
-}
-
-
-static int fetch_files(ssh_session session){
-  int size;
-  char buffer[BUF_SIZE];
-  int mode;
-  char *filename = NULL;
-  int r;
-  ssh_scp scp=ssh_scp_new(session, SSH_SCP_READ | SSH_SCP_RECURSIVE, "/tmp/libssh_tests/*");
-  if(ssh_scp_init(scp) != SSH_OK){
-	  fprintf(stderr,"error initializing scp: %s\n",ssh_get_error(session));
-	  ssh_scp_free(scp);
-	  return -1;
-  }
-  printf("Trying to download 3 files (a,b,d) and 1 directory (c)\n");
-  do {
-
-	  r=ssh_scp_pull_request(scp);
-	  switch(r){
-	  case SSH_SCP_REQUEST_NEWFILE:
-		  size=ssh_scp_request_get_size(scp);
-		  filename=strdup(ssh_scp_request_get_filename(scp));
-		  mode=ssh_scp_request_get_permissions(scp);
-		  printf("downloading file %s, size %d, perms 0%o\n",filename,size,mode);
-		  free(filename);
-		  ssh_scp_accept_request(scp);
-		  r=ssh_scp_read(scp,buffer,sizeof(buffer));
-		  if(r==SSH_ERROR){
-			  fprintf(stderr,"Error reading scp: %s\n",ssh_get_error(session));
-			  ssh_scp_close(scp);
-			  ssh_scp_free(scp);
-			  return -1;
-		  }
-		  printf("done\n");
-		  break;
-	  case SSH_ERROR:
-		  fprintf(stderr,"Error: %s\n",ssh_get_error(session));
-		  ssh_scp_close(scp);
-		  ssh_scp_free(scp);
-		  return -1;
-	  case SSH_SCP_REQUEST_WARNING:
-		  fprintf(stderr,"Warning: %s\n",ssh_scp_request_get_warning(scp));
-		  break;
-	  case SSH_SCP_REQUEST_NEWDIR:
-		  filename=strdup(ssh_scp_request_get_filename(scp));
-		  mode=ssh_scp_request_get_permissions(scp);
-		  printf("downloading directory %s, perms 0%o\n",filename,mode);
-		  free(filename);
-		  ssh_scp_accept_request(scp);
-		  break;
-	  case SSH_SCP_REQUEST_ENDDIR:
-		  printf("End of directory\n");
-		  break;
-	  case SSH_SCP_REQUEST_EOF:
-		  printf("End of requests\n");
-		  goto end;
-	  }
-  } while (1);
-  end:
-  ssh_scp_close(scp);
-  ssh_scp_free(scp);
-  return 0;
-}
-
-int main(int argc, char **argv){
-  ssh_session session = NULL;
-  if(opts(argc,argv)<0)
-    return EXIT_FAILURE;
-  session=connect_ssh(host,NULL,verbosity);
-  if(session == NULL)
-	  return EXIT_FAILURE;
-  create_files(session);
-  fetch_files(session);
-  ssh_disconnect(session);
-  ssh_free(session);
-  ssh_finalize();
-  return 0;
+int main(int argc, char **argv)
+{
+    ssh_session session = NULL;
+    if (opts(argc, argv) < 0)
+        return EXIT_FAILURE;
+    session = connect_ssh(host, NULL, verbosity);
+    if (session == NULL)
+        return EXIT_FAILURE;
+    create_files(session);
+    fetch_files(session);
+    ssh_disconnect(session);
+    ssh_free(session);
+    ssh_finalize();
+    return 0;
 }

examples/senddata.c

@@ -5,60 +5,60 @@
 
 #define LIMIT 0x100000000UL
 
-int main(void) {
-  ssh_session session = NULL;
-  ssh_channel channel;
-  char buffer[1024*1024];
-  int rc;
-  uint64_t total=0;
-  uint64_t lastshown=4096;
-  session = connect_ssh("localhost", NULL, 0);
-  if (session == NULL) {
-    return 1;
-  }
-
-  channel = ssh_channel_new(session);
-  if (channel == NULL) {
-    ssh_disconnect(session);
-    return 1;
-  }
-
-  rc = ssh_channel_open_session(channel);
-  if (rc < 0) {
-    ssh_channel_close(channel);
-    ssh_disconnect(session);
-    return 1;
-  }
-
-  rc = ssh_channel_request_exec(channel, "cat > /dev/null");
-  if (rc < 0) {
-    ssh_channel_close(channel);
-    ssh_disconnect(session);
-    return 1;
-  }
-
-
-  while ((rc = ssh_channel_write(channel, buffer, sizeof(buffer))) > 0) {
-    total += rc;
-    if(total/2 >= lastshown){
-      printf("written %llx\n", (long long unsigned int) total);
-      lastshown=total;
+int main(void)
+{
+    ssh_session session = NULL;
+    ssh_channel channel = NULL;
+    char buffer[1024 * 1024] = {0};
+    int rc;
+    uint64_t total = 0;
+    uint64_t lastshown = 4096;
+    session = connect_ssh("localhost", NULL, 0);
+    if (session == NULL) {
+        return 1;
     }
-    if(total > LIMIT)
-      break;
-  }
 
-  if (rc < 0) {
-    printf("error : %s\n",ssh_get_error(session));
+    channel = ssh_channel_new(session);
+    if (channel == NULL) {
+        ssh_disconnect(session);
+        return 1;
+    }
+
+    rc = ssh_channel_open_session(channel);
+    if (rc < 0) {
+        ssh_channel_close(channel);
+        ssh_disconnect(session);
+        return 1;
+    }
+
+    rc = ssh_channel_request_exec(channel, "cat > /dev/null");
+    if (rc < 0) {
+        ssh_channel_close(channel);
+        ssh_disconnect(session);
+        return 1;
+    }
+
+    while ((rc = ssh_channel_write(channel, buffer, sizeof(buffer))) > 0) {
+        total += rc;
+        if (total / 2 >= lastshown) {
+            printf("written %llx\n", (long long unsigned int)total);
+            lastshown = total;
+        }
+        if (total > LIMIT)
+            break;
+    }
+
+    if (rc < 0) {
+        printf("error : %s\n", ssh_get_error(session));
+        ssh_channel_close(channel);
+        ssh_disconnect(session);
+        return 1;
+    }
+
+    ssh_channel_send_eof(channel);
     ssh_channel_close(channel);
+
     ssh_disconnect(session);
-    return 1;
-  }
 
-  ssh_channel_send_eof(channel);
-  ssh_channel_close(channel);
-
-  ssh_disconnect(session);
-
-  return 0;
+    return 0;
 }

examples/ssh_server.c

@@ -192,9 +192,6 @@ static struct argp argp = {options, parse_opt, args_doc, doc, NULL, NULL, NULL};
 static int
 parse_opt(int argc, char **argv, ssh_bind sshbind)
 {
-    int no_default_keys = 0;
-    int rsa_already_set = 0;
-    int ecdsa_already_set = 0;
     int key;
 
     while((key = getopt(argc, argv, "a:e:k:p:P:r:u:v")) != -1) {
@@ -202,16 +199,10 @@ parse_opt(int argc, char **argv, ssh_bind sshbind)
             ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_BINDPORT_STR, optarg);
         } else if (key == 'k') {
             ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_HOSTKEY, optarg);
-            /* We can't track the types of keys being added with this
-            option, so let's ensure we keep the keys we're adding
-            by just not setting the default keys */
-            no_default_keys = 1;
         } else if (key == 'r') {
             ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_HOSTKEY, optarg);
-            rsa_already_set = 1;
         } else if (key == 'e') {
             ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_HOSTKEY, optarg);
-            ecdsa_already_set = 1;
         } else if (key == 'a') {
             strncpy(authorizedkeys, optarg, DEF_STR_SIZE-1);
         } else if (key == 'u') {
@@ -256,12 +247,6 @@ parse_opt(int argc, char **argv, ssh_bind sshbind)
 
     ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_BINDADDR, argv[optind]);
 
-    if (!no_default_keys) {
-        set_default_keys(sshbind,
-                         rsa_already_set,
-                         ecdsa_already_set);
-    }
-
     return 0;
 }
 #endif /* HAVE_ARGP_H */

examples/sshnetcat.c

@@ -40,222 +40,236 @@ clients must be made or how a client should react.
 #endif
 
 char *host = NULL;
-const char *desthost="localhost";
-const char *port="22";
+const char *desthost = "localhost";
+const char *port = "22";
 
 #ifdef WITH_PCAP
 #include <libssh/pcap.h>
-char *pcap_file=NULL;
+char *pcap_file = NULL;
 #endif
 
 static void usage(void)
 {
-  fprintf(stderr,"Usage : sshnetcat [user@]host forwarded_host forwarded_port\n");
-  exit(1);
+    fprintf(stderr,
+            "Usage : sshnetcat [user@]host forwarded_host forwarded_port\n");
+    exit(1);
 }
 
-static int opts(int argc, char **argv){
+static int opts(int argc, char **argv)
+{
     int i;
-    while((i=getopt(argc,argv,"P:"))!=-1){
-        switch(i){
+    while ((i = getopt(argc, argv, "P:")) != -1) {
+        switch (i) {
 #ifdef WITH_PCAP
-        	case 'P':
-        		pcap_file=optarg;
-        		break;
+        case 'P':
+            pcap_file = optarg;
+            break;
 #endif
-            default:
-                fprintf(stderr,"unknown option %c\n",optopt);
-                usage();
+        default:
+            fprintf(stderr, "unknown option %c\n", optopt);
+            usage();
         }
     }
-    if(optind < argc)
-        host=argv[optind++];
-    if(optind < argc)
-        desthost=argv[optind++];
-    if(optind < argc)
-        port=argv[optind++];
-    if(host==NULL)
+    if (optind < argc)
+        host = argv[optind++];
+    if (optind < argc)
+        desthost = argv[optind++];
+    if (optind < argc)
+        port = argv[optind++];
+    if (host == NULL)
         usage();
     return 0;
 }
 
-static void select_loop(ssh_session session,ssh_channel channel){
-	fd_set fds;
-	struct timeval timeout;
-	char buffer[BUF_SIZE];
-	/* channels will be set to the channels to poll.
-	 * outchannels will contain the result of the poll
-	 */
-	ssh_channel channels[2], outchannels[2];
-	int lus;
-	int eof=0;
-	int maxfd;
-	int ret;
-	while(channel){
-		do{
+static void select_loop(ssh_session session, ssh_channel channel)
+{
+    fd_set fds;
+    struct timeval timeout;
+    char buffer[BUF_SIZE];
+    /* channels will be set to the channels to poll.
+     * outchannels will contain the result of the poll
+     */
+    ssh_channel channels[2], outchannels[2];
+    int lus;
+    int eof = 0;
+    int maxfd;
+    int ret;
+    while (channel) {
+        do {
             int fd;
 
             ZERO_STRUCT(fds);
-			FD_ZERO(&fds);
-			if(!eof)
-				FD_SET(0,&fds);
-			timeout.tv_sec=30;
-			timeout.tv_usec=0;
+            FD_ZERO(&fds);
+            if (!eof)
+                FD_SET(0, &fds);
+            timeout.tv_sec = 30;
+            timeout.tv_usec = 0;
 
             fd = ssh_get_fd(session);
             if (fd == -1) {
-                fprintf(stderr, "Error getting the session file descriptor: %s\n",
-                                ssh_get_error(session));
+                fprintf(stderr,
+                        "Error getting the session file descriptor: %s\n",
+                        ssh_get_error(session));
                 return;
             }
             FD_SET(fd, &fds);
             maxfd = fd + 1;
 
-			channels[0]=channel; // set the first channel we want to read from
-			channels[1]=NULL;
-			ret=ssh_select(channels,outchannels,maxfd,&fds,&timeout);
-			if(ret==EINTR)
-				continue;
-			if(FD_ISSET(0,&fds)){
-				lus=read(0,buffer,sizeof(buffer));
-				if(lus)
-					ssh_channel_write(channel,buffer,lus);
-				else {
-					eof=1;
-					ssh_channel_send_eof(channel);
-				}
-			}
-			if(channel && ssh_channel_is_closed(channel)){
-				ssh_channel_free(channel);
-				channel=NULL;
-				channels[0]=NULL;
-			}
-			if(outchannels[0]){
-				while(channel && ssh_channel_is_open(channel) && ssh_channel_poll(channel,0)){
-					lus = ssh_channel_read(channel,buffer,sizeof(buffer),0);
-					if(lus==-1){
-						fprintf(stderr, "Error reading channel: %s\n",
-								ssh_get_error(session));
-						return;
-					}
-					if(lus==0){
-						ssh_channel_free(channel);
-						channel=channels[0]=NULL;
-					} else {
-						ret = write(1, buffer, lus);
-						if (ret < 0) {
-							fprintf(stderr, "Error writing to stdin: %s",
-								strerror(errno));
-							return;
-						}
-					}
-				}
-				while(channel && ssh_channel_is_open(channel) && ssh_channel_poll(channel,1)){ /* stderr */
-					lus = ssh_channel_read(channel, buffer, sizeof(buffer), 1);
-					if(lus==-1){
-						fprintf(stderr, "Error reading channel: %s\n",
-								ssh_get_error(session));
-						return;
-					}
-					if(lus==0){
-						ssh_channel_free(channel);
-						channel=channels[0]=NULL;
-					} else {
-						ret = write(2, buffer, lus);
-						if (ret < 0) {
-							fprintf(stderr, "Error writing to stderr: %s",
-								strerror(errno));
-							return;
-						}
+            channels[0] = channel; // set the first channel we want to read from
+            channels[1] = NULL;
+            ret = ssh_select(channels, outchannels, maxfd, &fds, &timeout);
+            if (ret == EINTR)
+                continue;
+            if (FD_ISSET(0, &fds)) {
+                lus = read(0, buffer, sizeof(buffer));
+                if (lus)
+                    ssh_channel_write(channel, buffer, lus);
+                else {
+                    eof = 1;
+                    ssh_channel_send_eof(channel);
+                }
+            }
+            if (channel && ssh_channel_is_closed(channel)) {
+                ssh_channel_free(channel);
+                channel = NULL;
+                channels[0] = NULL;
+            }
+            if (outchannels[0]) {
+                while (channel && ssh_channel_is_open(channel) &&
+                       ssh_channel_poll(channel, 0)) {
+                    lus = ssh_channel_read(channel, buffer, sizeof(buffer), 0);
+                    if (lus == -1) {
+                        fprintf(stderr,
+                                "Error reading channel: %s\n",
+                                ssh_get_error(session));
+                        return;
                     }
-				}
-			}
-			if(channel && ssh_channel_is_closed(channel)){
-				ssh_channel_free(channel);
-				channel=NULL;
-			}
-		} while (ret==EINTR || ret==SSH_EINTR);
-
-	}
+                    if (lus == 0) {
+                        ssh_channel_free(channel);
+                        channel = channels[0] = NULL;
+                    } else {
+                        ret = write(1, buffer, lus);
+                        if (ret < 0) {
+                            fprintf(stderr,
+                                    "Error writing to stdin: %s",
+                                    strerror(errno));
+                            return;
+                        }
+                    }
+                }
+                while (channel && ssh_channel_is_open(channel) &&
+                       ssh_channel_poll(channel, 1)) { /* stderr */
+                    lus = ssh_channel_read(channel, buffer, sizeof(buffer), 1);
+                    if (lus == -1) {
+                        fprintf(stderr,
+                                "Error reading channel: %s\n",
+                                ssh_get_error(session));
+                        return;
+                    }
+                    if (lus == 0) {
+                        ssh_channel_free(channel);
+                        channel = channels[0] = NULL;
+                    } else {
+                        ret = write(2, buffer, lus);
+                        if (ret < 0) {
+                            fprintf(stderr,
+                                    "Error writing to stderr: %s",
+                                    strerror(errno));
+                            return;
+                        }
+                    }
+                }
+            }
+            if (channel && ssh_channel_is_closed(channel)) {
+                ssh_channel_free(channel);
+                channel = NULL;
+            }
+        } while (ret == EINTR || ret == SSH_EINTR);
+    }
 }
 
-static void forwarding(ssh_session session){
+static void forwarding(ssh_session session)
+{
     ssh_channel channel;
     int r;
     channel = ssh_channel_new(session);
     r = ssh_channel_open_forward(channel, desthost, atoi(port), "localhost", 22);
-    if(r<0) {
-        printf("error forwarding port : %s\n",ssh_get_error(session));
+    if (r < 0) {
+        printf("error forwarding port : %s\n", ssh_get_error(session));
         return;
     }
-    select_loop(session,channel);
+    select_loop(session, channel);
 }
 
-static int client(ssh_session session){
-  int auth=0;
-  char *banner = NULL;
-  int state;
+static int client(ssh_session session)
+{
+    int auth = 0;
+    char *banner = NULL;
+    int state;
 
-  if (ssh_options_set(session, SSH_OPTIONS_HOST ,host) < 0)
-    return -1;
-  ssh_options_parse_config(session, NULL);
+    if (ssh_options_set(session, SSH_OPTIONS_HOST, host) < 0)
+        return -1;
+    ssh_options_parse_config(session, NULL);
 
-  if(ssh_connect(session)){
-      fprintf(stderr,"Connection failed : %s\n",ssh_get_error(session));
-      return -1;
-  }
-  state=verify_knownhost(session);
-  if (state != 0)
-  	return -1;
-  ssh_userauth_none(session, NULL);
-  banner=ssh_get_issue_banner(session);
-  if(banner){
-      printf("%s\n",banner);
-      free(banner);
-  }
-  auth=authenticate_console(session);
-  if(auth != SSH_AUTH_SUCCESS){
-  	return -1;
-  }
- 	forwarding(session);
-  return 0;
+    if (ssh_connect(session)) {
+        fprintf(stderr, "Connection failed : %s\n", ssh_get_error(session));
+        return -1;
+    }
+    state = verify_knownhost(session);
+    if (state != 0)
+        return -1;
+    ssh_userauth_none(session, NULL);
+    banner = ssh_get_issue_banner(session);
+    if (banner) {
+        printf("%s\n", banner);
+        free(banner);
+    }
+    auth = authenticate_console(session);
+    if (auth != SSH_AUTH_SUCCESS) {
+        return -1;
+    }
+    forwarding(session);
+    return 0;
 }
 
 #ifdef WITH_PCAP
 ssh_pcap_file pcap;
 void set_pcap(ssh_session session);
-void set_pcap(ssh_session session){
-	if(!pcap_file)
-		return;
-	pcap=ssh_pcap_file_new();
-	if(ssh_pcap_file_open(pcap,pcap_file) == SSH_ERROR){
-		printf("Error opening pcap file\n");
-		ssh_pcap_file_free(pcap);
-		pcap=NULL;
-		return;
-	}
-	ssh_set_pcap_file(session,pcap);
+void set_pcap(ssh_session session)
+{
+    if (!pcap_file)
+        return;
+    pcap = ssh_pcap_file_new();
+    if (ssh_pcap_file_open(pcap, pcap_file) == SSH_ERROR) {
+        printf("Error opening pcap file\n");
+        ssh_pcap_file_free(pcap);
+        pcap = NULL;
+        return;
+    }
+    ssh_set_pcap_file(session, pcap);
 }
 
 void cleanup_pcap(void);
 void cleanup_pcap(void)
 {
-	ssh_pcap_file_free(pcap);
-	pcap = NULL;
+    ssh_pcap_file_free(pcap);
+    pcap = NULL;
 }
 #endif
 
-int main(int argc, char **argv){
+int main(int argc, char **argv)
+{
     ssh_session session = NULL;
 
     session = ssh_new();
 
-    if(ssh_options_getopt(session, &argc, argv)) {
-      fprintf(stderr, "error parsing command line :%s\n",
-          ssh_get_error(session));
-      usage();
+    if (ssh_options_getopt(session, &argc, argv)) {
+        fprintf(stderr,
+                "error parsing command line :%s\n",
+                ssh_get_error(session));
+        usage();
     }
-    opts(argc,argv);
+    opts(argc, argv);
 #ifdef WITH_PCAP
     set_pcap(session);
 #endif

include/libssh/bignum.h

@@ -31,6 +31,7 @@ extern "C" {
 
 bignum ssh_make_string_bn(ssh_string string);
 ssh_string ssh_make_bignum_string(bignum num);
+ssh_string ssh_make_padded_bignum_string(bignum num, size_t pad_len);
 void ssh_print_bignum(const char *which, const_bignum num);
 
 #ifdef __cplusplus

include/libssh/callbacks.h

@@ -113,6 +113,17 @@ typedef void (*ssh_status_callback) (ssh_session session, float status,
 typedef void (*ssh_global_request_callback) (ssh_session session,
                                         ssh_message message, void *userdata);
 
+/**
+ * @brief SSH connect status callback. These are functions that report the
+ * status of the connection i,e. a function indicating the completed percentage
+ * of the connection
+ * steps.
+ * @param userdata Userdata to be passed to the callback function.
+ * @param status Percentage of connection status, going from 0.0 to 1.0
+ * once connection is done.
+ */
+typedef void (*ssh_connect_status_callback)(void *userdata, float status);
+
 /**
  * @brief Handles an SSH new channel open X11 request. This happens when the server
  * sends back an X11 connection attempt. This is a client-side API
@@ -181,7 +192,7 @@ struct ssh_callbacks_struct {
    * This function gets called during connection time to indicate the
    * percentage of connection steps completed.
    */
-  void (*connect_status_function)(void *userdata, float status);
+  ssh_connect_status_callback connect_status_function;
   /**
    * This function will be called each time a global request is received.
    */
@@ -325,6 +336,28 @@ typedef int (*ssh_gssapi_accept_sec_ctx_callback) (ssh_session session,
 typedef int (*ssh_gssapi_verify_mic_callback) (ssh_session session,
 		ssh_string mic, void *mic_buffer, size_t mic_buffer_size, void *userdata);
 
+/**
+ * @brief Handles an SSH new channel open "direct-tcpip" request. This
+ * happens when the client forwards an incoming TCP connection on a port it
+ * wants to forward to the destination. This is a server-side API
+ * @param session current session handler
+ * @param destination_address the address that the TCP connection connected to
+ * @param destination_port the port that the TCP connection connected to
+ * @param originator_address the originator IP address
+ * @param originator_port the originator port
+ * @param userdata Userdata to be passed to the callback function.
+ * @returns a valid ssh_channel handle if the request is to be allowed
+ * @returns NULL if the request should not be allowed
+ * @warning The channel pointer returned by this callback must be closed by the
+ * application.
+ */
+typedef ssh_channel (*ssh_channel_open_request_direct_tcpip_callback)(
+    ssh_session session,
+    const char *destination_address,
+    int destination_port,
+    const char *originator_address,
+    int originator_port,
+    void *userdata);
 
 /**
  * This structure can be used to implement a libssh server, with appropriate callbacks.
@@ -375,6 +408,12 @@ struct ssh_server_callbacks_struct {
   /* This function will be called when a MIC needs to be verified.
    */
   ssh_gssapi_verify_mic_callback gssapi_verify_mic_function;
+  /**
+   * This function will be called when an incoming "direct-tcpip"
+   * request is received.
+   */
+  ssh_channel_open_request_direct_tcpip_callback
+      channel_open_request_direct_tcpip_function;
 };
 typedef struct ssh_server_callbacks_struct *ssh_server_callbacks;
 

include/libssh/crypto.h

@@ -45,10 +45,11 @@
 #ifdef HAVE_OPENSSL_ECDH_H
 #include <openssl/ecdh.h>
 #endif
+#include "libssh/curve25519.h"
 #include "libssh/dh.h"
 #include "libssh/ecdh.h"
 #include "libssh/kex.h"
-#include "libssh/curve25519.h"
+#include "libssh/sntrup761.h"
 
 #define DIGEST_MAX_LEN 64
 
@@ -56,32 +57,34 @@
 #define AES_GCM_IVLEN  12
 
 enum ssh_key_exchange_e {
-  /* diffie-hellman-group1-sha1 */
-  SSH_KEX_DH_GROUP1_SHA1=1,
-  /* diffie-hellman-group14-sha1 */
-  SSH_KEX_DH_GROUP14_SHA1,
+    /* diffie-hellman-group1-sha1 */
+    SSH_KEX_DH_GROUP1_SHA1 = 1,
+    /* diffie-hellman-group14-sha1 */
+    SSH_KEX_DH_GROUP14_SHA1,
 #ifdef WITH_GEX
-  /* diffie-hellman-group-exchange-sha1 */
-  SSH_KEX_DH_GEX_SHA1,
-  /* diffie-hellman-group-exchange-sha256 */
-  SSH_KEX_DH_GEX_SHA256,
+    /* diffie-hellman-group-exchange-sha1 */
+    SSH_KEX_DH_GEX_SHA1,
+    /* diffie-hellman-group-exchange-sha256 */
+    SSH_KEX_DH_GEX_SHA256,
 #endif /* WITH_GEX */
-  /* ecdh-sha2-nistp256 */
-  SSH_KEX_ECDH_SHA2_NISTP256,
-  /* ecdh-sha2-nistp384 */
-  SSH_KEX_ECDH_SHA2_NISTP384,
-  /* ecdh-sha2-nistp521 */
-  SSH_KEX_ECDH_SHA2_NISTP521,
-  /* curve25519-sha256@libssh.org */
-  SSH_KEX_CURVE25519_SHA256_LIBSSH_ORG,
-  /* curve25519-sha256 */
-  SSH_KEX_CURVE25519_SHA256,
-  /* diffie-hellman-group16-sha512 */
-  SSH_KEX_DH_GROUP16_SHA512,
-  /* diffie-hellman-group18-sha512 */
-  SSH_KEX_DH_GROUP18_SHA512,
-  /* diffie-hellman-group14-sha256 */
-  SSH_KEX_DH_GROUP14_SHA256,
+    /* ecdh-sha2-nistp256 */
+    SSH_KEX_ECDH_SHA2_NISTP256,
+    /* ecdh-sha2-nistp384 */
+    SSH_KEX_ECDH_SHA2_NISTP384,
+    /* ecdh-sha2-nistp521 */
+    SSH_KEX_ECDH_SHA2_NISTP521,
+    /* curve25519-sha256@libssh.org */
+    SSH_KEX_CURVE25519_SHA256_LIBSSH_ORG,
+    /* curve25519-sha256 */
+    SSH_KEX_CURVE25519_SHA256,
+    /* diffie-hellman-group16-sha512 */
+    SSH_KEX_DH_GROUP16_SHA512,
+    /* diffie-hellman-group18-sha512 */
+    SSH_KEX_DH_GROUP18_SHA512,
+    /* diffie-hellman-group14-sha256 */
+    SSH_KEX_DH_GROUP14_SHA256,
+    /* sntrup761x25519-sha512@openssh.com */
+    SSH_KEX_SNTRUP761X25519_SHA512_OPENSSH_COM,
 };
 
 enum ssh_cipher_e {
@@ -125,9 +128,20 @@ struct ssh_crypto_struct {
     ssh_string ecdh_server_pubkey;
 #endif
 #ifdef HAVE_CURVE25519
+#ifdef HAVE_LIBCRYPTO
+    EVP_PKEY *curve25519_privkey;
+#elif defined(HAVE_GCRYPT_CURVE25519)
+    gcry_sexp_t curve25519_privkey;
+#else
     ssh_curve25519_privkey curve25519_privkey;
+#endif
     ssh_curve25519_pubkey curve25519_client_pubkey;
     ssh_curve25519_pubkey curve25519_server_pubkey;
+#endif
+#ifdef HAVE_SNTRUP761
+    ssh_sntrup761_privkey sntrup761_privkey;
+    ssh_sntrup761_pubkey sntrup761_client_pubkey;
+    ssh_sntrup761_ciphertext sntrup761_ciphertext;
 #endif
     ssh_string dh_server_signature; /* information used by dh_handshake. */
     size_t session_id_len;
@@ -223,9 +237,6 @@ int sshkdf_derive_key(struct ssh_crypto_struct *crypto,
                       size_t requested_len);
 
 int secure_memcmp(const void *s1, const void *s2, size_t n);
-#if defined(HAVE_LIBCRYPTO) && !defined(WITH_PKCS11_PROVIDER)
-ENGINE *pki_get_engine(void);
-#endif /* HAVE_LIBCRYPTO */
 
 void compress_cleanup(struct ssh_crypto_struct *crypto);
 

include/libssh/curve25519.h

@@ -50,6 +50,9 @@ int crypto_scalarmult(unsigned char *q, const unsigned char *n, const unsigned c
 typedef unsigned char ssh_curve25519_pubkey[CURVE25519_PUBKEY_SIZE];
 typedef unsigned char ssh_curve25519_privkey[CURVE25519_PRIVKEY_SIZE];
 
+int ssh_curve25519_init(ssh_session session);
+int curve25519_do_create_k(ssh_session session, ssh_curve25519_pubkey k);
+int ssh_curve25519_create_k(ssh_session session, ssh_curve25519_pubkey k);
 
 int ssh_client_curve25519_init(ssh_session session);
 void ssh_client_curve25519_remove_callbacks(ssh_session session);

include/libssh/kex.h

@@ -52,10 +52,10 @@ char *ssh_prefix_default_algos(enum ssh_kex_types_e algo, const char *list);
 char **ssh_space_tokenize(const char *chain);
 int ssh_get_kex1(ssh_session session);
 char *ssh_find_matching(const char *in_d, const char *what_d);
-const char *ssh_kex_get_supported_method(uint32_t algo);
-const char *ssh_kex_get_default_methods(uint32_t algo);
-const char *ssh_kex_get_fips_methods(uint32_t algo);
-const char *ssh_kex_get_description(uint32_t algo);
+const char *ssh_kex_get_supported_method(enum ssh_kex_types_e type);
+const char *ssh_kex_get_default_methods(enum ssh_kex_types_e type);
+const char *ssh_kex_get_fips_methods(enum ssh_kex_types_e type);
+const char *ssh_kex_get_description(enum ssh_kex_types_e type);
 char *ssh_client_select_hostkeys(ssh_session session);
 int ssh_send_rekex(ssh_session session);
 int server_set_kex(ssh_session session);

include/libssh/libcrypto.h

@@ -121,6 +121,15 @@ typedef BN_CTX* bignum_CTX;
 
 ssh_string pki_key_make_ecpoint_string(const EC_GROUP *g, const EC_POINT *p);
 int pki_key_ecgroup_name_to_nid(const char *group);
+
+#if defined(WITH_PKCS11_URI)
+#if defined(WITH_PKCS11_PROVIDER)
+int pki_load_pkcs11_provider(void);
+#else
+ENGINE *pki_get_engine(void);
+#endif
+#endif /* WITH_PKCS11_PROVIDER */
+
 #endif /* HAVE_LIBCRYPTO */
 
 #endif /* LIBCRYPTO_H_ */

include/libssh/libssh.h

@@ -49,9 +49,10 @@
   #endif
 #endif
 
-#include <stdarg.h>
-#include <stdint.h>
 #include <inttypes.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
 
 #ifdef _MSC_VER
   typedef int mode_t;
@@ -850,6 +851,7 @@ LIBSSH_API char *ssh_string_to_char(ssh_string str);
 #define SSH_STRING_FREE_CHAR(x) \
     do { if ((x) != NULL) { ssh_string_free_char(x); x = NULL; } } while(0)
 LIBSSH_API void ssh_string_free_char(char *s);
+LIBSSH_API int ssh_string_cmp(ssh_string s1, ssh_string s2);
 
 LIBSSH_API int ssh_getpass(const char *prompt, char *buf, size_t len, int echo,
     int verify);
@@ -874,6 +876,7 @@ LIBSSH_API const char* ssh_get_cipher_in(ssh_session session);
 LIBSSH_API const char* ssh_get_cipher_out(ssh_session session);
 LIBSSH_API const char* ssh_get_hmac_in(ssh_session session);
 LIBSSH_API const char* ssh_get_hmac_out(ssh_session session);
+LIBSSH_API const char *ssh_get_supported_methods(enum ssh_kex_types_e type);
 
 LIBSSH_API ssh_buffer ssh_buffer_new(void);
 LIBSSH_API void ssh_buffer_free(ssh_buffer buffer);
@@ -886,6 +889,27 @@ LIBSSH_API void *ssh_buffer_get(ssh_buffer buffer);
 LIBSSH_API uint32_t ssh_buffer_get_len(ssh_buffer buffer);
 LIBSSH_API int ssh_session_set_disconnect_message(ssh_session session, const char *message);
 
+/* SSHSIG hashes data independently from the key used, so we use a new enum
+   to avoid confusion. See
+   https://gitlab.com/jas/ietf-sshsig-format/-/blob/cc70a225cbd695d5a6f20aaebdb4b92b0818e43a/ietf-sshsig-format.md#L137
+ */
+enum sshsig_digest_e {
+    SSHSIG_DIGEST_SHA2_256 = 0,
+    SSHSIG_DIGEST_SHA2_512 = 1,
+};
+
+LIBSSH_API int sshsig_sign(const void *data,
+                           size_t data_length,
+                           ssh_key privkey,
+                           const char *sig_namespace,
+                           enum sshsig_digest_e hash_alg,
+                           char **signature);
+LIBSSH_API int sshsig_verify(const void *data,
+                             size_t data_length,
+                             const char *signature,
+                             const char *sig_namespace,
+                             ssh_key *sign_key);
+
 #ifndef LIBSSH_LEGACY_0_4
 #include "libssh/legacy.h"
 #endif

include/libssh/messages.h

@@ -28,6 +28,7 @@ struct ssh_auth_request {
     int method;
     char *password;
     struct ssh_key_struct *pubkey;
+    struct ssh_key_struct *server_pubkey;
     char *sigtype;
     enum ssh_publickey_state_e signature_state;
     char kbdint_response;

include/libssh/options.h

@@ -25,6 +25,7 @@
 extern "C" {
 #endif
 
+int ssh_config_parse(ssh_session session, FILE *fp, bool global);
 int ssh_config_parse_file(ssh_session session, const char *filename);
 int ssh_config_parse_string(ssh_session session, const char *input);
 int ssh_options_set_algo(ssh_session session,

include/libssh/pki.h

@@ -51,6 +51,15 @@
 #define SSH_KEY_FLAG_PRIVATE 0x0002
 #define SSH_KEY_FLAG_PKCS11_URI 0x0004
 
+/* Constants matching the Lightweight Secure Shell Signature Format */
+/* https://datatracker.ietf.org/doc/draft-josefsson-sshsig-format */
+#define SSHSIG_VERSION            0x01
+#define SSHSIG_MAGIC_PREAMBLE     "SSHSIG"
+#define SSHSIG_MAGIC_PREAMBLE_LEN (sizeof(SSHSIG_MAGIC_PREAMBLE) - 1)
+#define SSHSIG_BEGIN_SIGNATURE    "-----BEGIN SSH SIGNATURE-----"
+#define SSHSIG_END_SIGNATURE      "-----END SSH SIGNATURE-----"
+#define SSHSIG_LINE_LENGTH        76
+
 struct ssh_key_struct {
     enum ssh_keytypes_e type;
     int flags;
@@ -63,11 +72,12 @@ struct ssh_key_struct {
     mbedtls_pk_context *pk;
     mbedtls_ecdsa_context *ecdsa;
 #elif defined(HAVE_LIBCRYPTO)
-    /* This holds either ENGINE key for PKCS#11 support or just key in
-     * high-level format */
+    /* This holds either ENGINE/PROVIDER key for PKCS#11 support
+     * or just key in high-level format */
     EVP_PKEY *key;
+    /* keep this around for FIPS mode so we can parse the public keys. We won't
+     * be able to use them nor use the private keys though */
     uint8_t *ed25519_pubkey;
-    uint8_t *ed25519_privkey;
 #endif /* HAVE_LIBGCRYPT */
 #ifndef HAVE_LIBCRYPTO
     ed25519_pubkey *ed25519_pubkey;
@@ -76,6 +86,11 @@ struct ssh_key_struct {
     ssh_string sk_application;
     ssh_buffer cert;
     enum ssh_keytypes_e cert_type;
+
+    /* Security Key specific private data */
+    uint8_t sk_flags;
+    ssh_string sk_key_handle;
+    ssh_string sk_reserved;
 };
 
 struct ssh_signature_struct {
@@ -127,6 +142,11 @@ enum ssh_digest_e ssh_key_hash_from_name(const char *name);
     ((kt) >= SSH_KEYTYPE_ECDSA_P256_CERT01 &&\
      (kt) <= SSH_KEYTYPE_ED25519_CERT01))
 
+#define is_sk_key_type(kt)                                             \
+    ((kt) == SSH_KEYTYPE_SK_ECDSA || (kt) == SSH_KEYTYPE_SK_ED25519 || \
+     (kt) == SSH_KEYTYPE_SK_ECDSA_CERT01 ||                            \
+     (kt) == SSH_KEYTYPE_SK_ED25519_CERT01)
+
 /* SSH Signature Functions */
 ssh_signature ssh_signature_new(void);
 void ssh_signature_free(ssh_signature sign);

include/libssh/pki_priv.h

@@ -61,6 +61,7 @@ enum ssh_digest_e ssh_key_type_to_hash(ssh_session session,
                                        enum ssh_keytypes_e type);
 
 /* SSH Key Functions */
+ssh_key pki_key_dup_common_init(const ssh_key key, int demote);
 ssh_key pki_key_dup(const ssh_key key, int demote);
 int pki_key_generate_rsa(ssh_key key, int parameter);
 int pki_key_generate_ecdsa(ssh_key key, int parameter);
@@ -148,6 +149,7 @@ int pki_signature_from_ed25519_blob(ssh_signature sig, ssh_string sig_blob);
 int pki_privkey_build_ed25519(ssh_key key,
                               ssh_string pubkey,
                               ssh_string privkey);
+int pki_pubkey_build_ed25519(ssh_key key, ssh_string pubkey);
 
 /* PKI Container OpenSSH */
 ssh_key ssh_pki_openssh_pubkey_import(const char *text_key);
@@ -162,6 +164,11 @@ int pki_uri_import(const char *uri_name, ssh_key *key, enum ssh_key_e key_type);
 #endif /* WITH_PKCS11_URI */
 
 bool ssh_key_size_allowed_rsa(int min_size, ssh_key key);
+
+/* Security Key Helper Functions */
+int pki_buffer_pack_sk_priv_data(ssh_buffer buffer, const ssh_key key);
+int pki_buffer_unpack_sk_priv_data(ssh_buffer buffer, ssh_key key);
+
 #ifdef __cplusplus
 }
 #endif

include/libssh/priv.h

@@ -30,10 +30,11 @@
 #define _LIBSSH_PRIV_H
 
 #include <limits.h>
+#include <stdbool.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
-#include <stdbool.h>
+#include <time.h>
 
 #if !defined(HAVE_STRTOULL)
 # if defined(HAVE___STRTOULL)
@@ -164,6 +165,9 @@ int ssh_gettimeofday(struct timeval *__p, void *__t);
 
 #define gettimeofday ssh_gettimeofday
 
+struct tm *ssh_localtime(const time_t *timer, struct tm *result);
+# define localtime_r ssh_localtime
+
 #define _XCLOSESOCKET closesocket
 
 # ifdef HAVE_IO_H
@@ -329,7 +333,7 @@ int decompress_buffer(ssh_session session,ssh_buffer buf, size_t maxlen);
 /* match.c */
 int match_pattern_list(const char *string, const char *pattern,
     size_t len, int dolower);
-int match_hostname(const char *host, const char *pattern, unsigned int len);
+int match_hostname(const char *host, const char *pattern, size_t len);
 #ifndef _WIN32
 int match_cidr_address_list(const char *address,
                             const char *addrlist,
@@ -353,10 +357,10 @@ int ssh_connector_remove_event(ssh_connector connector);
 #define SAFE_FREE(x) do { if ((x) != NULL) {free(x); x=NULL;} } while(0)
 
 /** Zero a structure */
-#define ZERO_STRUCT(x) memset((char *)&(x), 0, sizeof(x))
+#define ZERO_STRUCT(x) memset(&(x), 0, sizeof(x))
 
 /** Zero a structure given a pointer to the structure */
-#define ZERO_STRUCTP(x) do { if ((x) != NULL) memset((char *)(x), 0, sizeof(*(x))); } while(0)
+#define ZERO_STRUCTP(x) do { if ((x) != NULL) memset((x), 0, sizeof(*(x))); } while(0)
 
 /** Get the size of an array */
 #define ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0]))
@@ -365,6 +369,17 @@ int ssh_connector_remove_event(ssh_connector connector);
 void explicit_bzero(void *s, size_t n);
 #endif /* !HAVE_EXPLICIT_BZERO */
 
+void burn_free(void *ptr, size_t len);
+
+/** Free memory space after zeroing it */
+#define BURN_FREE(x, len)          \
+    do {                           \
+        if ((x) != NULL) {         \
+            burn_free((x), (len)); \
+            (x) = NULL;            \
+        }                          \
+    } while (0)
+
 /**
  * This is a hack to fix warnings. The idea is to use this everywhere that we
  * get the "discarding const" warning by the compiler. That doesn't actually

include/libssh/session.h

@@ -120,6 +120,8 @@ enum ssh_pending_call_e {
 /* server-sig-algs extension */
 #define SSH_EXT_SIG_RSA_SHA256  0x02
 #define SSH_EXT_SIG_RSA_SHA512  0x04
+/* Host-bound public key authentication extension */
+#define SSH_EXT_PUBLICKEY_HOSTBOUND 0x08
 
 /* members that are common to ssh_session and ssh_bind */
 struct ssh_common_struct {

include/libssh/sftp.h

@@ -79,6 +79,7 @@ typedef struct sftp_status_message_struct* sftp_status_message;
 typedef struct sftp_statvfs_struct* sftp_statvfs_t;
 typedef struct sftp_limits_struct* sftp_limits_t;
 typedef struct sftp_aio_struct* sftp_aio;
+typedef struct sftp_name_id_map_struct *sftp_name_id_map;
 
 struct sftp_session_struct {
     ssh_session session;
@@ -213,6 +214,22 @@ struct sftp_limits_struct {
     uint64_t max_open_handles;    /** maximum number of active handles allowed by server */
 };
 
+/**
+ * @brief SFTP names map structure to store the mapping between ids and names.
+ *
+ * This is mainly for the use of sftp_get_users_groups_by_id() function.
+ */
+struct sftp_name_id_map_struct {
+    /** @brief Count of name-id pairs in the map */
+    uint32_t count;
+
+    /** @brief Array of ids, ids[i] mapped to names[i] */
+    uint32_t *ids;
+
+    /** @brief Array of names, names[i] mapped to ids[i] */
+    char **names;
+};
+
 /**
  * @brief Creates a new sftp session.
  *
@@ -220,24 +237,30 @@ struct sftp_limits_struct {
  * with the server inside of the provided ssh session. This function call is
  * usually followed by the sftp_init(), which initializes SFTP protocol itself.
  *
- * @param session       The ssh session to use.
+ * @param session       The ssh session to use. The session *must* be in
+ *                      blocking mode since most `sftp_*` functions do not
+ *                      support the non-blocking API.
  *
  * @return              A new sftp session or NULL on error.
  *
  * @see sftp_free()
  * @see sftp_init()
+ * @see ssh_set_blocking()
  */
 LIBSSH_API sftp_session sftp_new(ssh_session session);
 
 /**
  * @brief Start a new sftp session with an existing channel.
  *
- * @param session       The ssh session to use.
+ * @param session       The ssh session to use. The session *must* be in
+ *                      blocking mode since most `sftp_*` functions do not
+ *                      support the non-blocking API.
  * @param channel		An open session channel with subsystem already allocated
  *
  * @return              A new sftp session or NULL on error.
  *
  * @see sftp_free()
+ * @see ssh_set_blocking()
  */
 LIBSSH_API sftp_session sftp_new_channel(ssh_session session, ssh_channel channel);
 
@@ -1188,6 +1211,58 @@ LIBSSH_API char *sftp_expand_path(sftp_session sftp, const char *path);
  */
 LIBSSH_API char *sftp_home_directory(sftp_session sftp, const char *username);
 
+/**
+ * @brief Create a new sftp_name_id_map struct.
+ *
+ * @param count         The number of ids/names to store in the map.
+ *
+ * @return              A pointer to the newly allocated sftp_name_id_map
+ * struct.
+ */
+LIBSSH_API sftp_name_id_map sftp_name_id_map_new(uint32_t count);
+
+/**
+ * @brief Free the memory of an allocated `sftp_name_id_map` struct.
+ *
+ * @param  map          A pointer to the `sftp_name_id_map` struct to free.
+ */
+LIBSSH_API void sftp_name_id_map_free(sftp_name_id_map map);
+
+/**
+ * @brief Retrieves usernames and group names based on provided user and group
+ *        IDs.
+ *
+ * The retrieved names are stored in the `names` field of the
+ * `sftp_name_id_map` structure. In case a uid or gid is not found, an empty
+ * string is stored.
+ *
+ * This calls the "users-groups-by-id@openssh.com" extension.
+ * You should check if the extension is supported using:
+ *
+ * @code
+ * int supported = sftp_extension_supported(sftp,
+ * "users-groups-by-id@openssh.com", "1");
+ * @endcode
+ *
+ * @param sftp           The SFTP session handle.
+ *
+ * @param users_map      A pointer to a `sftp_name_id_map` struct with the user
+ *                       IDs. Can be NULL if only group names are needed.
+ *
+ * @param groups_map     A pointer to a `sftp_name_id_map` struct with the group
+ *                       IDs. Can be NULL if only user names are needed.
+ *
+ * @return               0 on success, < 0 on error with ssh and sftp error set.
+ *
+ * @note                 The caller needs to free the memory used for
+ *                       the maps later using `sftp_name_id_map_free()`.
+ *
+ * @see sftp_get_error()
+ */
+LIBSSH_API int sftp_get_users_groups_by_id(sftp_session sftp,
+                                           sftp_name_id_map users_map,
+                                           sftp_name_id_map groups_map);
+
 #ifdef WITH_SERVER
 /**
  * @brief Create a new sftp server session.

include/libssh/sftp_priv.h

@@ -21,6 +21,8 @@
 #ifndef SFTP_PRIV_H
 #define SFTP_PRIV_H
 
+#include <stdbool.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -62,6 +64,39 @@ int sftp_read_and_dispatch(sftp_session sftp);
 
 sftp_message sftp_dequeue(sftp_session sftp, uint32_t id);
 
+/**
+ * @brief Receive the response of an sftp request
+ *
+ * In blocking mode, if the response hasn't arrived at the time of call, this
+ * function waits for the response to arrive.
+ *
+ * @param sftp           The sftp session via which the request was sent.
+ *
+ * @param id             The request identifier of the request whose
+ *                       corresponding response is required.
+ *
+ * @param blocking       Flag to indicate the operating mode. true indicates
+ *                       blocking mode and false indicates non-blocking mode
+ *
+ * @param msg_ptr        Pointer to the location to store the response message.
+ *                       In case of success, the message is allocated
+ *                       dynamically and must be freed (using
+ *                       sftp_message_free()) by the caller after usage. In case
+ *                       of failure, this is left untouched.
+ *
+ * @returns SSH_OK on success
+ * @returns SSH_ERROR on failure with the sftp and ssh errors set
+ * @returns SSH_AGAIN in case of non-blocking mode if the response hasn't
+ *          arrived yet.
+ *
+ * @warning In blocking mode, this may block indefinitely for an invalid request
+ *          identifier.
+ */
+int sftp_recv_response_msg(sftp_session sftp,
+                           uint32_t id,
+                           bool blocking,
+                           sftp_message *msg_ptr);
+
 /*
  * Assigns a new SFTP ID for new requests and assures there is no collision
  * between them.

include/libssh/sntrup761.h

@@ -0,0 +1,86 @@
+/*
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2013 by Aris Adamantiadis <aris@badcode.be>
+ * Copyright (c) 2023 Simon Josefsson <simon@josefsson.org>
+ * Copyright (c) 2025 Jakub Jelen <jjelen@redhat.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation,
+ * version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef SNTRUP761_H_
+#define SNTRUP761_H_
+
+#include "config.h"
+#include "curve25519.h"
+#include "libssh.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef HAVE_CURVE25519
+#define HAVE_SNTRUP761 1
+#endif
+
+extern void crypto_hash_sha512(unsigned char *out,
+                               const unsigned char *in,
+                               unsigned long long inlen);
+
+/*
+ * Derived from public domain source, written by (in alphabetical order):
+ * - Daniel J. Bernstein
+ * - Chitchanok Chuengsatiansup
+ * - Tanja Lange
+ * - Christine van Vredendaal
+ */
+
+#include <stdint.h>
+#include <string.h>
+
+#define SNTRUP761_SECRETKEY_SIZE 1763
+#define SNTRUP761_PUBLICKEY_SIZE 1158
+#define SNTRUP761_CIPHERTEXT_SIZE 1039
+#define SNTRUP761_SIZE 32
+
+typedef void sntrup761_random_func(void *ctx, size_t length, uint8_t *dst);
+
+void sntrup761_keypair(uint8_t *pk,
+                       uint8_t *sk,
+                       void *random_ctx,
+                       sntrup761_random_func *random);
+void sntrup761_enc(uint8_t *c,
+                   uint8_t *k,
+                   const uint8_t *pk,
+                   void *random_ctx,
+                   sntrup761_random_func *random);
+void sntrup761_dec(uint8_t *k, const uint8_t *c, const uint8_t *sk);
+
+typedef unsigned char ssh_sntrup761_pubkey[SNTRUP761_PUBLICKEY_SIZE];
+typedef unsigned char ssh_sntrup761_privkey[SNTRUP761_SECRETKEY_SIZE];
+typedef unsigned char ssh_sntrup761_ciphertext[SNTRUP761_CIPHERTEXT_SIZE];
+
+int ssh_client_sntrup761x25519_init(ssh_session session);
+void ssh_client_sntrup761x25519_remove_callbacks(ssh_session session);
+
+#ifdef WITH_SERVER
+void ssh_server_sntrup761x25519_init(ssh_session session);
+#endif /* WITH_SERVER */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* SNTRUP761_H_ */

include/libssh/socket.h

@@ -33,7 +33,7 @@ void ssh_socket_cleanup(void);
 ssh_socket ssh_socket_new(ssh_session session);
 void ssh_socket_reset(ssh_socket s);
 void ssh_socket_free(ssh_socket s);
-void ssh_socket_set_fd(ssh_socket s, socket_t fd);
+int ssh_socket_set_fd(ssh_socket s, socket_t fd);
 socket_t ssh_socket_get_fd(ssh_socket s);
 void ssh_socket_set_connected(ssh_socket s, struct ssh_poll_handle_struct *p);
 int ssh_socket_unix(ssh_socket s, const char *path);

include/libssh/wrapper.h

@@ -129,6 +129,7 @@ int evp_build_pkey(const char* name, OSSL_PARAM_BLD *param_bld, EVP_PKEY **pkey,
 int evp_dup_dsa_pkey(const ssh_key key, ssh_key new_key, int demote);
 int evp_dup_rsa_pkey(const ssh_key key, ssh_key new_key, int demote);
 int evp_dup_ecdsa_pkey(const ssh_key key, ssh_key new_key, int demote);
+int evp_dup_ed25519_pkey(const ssh_key key, ssh_key new_key, int demote);
 #endif /* HAVE_LIBCRYPTO && OPENSSL_VERSION_NUMBER */
 
 #ifdef __cplusplus

libssh.pc.cmake

@@ -8,3 +8,4 @@ Description: The SSH Library
 Version: @PROJECT_VERSION@
 Libs: -L${libdir} -lssh
 Cflags: -I${includedir}
+Requires.private: @LIBSSH_PC_REQUIRES_PRIVATE@

src/ABI/current

@@ -1 +1 @@
-4.10.2
+4.10.0

src/ABI/libssh-4.10.1.symbols

@@ -1,445 +0,0 @@
-_ssh_log
-buffer_free
-buffer_get
-buffer_get_len
-buffer_new
-channel_accept_x11
-channel_change_pty_size
-channel_close
-channel_forward_accept
-channel_forward_cancel
-channel_forward_listen
-channel_free
-channel_get_exit_status
-channel_get_session
-channel_is_closed
-channel_is_eof
-channel_is_open
-channel_new
-channel_open_forward
-channel_open_session
-channel_poll
-channel_read
-channel_read_buffer
-channel_read_nonblocking
-channel_request_env
-channel_request_exec
-channel_request_pty
-channel_request_pty_size
-channel_request_send_signal
-channel_request_sftp
-channel_request_shell
-channel_request_subsystem
-channel_request_x11
-channel_select
-channel_send_eof
-channel_set_blocking
-channel_write
-channel_write_stderr
-privatekey_free
-privatekey_from_file
-publickey_free
-publickey_from_file
-publickey_from_privatekey
-publickey_to_string
-sftp_aio_begin_read
-sftp_aio_begin_write
-sftp_aio_free
-sftp_aio_wait_read
-sftp_aio_wait_write
-sftp_async_read
-sftp_async_read_begin
-sftp_attributes_free
-sftp_canonicalize_path
-sftp_channel_default_data_callback
-sftp_channel_default_subsystem_request
-sftp_chmod
-sftp_chown
-sftp_client_message_free
-sftp_client_message_get_data
-sftp_client_message_get_filename
-sftp_client_message_get_flags
-sftp_client_message_get_submessage
-sftp_client_message_get_type
-sftp_client_message_set_filename
-sftp_close
-sftp_closedir
-sftp_dir_eof
-sftp_expand_path
-sftp_extension_supported
-sftp_extensions_get_count
-sftp_extensions_get_data
-sftp_extensions_get_name
-sftp_file_set_blocking
-sftp_file_set_nonblocking
-sftp_free
-sftp_fstat
-sftp_fstatvfs
-sftp_fsync
-sftp_get_client_message
-sftp_get_error
-sftp_handle
-sftp_handle_alloc
-sftp_handle_remove
-sftp_hardlink
-sftp_home_directory
-sftp_init
-sftp_limits
-sftp_limits_free
-sftp_lsetstat
-sftp_lstat
-sftp_mkdir
-sftp_new
-sftp_new_channel
-sftp_open
-sftp_opendir
-sftp_read
-sftp_readdir
-sftp_readlink
-sftp_rename
-sftp_reply_attr
-sftp_reply_data
-sftp_reply_handle
-sftp_reply_name
-sftp_reply_names
-sftp_reply_names_add
-sftp_reply_status
-sftp_rewind
-sftp_rmdir
-sftp_seek
-sftp_seek64
-sftp_send_client_message
-sftp_server_free
-sftp_server_init
-sftp_server_new
-sftp_server_version
-sftp_setstat
-sftp_stat
-sftp_statvfs
-sftp_statvfs_free
-sftp_symlink
-sftp_tell
-sftp_tell64
-sftp_unlink
-sftp_utimes
-sftp_write
-ssh_accept
-ssh_add_channel_callbacks
-ssh_auth_list
-ssh_basename
-ssh_bind_accept
-ssh_bind_accept_fd
-ssh_bind_fd_toaccept
-ssh_bind_free
-ssh_bind_get_fd
-ssh_bind_listen
-ssh_bind_new
-ssh_bind_options_parse_config
-ssh_bind_options_set
-ssh_bind_set_blocking
-ssh_bind_set_callbacks
-ssh_bind_set_fd
-ssh_blocking_flush
-ssh_buffer_add_data
-ssh_buffer_free
-ssh_buffer_get
-ssh_buffer_get_data
-ssh_buffer_get_len
-ssh_buffer_new
-ssh_buffer_reinit
-ssh_channel_accept_forward
-ssh_channel_accept_x11
-ssh_channel_cancel_forward
-ssh_channel_change_pty_size
-ssh_channel_close
-ssh_channel_free
-ssh_channel_get_exit_state
-ssh_channel_get_exit_status
-ssh_channel_get_session
-ssh_channel_is_closed
-ssh_channel_is_eof
-ssh_channel_is_open
-ssh_channel_listen_forward
-ssh_channel_new
-ssh_channel_open_auth_agent
-ssh_channel_open_forward
-ssh_channel_open_forward_port
-ssh_channel_open_forward_unix
-ssh_channel_open_reverse_forward
-ssh_channel_open_session
-ssh_channel_open_x11
-ssh_channel_poll
-ssh_channel_poll_timeout
-ssh_channel_read
-ssh_channel_read_nonblocking
-ssh_channel_read_timeout
-ssh_channel_request_auth_agent
-ssh_channel_request_env
-ssh_channel_request_exec
-ssh_channel_request_pty
-ssh_channel_request_pty_size
-ssh_channel_request_pty_size_modes
-ssh_channel_request_send_break
-ssh_channel_request_send_exit_signal
-ssh_channel_request_send_exit_status
-ssh_channel_request_send_signal
-ssh_channel_request_sftp
-ssh_channel_request_shell
-ssh_channel_request_subsystem
-ssh_channel_request_x11
-ssh_channel_select
-ssh_channel_send_eof
-ssh_channel_set_blocking
-ssh_channel_set_counter
-ssh_channel_window_size
-ssh_channel_write
-ssh_channel_write_stderr
-ssh_clean_pubkey_hash
-ssh_connect
-ssh_connector_free
-ssh_connector_new
-ssh_connector_set_in_channel
-ssh_connector_set_in_fd
-ssh_connector_set_out_channel
-ssh_connector_set_out_fd
-ssh_copyright
-ssh_dirname
-ssh_disconnect
-ssh_dump_knownhost
-ssh_event_add_connector
-ssh_event_add_fd
-ssh_event_add_session
-ssh_event_dopoll
-ssh_event_free
-ssh_event_new
-ssh_event_remove_connector
-ssh_event_remove_fd
-ssh_event_remove_session
-ssh_execute_message_callbacks
-ssh_finalize
-ssh_forward_accept
-ssh_forward_cancel
-ssh_forward_listen
-ssh_free
-ssh_get_cipher_in
-ssh_get_cipher_out
-ssh_get_clientbanner
-ssh_get_disconnect_message
-ssh_get_error
-ssh_get_error_code
-ssh_get_fd
-ssh_get_fingerprint_hash
-ssh_get_hexa
-ssh_get_hmac_in
-ssh_get_hmac_out
-ssh_get_issue_banner
-ssh_get_kex_algo
-ssh_get_log_callback
-ssh_get_log_level
-ssh_get_log_userdata
-ssh_get_openssh_version
-ssh_get_poll_flags
-ssh_get_pubkey
-ssh_get_pubkey_hash
-ssh_get_publickey
-ssh_get_publickey_hash
-ssh_get_random
-ssh_get_server_publickey
-ssh_get_serverbanner
-ssh_get_status
-ssh_get_version
-ssh_getpass
-ssh_gssapi_get_creds
-ssh_gssapi_set_creds
-ssh_handle_key_exchange
-ssh_init
-ssh_is_blocking
-ssh_is_connected
-ssh_is_server_known
-ssh_key_cmp
-ssh_key_dup
-ssh_key_free
-ssh_key_is_private
-ssh_key_is_public
-ssh_key_new
-ssh_key_type
-ssh_key_type_from_name
-ssh_key_type_to_char
-ssh_known_hosts_parse_line
-ssh_knownhosts_entry_free
-ssh_log
-ssh_message_auth_interactive_request
-ssh_message_auth_kbdint_is_response
-ssh_message_auth_password
-ssh_message_auth_pubkey
-ssh_message_auth_publickey
-ssh_message_auth_publickey_state
-ssh_message_auth_reply_pk_ok
-ssh_message_auth_reply_pk_ok_simple
-ssh_message_auth_reply_success
-ssh_message_auth_set_methods
-ssh_message_auth_user
-ssh_message_channel_request_channel
-ssh_message_channel_request_command
-ssh_message_channel_request_env_name
-ssh_message_channel_request_env_value
-ssh_message_channel_request_open_destination
-ssh_message_channel_request_open_destination_port
-ssh_message_channel_request_open_originator
-ssh_message_channel_request_open_originator_port
-ssh_message_channel_request_open_reply_accept
-ssh_message_channel_request_open_reply_accept_channel
-ssh_message_channel_request_pty_height
-ssh_message_channel_request_pty_pxheight
-ssh_message_channel_request_pty_pxwidth
-ssh_message_channel_request_pty_term
-ssh_message_channel_request_pty_width
-ssh_message_channel_request_reply_success
-ssh_message_channel_request_subsystem
-ssh_message_channel_request_x11_auth_cookie
-ssh_message_channel_request_x11_auth_protocol
-ssh_message_channel_request_x11_screen_number
-ssh_message_channel_request_x11_single_connection
-ssh_message_free
-ssh_message_get
-ssh_message_global_request_address
-ssh_message_global_request_port
-ssh_message_global_request_reply_success
-ssh_message_reply_default
-ssh_message_retrieve
-ssh_message_service_reply_success
-ssh_message_service_service
-ssh_message_subtype
-ssh_message_type
-ssh_mkdir
-ssh_new
-ssh_options_copy
-ssh_options_get
-ssh_options_get_port
-ssh_options_getopt
-ssh_options_parse_config
-ssh_options_set
-ssh_pcap_file_close
-ssh_pcap_file_free
-ssh_pcap_file_new
-ssh_pcap_file_open
-ssh_pki_copy_cert_to_privkey
-ssh_pki_export_privkey_base64
-ssh_pki_export_privkey_base64_format
-ssh_pki_export_privkey_file
-ssh_pki_export_privkey_file_format
-ssh_pki_export_privkey_to_pubkey
-ssh_pki_export_pubkey_base64
-ssh_pki_export_pubkey_file
-ssh_pki_generate
-ssh_pki_import_cert_base64
-ssh_pki_import_cert_file
-ssh_pki_import_privkey_base64
-ssh_pki_import_privkey_file
-ssh_pki_import_pubkey_base64
-ssh_pki_import_pubkey_file
-ssh_pki_key_ecdsa_name
-ssh_print_hash
-ssh_print_hexa
-ssh_privatekey_type
-ssh_publickey_to_file
-ssh_remove_channel_callbacks
-ssh_request_no_more_sessions
-ssh_scp_accept_request
-ssh_scp_close
-ssh_scp_deny_request
-ssh_scp_free
-ssh_scp_init
-ssh_scp_leave_directory
-ssh_scp_new
-ssh_scp_pull_request
-ssh_scp_push_directory
-ssh_scp_push_file
-ssh_scp_push_file64
-ssh_scp_read
-ssh_scp_request_get_filename
-ssh_scp_request_get_permissions
-ssh_scp_request_get_size
-ssh_scp_request_get_size64
-ssh_scp_request_get_warning
-ssh_scp_write
-ssh_select
-ssh_send_debug
-ssh_send_ignore
-ssh_send_issue_banner
-ssh_send_keepalive
-ssh_server_init_kex
-ssh_service_request
-ssh_session_export_known_hosts_entry
-ssh_session_get_known_hosts_entry
-ssh_session_has_known_hosts_entry
-ssh_session_is_known_server
-ssh_session_set_disconnect_message
-ssh_session_update_known_hosts
-ssh_set_agent_channel
-ssh_set_agent_socket
-ssh_set_auth_methods
-ssh_set_blocking
-ssh_set_callbacks
-ssh_set_channel_callbacks
-ssh_set_counters
-ssh_set_fd_except
-ssh_set_fd_toread
-ssh_set_fd_towrite
-ssh_set_log_callback
-ssh_set_log_level
-ssh_set_log_userdata
-ssh_set_message_callback
-ssh_set_pcap_file
-ssh_set_server_callbacks
-ssh_silent_disconnect
-ssh_string_burn
-ssh_string_copy
-ssh_string_data
-ssh_string_fill
-ssh_string_free
-ssh_string_free_char
-ssh_string_from_char
-ssh_string_get_char
-ssh_string_len
-ssh_string_new
-ssh_string_to_char
-ssh_threads_get_default
-ssh_threads_get_noop
-ssh_threads_get_pthread
-ssh_threads_set_callbacks
-ssh_try_publickey_from_file
-ssh_userauth_agent
-ssh_userauth_agent_pubkey
-ssh_userauth_autopubkey
-ssh_userauth_gssapi
-ssh_userauth_kbdint
-ssh_userauth_kbdint_getanswer
-ssh_userauth_kbdint_getinstruction
-ssh_userauth_kbdint_getname
-ssh_userauth_kbdint_getnanswers
-ssh_userauth_kbdint_getnprompts
-ssh_userauth_kbdint_getprompt
-ssh_userauth_kbdint_setanswer
-ssh_userauth_list
-ssh_userauth_none
-ssh_userauth_offer_pubkey
-ssh_userauth_password
-ssh_userauth_privatekey_file
-ssh_userauth_pubkey
-ssh_userauth_publickey
-ssh_userauth_publickey_auto
-ssh_userauth_publickey_auto_get_current_identity
-ssh_userauth_try_publickey
-ssh_version
-ssh_vlog
-ssh_write_knownhost
-string_burn
-string_copy
-string_data
-string_fill
-string_free
-string_from_char
-string_len
-string_new
-string_to_char

src/ABI/libssh-4.10.2.symbols

@@ -1,445 +0,0 @@
-_ssh_log
-buffer_free
-buffer_get
-buffer_get_len
-buffer_new
-channel_accept_x11
-channel_change_pty_size
-channel_close
-channel_forward_accept
-channel_forward_cancel
-channel_forward_listen
-channel_free
-channel_get_exit_status
-channel_get_session
-channel_is_closed
-channel_is_eof
-channel_is_open
-channel_new
-channel_open_forward
-channel_open_session
-channel_poll
-channel_read
-channel_read_buffer
-channel_read_nonblocking
-channel_request_env
-channel_request_exec
-channel_request_pty
-channel_request_pty_size
-channel_request_send_signal
-channel_request_sftp
-channel_request_shell
-channel_request_subsystem
-channel_request_x11
-channel_select
-channel_send_eof
-channel_set_blocking
-channel_write
-channel_write_stderr
-privatekey_free
-privatekey_from_file
-publickey_free
-publickey_from_file
-publickey_from_privatekey
-publickey_to_string
-sftp_aio_begin_read
-sftp_aio_begin_write
-sftp_aio_free
-sftp_aio_wait_read
-sftp_aio_wait_write
-sftp_async_read
-sftp_async_read_begin
-sftp_attributes_free
-sftp_canonicalize_path
-sftp_channel_default_data_callback
-sftp_channel_default_subsystem_request
-sftp_chmod
-sftp_chown
-sftp_client_message_free
-sftp_client_message_get_data
-sftp_client_message_get_filename
-sftp_client_message_get_flags
-sftp_client_message_get_submessage
-sftp_client_message_get_type
-sftp_client_message_set_filename
-sftp_close
-sftp_closedir
-sftp_dir_eof
-sftp_expand_path
-sftp_extension_supported
-sftp_extensions_get_count
-sftp_extensions_get_data
-sftp_extensions_get_name
-sftp_file_set_blocking
-sftp_file_set_nonblocking
-sftp_free
-sftp_fstat
-sftp_fstatvfs
-sftp_fsync
-sftp_get_client_message
-sftp_get_error
-sftp_handle
-sftp_handle_alloc
-sftp_handle_remove
-sftp_hardlink
-sftp_home_directory
-sftp_init
-sftp_limits
-sftp_limits_free
-sftp_lsetstat
-sftp_lstat
-sftp_mkdir
-sftp_new
-sftp_new_channel
-sftp_open
-sftp_opendir
-sftp_read
-sftp_readdir
-sftp_readlink
-sftp_rename
-sftp_reply_attr
-sftp_reply_data
-sftp_reply_handle
-sftp_reply_name
-sftp_reply_names
-sftp_reply_names_add
-sftp_reply_status
-sftp_rewind
-sftp_rmdir
-sftp_seek
-sftp_seek64
-sftp_send_client_message
-sftp_server_free
-sftp_server_init
-sftp_server_new
-sftp_server_version
-sftp_setstat
-sftp_stat
-sftp_statvfs
-sftp_statvfs_free
-sftp_symlink
-sftp_tell
-sftp_tell64
-sftp_unlink
-sftp_utimes
-sftp_write
-ssh_accept
-ssh_add_channel_callbacks
-ssh_auth_list
-ssh_basename
-ssh_bind_accept
-ssh_bind_accept_fd
-ssh_bind_fd_toaccept
-ssh_bind_free
-ssh_bind_get_fd
-ssh_bind_listen
-ssh_bind_new
-ssh_bind_options_parse_config
-ssh_bind_options_set
-ssh_bind_set_blocking
-ssh_bind_set_callbacks
-ssh_bind_set_fd
-ssh_blocking_flush
-ssh_buffer_add_data
-ssh_buffer_free
-ssh_buffer_get
-ssh_buffer_get_data
-ssh_buffer_get_len
-ssh_buffer_new
-ssh_buffer_reinit
-ssh_channel_accept_forward
-ssh_channel_accept_x11
-ssh_channel_cancel_forward
-ssh_channel_change_pty_size
-ssh_channel_close
-ssh_channel_free
-ssh_channel_get_exit_state
-ssh_channel_get_exit_status
-ssh_channel_get_session
-ssh_channel_is_closed
-ssh_channel_is_eof
-ssh_channel_is_open
-ssh_channel_listen_forward
-ssh_channel_new
-ssh_channel_open_auth_agent
-ssh_channel_open_forward
-ssh_channel_open_forward_port
-ssh_channel_open_forward_unix
-ssh_channel_open_reverse_forward
-ssh_channel_open_session
-ssh_channel_open_x11
-ssh_channel_poll
-ssh_channel_poll_timeout
-ssh_channel_read
-ssh_channel_read_nonblocking
-ssh_channel_read_timeout
-ssh_channel_request_auth_agent
-ssh_channel_request_env
-ssh_channel_request_exec
-ssh_channel_request_pty
-ssh_channel_request_pty_size
-ssh_channel_request_pty_size_modes
-ssh_channel_request_send_break
-ssh_channel_request_send_exit_signal
-ssh_channel_request_send_exit_status
-ssh_channel_request_send_signal
-ssh_channel_request_sftp
-ssh_channel_request_shell
-ssh_channel_request_subsystem
-ssh_channel_request_x11
-ssh_channel_select
-ssh_channel_send_eof
-ssh_channel_set_blocking
-ssh_channel_set_counter
-ssh_channel_window_size
-ssh_channel_write
-ssh_channel_write_stderr
-ssh_clean_pubkey_hash
-ssh_connect
-ssh_connector_free
-ssh_connector_new
-ssh_connector_set_in_channel
-ssh_connector_set_in_fd
-ssh_connector_set_out_channel
-ssh_connector_set_out_fd
-ssh_copyright
-ssh_dirname
-ssh_disconnect
-ssh_dump_knownhost
-ssh_event_add_connector
-ssh_event_add_fd
-ssh_event_add_session
-ssh_event_dopoll
-ssh_event_free
-ssh_event_new
-ssh_event_remove_connector
-ssh_event_remove_fd
-ssh_event_remove_session
-ssh_execute_message_callbacks
-ssh_finalize
-ssh_forward_accept
-ssh_forward_cancel
-ssh_forward_listen
-ssh_free
-ssh_get_cipher_in
-ssh_get_cipher_out
-ssh_get_clientbanner
-ssh_get_disconnect_message
-ssh_get_error
-ssh_get_error_code
-ssh_get_fd
-ssh_get_fingerprint_hash
-ssh_get_hexa
-ssh_get_hmac_in
-ssh_get_hmac_out
-ssh_get_issue_banner
-ssh_get_kex_algo
-ssh_get_log_callback
-ssh_get_log_level
-ssh_get_log_userdata
-ssh_get_openssh_version
-ssh_get_poll_flags
-ssh_get_pubkey
-ssh_get_pubkey_hash
-ssh_get_publickey
-ssh_get_publickey_hash
-ssh_get_random
-ssh_get_server_publickey
-ssh_get_serverbanner
-ssh_get_status
-ssh_get_version
-ssh_getpass
-ssh_gssapi_get_creds
-ssh_gssapi_set_creds
-ssh_handle_key_exchange
-ssh_init
-ssh_is_blocking
-ssh_is_connected
-ssh_is_server_known
-ssh_key_cmp
-ssh_key_dup
-ssh_key_free
-ssh_key_is_private
-ssh_key_is_public
-ssh_key_new
-ssh_key_type
-ssh_key_type_from_name
-ssh_key_type_to_char
-ssh_known_hosts_parse_line
-ssh_knownhosts_entry_free
-ssh_log
-ssh_message_auth_interactive_request
-ssh_message_auth_kbdint_is_response
-ssh_message_auth_password
-ssh_message_auth_pubkey
-ssh_message_auth_publickey
-ssh_message_auth_publickey_state
-ssh_message_auth_reply_pk_ok
-ssh_message_auth_reply_pk_ok_simple
-ssh_message_auth_reply_success
-ssh_message_auth_set_methods
-ssh_message_auth_user
-ssh_message_channel_request_channel
-ssh_message_channel_request_command
-ssh_message_channel_request_env_name
-ssh_message_channel_request_env_value
-ssh_message_channel_request_open_destination
-ssh_message_channel_request_open_destination_port
-ssh_message_channel_request_open_originator
-ssh_message_channel_request_open_originator_port
-ssh_message_channel_request_open_reply_accept
-ssh_message_channel_request_open_reply_accept_channel
-ssh_message_channel_request_pty_height
-ssh_message_channel_request_pty_pxheight
-ssh_message_channel_request_pty_pxwidth
-ssh_message_channel_request_pty_term
-ssh_message_channel_request_pty_width
-ssh_message_channel_request_reply_success
-ssh_message_channel_request_subsystem
-ssh_message_channel_request_x11_auth_cookie
-ssh_message_channel_request_x11_auth_protocol
-ssh_message_channel_request_x11_screen_number
-ssh_message_channel_request_x11_single_connection
-ssh_message_free
-ssh_message_get
-ssh_message_global_request_address
-ssh_message_global_request_port
-ssh_message_global_request_reply_success
-ssh_message_reply_default
-ssh_message_retrieve
-ssh_message_service_reply_success
-ssh_message_service_service
-ssh_message_subtype
-ssh_message_type
-ssh_mkdir
-ssh_new
-ssh_options_copy
-ssh_options_get
-ssh_options_get_port
-ssh_options_getopt
-ssh_options_parse_config
-ssh_options_set
-ssh_pcap_file_close
-ssh_pcap_file_free
-ssh_pcap_file_new
-ssh_pcap_file_open
-ssh_pki_copy_cert_to_privkey
-ssh_pki_export_privkey_base64
-ssh_pki_export_privkey_base64_format
-ssh_pki_export_privkey_file
-ssh_pki_export_privkey_file_format
-ssh_pki_export_privkey_to_pubkey
-ssh_pki_export_pubkey_base64
-ssh_pki_export_pubkey_file
-ssh_pki_generate
-ssh_pki_import_cert_base64
-ssh_pki_import_cert_file
-ssh_pki_import_privkey_base64
-ssh_pki_import_privkey_file
-ssh_pki_import_pubkey_base64
-ssh_pki_import_pubkey_file
-ssh_pki_key_ecdsa_name
-ssh_print_hash
-ssh_print_hexa
-ssh_privatekey_type
-ssh_publickey_to_file
-ssh_remove_channel_callbacks
-ssh_request_no_more_sessions
-ssh_scp_accept_request
-ssh_scp_close
-ssh_scp_deny_request
-ssh_scp_free
-ssh_scp_init
-ssh_scp_leave_directory
-ssh_scp_new
-ssh_scp_pull_request
-ssh_scp_push_directory
-ssh_scp_push_file
-ssh_scp_push_file64
-ssh_scp_read
-ssh_scp_request_get_filename
-ssh_scp_request_get_permissions
-ssh_scp_request_get_size
-ssh_scp_request_get_size64
-ssh_scp_request_get_warning
-ssh_scp_write
-ssh_select
-ssh_send_debug
-ssh_send_ignore
-ssh_send_issue_banner
-ssh_send_keepalive
-ssh_server_init_kex
-ssh_service_request
-ssh_session_export_known_hosts_entry
-ssh_session_get_known_hosts_entry
-ssh_session_has_known_hosts_entry
-ssh_session_is_known_server
-ssh_session_set_disconnect_message
-ssh_session_update_known_hosts
-ssh_set_agent_channel
-ssh_set_agent_socket
-ssh_set_auth_methods
-ssh_set_blocking
-ssh_set_callbacks
-ssh_set_channel_callbacks
-ssh_set_counters
-ssh_set_fd_except
-ssh_set_fd_toread
-ssh_set_fd_towrite
-ssh_set_log_callback
-ssh_set_log_level
-ssh_set_log_userdata
-ssh_set_message_callback
-ssh_set_pcap_file
-ssh_set_server_callbacks
-ssh_silent_disconnect
-ssh_string_burn
-ssh_string_copy
-ssh_string_data
-ssh_string_fill
-ssh_string_free
-ssh_string_free_char
-ssh_string_from_char
-ssh_string_get_char
-ssh_string_len
-ssh_string_new
-ssh_string_to_char
-ssh_threads_get_default
-ssh_threads_get_noop
-ssh_threads_get_pthread
-ssh_threads_set_callbacks
-ssh_try_publickey_from_file
-ssh_userauth_agent
-ssh_userauth_agent_pubkey
-ssh_userauth_autopubkey
-ssh_userauth_gssapi
-ssh_userauth_kbdint
-ssh_userauth_kbdint_getanswer
-ssh_userauth_kbdint_getinstruction
-ssh_userauth_kbdint_getname
-ssh_userauth_kbdint_getnanswers
-ssh_userauth_kbdint_getnprompts
-ssh_userauth_kbdint_getprompt
-ssh_userauth_kbdint_setanswer
-ssh_userauth_list
-ssh_userauth_none
-ssh_userauth_offer_pubkey
-ssh_userauth_password
-ssh_userauth_privatekey_file
-ssh_userauth_pubkey
-ssh_userauth_publickey
-ssh_userauth_publickey_auto
-ssh_userauth_publickey_auto_get_current_identity
-ssh_userauth_try_publickey
-ssh_version
-ssh_vlog
-ssh_write_knownhost
-string_burn
-string_copy
-string_data
-string_fill
-string_free
-string_from_char
-string_len
-string_new
-string_to_char

src/CMakeLists.txt

@@ -87,6 +87,7 @@ set(libssh_SRCS
   connector.c
   crypto_common.c
   curve25519.c
+  sntrup761.c
   dh.c
   ecdh.c
   error.c
@@ -174,6 +175,13 @@ if (WITH_GCRYPT)
             chachapoly.c
         )
     endif (NOT HAVE_GCRYPT_CHACHA_POLY)
+
+    if (HAVE_GCRYPT_CURVE25519)
+        set(libssh_SRCS
+            ${libssh_SRCS}
+            curve25519_gcrypt.c
+        )
+    endif(HAVE_GCRYPT_CURVE25519)
 elseif (WITH_MBEDTLS)
     set(libssh_SRCS
         ${libssh_SRCS}
@@ -190,6 +198,7 @@ elseif (WITH_MBEDTLS)
         external/fe25519.c
         external/ge25519.c
         external/sc25519.c
+        external/sntrup761.c
        )
     if (NOT (HAVE_MBEDTLS_CHACHA20_H AND HAVE_MBEDTLS_POLY1305_H))
         set(libssh_SRCS
@@ -199,17 +208,24 @@ elseif (WITH_MBEDTLS)
             chachapoly.c
            )
     endif()
-
+    if (HAVE_MBEDTLS_CURVE25519)
+        set(libssh_SRCS
+            ${libssh_SRCS}
+            curve25519_mbedcrypto.c
+        )
+    endif(HAVE_MBEDTLS_CURVE25519)
 else (WITH_GCRYPT)
     set(libssh_SRCS
         ${libssh_SRCS}
         threads/libcrypto.c
         pki_crypto.c
         ecdh_crypto.c
+        curve25519_crypto.c
         getrandom_crypto.c
         md_crypto.c
         libcrypto.c
         dh_crypto.c
+        external/sntrup761.c
        )
     if (NOT HAVE_OPENSSL_EVP_CHACHA20)
         set(libssh_SRCS
@@ -261,9 +277,10 @@ if (WITH_GSSAPI AND GSSAPI_FOUND)
 endif (WITH_GSSAPI AND GSSAPI_FOUND)
 
 if (NOT WITH_NACL)
-    if (NOT HAVE_LIBCRYPTO)
+    if (NOT (HAVE_LIBCRYPTO OR HAVE_MBEDTLS_CURVE25519 OR HAVE_GCRYPT_CURVE25519))
         set(libssh_SRCS
             ${libssh_SRCS}
+            curve25519_fallback.c
             external/curve25519_ref.c
            )
     endif()

src/agent.c

@@ -67,87 +67,94 @@
   (((x) == SSH_AGENT_FAILURE) || ((x) == SSH_COM_AGENT2_FAILURE) || \
    ((x) == SSH2_AGENT_FAILURE))
 
-static uint32_t atomicio(struct ssh_agent_struct *agent, void *buf, uint32_t n, int do_read) {
-  char *b = buf;
-  uint32_t pos = 0;
-  ssize_t res;
-  ssh_pollfd_t pfd;
-  ssh_channel channel = agent->channel;
-  socket_t fd;
+static uint32_t
+atomicio(struct ssh_agent_struct *agent, void *buf, uint32_t n, int do_read)
+{
+    char *b = buf;
+    uint32_t pos = 0;
+    ssize_t res;
+    ssh_pollfd_t pfd;
+    ssh_channel channel = agent->channel;
+    socket_t fd;
 
-  /* Using a socket ? */
-  if (channel == NULL) {
-    fd = ssh_socket_get_fd(agent->sock);
-    pfd.fd = fd;
-    pfd.events = do_read ? POLLIN : POLLOUT;
+    /* Using a socket ? */
+    if (channel == NULL) {
+        fd = ssh_socket_get_fd(agent->sock);
+        pfd.fd = fd;
+        pfd.events = do_read ? POLLIN : POLLOUT;
 
-    while (n > pos) {
-      if (do_read) {
-        res = recv(fd, b + pos, n - pos, 0);
-      } else {
-        res = send(fd, b + pos, n - pos, 0);
-      }
-      switch (res) {
-      case -1:
-        if (errno == EINTR) {
-          continue;
-        }
+        while (n > pos) {
+            if (do_read) {
+                res = recv(fd, b + pos, n - pos, 0);
+            } else {
+                res = send(fd, b + pos, n - pos, 0);
+            }
+            switch (res) {
+            case -1:
+                if (errno == EINTR) {
+                    continue;
+                }
 #ifdef EWOULDBLOCK
-        if (errno == EAGAIN || errno == EWOULDBLOCK) {
+                if (errno == EAGAIN || errno == EWOULDBLOCK) {
 #else
-          if (errno == EAGAIN) {
+                if (errno == EAGAIN) {
 #endif
-            (void) ssh_poll(&pfd, 1, -1);
-            continue;
-          }
-          return 0;
-      case 0:
-        /* read returns 0 on end-of-file */
-        errno = do_read ? 0 : EPIPE;
-        return pos;
-      default:
-        pos += (uint32_t) res;
+                    (void)ssh_poll(&pfd, 1, -1);
+                    continue;
+                }
+                return 0;
+            case 0:
+                /* read returns 0 on end-of-file */
+                errno = do_read ? 0 : EPIPE;
+                return pos;
+            default:
+                pos += (uint32_t)res;
+            }
         }
-      }
-      return pos;
+        return pos;
     } else {
-      /* using an SSH channel */
-      while (n > pos){
-        if (do_read)
-          res = ssh_channel_read(channel,b + pos, n-pos, 0);
-        else
-          res = ssh_channel_write(channel, b+pos, n-pos);
-        if (res == SSH_AGAIN)
-          continue;
-        if (res == SSH_ERROR)
-          return 0;
-        pos += (uint32_t)res;
-      }
-      return pos;
+        /* using an SSH channel */
+        while (n > pos) {
+            if (do_read) {
+                res = ssh_channel_read(channel, b + pos, n - pos, 0);
+            } else {
+                res = ssh_channel_write(channel, b + pos, n - pos);
+            }
+            if (res == SSH_AGAIN) {
+                continue;
+            }
+            if (res == SSH_ERROR) {
+                return 0;
+            }
+            pos += (uint32_t)res;
+        }
+        return pos;
     }
 }
 
-ssh_agent ssh_agent_new(struct ssh_session_struct *session) {
-  ssh_agent agent = NULL;
+ssh_agent ssh_agent_new(struct ssh_session_struct *session)
+{
+    ssh_agent agent = NULL;
 
-  agent = malloc(sizeof(struct ssh_agent_struct));
-  if (agent == NULL) {
-    return NULL;
-  }
-  ZERO_STRUCTP(agent);
+    agent = calloc(1, sizeof(struct ssh_agent_struct));
+    if (agent == NULL) {
+        return NULL;
+    }
 
-  agent->count = 0;
-  agent->sock = ssh_socket_new(session);
-  if (agent->sock == NULL) {
-    SAFE_FREE(agent);
-    return NULL;
-  }
-  agent->channel = NULL;
-  return agent;
+    agent->count = 0;
+    agent->sock = ssh_socket_new(session);
+    if (agent->sock == NULL) {
+        SAFE_FREE(agent);
+        return NULL;
+    }
+    agent->channel = NULL;
+    return agent;
 }
 
-static void agent_set_channel(struct ssh_agent_struct *agent, ssh_channel channel){
-  agent->channel = channel;
+static void agent_set_channel(struct ssh_agent_struct *agent,
+                              ssh_channel channel)
+{
+    agent->channel = channel;
 }
 
 /**
@@ -168,15 +175,19 @@ static void agent_set_channel(struct ssh_agent_struct *agent, ssh_channel channe
  * @returns SSH_OK in case of success
  *          SSH_ERROR in case of an error
  */
-int ssh_set_agent_channel(ssh_session session, ssh_channel channel){
-  if (!session)
-    return SSH_ERROR;
-  if (!session->agent){
-    ssh_set_error(session, SSH_REQUEST_DENIED, "Session has no active agent");
-    return SSH_ERROR;
-  }
-  agent_set_channel(session->agent, channel);
-  return SSH_OK;
+int ssh_set_agent_channel(ssh_session session, ssh_channel channel)
+{
+    if (!session) {
+        return SSH_ERROR;
+    }
+    if (!session->agent) {
+        ssh_set_error(session,
+                      SSH_REQUEST_DENIED,
+                      "Session has no active agent");
+        return SSH_ERROR;
+    }
+    agent_set_channel(session->agent, channel);
+    return SSH_OK;
 }
 
 /** @brief sets the SSH agent socket.
@@ -187,64 +198,71 @@ int ssh_set_agent_channel(ssh_session session, ssh_channel channel){
  * @returns SSH_OK in case of success
  *          SSH_ERROR in case of an error
  */
-int ssh_set_agent_socket(ssh_session session, socket_t fd){
-  if (!session)
-    return SSH_ERROR;
-  if (!session->agent){
-    ssh_set_error(session, SSH_REQUEST_DENIED, "Session has no active agent");
-    return SSH_ERROR;
-  }
+int ssh_set_agent_socket(ssh_session session, socket_t fd)
+{
+    if (!session) {
+        return SSH_ERROR;
+    }
+    if (!session->agent) {
+        ssh_set_error(session,
+                      SSH_REQUEST_DENIED,
+                      "Session has no active agent");
+        return SSH_ERROR;
+    }
 
-  ssh_socket_set_fd(session->agent->sock, fd);
-  return SSH_OK;
+    return ssh_socket_set_fd(session->agent->sock, fd);
 }
 
 /**
  * @}
  */
 
-void ssh_agent_close(struct ssh_agent_struct *agent) {
-  if (agent == NULL) {
-    return;
-  }
+void ssh_agent_close(struct ssh_agent_struct *agent)
+{
+    if (agent == NULL) {
+        return;
+    }
 
-  ssh_socket_close(agent->sock);
+    ssh_socket_close(agent->sock);
 }
 
-void ssh_agent_free(ssh_agent agent) {
-  if (agent) {
-    if (agent->ident) {
-      SSH_BUFFER_FREE(agent->ident);
+void ssh_agent_free(ssh_agent agent)
+{
+    if (agent) {
+        if (agent->ident) {
+            SSH_BUFFER_FREE(agent->ident);
+        }
+        if (agent->sock) {
+            ssh_agent_close(agent);
+            ssh_socket_free(agent->sock);
+        }
+        SAFE_FREE(agent);
     }
-    if (agent->sock) {
-      ssh_agent_close(agent);
-      ssh_socket_free(agent->sock);
-    }
-    SAFE_FREE(agent);
-  }
 }
 
-static int agent_connect(ssh_session session) {
-  const char *auth_sock = NULL;
+static int agent_connect(ssh_session session)
+{
+    const char *auth_sock = NULL;
+
+    if (session == NULL || session->agent == NULL) {
+        return -1;
+    }
+
+    if (session->agent->channel != NULL) {
+        return 0;
+    }
+
+    auth_sock = session->opts.agent_socket ? session->opts.agent_socket
+                                           : getenv("SSH_AUTH_SOCK");
+
+    if (auth_sock && *auth_sock) {
+        if (ssh_socket_unix(session->agent->sock, auth_sock) < 0) {
+            return -1;
+        }
+        return 0;
+    }
 
-  if (session == NULL || session->agent == NULL) {
     return -1;
-  }
-
-  if (session->agent->channel != NULL)
-    return 0;
-
-  auth_sock = session->opts.agent_socket ?
-    session->opts.agent_socket : getenv("SSH_AUTH_SOCK");
-
-  if (auth_sock && *auth_sock) {
-    if (ssh_socket_unix(session->agent->sock, auth_sock) < 0) {
-      return -1;
-    }
-    return 0;
-  }
-
-  return -1;
 }
 
 #if 0
@@ -268,61 +286,66 @@ static int agent_decode_reply(struct ssh_session_struct *session, int type) {
 #endif
 
 static int agent_talk(struct ssh_session_struct *session,
-    struct ssh_buffer_struct *request, struct ssh_buffer_struct *reply) {
-  uint32_t len = 0;
-  uint8_t tmpbuf[4];
-  uint8_t *payload = tmpbuf;
-  char err_msg[SSH_ERRNO_MSG_MAX] = {0};
+                      struct ssh_buffer_struct *request,
+                      struct ssh_buffer_struct *reply)
+{
+    uint32_t len = 0;
+    uint8_t tmpbuf[4];
+    uint8_t *payload = tmpbuf;
+    char err_msg[SSH_ERRNO_MSG_MAX] = {0};
 
-  len = ssh_buffer_get_len(request);
-  SSH_LOG(SSH_LOG_TRACE, "Request length: %" PRIu32, len);
-  PUSH_BE_U32(payload, 0, len);
+    len = ssh_buffer_get_len(request);
+    SSH_LOG(SSH_LOG_TRACE, "Request length: %" PRIu32, len);
+    PUSH_BE_U32(payload, 0, len);
 
-  /* send length and then the request packet */
-  if (atomicio(session->agent, payload, 4, 0) == 4) {
-    if (atomicio(session->agent, ssh_buffer_get(request), len, 0)
-        != len) {
-      SSH_LOG(SSH_LOG_TRACE, "atomicio sending request failed: %s",
-          strerror(errno));
-      return -1;
+    /* send length and then the request packet */
+    if (atomicio(session->agent, payload, 4, 0) == 4) {
+        if (atomicio(session->agent, ssh_buffer_get(request), len, 0) != len) {
+            SSH_LOG(SSH_LOG_TRACE,
+                    "atomicio sending request failed: %s",
+                    ssh_strerror(errno, err_msg, SSH_ERRNO_MSG_MAX));
+            return -1;
+        }
+    } else {
+        SSH_LOG(SSH_LOG_TRACE,
+                "atomicio sending request length failed: %s",
+                ssh_strerror(errno, err_msg, SSH_ERRNO_MSG_MAX));
+        return -1;
     }
-  } else {
-    SSH_LOG(SSH_LOG_TRACE,
-        "atomicio sending request length failed: %s",
-        ssh_strerror(errno, err_msg, SSH_ERRNO_MSG_MAX));
-    return -1;
-  }
 
-  /* wait for response, read the length of the response packet */
-  if (atomicio(session->agent, payload, 4, 1) != 4) {
-    SSH_LOG(SSH_LOG_TRACE, "atomicio read response length failed: %s",
-        strerror(errno));
-    return -1;
-  }
+    /* wait for response, read the length of the response packet */
+    if (atomicio(session->agent, payload, 4, 1) != 4) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "atomicio read response length failed: %s",
+                ssh_strerror(errno, err_msg, SSH_ERRNO_MSG_MAX));
+        return -1;
+    }
 
-  len = PULL_BE_U32(payload, 0);
-  if (len > 256 * 1024) {
-    ssh_set_error(session, SSH_FATAL,
-        "Authentication response too long: %" PRIu32, len);
-    return -1;
-  }
-  SSH_LOG(SSH_LOG_TRACE, "Response length: %" PRIu32, len);
+    len = PULL_BE_U32(payload, 0);
+    if (len > 256 * 1024) {
+        ssh_set_error(session,
+                      SSH_FATAL,
+                      "Authentication response too long: %" PRIu32,
+                      len);
+        return -1;
+    }
+    SSH_LOG(SSH_LOG_TRACE, "Response length: %" PRIu32, len);
 
-  payload = ssh_buffer_allocate(reply, len);
-  if (payload == NULL) {
-    SSH_LOG(SSH_LOG_DEBUG, "Not enough space");
-    return -1;
-  }
+    payload = ssh_buffer_allocate(reply, len);
+    if (payload == NULL) {
+        SSH_LOG(SSH_LOG_DEBUG, "Not enough space");
+        return -1;
+    }
 
-  if (atomicio(session->agent, payload, len, 1) != len) {
-    SSH_LOG(SSH_LOG_DEBUG,
-        "Error reading response from authentication socket.");
-    /* Rollback the unused space */
-    ssh_buffer_pass_bytes_end(reply, len);
-    return -1;
-  }
+    if (atomicio(session->agent, payload, len, 1) != len) {
+        SSH_LOG(SSH_LOG_DEBUG,
+                "Error reading response from authentication socket.");
+        /* Rollback the unused space */
+        ssh_buffer_pass_bytes_end(reply, len);
+        return -1;
+    }
 
-  return 0;
+    return 0;
 }
 
 uint32_t ssh_agent_get_ident_count(struct ssh_session_struct *session)
@@ -471,22 +494,23 @@ ssh_key ssh_agent_get_next_ident(struct ssh_session_struct *session,
     return key;
 }
 
-int ssh_agent_is_running(ssh_session session) {
-  if (session == NULL || session->agent == NULL) {
-    return 0;
-  }
-
-  if (ssh_socket_is_open(session->agent->sock)) {
-    return 1;
-  } else {
-    if (agent_connect(session) < 0) {
-      return 0;
-    } else {
-      return 1;
+int ssh_agent_is_running(ssh_session session)
+{
+    if (session == NULL || session->agent == NULL) {
+        return 0;
     }
-  }
 
-  return 0;
+    if (ssh_socket_is_open(session->agent->sock)) {
+        return 1;
+    } else {
+        if (agent_connect(session) < 0) {
+            return 0;
+        } else {
+            return 1;
+        }
+    }
+
+    return 0;
 }
 
 ssh_string ssh_agent_sign_data(ssh_session session,
@@ -500,6 +524,7 @@ ssh_string ssh_agent_sign_data(ssh_session session,
     unsigned int type = 0;
     unsigned int flags = 0;
     uint32_t dlen;
+    size_t request_len;
     int rc;
 
     request = ssh_buffer_new();
@@ -525,11 +550,14 @@ ssh_string ssh_agent_sign_data(ssh_session session,
      * - 2 x uint32_t
      * - 1 x ssh_string (uint8_t + data)
      */
-    rc = ssh_buffer_allocate_size(request,
-                                  sizeof(uint8_t) * 2 +
-                                  sizeof(uint32_t) * 2 +
-                                  ssh_string_len(key_blob));
+    request_len = sizeof(uint8_t) * 2 +
+                  sizeof(uint32_t) * 2 +
+                  ssh_string_len(key_blob);
+    /* this can't overflow the uint32_t as the
+     * STRING_SIZE_MAX is (UINT32_MAX >> 8) + 1 */
+    rc = ssh_buffer_allocate_size(request, (uint32_t)request_len);
     if (rc < 0) {
+        SSH_STRING_FREE(key_blob);
         SSH_BUFFER_FREE(request);
         return NULL;
     }

src/auth.c

@@ -463,6 +463,108 @@ fail:
     return SSH_AUTH_ERROR;
 }
 
+/**
+ * @internal
+ *
+ * @brief Adds the server's public key to the authentication request.
+ *
+ * This function is used internally when the hostbound public key authentication
+ * extension is enabled. It export the server's public key and adds it to the
+ * authentication buffer.
+ *
+ * @param[in]  session          The SSH session.
+ *
+ * @returns SSH_OK on success, SSH_ERROR if an error occurred.
+ */
+static int add_hostbound_pubkey(ssh_session session)
+{
+    int rc;
+    ssh_string server_pubkey_s = NULL;
+
+    if (session == NULL) {
+        return SSH_ERROR;
+    }
+
+    if (session->current_crypto == NULL ||
+        session->current_crypto->server_pubkey == NULL) {
+        ssh_set_error(session,
+                      SSH_FATAL,
+                      "Invalid session or server public key");
+        return SSH_ERROR;
+    }
+
+    rc = ssh_pki_export_pubkey_blob(session->current_crypto->server_pubkey,
+                                    &server_pubkey_s);
+    if (rc < 0) {
+        goto error;
+    }
+
+    rc = ssh_buffer_add_ssh_string(session->out_buffer, server_pubkey_s);
+    if (rc < 0) {
+        goto error;
+    }
+
+error:
+    SSH_STRING_FREE(server_pubkey_s);
+    return rc;
+}
+
+/**
+ * @internal
+ *
+ * @brief Build a public key authentication request.
+ *
+ * This helper function creates a SSH2_MSG_USERAUTH_REQUEST message for public
+ * key authentication and adds the server's public key if the hostbound
+ * extension is enabled.
+ *
+ * @param[in] session       The SSH session.
+ * @param[in] username      The username, may be NULL.
+ * @param[in] auth_type     Authentication type (0 for key offer, 1 for actual
+ * auth).
+ * @param[in] sig_type_c    The signature algorithm name.
+ * @param[in] pubkey_s      The public key string.
+ *
+ * @return  SSH_OK on success, SSH_ERROR if an error occurred.
+ */
+static int build_pubkey_auth_request(ssh_session session,
+                                     const char *username,
+                                     int has_signature,
+                                     const char *sig_type_c,
+                                     ssh_string pubkey_s)
+{
+    int rc;
+    const char *auth_method = "publickey";
+
+    if (session->extensions & SSH_EXT_PUBLICKEY_HOSTBOUND) {
+        auth_method = "publickey-hostbound-v00@openssh.com";
+    }
+
+    /* request */
+    rc = ssh_buffer_pack(session->out_buffer,
+                         "bsssbsS",
+                         SSH2_MSG_USERAUTH_REQUEST,
+                         username ? username : session->opts.username,
+                         "ssh-connection",
+                         auth_method,
+                         has_signature, /* private key? */
+                         sig_type_c,    /* algo */
+                         pubkey_s       /* public key */
+    );
+    if (rc < 0) {
+        return SSH_ERROR;
+    }
+
+    if (session->extensions & SSH_EXT_PUBLICKEY_HOSTBOUND) {
+        rc = add_hostbound_pubkey(session);
+        if (rc < 0) {
+            return SSH_ERROR;
+        }
+    }
+
+    return SSH_OK;
+}
+
 /**
  * @brief Try to authenticate with the given public key.
  *
@@ -509,17 +611,17 @@ int ssh_userauth_try_publickey(ssh_session session,
         return SSH_AUTH_ERROR;
     }
 
-    switch(session->pending_call_state) {
-        case SSH_PENDING_CALL_NONE:
-            break;
-        case SSH_PENDING_CALL_AUTH_OFFER_PUBKEY:
-            goto pending;
-        default:
-            ssh_set_error(session,
-                          SSH_FATAL,
-                          "Wrong state (%d) during pending SSH call",
-                          session->pending_call_state);
-            return SSH_AUTH_ERROR;
+    switch (session->pending_call_state) {
+    case SSH_PENDING_CALL_NONE:
+        break;
+    case SSH_PENDING_CALL_AUTH_OFFER_PUBKEY:
+        goto pending;
+    default:
+        ssh_set_error(session,
+                      SSH_FATAL,
+                      "Wrong state (%d) during pending SSH call",
+                      session->pending_call_state);
+        return SSH_AUTH_ERROR;
     }
 
     /* Note, that this is intentionally before checking the signature type
@@ -536,13 +638,15 @@ int ssh_userauth_try_publickey(ssh_session session,
     /* Check if the given public key algorithm is allowed */
     sig_type_c = ssh_key_get_signature_algorithm(session, pubkey->type);
     if (sig_type_c == NULL) {
-        ssh_set_error(session, SSH_REQUEST_DENIED,
+        ssh_set_error(session,
+                      SSH_REQUEST_DENIED,
                       "Invalid key type (unknown)");
         return SSH_AUTH_DENIED;
     }
     rc = ssh_key_algorithm_allowed(session, sig_type_c);
     if (!rc) {
-        ssh_set_error(session, SSH_REQUEST_DENIED,
+        ssh_set_error(session,
+                      SSH_REQUEST_DENIED,
                       "The key algorithm '%s' is not allowed to be used by"
                       " PUBLICKEY_ACCEPTED_TYPES configuration option",
                       sig_type_c);
@@ -550,9 +654,12 @@ int ssh_userauth_try_publickey(ssh_session session,
     }
     allowed = ssh_key_size_allowed(session, pubkey);
     if (!allowed) {
-        ssh_set_error(session, SSH_REQUEST_DENIED,
+        ssh_set_error(session,
+                      SSH_REQUEST_DENIED,
                       "The '%s' key type of size %d is not allowed by "
-                      "RSA_MIN_SIZE", sig_type_c, ssh_key_size(pubkey));
+                      "RSA_MIN_SIZE",
+                      sig_type_c,
+                      ssh_key_size(pubkey));
         return SSH_AUTH_DENIED;
     }
 
@@ -563,20 +670,10 @@ int ssh_userauth_try_publickey(ssh_session session,
     }
 
     SSH_LOG(SSH_LOG_TRACE, "Trying signature type %s", sig_type_c);
-    /* request */
-    rc = ssh_buffer_pack(session->out_buffer, "bsssbsS",
-            SSH2_MSG_USERAUTH_REQUEST,
-            username ? username : session->opts.username,
-            "ssh-connection",
-            "publickey",
-            0, /* private key ? */
-            sig_type_c, /* algo */
-            pubkey_s /* public key */
-            );
+    rc = build_pubkey_auth_request(session, username, 0, sig_type_c, pubkey_s);
     if (rc < 0) {
         goto fail;
     }
-
     SSH_STRING_FREE(pubkey_s);
 
     session->auth.current_method = SSH_AUTH_METHOD_PUBLICKEY;
@@ -645,16 +742,17 @@ int ssh_userauth_publickey(ssh_session session,
         return SSH_AUTH_ERROR;
     }
 
-    switch(session->pending_call_state) {
-        case SSH_PENDING_CALL_NONE:
-            break;
-        case SSH_PENDING_CALL_AUTH_PUBKEY:
-            goto pending;
-        default:
-            ssh_set_error(session,
-                          SSH_FATAL,
-                          "Bad call during pending SSH call in ssh_userauth_try_publickey");
-            return SSH_AUTH_ERROR;
+    switch (session->pending_call_state) {
+    case SSH_PENDING_CALL_NONE:
+        break;
+    case SSH_PENDING_CALL_AUTH_PUBKEY:
+        goto pending;
+    default:
+        ssh_set_error(
+            session,
+            SSH_FATAL,
+            "Bad call during pending SSH call in ssh_userauth_try_publickey");
+        return SSH_AUTH_ERROR;
     }
 
     /* Note, that this is intentionally before checking the signature type
@@ -674,13 +772,15 @@ int ssh_userauth_publickey(ssh_session session,
     /* Check if the given public key algorithm is allowed */
     sig_type_c = ssh_key_get_signature_algorithm(session, key_type);
     if (sig_type_c == NULL) {
-        ssh_set_error(session, SSH_REQUEST_DENIED,
+        ssh_set_error(session,
+                      SSH_REQUEST_DENIED,
                       "Invalid key type (unknown)");
         return SSH_AUTH_DENIED;
     }
     rc = ssh_key_algorithm_allowed(session, sig_type_c);
     if (!rc) {
-        ssh_set_error(session, SSH_REQUEST_DENIED,
+        ssh_set_error(session,
+                      SSH_REQUEST_DENIED,
                       "The key algorithm '%s' is not allowed to be used by"
                       " PUBLICKEY_ACCEPTED_TYPES configuration option",
                       sig_type_c);
@@ -688,9 +788,12 @@ int ssh_userauth_publickey(ssh_session session,
     }
     allowed = ssh_key_size_allowed(session, privkey);
     if (!allowed) {
-        ssh_set_error(session, SSH_REQUEST_DENIED,
+        ssh_set_error(session,
+                      SSH_REQUEST_DENIED,
                       "The '%s' key type of size %d is not allowed by "
-                      "RSA_MIN_SIZE", sig_type_c, ssh_key_size(privkey));
+                      "RSA_MIN_SIZE",
+                      sig_type_c,
+                      ssh_key_size(privkey));
         return SSH_AUTH_DENIED;
     }
 
@@ -701,16 +804,7 @@ int ssh_userauth_publickey(ssh_session session,
     }
 
     SSH_LOG(SSH_LOG_TRACE, "Sending signature type %s", sig_type_c);
-    /* request */
-    rc = ssh_buffer_pack(session->out_buffer, "bsssbsS",
-            SSH2_MSG_USERAUTH_REQUEST,
-            username ? username : session->opts.username,
-            "ssh-connection",
-            "publickey",
-            1, /* private key */
-            sig_type_c, /* algo */
-            str /* public key or cert */
-            );
+    rc = build_pubkey_auth_request(session, username, 1, sig_type_c, str);
     if (rc < 0) {
         goto fail;
     }
@@ -798,14 +892,16 @@ static int ssh_userauth_agent_publickey(ssh_session session,
     /* Check if the given public key algorithm is allowed */
     sig_type_c = ssh_key_get_signature_algorithm(session, pubkey->type);
     if (sig_type_c == NULL) {
-        ssh_set_error(session, SSH_REQUEST_DENIED,
+        ssh_set_error(session,
+                      SSH_REQUEST_DENIED,
                       "Invalid key type (unknown)");
         SSH_STRING_FREE(pubkey_s);
         return SSH_AUTH_DENIED;
     }
     rc = ssh_key_algorithm_allowed(session, sig_type_c);
     if (!rc) {
-        ssh_set_error(session, SSH_REQUEST_DENIED,
+        ssh_set_error(session,
+                      SSH_REQUEST_DENIED,
                       "The key algorithm '%s' is not allowed to be used by"
                       " PUBLICKEY_ACCEPTED_TYPES configuration option",
                       sig_type_c);
@@ -814,27 +910,21 @@ static int ssh_userauth_agent_publickey(ssh_session session,
     }
     allowed = ssh_key_size_allowed(session, pubkey);
     if (!allowed) {
-        ssh_set_error(session, SSH_REQUEST_DENIED,
+        ssh_set_error(session,
+                      SSH_REQUEST_DENIED,
                       "The '%s' key type of size %d is not allowed by "
-                      "RSA_MIN_SIZE", sig_type_c, ssh_key_size(pubkey));
+                      "RSA_MIN_SIZE",
+                      sig_type_c,
+                      ssh_key_size(pubkey));
         SSH_STRING_FREE(pubkey_s);
         return SSH_AUTH_DENIED;
     }
 
-    /* request */
-    rc = ssh_buffer_pack(session->out_buffer, "bsssbsS",
-                         SSH2_MSG_USERAUTH_REQUEST,
-                         username ? username : session->opts.username,
-                         "ssh-connection",
-                         "publickey",
-                         1, /* private key */
-                         sig_type_c, /* algo */
-                         pubkey_s /* public key */
-                         );
-    SSH_STRING_FREE(pubkey_s);
+    rc = build_pubkey_auth_request(session, username, 1, sig_type_c, pubkey_s);
     if (rc < 0) {
         goto fail;
     }
+    SSH_STRING_FREE(pubkey_s);
 
     /* sign the buffer with the private key */
     sig_blob = ssh_pki_do_sign_agent(session, session->out_buffer, pubkey);
@@ -892,7 +982,7 @@ void ssh_agent_state_free(void *data)
     if (state) {
         SSH_STRING_FREE_CHAR(state->comment);
         ssh_key_free(state->pubkey);
-        free (state);
+        free(state);
     }
 }
 
@@ -918,8 +1008,7 @@ void ssh_agent_state_free(void *data)
  * authentication. The username should only be set with ssh_options_set() only
  * before you connect to the server.
  */
-int ssh_userauth_agent(ssh_session session,
-                       const char *username)
+int ssh_userauth_agent(ssh_session session, const char *username)
 {
     int rc = SSH_AUTH_ERROR;
     struct ssh_agent_state_struct *state = NULL;
@@ -938,12 +1027,11 @@ int ssh_userauth_agent(ssh_session session,
     }
 
     if (!session->agent_state) {
-        session->agent_state = malloc(sizeof(struct ssh_agent_state_struct));
+        session->agent_state = calloc(1, sizeof(struct ssh_agent_state_struct));
         if (!session->agent_state) {
             ssh_set_error_oom(session);
             return SSH_AUTH_ERROR;
         }
-        ZERO_STRUCTP(session->agent_state);
         session->agent_state->state = SSH_AGENT_STATE_NONE;
     }
 

src/base64.c

@@ -186,7 +186,7 @@ error:
 static int to_block4(unsigned long *block, const char *source, int num)
 {
     const char *ptr = NULL;
-    unsigned int i;
+    size_t i;
 
     *block = 0;
     if (num < 1) {

src/bignum.c

@@ -27,40 +27,52 @@
 #include "libssh/bignum.h"
 #include "libssh/string.h"
 
-ssh_string ssh_make_bignum_string(bignum num) {
-  ssh_string ptr = NULL;
-  size_t pad = 0;
-  size_t len = bignum_num_bytes(num);
-  size_t bits = bignum_num_bits(num);
+static ssh_string make_bignum_string(bignum num, size_t pad_to_len)
+{
+    ssh_string ptr = NULL;
+    size_t pad = 0;
+    size_t len = bignum_num_bytes(num);
+    size_t bits = bignum_num_bits(num);
 
-  if (len == 0) {
-      return NULL;
-  }
-
-  /* If the first bit is set we have a negative number */
-  if (!(bits % 8) && bignum_is_bit_set(num, bits - 1)) {
-    pad++;
-  }
+    if (pad_to_len == 0) {
+        /* If the first bit is set we have a negative number */
+        if (!(bits % 8) && bignum_is_bit_set(num, bits - 1)) {
+            pad++;
+        }
+    } else {
+        if (len > pad_to_len) {
+            return NULL;
+        }
+        pad = pad_to_len - len;
+    }
 
 #ifdef DEBUG_CRYPTO
-  SSH_LOG(SSH_LOG_TRACE,
-          "%zu bits, %zu bytes, %zu padding",
-          bits, len, pad);
+    SSH_LOG(SSH_LOG_TRACE, "%zu bits, %zu bytes, %zu padding", bits, len, pad);
 #endif /* DEBUG_CRYPTO */
 
-  ptr = ssh_string_new(len + pad);
-  if (ptr == NULL) {
-    return NULL;
-  }
+    ptr = ssh_string_new(len + pad);
+    if (ptr == NULL) {
+        return NULL;
+    }
 
-  /* We have a negative number so we need a leading zero */
-  if (pad) {
-    ptr->data[0] = 0;
-  }
+    /* We have a negative number so we need a leading zero */
+    if (pad) {
+        memset(ptr->data, 0, pad);
+    }
 
-  bignum_bn2bin(num, len, ptr->data + pad);
+    bignum_bn2bin(num, len, ptr->data + pad);
 
-  return ptr;
+    return ptr;
+}
+
+ssh_string ssh_make_bignum_string(bignum num)
+{
+    return make_bignum_string(num, 0);
+}
+
+ssh_string ssh_make_padded_bignum_string(bignum num, size_t pad_len)
+{
+    return make_bignum_string(num, pad_len);
 }
 
 bignum ssh_make_string_bn(ssh_string string)
@@ -71,10 +83,11 @@ bignum ssh_make_string_bn(ssh_string string)
 #ifdef DEBUG_CRYPTO
     SSH_LOG(SSH_LOG_TRACE,
             "Importing a %zu bits, %zu bytes object ...",
-            len * 8, len);
+            len * 8,
+            len);
 #endif /* DEBUG_CRYPTO */
 
-    bignum_bin2bn(string->data, len, &bn);
+    bignum_bin2bn(string->data, (int)len, &bn);
 
     return bn;
 }
@@ -86,7 +99,9 @@ void ssh_print_bignum(const char *name, const_bignum num)
     if (num != NULL) {
         bignum_bn2hex(num, &hex);
     }
-    SSH_LOG(SSH_LOG_DEBUG, "%s value: %s", name,
+    SSH_LOG(SSH_LOG_DEBUG,
+            "%s value: %s",
+            name,
             (hex == NULL) ? "(null)" : (char *)hex);
     ssh_crypto_free(hex);
 }

src/bind.c

@@ -505,7 +505,10 @@ int ssh_bind_accept_fd(ssh_bind sshbind, ssh_session session, socket_t fd)
       ssh_set_error_oom(sshbind);
       return SSH_ERROR;
     }
-    ssh_socket_set_fd(session->socket, fd);
+    rc = ssh_socket_set_fd(session->socket, fd);
+    if (rc != SSH_OK) {
+        return rc;
+    }
     handle = ssh_socket_get_poll_handle(session->socket);
     if (handle == NULL) {
         ssh_set_error_oom(sshbind);

src/bind_config.c

@@ -669,7 +669,8 @@ int ssh_bind_config_parse_string(ssh_bind bind, const char *input)
 {
     char line[MAX_LINE_SIZE] = {0};
     const char *c = input, *line_start = input;
-    unsigned int line_num = 0, line_len;
+    unsigned int line_num = 0;
+    size_t line_len;
     uint32_t parser_flags;
     int rv;
 
@@ -698,8 +699,10 @@ int ssh_bind_config_parse_string(ssh_bind bind, const char *input)
         }
         line_len = c - line_start;
         if (line_len > MAX_LINE_SIZE - 1) {
-            SSH_LOG(SSH_LOG_WARN, "Line %u too long: %u characters",
-                    line_num, line_len);
+            SSH_LOG(SSH_LOG_WARN,
+                    "Line %u too long: %zu characters",
+                    line_num,
+                    line_len);
             return SSH_ERROR;
         }
         memcpy(line, line_start, line_len);

src/buffer.c

@@ -407,20 +407,26 @@ void *ssh_buffer_allocate(struct ssh_buffer_struct *buffer, uint32_t len)
  *
  * @return              0 on success, < 0 on error.
  */
-int ssh_buffer_add_ssh_string(struct ssh_buffer_struct *buffer,
-    struct ssh_string_struct *string) {
-  uint32_t len = 0;
+int
+ssh_buffer_add_ssh_string(struct ssh_buffer_struct *buffer,
+                          struct ssh_string_struct *string)
+{
+    size_t len;
+    int rc;
 
-  if (string == NULL) {
-      return -1;
-  }
+    if (string == NULL) {
+        return -1;
+    }
 
-  len = ssh_string_len(string);
-  if (ssh_buffer_add_data(buffer, string, len + sizeof(uint32_t)) < 0) {
-    return -1;
-  }
+    len = ssh_string_len(string) + sizeof(uint32_t);
+    /* this can't overflow the uint32_t as the
+     * STRING_SIZE_MAX is (UINT32_MAX >> 8) + 1 */
+    rc = ssh_buffer_add_data(buffer, string, (uint32_t)len);
+    if (rc < 0) {
+        return -1;
+    }
 
-  return 0;
+    return 0;
 }
 
 /**
@@ -823,6 +829,7 @@ static int ssh_buffer_pack_allocate_va(struct ssh_buffer_struct *buffer,
     const char *p = NULL;
     ssh_string string = NULL;
     char *cstring = NULL;
+    bignum b = NULL;
     size_t needed_size = 0;
     size_t len;
     size_t count;
@@ -867,13 +874,18 @@ static int ssh_buffer_pack_allocate_va(struct ssh_buffer_struct *buffer,
             va_arg(ap, void *);
             count++; /* increase argument count */
             break;
+        case 'F':
         case 'B':
-            va_arg(ap, bignum);
-            /*
-             * Use a fixed size for a bignum
-             * (they should normally be around 32)
-             */
-            needed_size += 64;
+            b = va_arg(ap, bignum);
+            if (*p == 'F') {
+                /* For padded bignum, we know the exact length */
+                len = va_arg(ap, size_t);
+                count++; /* increase argument count */
+                needed_size += sizeof(uint32_t) + len;
+            } else {
+                /* The bignum bytes + 1 for possible padding */
+                needed_size += sizeof(uint32_t) + bignum_num_bytes(b) + 1;
+            }
             break;
         case 't':
             cstring = va_arg(ap, char *);
@@ -979,24 +991,40 @@ ssh_buffer_pack_va(struct ssh_buffer_struct *buffer,
         case 's':
             cstring = va_arg(ap, char *);
             len = strlen(cstring);
-            rc = ssh_buffer_add_u32(buffer, htonl(len));
+            if (len > UINT32_MAX) {
+                rc = SSH_ERROR;
+                break;
+            }
+            o.dword = (uint32_t)len;
+            rc = ssh_buffer_add_u32(buffer, htonl(o.dword));
             if (rc == SSH_OK){
-                rc = ssh_buffer_add_data(buffer, cstring, len);
+                rc = ssh_buffer_add_data(buffer, cstring, o.dword);
             }
             cstring = NULL;
             break;
         case 'P':
             len = va_arg(ap, size_t);
+            if (len > UINT32_MAX) {
+                rc = SSH_ERROR;
+                break;
+            }
 
             o.data = va_arg(ap, void *);
             count++; /* increase argument count */
 
-            rc = ssh_buffer_add_data(buffer, o.data, len);
+            rc = ssh_buffer_add_data(buffer, o.data, (uint32_t)len);
             o.data = NULL;
             break;
+        case 'F':
         case 'B':
             b = va_arg(ap, bignum);
-            o.string = ssh_make_bignum_string(b);
+            if (*p == 'F') {
+                len = va_arg(ap, size_t);
+                count++; /* increase argument count */
+                o.string = ssh_make_padded_bignum_string(b, len);
+            } else {
+                o.string = ssh_make_bignum_string(b);
+            }
             if(o.string == NULL){
                 rc = SSH_ERROR;
                 break;
@@ -1007,7 +1035,11 @@ ssh_buffer_pack_va(struct ssh_buffer_struct *buffer,
         case 't':
             cstring = va_arg(ap, char *);
             len = strlen(cstring);
-            rc = ssh_buffer_add_data(buffer, cstring, len);
+            if (len > UINT32_MAX) {
+                rc = SSH_ERROR;
+                break;
+            }
+            rc = ssh_buffer_add_data(buffer, cstring, (uint32_t)len);
             cstring = NULL;
             break;
         default:
@@ -1048,6 +1080,8 @@ ssh_buffer_pack_va(struct ssh_buffer_struct *buffer,
  *                         'P': size_t, void * (len of data, pointer to data)
  *                              only pushes data.
  *                         'B': bignum (pushed as SSH string)
+ *                         'F': bignum, size_t (bignum, padded to fixed length,
+ *                              pushed as SSH string)
  * @returns             SSH_OK on success
  *                      SSH_ERROR on error
  * @warning             when using 'P' with a constant size (e.g. 8), do not
@@ -1187,28 +1221,28 @@ int ssh_buffer_unpack_va(struct ssh_buffer_struct *buffer,
             if (rlen != 4){
                 break;
             }
-            len = ntohl(u32len);
-            if (len > max_len - 1) {
+            u32len = ntohl(u32len);
+            if (u32len > max_len - 1) {
                 break;
             }
 
-            rc = ssh_buffer_validate_length(buffer, len);
+            rc = ssh_buffer_validate_length(buffer, u32len);
             if (rc != SSH_OK) {
                 break;
             }
 
-            *o.cstring = malloc(len + 1);
+            *o.cstring = malloc(u32len + 1);
             if (*o.cstring == NULL){
                 rc = SSH_ERROR;
                 break;
             }
-            rlen = ssh_buffer_get_data(buffer, *o.cstring, len);
-            if (rlen != len){
+            rlen = ssh_buffer_get_data(buffer, *o.cstring, u32len);
+            if (rlen != u32len) {
                 SAFE_FREE(*o.cstring);
                 rc = SSH_ERROR;
                 break;
             }
-            (*o.cstring)[len] = '\0';
+            (*o.cstring)[u32len] = '\0';
             o.cstring = NULL;
             rc = SSH_OK;
             break;
@@ -1233,7 +1267,7 @@ int ssh_buffer_unpack_va(struct ssh_buffer_struct *buffer,
                 rc = SSH_ERROR;
                 break;
             }
-            rlen = ssh_buffer_get_data(buffer, *o.data, len);
+            rlen = ssh_buffer_get_data(buffer, *o.data, (uint32_t)len);
             if (rlen != len){
                 SAFE_FREE(*o.data);
                 rc = SSH_ERROR;

src/callbacks.c

@@ -24,11 +24,11 @@
 #include "config.h"
 
 #include "libssh/callbacks.h"
-#include "libssh/session.h"
 #include "libssh/misc.h"
+#include "libssh/session.h"
 
 #define is_callback_valid(session, cb) \
-    (cb->size <= 0 || cb->size > 1024 * sizeof(void *))
+    (cb->size > 0 || cb->size <= 1024 * sizeof(void *))
 
 /* LEGACY */
 static void ssh_legacy_log_callback(int priority,
@@ -45,8 +45,7 @@ static void ssh_legacy_log_callback(int priority,
     log_fn(session, priority, buffer, log_data);
 }
 
-void
-_ssh_remove_legacy_log_cb(void)
+void _ssh_remove_legacy_log_cb(void)
 {
     if (ssh_get_log_callback() == ssh_legacy_log_callback) {
         _ssh_reset_log_cb();
@@ -54,26 +53,27 @@ _ssh_remove_legacy_log_cb(void)
     }
 }
 
-int ssh_set_callbacks(ssh_session session, ssh_callbacks cb) {
-  if (session == NULL || cb == NULL) {
-    return SSH_ERROR;
-  }
+int ssh_set_callbacks(ssh_session session, ssh_callbacks cb)
+{
+    if (session == NULL || cb == NULL) {
+        return SSH_ERROR;
+    }
 
-  if (is_callback_valid(session, cb)) {
-      ssh_set_error(session,
-                    SSH_FATAL,
-                    "Invalid callback passed in (badly initialized)");
-      return SSH_ERROR;
-  };
-  session->common.callbacks = cb;
+    if (!is_callback_valid(session, cb)) {
+        ssh_set_error(session,
+                      SSH_FATAL,
+                      "Invalid callback passed in (badly initialized)");
+        return SSH_ERROR;
+    };
+    session->common.callbacks = cb;
 
-  /* LEGACY */
-  if (ssh_get_log_callback() == NULL && cb->log_function) {
-      ssh_set_log_callback(ssh_legacy_log_callback);
-      ssh_set_log_userdata(session);
-  }
+    /* LEGACY */
+    if (ssh_get_log_callback() == NULL && cb->log_function) {
+        ssh_set_log_callback(ssh_legacy_log_callback);
+        ssh_set_log_userdata(session);
+    }
 
-  return 0;
+    return 0;
 }
 
 static int ssh_add_set_channel_callbacks(ssh_channel channel,
@@ -84,11 +84,11 @@ static int ssh_add_set_channel_callbacks(ssh_channel channel,
     int rc;
 
     if (channel == NULL || cb == NULL) {
-      return SSH_ERROR;
+        return SSH_ERROR;
     }
     session = channel->session;
 
-    if (is_callback_valid(session, cb)) {
+    if (!is_callback_valid(session, cb)) {
         ssh_set_error(session,
                       SSH_FATAL,
                       "Invalid callback passed in (badly initialized)");
@@ -96,7 +96,7 @@ static int ssh_add_set_channel_callbacks(ssh_channel channel,
     };
     if (channel->callbacks == NULL) {
         channel->callbacks = ssh_list_new();
-        if (channel->callbacks == NULL){
+        if (channel->callbacks == NULL) {
             ssh_set_error_oom(session);
             return SSH_ERROR;
         }
@@ -124,12 +124,12 @@ int ssh_remove_channel_callbacks(ssh_channel channel, ssh_channel_callbacks cb)
 {
     struct ssh_iterator *it = NULL;
 
-    if (channel == NULL || channel->callbacks == NULL){
+    if (channel == NULL || channel->callbacks == NULL) {
         return SSH_ERROR;
     }
 
     it = ssh_list_find(channel->callbacks, cb);
-    if (it == NULL){
+    if (it == NULL) {
         return SSH_ERROR;
     }
 
@@ -138,19 +138,19 @@ int ssh_remove_channel_callbacks(ssh_channel channel, ssh_channel_callbacks cb)
     return SSH_OK;
 }
 
+int ssh_set_server_callbacks(ssh_session session, ssh_server_callbacks cb)
+{
+    if (session == NULL || cb == NULL) {
+        return SSH_ERROR;
+    }
 
-int ssh_set_server_callbacks(ssh_session session, ssh_server_callbacks cb){
-	if (session == NULL || cb == NULL) {
-		return SSH_ERROR;
-	}
-
-    if (is_callback_valid(session, cb)) {
+    if (!is_callback_valid(session, cb)) {
         ssh_set_error(session,
                       SSH_FATAL,
                       "Invalid callback passed in (badly initialized)");
         return SSH_ERROR;
     };
-	session->server_callbacks = cb;
+    session->server_callbacks = cb;
 
-	return 0;
+    return 0;
 }

src/client.c

@@ -226,7 +226,7 @@ int ssh_send_banner(ssh_session session, int server)
                  terminator);
     }
 
-    rc = ssh_socket_write(session->socket, buffer, strlen(buffer));
+    rc = ssh_socket_write(session->socket, buffer, (uint32_t)strlen(buffer));
     if (rc == SSH_ERROR) {
         goto end;
     }
@@ -235,8 +235,8 @@ int ssh_send_banner(ssh_session session, int server)
         ssh_pcap_context_write(session->pcap_ctx,
                                SSH_PCAP_DIR_OUT,
                                buffer,
-                               strlen(buffer),
-                               strlen(buffer));
+                               (uint32_t)strlen(buffer),
+                               (uint32_t)strlen(buffer));
     }
 #endif
 
@@ -254,45 +254,52 @@ end:
  */
 int dh_handshake(ssh_session session)
 {
-  int rc = SSH_AGAIN;
+    int rc = SSH_AGAIN;
 
-  SSH_LOG(SSH_LOG_TRACE, "dh_handshake_state = %d, kex_type = %d",
-          session->dh_handshake_state,  session->next_crypto->kex_type);
+    SSH_LOG(SSH_LOG_TRACE,
+            "dh_handshake_state = %d, kex_type = %d",
+            session->dh_handshake_state,
+            session->next_crypto->kex_type);
 
-  switch (session->dh_handshake_state) {
+    switch (session->dh_handshake_state) {
     case DH_STATE_INIT:
-      switch(session->next_crypto->kex_type){
+        switch (session->next_crypto->kex_type) {
         case SSH_KEX_DH_GROUP1_SHA1:
         case SSH_KEX_DH_GROUP14_SHA1:
         case SSH_KEX_DH_GROUP14_SHA256:
         case SSH_KEX_DH_GROUP16_SHA512:
         case SSH_KEX_DH_GROUP18_SHA512:
-          rc = ssh_client_dh_init(session);
-          break;
+            rc = ssh_client_dh_init(session);
+            break;
 #ifdef WITH_GEX
         case SSH_KEX_DH_GEX_SHA1:
         case SSH_KEX_DH_GEX_SHA256:
-          rc = ssh_client_dhgex_init(session);
-          break;
+            rc = ssh_client_dhgex_init(session);
+            break;
 #endif /* WITH_GEX */
 #ifdef HAVE_ECDH
         case SSH_KEX_ECDH_SHA2_NISTP256:
         case SSH_KEX_ECDH_SHA2_NISTP384:
         case SSH_KEX_ECDH_SHA2_NISTP521:
-          rc = ssh_client_ecdh_init(session);
-          break;
+            rc = ssh_client_ecdh_init(session);
+            break;
 #endif
 #ifdef HAVE_CURVE25519
         case SSH_KEX_CURVE25519_SHA256:
         case SSH_KEX_CURVE25519_SHA256_LIBSSH_ORG:
-          rc = ssh_client_curve25519_init(session);
-          break;
+            rc = ssh_client_curve25519_init(session);
+            break;
+#endif
+#ifdef HAVE_SNTRUP761
+        case SSH_KEX_SNTRUP761X25519_SHA512_OPENSSH_COM:
+            rc = ssh_client_sntrup761x25519_init(session);
+            break;
 #endif
         default:
-          rc = SSH_ERROR;
-      }
+            rc = SSH_ERROR;
+        }
 
-      break;
+        break;
     case DH_STATE_INIT_SENT:
     	/* wait until ssh_packet_dh_reply is called */
     	break;
@@ -300,15 +307,17 @@ int dh_handshake(ssh_session session)
     	/* wait until ssh_packet_newkeys is called */
     	break;
     case DH_STATE_FINISHED:
-      return SSH_OK;
+        return SSH_OK;
     default:
-      ssh_set_error(session, SSH_FATAL, "Invalid state in dh_handshake(): %d",
-          session->dh_handshake_state);
+        ssh_set_error(session,
+                      SSH_FATAL,
+                      "Invalid state in dh_handshake(): %d",
+                      session->dh_handshake_state);
 
-      return SSH_ERROR;
-  }
+        return SSH_ERROR;
+    }
 
-  return rc;
+    return rc;
 }
 
 static int ssh_service_request_termination(void *s)
@@ -593,8 +602,7 @@ int ssh_connect(ssh_session session)
 
     if (session->opts.fd != SSH_INVALID_SOCKET) {
         session->session_state = SSH_SESSION_STATE_SOCKET_CONNECTED;
-        ssh_socket_set_fd(session->socket, session->opts.fd);
-        ret = SSH_OK;
+        ret = ssh_socket_set_fd(session->socket, session->opts.fd);
 #ifndef _WIN32
 #ifdef HAVE_PTHREAD
     } else if (ssh_libssh_proxy_jumps() &&

src/config.c

@@ -1451,6 +1451,32 @@ ssh_config_parse_line(ssh_session session,
   return 0;
 }
 
+/* @brief Parse configuration from a file pointer
+ *
+ * @params[in] session   The ssh session
+ * @params[in] fp        A valid file pointer
+ * @params[in] global    Whether the config is global or not
+ *
+ * @returns    0 on successful parsing the configuration file, -1 on error
+ */
+int ssh_config_parse(ssh_session session, FILE *fp, bool global)
+{
+    char line[MAX_LINE_SIZE] = {0};
+    unsigned int count = 0;
+    int parsing, rv;
+
+    parsing = 1;
+    while (fgets(line, sizeof(line), fp)) {
+        count++;
+        rv = ssh_config_parse_line(session, line, count, &parsing, 0, global);
+        if (rv < 0) {
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
 /* @brief Parse configuration file and set the options to the given session
  *
  * @params[in] session   The ssh session
@@ -1460,36 +1486,32 @@ ssh_config_parse_line(ssh_session session,
  */
 int ssh_config_parse_file(ssh_session session, const char *filename)
 {
-    char line[MAX_LINE_SIZE] = {0};
-    unsigned int count = 0;
-    FILE *f = NULL;
-    int parsing, rv;
+    FILE *fp = NULL;
+    int rv;
     bool global = 0;
 
-    f = fopen(filename, "r");
-    if (f == NULL) {
+    fp = fopen(filename, "r");
+    if (fp == NULL) {
         return 0;
     }
 
     rv = strcmp(filename, GLOBAL_CLIENT_CONFIG);
+#ifdef USR_GLOBAL_CLIENT_CONFIG
+    if (rv != 0) {
+        rv = strcmp(filename, USR_GLOBAL_CLIENT_CONFIG);
+    }
+#endif
+
     if (rv == 0) {
         global = true;
     }
 
     SSH_LOG(SSH_LOG_PACKET, "Reading configuration data from %s", filename);
 
-    parsing = 1;
-    while (fgets(line, sizeof(line), f)) {
-        count++;
-        rv = ssh_config_parse_line(session, line, count, &parsing, 0, global);
-        if (rv < 0) {
-            fclose(f);
-            return -1;
-        }
-    }
+    rv = ssh_config_parse(session, fp, global);
 
-    fclose(f);
-    return 0;
+    fclose(fp);
+    return rv;
 }
 
 /* @brief Parse configuration string and set the options to the given session
@@ -1504,7 +1526,8 @@ int ssh_config_parse_string(ssh_session session, const char *input)
 {
     char line[MAX_LINE_SIZE] = {0};
     const char *c = input, *line_start = input;
-    unsigned int line_num = 0, line_len;
+    unsigned int line_num = 0;
+    size_t line_len;
     int parsing, rv;
 
     SSH_LOG(SSH_LOG_DEBUG, "Reading configuration data from string:");
@@ -1526,8 +1549,10 @@ int ssh_config_parse_string(ssh_session session, const char *input)
         }
         line_len = c - line_start;
         if (line_len > MAX_LINE_SIZE - 1) {
-            SSH_LOG(SSH_LOG_TRACE, "Line %u too long: %u characters",
-                    line_num, line_len);
+            SSH_LOG(SSH_LOG_TRACE,
+                    "Line %u too long: %zu characters",
+                    line_num,
+                    line_len);
             return SSH_ERROR;
         }
         memcpy(line, line_start, line_len);

src/connect.c

@@ -209,7 +209,8 @@ socket_t ssh_connect_host_nonblocking(ssh_session session, const char *host,
                  bind_itr != NULL;
                  bind_itr = bind_itr->ai_next)
             {
-                if (bind(s, bind_itr->ai_addr, bind_itr->ai_addrlen) < 0) {
+                rc = bind(s, bind_itr->ai_addr, bind_itr->ai_addrlen);
+                if (rc < 0) {
                     ssh_set_error(session, SSH_FATAL,
                                   "Binding local address: %s",
                                   ssh_strerror(errno, err_msg, SSH_ERRNO_MSG_MAX));

src/connector.c

@@ -264,17 +264,17 @@ static void ssh_connector_fd_in_cb(ssh_connector connector)
                 }
                 connector->in_available = 1; /* Don't poll on it */
                 return;
-            } else if (r> 0) {
+            } else if (r > 0) {
                 /* loop around ssh_channel_write in case our window reduced due to a race */
                 while (total != r){
                     if (connector->out_flags & SSH_CONNECTOR_STDOUT) {
                         w = ssh_channel_write(connector->out_channel,
                                               buffer + total,
-                                              r - total);
+                                              (uint32_t)(r - total));
                     } else {
                         w = ssh_channel_write_stderr(connector->out_channel,
                                                      buffer + total,
-                                                     r - total);
+                                                     (uint32_t)(r - total));
                     }
                     if (w == SSH_ERROR) {
                         return;
@@ -294,7 +294,7 @@ static void ssh_connector_fd_in_cb(ssh_connector connector)
                 while (total < r) {
                     w = ssh_connector_fd_write(connector,
                                                buffer + total,
-                                               r - total);
+                                               (uint32_t)(r - total));
                     if (w < 0) {
                         ssh_connector_except(connector, connector->out_fd);
                         return;
@@ -340,8 +340,9 @@ ssh_connector_fd_out_cb(ssh_connector connector)
             } else if (r > 0) {
                 /* loop around write in case the write blocks even for CHUNKSIZE bytes */
                 while (total != r) {
-                    w = ssh_connector_fd_write(connector, buffer + total,
-                                               r - total);
+                    w = ssh_connector_fd_write(connector,
+                                               buffer + total,
+                                               (uint32_t)(r - total));
                     if (w < 0) {
                         ssh_connector_except(connector, connector->out_fd);
                         return;
@@ -476,9 +477,11 @@ static int ssh_connector_channel_data_cb(ssh_session session,
                 ssh_connector_except_channel(connector, connector->out_channel);
             }
         } else if (connector->out_fd != SSH_INVALID_SOCKET) {
-                w = ssh_connector_fd_write(connector, data, len);
-            if (w < 0)
+            ssize_t ws = ssh_connector_fd_write(connector, data, len);
+            if (ws < 0) {
                 ssh_connector_except(connector, connector->out_fd);
+            }
+            w = (int)ws;
         } else {
             ssh_set_error(session, SSH_FATAL, "output socket or channel closed");
             return SSH_ERROR;

src/curve25519.c

@@ -26,119 +26,43 @@
 #include "libssh/curve25519.h"
 #ifdef HAVE_CURVE25519
 
-#ifdef WITH_NACL
-#include "nacl/crypto_scalarmult_curve25519.h"
-#endif
-
-#include "libssh/ssh2.h"
+#include "libssh/bignum.h"
 #include "libssh/buffer.h"
-#include "libssh/priv.h"
-#include "libssh/session.h"
 #include "libssh/crypto.h"
 #include "libssh/dh.h"
 #include "libssh/pki.h"
-#include "libssh/bignum.h"
-
-#ifdef HAVE_LIBCRYPTO
-#include <openssl/err.h>
-#endif
+#include "libssh/priv.h"
+#include "libssh/session.h"
+#include "libssh/ssh2.h"
 
 static SSH_PACKET_CALLBACK(ssh_packet_client_curve25519_reply);
 
 static ssh_packet_callback dh_client_callbacks[] = {
-    ssh_packet_client_curve25519_reply
+    ssh_packet_client_curve25519_reply,
 };
 
 static struct ssh_packet_callbacks_struct ssh_curve25519_client_callbacks = {
     .start = SSH2_MSG_KEX_ECDH_REPLY,
     .n_callbacks = 1,
     .callbacks = dh_client_callbacks,
-    .user = NULL
+    .user = NULL,
 };
 
-static int ssh_curve25519_init(ssh_session session)
+int ssh_curve25519_create_k(ssh_session session, ssh_curve25519_pubkey k)
 {
     int rc;
-#ifdef HAVE_LIBCRYPTO
-    EVP_PKEY_CTX *pctx = NULL;
-    EVP_PKEY *pkey = NULL;
-    size_t pubkey_len = CURVE25519_PUBKEY_SIZE;
-    size_t pkey_len = CURVE25519_PRIVKEY_SIZE;
 
-    pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_X25519, NULL);
-    if (pctx == NULL) {
-        SSH_LOG(SSH_LOG_TRACE,
-                "Failed to initialize X25519 context: %s",
-                ERR_error_string(ERR_get_error(), NULL));
-        return SSH_ERROR;
-    }
+#ifdef DEBUG_CRYPTO
+    ssh_log_hexdump("Session server cookie",
+                    session->next_crypto->server_kex.cookie,
+                    16);
+    ssh_log_hexdump("Session client cookie",
+                    session->next_crypto->client_kex.cookie,
+                    16);
+#endif
 
-    rc = EVP_PKEY_keygen_init(pctx);
-    if (rc != 1) {
-        SSH_LOG(SSH_LOG_TRACE,
-                "Failed to initialize X25519 keygen: %s",
-                ERR_error_string(ERR_get_error(), NULL));
-        EVP_PKEY_CTX_free(pctx);
-        return SSH_ERROR;
-    }
-
-    rc = EVP_PKEY_keygen(pctx, &pkey);
-    EVP_PKEY_CTX_free(pctx);
-    if (rc != 1) {
-        SSH_LOG(SSH_LOG_TRACE,
-                "Failed to generate X25519 keys: %s",
-                ERR_error_string(ERR_get_error(), NULL));
-        return SSH_ERROR;
-    }
-
-    if (session->server) {
-        rc = EVP_PKEY_get_raw_public_key(pkey,
-                                         session->next_crypto->curve25519_server_pubkey,
-                                         &pubkey_len);
-    } else {
-        rc = EVP_PKEY_get_raw_public_key(pkey,
-                                         session->next_crypto->curve25519_client_pubkey,
-                                         &pubkey_len);
-    }
-
-    if (rc != 1) {
-        SSH_LOG(SSH_LOG_TRACE,
-                "Failed to get X25519 raw public key: %s",
-                ERR_error_string(ERR_get_error(), NULL));
-        EVP_PKEY_free(pkey);
-        return SSH_ERROR;
-    }
-
-    rc = EVP_PKEY_get_raw_private_key(pkey,
-                                      session->next_crypto->curve25519_privkey,
-                                      &pkey_len);
-    if (rc != 1) {
-        SSH_LOG(SSH_LOG_TRACE,
-                "Failed to get X25519 raw private key: %s",
-                ERR_error_string(ERR_get_error(), NULL));
-        EVP_PKEY_free(pkey);
-        return SSH_ERROR;
-    }
-
-    EVP_PKEY_free(pkey);
-#else
-    rc = ssh_get_random(session->next_crypto->curve25519_privkey,
-                        CURVE25519_PRIVKEY_SIZE, 1);
-    if (rc != 1) {
-        ssh_set_error(session, SSH_FATAL, "PRNG error");
-        return SSH_ERROR;
-    }
-
-    if (session->server) {
-        crypto_scalarmult_base(session->next_crypto->curve25519_server_pubkey,
-                               session->next_crypto->curve25519_privkey);
-    } else {
-        crypto_scalarmult_base(session->next_crypto->curve25519_client_pubkey,
-                               session->next_crypto->curve25519_privkey);
-    }
-#endif /* HAVE_LIBCRYPTO */
-
-    return SSH_OK;
+    rc = curve25519_do_create_k(session, k);
+    return rc;
 }
 
 /** @internal
@@ -180,193 +104,120 @@ void ssh_client_curve25519_remove_callbacks(ssh_session session)
 static int ssh_curve25519_build_k(ssh_session session)
 {
     ssh_curve25519_pubkey k;
+    int rc;
 
-#ifdef HAVE_LIBCRYPTO
-    EVP_PKEY_CTX *pctx = NULL;
-    EVP_PKEY *pkey = NULL, *pubkey = NULL;
-    size_t shared_key_len = sizeof(k);
-    int rc, ret = SSH_ERROR;
-
-    pkey = EVP_PKEY_new_raw_private_key(EVP_PKEY_X25519, NULL,
-                                        session->next_crypto->curve25519_privkey,
-                                        CURVE25519_PRIVKEY_SIZE);
-    if (pkey == NULL) {
-        SSH_LOG(SSH_LOG_TRACE,
-                "Failed to create X25519 EVP_PKEY: %s",
-                ERR_error_string(ERR_get_error(), NULL));
-        return SSH_ERROR;
+    rc = ssh_curve25519_create_k(session, k);
+    if (rc != SSH_OK) {
+        return rc;
     }
 
-    pctx = EVP_PKEY_CTX_new(pkey, NULL);
-    if (pctx == NULL) {
-        SSH_LOG(SSH_LOG_TRACE,
-                "Failed to initialize X25519 context: %s",
-                ERR_error_string(ERR_get_error(), NULL));
-        goto out;
-    }
-
-    rc = EVP_PKEY_derive_init(pctx);
-    if (rc != 1) {
-        SSH_LOG(SSH_LOG_TRACE,
-                "Failed to initialize X25519 key derivation: %s",
-                ERR_error_string(ERR_get_error(), NULL));
-        goto out;
-    }
-
-    if (session->server) {
-        pubkey = EVP_PKEY_new_raw_public_key(EVP_PKEY_X25519, NULL,
-                                             session->next_crypto->curve25519_client_pubkey,
-                                             CURVE25519_PUBKEY_SIZE);
-    } else {
-        pubkey = EVP_PKEY_new_raw_public_key(EVP_PKEY_X25519, NULL,
-                                             session->next_crypto->curve25519_server_pubkey,
-                                             CURVE25519_PUBKEY_SIZE);
-    }
-    if (pubkey == NULL) {
-        SSH_LOG(SSH_LOG_TRACE,
-                "Failed to create X25519 public key EVP_PKEY: %s",
-                ERR_error_string(ERR_get_error(), NULL));
-        goto out;
-    }
-
-    rc = EVP_PKEY_derive_set_peer(pctx, pubkey);
-    if (rc != 1) {
-        SSH_LOG(SSH_LOG_TRACE,
-                "Failed to set peer X25519 public key: %s",
-                ERR_error_string(ERR_get_error(), NULL));
-        goto out;
-    }
-
-    rc = EVP_PKEY_derive(pctx, k, &shared_key_len);
-    if (rc != 1) {
-        SSH_LOG(SSH_LOG_TRACE,
-                "Failed to derive X25519 shared secret: %s",
-                ERR_error_string(ERR_get_error(), NULL));
-        goto out;
-    }
-    ret = SSH_OK;
-out:
-    EVP_PKEY_free(pkey);
-    EVP_PKEY_free(pubkey);
-    EVP_PKEY_CTX_free(pctx);
-    if (ret == SSH_ERROR) {
-        return ret;
-    }
-#else
-    if (session->server) {
-        crypto_scalarmult(k, session->next_crypto->curve25519_privkey,
-                          session->next_crypto->curve25519_client_pubkey);
-    } else {
-        crypto_scalarmult(k, session->next_crypto->curve25519_privkey,
-                          session->next_crypto->curve25519_server_pubkey);
-    }
-#endif /* HAVE_LIBCRYPTO */
-
-    bignum_bin2bn(k, CURVE25519_PUBKEY_SIZE, &session->next_crypto->shared_secret);
+    bignum_bin2bn(k,
+                  CURVE25519_PUBKEY_SIZE,
+                  &session->next_crypto->shared_secret);
     if (session->next_crypto->shared_secret == NULL) {
         return SSH_ERROR;
     }
 
 #ifdef DEBUG_CRYPTO
-    ssh_log_hexdump("Session server cookie",
-                   session->next_crypto->server_kex.cookie, 16);
-    ssh_log_hexdump("Session client cookie",
-                   session->next_crypto->client_kex.cookie, 16);
     ssh_print_bignum("Shared secret key", session->next_crypto->shared_secret);
 #endif
 
-  return 0;
+    return SSH_OK;
 }
 
 /** @internal
  * @brief parses a SSH_MSG_KEX_ECDH_REPLY packet and sends back
  * a SSH_MSG_NEWKEYS
  */
-static SSH_PACKET_CALLBACK(ssh_packet_client_curve25519_reply){
-  ssh_string q_s_string = NULL;
-  ssh_string pubkey_blob = NULL;
-  ssh_string signature = NULL;
-  int rc;
-  (void)type;
-  (void)user;
+static SSH_PACKET_CALLBACK(ssh_packet_client_curve25519_reply)
+{
+    ssh_string q_s_string = NULL;
+    ssh_string pubkey_blob = NULL;
+    ssh_string signature = NULL;
+    int rc;
+    (void)type;
+    (void)user;
 
-  ssh_client_curve25519_remove_callbacks(session);
+    ssh_client_curve25519_remove_callbacks(session);
 
-  pubkey_blob = ssh_buffer_get_ssh_string(packet);
-  if (pubkey_blob == NULL) {
-    ssh_set_error(session,SSH_FATAL, "No public key in packet");
-    goto error;
-  }
+    pubkey_blob = ssh_buffer_get_ssh_string(packet);
+    if (pubkey_blob == NULL) {
+        ssh_set_error(session, SSH_FATAL, "No public key in packet");
+        goto error;
+    }
 
-  rc = ssh_dh_import_next_pubkey_blob(session, pubkey_blob);
-  SSH_STRING_FREE(pubkey_blob);
-  if (rc != 0) {
-      ssh_set_error(session,
-                    SSH_FATAL,
-                    "Failed to import next public key");
-      goto error;
-  }
+    rc = ssh_dh_import_next_pubkey_blob(session, pubkey_blob);
+    SSH_STRING_FREE(pubkey_blob);
+    if (rc != 0) {
+        ssh_set_error(session, SSH_FATAL, "Failed to import next public key");
+        goto error;
+    }
 
-  q_s_string = ssh_buffer_get_ssh_string(packet);
-  if (q_s_string == NULL) {
-	  ssh_set_error(session,SSH_FATAL, "No Q_S ECC point in packet");
-	  goto error;
-  }
-  if (ssh_string_len(q_s_string) != CURVE25519_PUBKEY_SIZE){
-	  ssh_set_error(session, SSH_FATAL, "Incorrect size for server Curve25519 public key: %d",
-			  (int)ssh_string_len(q_s_string));
-	  SSH_STRING_FREE(q_s_string);
-	  goto error;
-  }
-  memcpy(session->next_crypto->curve25519_server_pubkey, ssh_string_data(q_s_string), CURVE25519_PUBKEY_SIZE);
-  SSH_STRING_FREE(q_s_string);
+    q_s_string = ssh_buffer_get_ssh_string(packet);
+    if (q_s_string == NULL) {
+        ssh_set_error(session, SSH_FATAL, "No Q_S ECC point in packet");
+        goto error;
+    }
+    if (ssh_string_len(q_s_string) != CURVE25519_PUBKEY_SIZE) {
+        ssh_set_error(session,
+                      SSH_FATAL,
+                      "Incorrect size for server Curve25519 public key: %zu",
+                      ssh_string_len(q_s_string));
+        SSH_STRING_FREE(q_s_string);
+        goto error;
+    }
+    memcpy(session->next_crypto->curve25519_server_pubkey,
+           ssh_string_data(q_s_string),
+           CURVE25519_PUBKEY_SIZE);
+    SSH_STRING_FREE(q_s_string);
 
-  signature = ssh_buffer_get_ssh_string(packet);
-  if (signature == NULL) {
-    ssh_set_error(session, SSH_FATAL, "No signature in packet");
-    goto error;
-  }
-  session->next_crypto->dh_server_signature = signature;
-  signature=NULL; /* ownership changed */
-  /* TODO: verify signature now instead of waiting for NEWKEYS */
-  if (ssh_curve25519_build_k(session) < 0) {
-    ssh_set_error(session, SSH_FATAL, "Cannot build k number");
-    goto error;
-  }
+    signature = ssh_buffer_get_ssh_string(packet);
+    if (signature == NULL) {
+        ssh_set_error(session, SSH_FATAL, "No signature in packet");
+        goto error;
+    }
+    session->next_crypto->dh_server_signature = signature;
+    signature = NULL; /* ownership changed */
+    /* TODO: verify signature now instead of waiting for NEWKEYS */
+    if (ssh_curve25519_build_k(session) < 0) {
+        ssh_set_error(session, SSH_FATAL, "Cannot build k number");
+        goto error;
+    }
 
-  /* Send the MSG_NEWKEYS */
-  rc = ssh_packet_send_newkeys(session);
-  if (rc == SSH_ERROR) {
-    goto error;
-  }
-  session->dh_handshake_state = DH_STATE_NEWKEYS_SENT;
+    /* Send the MSG_NEWKEYS */
+    rc = ssh_packet_send_newkeys(session);
+    if (rc == SSH_ERROR) {
+        goto error;
+    }
+    session->dh_handshake_state = DH_STATE_NEWKEYS_SENT;
 
-  return SSH_PACKET_USED;
+    return SSH_PACKET_USED;
 
 error:
-  session->session_state=SSH_SESSION_STATE_ERROR;
-  return SSH_PACKET_USED;
+    session->session_state = SSH_SESSION_STATE_ERROR;
+    return SSH_PACKET_USED;
 }
 
 #ifdef WITH_SERVER
 
 static SSH_PACKET_CALLBACK(ssh_packet_server_curve25519_init);
 
-static ssh_packet_callback dh_server_callbacks[]= {
-    ssh_packet_server_curve25519_init
+static ssh_packet_callback dh_server_callbacks[] = {
+    ssh_packet_server_curve25519_init,
 };
 
 static struct ssh_packet_callbacks_struct ssh_curve25519_server_callbacks = {
     .start = SSH2_MSG_KEX_ECDH_INIT,
     .n_callbacks = 1,
     .callbacks = dh_server_callbacks,
-    .user = NULL
+    .user = NULL,
 };
 
 /** @internal
  * @brief sets up the curve25519-sha256@libssh.org kex callbacks
  */
-void ssh_server_curve25519_init(ssh_session session){
+void ssh_server_curve25519_init(ssh_session session)
+{
     /* register the packet callbacks */
     ssh_packet_set_callbacks(session, &ssh_curve25519_server_callbacks);
 }
@@ -374,7 +225,8 @@ void ssh_server_curve25519_init(ssh_session session){
 /** @brief Parse a SSH_MSG_KEXDH_INIT packet (server) and send a
  * SSH_MSG_KEXDH_REPLY
  */
-static SSH_PACKET_CALLBACK(ssh_packet_server_curve25519_init){
+static SSH_PACKET_CALLBACK(ssh_packet_server_curve25519_init)
+{
     /* ECDH keys */
     ssh_string q_c_string = NULL;
     ssh_string q_s_string = NULL;
@@ -393,10 +245,10 @@ static SSH_PACKET_CALLBACK(ssh_packet_server_curve25519_init){
     /* Extract the client pubkey from the init packet */
     q_c_string = ssh_buffer_get_ssh_string(packet);
     if (q_c_string == NULL) {
-        ssh_set_error(session,SSH_FATAL, "No Q_C ECC point in packet");
+        ssh_set_error(session, SSH_FATAL, "No Q_C ECC point in packet");
         goto error;
     }
-    if (ssh_string_len(q_c_string) != CURVE25519_PUBKEY_SIZE){
+    if (ssh_string_len(q_c_string) != CURVE25519_PUBKEY_SIZE) {
         ssh_set_error(session,
                       SSH_FATAL,
                       "Incorrect size for server Curve25519 public key: %zu",
@@ -405,7 +257,8 @@ static SSH_PACKET_CALLBACK(ssh_packet_server_curve25519_init){
     }
 
     memcpy(session->next_crypto->curve25519_client_pubkey,
-           ssh_string_data(q_c_string), CURVE25519_PUBKEY_SIZE);
+           ssh_string_data(q_c_string),
+           CURVE25519_PUBKEY_SIZE);
     SSH_STRING_FREE(q_c_string);
 
     /* Build server's key pair */
@@ -447,8 +300,7 @@ static SSH_PACKET_CALLBACK(ssh_packet_server_curve25519_init){
     }
 
     /* add host's public key */
-    rc = ssh_buffer_add_ssh_string(session->out_buffer,
-                                   server_pubkey_blob);
+    rc = ssh_buffer_add_ssh_string(session->out_buffer, server_pubkey_blob);
     SSH_STRING_FREE(server_pubkey_blob);
     if (rc < 0) {
         ssh_set_error_oom(session);
@@ -509,7 +361,7 @@ error:
     SSH_STRING_FREE(q_c_string);
     SSH_STRING_FREE(q_s_string);
     ssh_buffer_reinit(session->out_buffer);
-    session->session_state=SSH_SESSION_STATE_ERROR;
+    session->session_state = SSH_SESSION_STATE_ERROR;
     return SSH_PACKET_USED;
 }
 

src/curve25519_crypto.c

@@ -0,0 +1,158 @@
+/*
+ * curve25519_crypto.c - Curve25519 ECDH functions for key exchange (OpenSSL)
+ *
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2013-2023 by Aris Adamantiadis <aris@badcode.be>
+ *
+ * The SSH Library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, version 2.1 of the License.
+ *
+ * The SSH Library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the SSH Library; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#include "config.h"
+#include "libssh/curve25519.h"
+
+#include "libssh/crypto.h"
+#include "libssh/priv.h"
+#include "libssh/session.h"
+
+#include <openssl/err.h>
+#include <openssl/evp.h>
+
+int ssh_curve25519_init(ssh_session session)
+{
+    ssh_curve25519_pubkey *pubkey_loc = NULL;
+    EVP_PKEY_CTX *pctx = NULL;
+    EVP_PKEY *pkey = NULL;
+    size_t pubkey_len = CURVE25519_PUBKEY_SIZE;
+    int rc;
+
+    if (session->server) {
+        pubkey_loc = &session->next_crypto->curve25519_server_pubkey;
+    } else {
+        pubkey_loc = &session->next_crypto->curve25519_client_pubkey;
+    }
+
+    pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_X25519, NULL);
+    if (pctx == NULL) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to initialize X25519 context: %s",
+                ERR_error_string(ERR_get_error(), NULL));
+        return SSH_ERROR;
+    }
+
+    rc = EVP_PKEY_keygen_init(pctx);
+    if (rc != 1) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to initialize X25519 keygen: %s",
+                ERR_error_string(ERR_get_error(), NULL));
+        EVP_PKEY_CTX_free(pctx);
+        return SSH_ERROR;
+    }
+
+    rc = EVP_PKEY_keygen(pctx, &pkey);
+    EVP_PKEY_CTX_free(pctx);
+    if (rc != 1) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to generate X25519 keys: %s",
+                ERR_error_string(ERR_get_error(), NULL));
+        return SSH_ERROR;
+    }
+
+    rc = EVP_PKEY_get_raw_public_key(pkey, *pubkey_loc, &pubkey_len);
+    if (rc != 1) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to get X25519 raw public key: %s",
+                ERR_error_string(ERR_get_error(), NULL));
+        EVP_PKEY_free(pkey);
+        return SSH_ERROR;
+    }
+
+    session->next_crypto->curve25519_privkey = pkey;
+    pkey = NULL;
+
+    return SSH_OK;
+}
+
+int curve25519_do_create_k(ssh_session session, ssh_curve25519_pubkey k)
+{
+    ssh_curve25519_pubkey *peer_pubkey_loc = NULL;
+    int rc, ret = SSH_ERROR;
+    EVP_PKEY_CTX *pctx = NULL;
+    EVP_PKEY *pkey = NULL, *pubkey = NULL;
+    size_t shared_key_len = CURVE25519_PUBKEY_SIZE;
+
+    if (session->server) {
+        peer_pubkey_loc = &session->next_crypto->curve25519_client_pubkey;
+    } else {
+        peer_pubkey_loc = &session->next_crypto->curve25519_server_pubkey;
+    }
+
+    pkey = session->next_crypto->curve25519_privkey;
+    if (pkey == NULL) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to create X25519 EVP_PKEY: %s",
+                ERR_error_string(ERR_get_error(), NULL));
+        return SSH_ERROR;
+    }
+
+    pctx = EVP_PKEY_CTX_new(pkey, NULL);
+    if (pctx == NULL) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to initialize X25519 context: %s",
+                ERR_error_string(ERR_get_error(), NULL));
+        goto out;
+    }
+
+    rc = EVP_PKEY_derive_init(pctx);
+    if (rc != 1) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to initialize X25519 key derivation: %s",
+                ERR_error_string(ERR_get_error(), NULL));
+        goto out;
+    }
+
+    pubkey = EVP_PKEY_new_raw_public_key(EVP_PKEY_X25519,
+                                         NULL,
+                                         *peer_pubkey_loc,
+                                         CURVE25519_PUBKEY_SIZE);
+    if (pubkey == NULL) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to create X25519 public key EVP_PKEY: %s",
+                ERR_error_string(ERR_get_error(), NULL));
+        goto out;
+    }
+
+    rc = EVP_PKEY_derive_set_peer(pctx, pubkey);
+    if (rc != 1) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to set peer X25519 public key: %s",
+                ERR_error_string(ERR_get_error(), NULL));
+        goto out;
+    }
+
+    rc = EVP_PKEY_derive(pctx, k, &shared_key_len);
+    if (rc != 1) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to derive X25519 shared secret: %s",
+                ERR_error_string(ERR_get_error(), NULL));
+        goto out;
+    }
+    ret = SSH_OK;
+
+out:
+    EVP_PKEY_free(pubkey);
+    EVP_PKEY_CTX_free(pctx);
+    return ret;
+}

src/curve25519_fallback.c

@@ -0,0 +1,73 @@
+/*
+ * curve25519_fallback.c - Curve25519 ECDH functions for key exchange
+ *
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2013-2023 by Aris Adamantiadis <aris@badcode.be>
+ *
+ * The SSH Library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, version 2.1 of the License.
+ *
+ * The SSH Library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the SSH Library; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#include "config.h"
+#include "libssh/curve25519.h"
+
+#include "libssh/crypto.h"
+#include "libssh/priv.h"
+#include "libssh/session.h"
+
+#ifdef WITH_NACL
+#include "nacl/crypto_scalarmult_curve25519.h"
+#endif
+
+int ssh_curve25519_init(ssh_session session)
+{
+    ssh_curve25519_pubkey *pubkey_loc = NULL;
+    int rc;
+
+    if (session->server) {
+        pubkey_loc = &session->next_crypto->curve25519_server_pubkey;
+    } else {
+        pubkey_loc = &session->next_crypto->curve25519_client_pubkey;
+    }
+
+    rc = ssh_get_random(session->next_crypto->curve25519_privkey,
+                        CURVE25519_PRIVKEY_SIZE,
+                        1);
+    if (rc != 1) {
+        ssh_set_error(session, SSH_FATAL, "PRNG error");
+        return SSH_ERROR;
+    }
+
+    crypto_scalarmult_base(*pubkey_loc,
+                           session->next_crypto->curve25519_privkey);
+
+    return SSH_OK;
+}
+
+int curve25519_do_create_k(ssh_session session, ssh_curve25519_pubkey k)
+{
+    ssh_curve25519_pubkey *peer_pubkey_loc = NULL;
+
+    if (session->server) {
+        peer_pubkey_loc = &session->next_crypto->curve25519_client_pubkey;
+    } else {
+        peer_pubkey_loc = &session->next_crypto->curve25519_server_pubkey;
+    }
+
+    crypto_scalarmult(k,
+                      session->next_crypto->curve25519_privkey,
+                      *peer_pubkey_loc);
+    return SSH_OK;
+}

src/curve25519_gcrypt.c

@@ -0,0 +1,199 @@
+/*
+ * curve25519_gcrypt.c - Curve25519 ECDH functions for key exchange (Gcrypt)
+ *
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2013-2023 by Aris Adamantiadis <aris@badcode.be>
+ * Copyright (c) 2025 Praneeth Sarode <praneethsarode@gmail.com>
+ *
+ * The SSH Library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, version 2.1 of the License.
+ *
+ * The SSH Library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the SSH Library; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#include "config.h"
+#include "libssh/curve25519.h"
+
+#include "libssh/buffer.h"
+#include "libssh/crypto.h"
+#include "libssh/priv.h"
+#include "libssh/session.h"
+
+#include <gcrypt.h>
+
+int ssh_curve25519_init(ssh_session session)
+{
+    ssh_curve25519_pubkey *pubkey_loc = NULL;
+    gcry_error_t gcry_err;
+    gcry_sexp_t param = NULL, keypair_sexp = NULL;
+    ssh_string pubkey = NULL;
+    const char *pubkey_data = NULL;
+    int ret = SSH_ERROR;
+
+    if (session->server) {
+        pubkey_loc = &session->next_crypto->curve25519_server_pubkey;
+    } else {
+        pubkey_loc = &session->next_crypto->curve25519_client_pubkey;
+    }
+
+    gcry_err =
+        gcry_sexp_build(&param, NULL, "(genkey (ecdh (curve Curve25519)))");
+    if (gcry_err != GPG_ERR_NO_ERROR) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to create keypair sexp: %s",
+                gcry_strerror(gcry_err));
+        goto out;
+    }
+
+    gcry_err = gcry_pk_genkey(&keypair_sexp, param);
+    if (gcry_err != GPG_ERR_NO_ERROR) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to generate keypair: %s",
+                gcry_strerror(gcry_err));
+        goto out;
+    }
+
+    /* Extract the public key */
+    pubkey = ssh_sexp_extract_mpi(keypair_sexp,
+                                  "q",
+                                  GCRYMPI_FMT_USG,
+                                  GCRYMPI_FMT_STD);
+    if (pubkey == NULL) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to extract public key: %s",
+                gcry_strerror(gcry_err));
+        goto out;
+    }
+
+    /* Store the public key in the session */
+    /* The first byte should be 0x40 indicating that the point is compressed, so
+     * we skip storing it */
+    pubkey_data = (char *)ssh_string_data(pubkey);
+    if (ssh_string_len(pubkey) != CURVE25519_PUBKEY_SIZE + 1 ||
+        pubkey_data[0] != 0x40) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Invalid public key with length: %zu",
+                ssh_string_len(pubkey));
+        goto out;
+    }
+
+    memcpy(*pubkey_loc, pubkey_data + 1, CURVE25519_PUBKEY_SIZE);
+
+    /* Store the private key */
+    session->next_crypto->curve25519_privkey = keypair_sexp;
+    keypair_sexp = NULL;
+    ret = SSH_OK;
+
+out:
+    ssh_string_burn(pubkey);
+    SSH_STRING_FREE(pubkey);
+    gcry_sexp_release(param);
+    gcry_sexp_release(keypair_sexp);
+    return ret;
+}
+
+int curve25519_do_create_k(ssh_session session, ssh_curve25519_pubkey k)
+{
+    ssh_curve25519_pubkey *peer_pubkey_loc = NULL;
+    gcry_error_t gcry_err;
+    gcry_sexp_t pubkey_sexp = NULL, privkey_data_sexp = NULL,
+                result_sexp = NULL;
+    ssh_string shared_secret = NULL, privkey = NULL;
+    char *shared_secret_data = NULL;
+    int ret = SSH_ERROR;
+
+    if (session->server) {
+        peer_pubkey_loc = &session->next_crypto->curve25519_client_pubkey;
+    } else {
+        peer_pubkey_loc = &session->next_crypto->curve25519_server_pubkey;
+    }
+
+    gcry_err = gcry_sexp_build(
+        &pubkey_sexp,
+        NULL,
+        "(key-data(public-key (ecdh (curve Curve25519) (q %b))))",
+        CURVE25519_PUBKEY_SIZE,
+        *peer_pubkey_loc);
+    if (gcry_err != GPG_ERR_NO_ERROR) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to create peer public key sexp: %s",
+                gcry_strerror(gcry_err));
+        goto out;
+    }
+
+    privkey = ssh_sexp_extract_mpi(session->next_crypto->curve25519_privkey,
+                                   "d",
+                                   GCRYMPI_FMT_USG,
+                                   GCRYMPI_FMT_STD);
+    if (privkey == NULL) {
+        SSH_LOG(SSH_LOG_TRACE, "Failed to extract private key");
+        goto out;
+    }
+
+    gcry_err = gcry_sexp_build(&privkey_data_sexp,
+                               NULL,
+                               "(data(flags raw)(value %b))",
+                               ssh_string_len(privkey),
+                               ssh_string_data(privkey));
+    if (gcry_err != GPG_ERR_NO_ERROR) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to create private key sexp: %s",
+                gcry_strerror(gcry_err));
+        goto out;
+    }
+
+    gcry_err = gcry_pk_encrypt(&result_sexp, privkey_data_sexp, pubkey_sexp);
+    if (gcry_err != GPG_ERR_NO_ERROR) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to compute shared secret: %s",
+                gcry_strerror(gcry_err));
+        goto out;
+    }
+
+    shared_secret = ssh_sexp_extract_mpi(result_sexp,
+                                         "s",
+                                         GCRYMPI_FMT_USG,
+                                         GCRYMPI_FMT_USG);
+    if (shared_secret == NULL) {
+        SSH_LOG(SSH_LOG_TRACE, "Failed to extract shared secret");
+        goto out;
+    }
+
+    /* Copy the shared secret to the output buffer */
+    /* The first byte should be 0x40 indicating that it is a compressed point,
+     * so we skip it */
+    shared_secret_data = (char *)ssh_string_data(shared_secret);
+    if (ssh_string_len(shared_secret) != CURVE25519_PUBKEY_SIZE + 1 ||
+        shared_secret_data[0] != 0x40) {
+        SSH_LOG(SSH_LOG_TRACE,
+                "Invalid shared secret with length: %zu",
+                ssh_string_len(shared_secret));
+        goto out;
+    }
+
+    memcpy(k, shared_secret_data + 1, CURVE25519_PUBKEY_SIZE);
+
+    ret = SSH_OK;
+    gcry_sexp_release(session->next_crypto->curve25519_privkey);
+    session->next_crypto->curve25519_privkey = NULL;
+
+out:
+    ssh_string_burn(shared_secret);
+    SSH_STRING_FREE(shared_secret);
+    ssh_string_burn(privkey);
+    SSH_STRING_FREE(privkey);
+    gcry_sexp_release(privkey_data_sexp);
+    gcry_sexp_release(pubkey_sexp);
+    gcry_sexp_release(result_sexp);
+    return ret;
+}

src/curve25519_mbedcrypto.c

@@ -0,0 +1,189 @@
+/*
+ * curve25519_mbedcrypto.c - Curve25519 ECDH functions for key exchange
+ * (MbedTLS)
+ *
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2013-2023 by Aris Adamantiadis <aris@badcode.be>
+ * Copyright (c) 2025 Praneeth Sarode <praneethsarode@gmail.com>
+ *
+ * The SSH Library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, version 2.1 of the License.
+ *
+ * The SSH Library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the SSH Library; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#include "config.h"
+#include "libssh/curve25519.h"
+
+#include "libssh/crypto.h"
+#include "libssh/priv.h"
+#include "libssh/session.h"
+#include "mbedcrypto-compat.h"
+
+#include <mbedtls/ecdh.h>
+#include <mbedtls/error.h>
+
+int ssh_curve25519_init(ssh_session session)
+{
+    ssh_curve25519_pubkey *pubkey_loc = NULL;
+    mbedtls_ecdh_context ecdh_ctx;
+    mbedtls_ecdh_params *ecdh_params = NULL;
+    mbedtls_ctr_drbg_context *ctr_drbg = NULL;
+    int rc, ret = SSH_ERROR;
+    char error_buf[128];
+
+    if (session->server) {
+        pubkey_loc = &session->next_crypto->curve25519_server_pubkey;
+    } else {
+        pubkey_loc = &session->next_crypto->curve25519_client_pubkey;
+    }
+
+    ctr_drbg = ssh_get_mbedtls_ctr_drbg_context();
+
+    mbedtls_ecdh_init(&ecdh_ctx);
+    rc = mbedtls_ecdh_setup(&ecdh_ctx, MBEDTLS_ECP_DP_CURVE25519);
+    if (rc != 0) {
+        mbedtls_strerror(rc, error_buf, sizeof(error_buf));
+        SSH_LOG(SSH_LOG_TRACE, "Failed to setup X25519 context: %s", error_buf);
+        goto out;
+    }
+
+    ecdh_params = &MBEDTLS_ECDH_PARAMS(ecdh_ctx);
+
+    rc = mbedtls_ecdh_gen_public(&ecdh_params->MBEDTLS_ECDH_PRIVATE(grp),
+                                 &ecdh_params->MBEDTLS_ECDH_PRIVATE(d),
+                                 &ecdh_params->MBEDTLS_ECDH_PRIVATE(Q),
+                                 mbedtls_ctr_drbg_random,
+                                 ctr_drbg);
+    if (rc != 0) {
+        mbedtls_strerror(rc, error_buf, sizeof(error_buf));
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to generate X25519 keypair: %s",
+                error_buf);
+        goto out;
+    }
+
+    rc = mbedtls_mpi_write_binary_le(&ecdh_params->MBEDTLS_ECDH_PRIVATE(d),
+                                     session->next_crypto->curve25519_privkey,
+                                     CURVE25519_PRIVKEY_SIZE);
+    if (rc != 0) {
+        mbedtls_strerror(rc, error_buf, sizeof(error_buf));
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to write X25519 private key: %s",
+                error_buf);
+        goto out;
+    }
+
+    rc = mbedtls_mpi_write_binary_le(
+        &ecdh_params->MBEDTLS_ECDH_PRIVATE(Q).MBEDTLS_ECDH_PRIVATE(X),
+        *pubkey_loc,
+        CURVE25519_PUBKEY_SIZE);
+    if (rc != 0) {
+        mbedtls_strerror(rc, error_buf, sizeof(error_buf));
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to write X25519 public key: %s",
+                error_buf);
+        goto out;
+    }
+
+    ret = SSH_OK;
+
+out:
+    mbedtls_ecdh_free(&ecdh_ctx);
+    return ret;
+}
+
+int curve25519_do_create_k(ssh_session session, ssh_curve25519_pubkey k)
+{
+    ssh_curve25519_pubkey *peer_pubkey_loc = NULL;
+    int rc, ret = SSH_ERROR;
+    mbedtls_ecdh_context ecdh_ctx;
+    mbedtls_ecdh_params *ecdh_params = NULL;
+    mbedtls_ctr_drbg_context *ctr_drbg = NULL;
+    char error_buf[128];
+
+    if (session->server) {
+        peer_pubkey_loc = &session->next_crypto->curve25519_client_pubkey;
+    } else {
+        peer_pubkey_loc = &session->next_crypto->curve25519_server_pubkey;
+    }
+
+    ctr_drbg = ssh_get_mbedtls_ctr_drbg_context();
+
+    mbedtls_ecdh_init(&ecdh_ctx);
+    rc = mbedtls_ecdh_setup(&ecdh_ctx, MBEDTLS_ECP_DP_CURVE25519);
+    if (rc != 0) {
+        mbedtls_strerror(rc, error_buf, sizeof(error_buf));
+        SSH_LOG(SSH_LOG_TRACE, "Failed to setup X25519 context: %s", error_buf);
+        goto out;
+    }
+
+    ecdh_params = &MBEDTLS_ECDH_PARAMS(ecdh_ctx);
+
+    rc = mbedtls_mpi_read_binary_le(&ecdh_params->MBEDTLS_ECDH_PRIVATE(d),
+                                    session->next_crypto->curve25519_privkey,
+                                    CURVE25519_PRIVKEY_SIZE);
+    if (rc != 0) {
+        mbedtls_strerror(rc, error_buf, sizeof(error_buf));
+        SSH_LOG(SSH_LOG_TRACE, "Failed to read private key: %s", error_buf);
+        goto out;
+    }
+
+    rc = mbedtls_mpi_read_binary_le(
+        &ecdh_params->MBEDTLS_ECDH_PRIVATE(Qp).MBEDTLS_ECDH_PRIVATE(X),
+        *peer_pubkey_loc,
+        CURVE25519_PUBKEY_SIZE);
+    if (rc != 0) {
+        mbedtls_strerror(rc, error_buf, sizeof(error_buf));
+        SSH_LOG(SSH_LOG_TRACE, "Failed to read peer public key: %s", error_buf);
+        goto out;
+    }
+
+    rc = mbedtls_mpi_lset(
+        &ecdh_params->MBEDTLS_ECDH_PRIVATE(Qp).MBEDTLS_ECDH_PRIVATE(Z),
+        1);
+    if (rc != 0) {
+        mbedtls_strerror(rc, error_buf, sizeof(error_buf));
+        SSH_LOG(SSH_LOG_TRACE, "Failed to set Z coordinate: %s", error_buf);
+        goto out;
+    }
+
+    rc = mbedtls_ecdh_compute_shared(&ecdh_params->MBEDTLS_ECDH_PRIVATE(grp),
+                                     &ecdh_params->MBEDTLS_ECDH_PRIVATE(z),
+                                     &ecdh_params->MBEDTLS_ECDH_PRIVATE(Qp),
+                                     &ecdh_params->MBEDTLS_ECDH_PRIVATE(d),
+                                     mbedtls_ctr_drbg_random,
+                                     ctr_drbg);
+    if (rc != 0) {
+        mbedtls_strerror(rc, error_buf, sizeof(error_buf));
+        SSH_LOG(SSH_LOG_TRACE,
+                "Failed to compute shared secret: %s",
+                error_buf);
+        goto out;
+    }
+
+    rc = mbedtls_mpi_write_binary_le(&ecdh_params->MBEDTLS_ECDH_PRIVATE(z),
+                                     k,
+                                     CURVE25519_PUBKEY_SIZE);
+    if (rc != 0) {
+        mbedtls_strerror(rc, error_buf, sizeof(error_buf));
+        SSH_LOG(SSH_LOG_TRACE, "Failed to write shared secret: %s", error_buf);
+        goto out;
+    }
+
+    ret = SSH_OK;
+
+out:
+    mbedtls_ecdh_free(&ecdh_ctx);
+    return ret;
+}

src/dh-gex.c

@@ -416,6 +416,9 @@ static int ssh_retrieve_dhgroup_file(FILE *moduli,
             do {
                 firstbyte = getc(moduli);
             } while(firstbyte != '\n' && firstbyte != EOF);
+            if (firstbyte == EOF) {
+                break;
+            }
             continue;
         }
         if (firstbyte == EOF) {
@@ -439,6 +442,9 @@ static int ssh_retrieve_dhgroup_file(FILE *moduli,
             do {
                 firstbyte = getc(moduli);
             } while(firstbyte != '\n' && firstbyte != EOF);
+            if (firstbyte == EOF) {
+                break;
+            }
             continue;
         }
 

src/dh_crypto.c

@@ -592,7 +592,7 @@ int ssh_dh_compute_shared_secret(struct dh_ctx *dh_ctx, int local, int remote,
     }
 #endif /* OPENSSL_VERSION_NUMBER */
 
-    *dest = BN_bin2bn(kstring, klen, NULL);
+    *dest = BN_bin2bn(kstring, (int)klen, NULL);
     if (*dest == NULL) {
         rc = SSH_ERROR;
         goto done;

src/getpass.c

@@ -63,7 +63,7 @@ static int ssh_gets(const char *prompt, char *buf, size_t len, int verify)
             fprintf(stdout, "%s", prompt);
         }
         fflush(stdout);
-        if (fgets(tmp, len, stdin) == NULL) {
+        if (fgets(tmp, (int)len, stdin) == NULL) {
             free(tmp);
             return 0;
         }
@@ -87,7 +87,7 @@ static int ssh_gets(const char *prompt, char *buf, size_t len, int verify)
 
             fprintf(stdout, "\nVerifying, please re-enter. %s", prompt);
             fflush(stdout);
-            if (! fgets(key_string, len, stdin)) {
+            if (!fgets(key_string, (int)len, stdin)) {
                 explicit_bzero(key_string, len);
                 SAFE_FREE(key_string);
                 clearerr(stdin);

src/kex.c

@@ -40,6 +40,7 @@
 #include "libssh/ssh2.h"
 #include "libssh/string.h"
 #include "libssh/curve25519.h"
+#include "libssh/sntrup761.h"
 #include "libssh/knownhosts.h"
 #include "libssh/misc.h"
 #include "libssh/pki.h"
@@ -95,6 +96,12 @@
 #define CURVE25519 ""
 #endif /* HAVE_CURVE25519 */
 
+#ifdef HAVE_SNTRUP761
+#define SNTRUP761X25519 "sntrup761x25519-sha512@openssh.com,"
+#else
+#define SNTRUP761X25519 ""
+#endif /* HAVE_SNTRUP761 */
+
 #ifdef HAVE_ECC
 #define ECDH "ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,"
 #define EC_HOSTKEYS "ecdsa-sha2-nistp521," \
@@ -159,6 +166,7 @@
 
 #define DEFAULT_KEY_EXCHANGE \
     CURVE25519 \
+    SNTRUP761X25519 \
     ECDH \
     "diffie-hellman-group18-sha512,diffie-hellman-group16-sha512," \
     GEX_SHA256 \
@@ -267,38 +275,58 @@ static const char *ssh_kex_descriptions[] = {
   NULL
 };
 
-const char *ssh_kex_get_default_methods(uint32_t algo)
+const char *ssh_kex_get_default_methods(enum ssh_kex_types_e type)
 {
-    if (algo >= SSH_KEX_METHODS) {
+    if (type >= SSH_KEX_METHODS) {
         return NULL;
     }
 
-    return default_methods[algo];
+    return default_methods[type];
 }
-
-const char *ssh_kex_get_supported_method(uint32_t algo)
+const char *ssh_kex_get_supported_method(enum ssh_kex_types_e type)
 {
-    if (algo >= SSH_KEX_METHODS) {
+    if (type >= SSH_KEX_METHODS) {
         return NULL;
     }
 
-    return supported_methods[algo];
+    return supported_methods[type];
 }
 
-const char *ssh_kex_get_description(uint32_t algo) {
-  if (algo >= SSH_KEX_METHODS) {
-    return NULL;
-  }
+const char *ssh_kex_get_description(enum ssh_kex_types_e type)
+{
+    if (type >= SSH_KEX_METHODS) {
+        return NULL;
+    }
 
-  return ssh_kex_descriptions[algo];
+    return ssh_kex_descriptions[type];
 }
 
-const char *ssh_kex_get_fips_methods(uint32_t algo) {
-  if (algo >= SSH_KEX_METHODS) {
-    return NULL;
-  }
+const char *ssh_kex_get_fips_methods(enum ssh_kex_types_e type)
+{
+    if (type >= SSH_KEX_METHODS) {
+        return NULL;
+    }
 
-  return fips_methods[algo];
+    return fips_methods[type];
+}
+
+/**
+ * @brief Get a list of supported algorithms of a given type. This respects the
+ * FIPS mode status.
+ *
+ * @param[in] type The type of the algorithm to query (SSH_KEX, SSH_MAC_C_S,
+ * ...).
+ *
+ * @return The list of supported methods as comma-separated string, or NULL for
+ * unknown type.
+ */
+const char *ssh_get_supported_methods(enum ssh_kex_types_e type)
+{
+    if (ssh_fips_mode()) {
+        return ssh_kex_get_fips_methods(type);
+    } else {
+        return ssh_kex_get_supported_method(type);
+    }
 }
 
 /**
@@ -894,6 +922,8 @@ kex_select_kex_type(const char *kex)
         return SSH_KEX_CURVE25519_SHA256_LIBSSH_ORG;
     } else if (strcmp(kex, "curve25519-sha256") == 0) {
         return SSH_KEX_CURVE25519_SHA256;
+    } else if (strcmp(kex, "sntrup761x25519-sha512@openssh.com") == 0) {
+        return SSH_KEX_SNTRUP761X25519_SHA512_OPENSSH_COM;
     }
     /* should not happen. We should be getting only valid names at this stage */
     return 0;
@@ -933,6 +963,11 @@ static void revert_kex_callbacks(ssh_session session)
     case SSH_KEX_CURVE25519_SHA256_LIBSSH_ORG:
         ssh_client_curve25519_remove_callbacks(session);
         break;
+#endif
+#ifdef HAVE_SNTRUP761
+    case SSH_KEX_SNTRUP761X25519_SHA512_OPENSSH_COM:
+        ssh_client_sntrup761x25519_remove_callbacks(session);
+        break;
 #endif
     }
 }
@@ -1340,6 +1375,7 @@ int ssh_make_sessionid(ssh_session session)
 
     buf = ssh_buffer_new();
     if (buf == NULL) {
+        ssh_set_error_oom(session);
         return rc;
     }
 
@@ -1348,6 +1384,9 @@ int ssh_make_sessionid(ssh_session session)
                          session->clientbanner,
                          session->serverbanner);
     if (rc == SSH_ERROR) {
+        ssh_set_error(session,
+                      SSH_FATAL,
+                      "Failed to pack client and server banner");
         goto error;
     }
 
@@ -1361,6 +1400,9 @@ int ssh_make_sessionid(ssh_session session)
 
     rc = ssh_dh_get_next_server_publickey_blob(session, &server_pubkey_blob);
     if (rc != SSH_OK) {
+        ssh_set_error(session,
+                      SSH_FATAL,
+                      "Failed to get next server pubkey blob");
         goto error;
     }
 
@@ -1375,6 +1417,9 @@ int ssh_make_sessionid(ssh_session session)
                          server_pubkey_blob);
     SSH_STRING_FREE(server_pubkey_blob);
     if (rc != SSH_OK){
+        ssh_set_error(session,
+                      SSH_FATAL,
+                      "Failed to pack hashes and pubkey blob");
         goto error;
     }
 
@@ -1399,6 +1444,7 @@ int ssh_make_sessionid(ssh_session session)
                              client_pubkey,
                              server_pubkey);
         if (rc != SSH_OK) {
+            ssh_set_error(session, SSH_FATAL, "Failed to pack DH pubkeys");
             goto error;
         }
 #if defined(HAVE_LIBCRYPTO) && OPENSSL_VERSION_NUMBER >= 0x30000000L
@@ -1434,6 +1480,7 @@ int ssh_make_sessionid(ssh_session session)
                     client_pubkey,
                     server_pubkey);
         if (rc != SSH_OK) {
+            ssh_set_error(session, SSH_FATAL, "Failed to pack DH GEX params");
             goto error;
         }
 #if defined(HAVE_LIBCRYPTO) && OPENSSL_VERSION_NUMBER >= 0x30000000L
@@ -1456,6 +1503,7 @@ int ssh_make_sessionid(ssh_session session)
                              session->next_crypto->ecdh_client_pubkey,
                              session->next_crypto->ecdh_server_pubkey);
         if (rc != SSH_OK) {
+            ssh_set_error(session, SSH_FATAL, "Failed to pack ECDH pubkeys");
             goto error;
         }
         break;
@@ -1473,13 +1521,47 @@ int ssh_make_sessionid(ssh_session session)
                              session->next_crypto->curve25519_server_pubkey);
 
         if (rc != SSH_OK) {
+            ssh_set_error(session,
+                          SSH_FATAL,
+                          "Failed to pack Curve25519 pubkeys");
             goto error;
         }
         break;
 #endif /* HAVE_CURVE25519 */
+#ifdef HAVE_SNTRUP761
+    case SSH_KEX_SNTRUP761X25519_SHA512_OPENSSH_COM:
+        rc = ssh_buffer_pack(buf,
+                             "dPPdPP",
+                             SNTRUP761_PUBLICKEY_SIZE + CURVE25519_PUBKEY_SIZE,
+                             (size_t)SNTRUP761_PUBLICKEY_SIZE,
+                             session->next_crypto->sntrup761_client_pubkey,
+                             (size_t)CURVE25519_PUBKEY_SIZE,
+                             session->next_crypto->curve25519_client_pubkey,
+                             SNTRUP761_CIPHERTEXT_SIZE + CURVE25519_PUBKEY_SIZE,
+                             (size_t)SNTRUP761_CIPHERTEXT_SIZE,
+                             session->next_crypto->sntrup761_ciphertext,
+                             (size_t)CURVE25519_PUBKEY_SIZE,
+                             session->next_crypto->curve25519_server_pubkey);
+
+        if (rc != SSH_OK) {
+            ssh_set_error(session,
+                          SSH_FATAL,
+                          "Failed to pack SNTRU Prime params");
+            goto error;
+        }
+        break;
+#endif /* HAVE_SNTRUP761 */
+    }
+    if (session->next_crypto->kex_type == SSH_KEX_SNTRUP761X25519_SHA512_OPENSSH_COM) {
+        rc = ssh_buffer_pack(buf,
+                             "F",
+                             session->next_crypto->shared_secret,
+                             SHA512_DIGEST_LEN);
+    } else {
+        rc = ssh_buffer_pack(buf, "B", session->next_crypto->shared_secret);
     }
-    rc = ssh_buffer_pack(buf, "B", session->next_crypto->shared_secret);
     if (rc != SSH_OK) {
+        ssh_set_error(session, SSH_FATAL, "Failed to pack shared secret");
         goto error;
     }
 
@@ -1534,6 +1616,7 @@ int ssh_make_sessionid(ssh_session session)
     case SSH_KEX_DH_GROUP16_SHA512:
     case SSH_KEX_DH_GROUP18_SHA512:
     case SSH_KEX_ECDH_SHA2_NISTP521:
+    case SSH_KEX_SNTRUP761X25519_SHA512_OPENSSH_COM:
         session->next_crypto->digest_len = SHA512_DIGEST_LENGTH;
         session->next_crypto->digest_type = SSH_KDF_SHA512;
         session->next_crypto->secret_hash = malloc(session->next_crypto->digest_len);
@@ -1670,7 +1753,12 @@ int ssh_generate_session_keys(ssh_session session)
     size_t intkey_srv_to_cli_len = 0;
     int rc = -1;
 
-    k_string = ssh_make_bignum_string(crypto->shared_secret);
+    if (session->next_crypto->kex_type == SSH_KEX_SNTRUP761X25519_SHA512_OPENSSH_COM) {
+        k_string = ssh_make_padded_bignum_string(crypto->shared_secret,
+                                                 SHA512_DIGEST_LEN);
+    } else {
+        k_string = ssh_make_bignum_string(crypto->shared_secret);
+    }
     if (k_string == NULL) {
         ssh_set_error_oom(session);
         goto error;

src/knownhosts.c

@@ -171,7 +171,7 @@ static int known_hosts_read_line(FILE *fp,
                                  size_t *buf_len,
                                  size_t *lineno)
 {
-    while (fgets(buf, buf_size, fp) != NULL) {
+    while (fgets(buf, (int)buf_size, fp) != NULL) {
         size_t len;
         if (buf[0] == '\0') {
             continue;

src/libcrypto.c

@@ -49,8 +49,9 @@
 #include <openssl/rsa.h>
 #include <openssl/hmac.h>
 #else
-#include <openssl/param_build.h>
 #include <openssl/core_names.h>
+#include <openssl/param_build.h>
+#include <openssl/provider.h>
 #endif /* OPENSSL_VERSION_NUMBER */
 #include <openssl/rand.h>
 #if defined(WITH_PKCS11_URI) && !defined(WITH_PKCS11_PROVIDER)
@@ -96,7 +97,37 @@ void ssh_reseed(void){
 #endif
 }
 
-#if defined(WITH_PKCS11_URI) && !defined(WITH_PKCS11_PROVIDER)
+#if defined(WITH_PKCS11_URI)
+#if defined(WITH_PKCS11_PROVIDER)
+static OSSL_PROVIDER *provider = NULL;
+static bool pkcs11_provider_failed = false;
+
+int pki_load_pkcs11_provider(void)
+{
+    if (OSSL_PROVIDER_available(NULL, "pkcs11") == 1) {
+        /* the provider is already available.
+         * Loaded through a configuration file? */
+        return SSH_OK;
+    }
+
+    if (pkcs11_provider_failed) {
+        /* the loading failed previously -- do not retry */
+        return SSH_ERROR;
+    }
+
+    provider = OSSL_PROVIDER_try_load(NULL, "pkcs11", 1);
+    if (provider != NULL) {
+        return SSH_OK;
+    }
+
+    SSH_LOG(SSH_LOG_TRACE,
+            "Failed to load the pkcs11 provider: %s",
+            ERR_error_string(ERR_get_error(), NULL));
+    /* Do not attempt to load it again */
+    pkcs11_provider_failed = true;
+    return SSH_ERROR;
+}
+#else
 static ENGINE *engine = NULL;
 
 ENGINE *pki_get_engine(void)
@@ -128,7 +159,8 @@ ENGINE *pki_get_engine(void)
     }
     return engine;
 }
-#endif /* defined(WITH_PKCS11_URI) && !defined(WITH_PKCS11_PROVIDER) */
+#endif /* defined(WITH_PKCS11_PROVIDER) */
+#endif /* defined(WITH_PKCS11_URI) */
 
 #ifdef HAVE_OPENSSL_EVP_KDF_CTX
 #if OPENSSL_VERSION_NUMBER < 0x30000000L
@@ -317,7 +349,7 @@ HMACCTX hmac_init(const void *key, size_t len, enum ssh_hmac_e type)
         return NULL;
     }
 
-    pkey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, key, len);
+    pkey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, key, (int)len);
     if (pkey == NULL) {
         goto error;
     }
@@ -603,7 +635,7 @@ evp_cipher_aead_encrypt(struct ssh_cipher_struct *cipher,
                            (unsigned char *)out + aadlen,
                            &tmplen,
                            (unsigned char *)in + aadlen,
-                           (int)len - aadlen);
+                           (int)(len - aadlen));
     outlen = tmplen;
     if (rc != 1 || outlen != (int)len - aadlen) {
         SSH_LOG(SSH_LOG_TRACE, "EVP_EncryptUpdate failed");
@@ -621,7 +653,7 @@ evp_cipher_aead_encrypt(struct ssh_cipher_struct *cipher,
 
     rc = EVP_CIPHER_CTX_ctrl(cipher->ctx,
                              EVP_CTRL_GCM_GET_TAG,
-                             authlen,
+                             (int)authlen,
                              (unsigned char *)tag);
     if (rc != 1) {
         SSH_LOG(SSH_LOG_TRACE, "EVP_CTRL_GCM_GET_TAG failed");
@@ -659,7 +691,7 @@ evp_cipher_aead_decrypt(struct ssh_cipher_struct *cipher,
     /* set tag for authentication */
     rc = EVP_CIPHER_CTX_ctrl(cipher->ctx,
                              EVP_CTRL_GCM_SET_TAG,
-                             authlen,
+                             (int)authlen,
                              (unsigned char *)complete_packet + aadlen + encrypted_size);
     if (rc == 0) {
         SSH_LOG(SSH_LOG_TRACE, "EVP_CTRL_GCM_SET_TAG failed");
@@ -684,7 +716,7 @@ evp_cipher_aead_decrypt(struct ssh_cipher_struct *cipher,
                            (unsigned char *)out,
                            &outlen,
                            (unsigned char *)complete_packet + aadlen,
-                           encrypted_size /* already subtracted aadlen */);
+                           (int)encrypted_size /* already subtracted aadlen */);
     if (rc != 1) {
         SSH_LOG(SSH_LOG_TRACE, "EVP_DecryptUpdate failed");
         return SSH_ERROR;
@@ -966,7 +998,7 @@ chacha20_poly1305_aead_decrypt_length(struct ssh_cipher_struct *cipher,
         return SSH_ERROR;
     }
 
-    rv = EVP_CipherUpdate(ctx->header_evp, out, &outlen, in, len);
+    rv = EVP_CipherUpdate(ctx->header_evp, out, &outlen, in, (int)len);
     if (rv != 1 || outlen != sizeof(uint32_t)) {
         SSH_LOG(SSH_LOG_TRACE, "EVP_CipherUpdate failed");
         return SSH_ERROR;
@@ -1053,9 +1085,11 @@ chacha20_poly1305_aead_decrypt(struct ssh_cipher_struct *cipher,
     }
 
     /* Decrypt the message */
-    rv = EVP_CipherUpdate(ctx->main_evp, out, &len,
+    rv = EVP_CipherUpdate(ctx->main_evp,
+                          out,
+                          &len,
                           (uint8_t *)complete_packet + sizeof(uint32_t),
-                          encrypted_size);
+                          (int)encrypted_size);
     if (rv != 1) {
         SSH_LOG(SSH_LOG_TRACE, "EVP_CipherUpdate failed");
         goto out;
@@ -1122,7 +1156,7 @@ chacha20_poly1305_aead_encrypt(struct ssh_cipher_struct *cipher,
                            out_packet->payload,
                            &outlen,
                            in_packet->payload,
-                           len - sizeof(uint32_t));
+                           (int)(len - sizeof(uint32_t)));
     if (ret != 1) {
         SSH_LOG(SSH_LOG_TRACE, "EVP_CipherUpdate failed");
         return;
@@ -1402,6 +1436,14 @@ void ssh_crypto_finalize(void)
         engine = NULL;
     }
 #endif
+#if defined(WITH_PKCS11_URI)
+#if defined(WITH_PKCS11_PROVIDER)
+    if (provider != NULL) {
+        OSSL_PROVIDER_unload(provider);
+        provider = NULL;
+    }
+#endif /* WITH_PKCS11_PROVIDER */
+#endif /* WITH_PKCS11_URI */
 
     libcrypto_initialized = 0;
 }
@@ -1546,6 +1588,12 @@ int evp_dup_ecdsa_pkey(const ssh_key key, ssh_key new_key, int demote)
 {
     return evp_dup_pkey("EC", key, demote, new_key);
 }
+
+int evp_dup_ed25519_pkey(const ssh_key key, ssh_key new_key, int demote)
+{
+    return evp_dup_pkey("ED25519", key, demote, new_key);
+}
+
 #endif /* OPENSSL_VERSION_NUMBER */
 
 ssh_string

src/libgcrypt.c

@@ -966,7 +966,8 @@ int ssh_crypto_init(void)
     gcry_control (GCRYCTL_SUSPEND_SECMEM_WARN);
 
     if (!gcry_control(GCRYCTL_INITIALIZATION_FINISHED_P, 0)) {
-        gcry_control(GCRYCTL_INIT_SECMEM, 4096);
+        gcry_control(GCRYCTL_USE_SECURE_RNDPOOL);
+        gcry_control(GCRYCTL_INIT_SECMEM, 32768, 0);
         gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0);
     }
 

src/libssh.map

@@ -481,3 +481,16 @@ LIBSSH_4_10_0    # Released
         ssh_pki_export_privkey_file_format;
         ssh_request_no_more_sessions;
 } LIBSSH_4_9_0;
+
+LIBSSH_AFTER_4_10_0
+{
+    global:
+        sftp_get_users_groups_by_id;
+        sftp_name_id_map_free;
+        sftp_name_id_map_new;
+        ssh_get_supported_methods;
+        sshsig_sign;
+        sshsig_verify;
+        ssh_string_cmp;
+} LIBSSH_4_10_0;
+

src/log.c

@@ -59,22 +59,22 @@ static int current_timestring(int hires, char *buf, size_t len)
 {
     char tbuf[64];
     struct timeval tv;
-    struct tm *tm;
+    struct tm tm, *tm_ptr = NULL;
     time_t t;
 
     gettimeofday(&tv, NULL);
     t = (time_t) tv.tv_sec;
 
-    tm = localtime(&t);
-    if (tm == NULL) {
+    tm_ptr = localtime_r(&t, &tm);
+    if (tm_ptr == NULL) {
         return -1;
     }
 
     if (hires) {
-        strftime(tbuf, sizeof(tbuf) - 1, "%Y/%m/%d %H:%M:%S", tm);
+        strftime(tbuf, sizeof(tbuf), "%Y/%m/%d %H:%M:%S", &tm);
         snprintf(buf, len, "%s.%06ld", tbuf, (long)tv.tv_usec);
     } else {
-        strftime(tbuf, sizeof(tbuf) - 1, "%Y/%m/%d %H:%M:%S", tm);
+        strftime(tbuf, sizeof(tbuf), "%Y/%m/%d %H:%M:%S", &tm);
         snprintf(buf, len, "%s", tbuf);
     }
 

src/match.c

@@ -205,8 +205,10 @@ int match_pattern_list(const char *string, const char *pattern,
  * Returns -1 if negation matches, 1 if there is a positive match, 0 if there
  * is no match at all.
  */
-int match_hostname(const char *host, const char *pattern, unsigned int len) {
-  return match_pattern_list(host, pattern, len, 1);
+int
+match_hostname(const char *host, const char *pattern, size_t len)
+{
+    return match_pattern_list(host, pattern, len, 1);
 }
 
 #ifndef _WIN32

src/mbedcrypto-compat.h

@@ -5,13 +5,17 @@
  * v3 defines the version inside build_info.h so if it isn't defined
  * in version.h we should have v3
  */
-#include <mbedtls/version.h>
 #include <mbedtls/cipher.h>
-#ifdef MBEDTLS_VERSION_MAJOR
+#include <mbedtls/version.h>
+
+#ifndef MBEDTLS_VERSION_MAJOR
+#include <mbedtls/build_info.h>
+#endif /* MBEDTLS_VERSION_MAJOR */
+
 #if MBEDTLS_VERSION_MAJOR < 3
 
-static inline size_t mbedtls_cipher_info_get_key_bitlen(
-                         const mbedtls_cipher_info_t *info)
+static inline size_t
+mbedtls_cipher_info_get_key_bitlen(const mbedtls_cipher_info_t *info)
 {
     if (info == NULL) {
         return 0;
@@ -19,8 +23,8 @@ static inline size_t mbedtls_cipher_info_get_key_bitlen(
     return info->key_bitlen;
 }
 
-static inline size_t mbedtls_cipher_info_get_iv_size(
-                         const mbedtls_cipher_info_t *info)
+static inline size_t
+mbedtls_cipher_info_get_iv_size(const mbedtls_cipher_info_t *info)
 {
     if (info == NULL) {
         return 0;
@@ -29,11 +33,24 @@ static inline size_t mbedtls_cipher_info_get_iv_size(
 }
 
 #define MBEDTLS_PRIVATE(X) X
+
+#ifdef HAVE_MBEDTLS_CURVE25519
+#include <mbedtls/ecdh.h>
+
+#define MBEDTLS_ECDH_PRIVATE(X) X
+#define MBEDTLS_ECDH_PARAMS(X)  X
+typedef mbedtls_ecdh_context mbedtls_ecdh_params;
+#endif /* HAVE_MBEDTLS_CURVE25519 */
+
+#else /* MBEDTLS_VERSION_MAJOR < 3 */
+
+#ifdef HAVE_MBEDTLS_CURVE25519
+#include <mbedtls/ecdh.h>
+
+#define MBEDTLS_ECDH_PRIVATE(X) MBEDTLS_PRIVATE(X)
+#define MBEDTLS_ECDH_PARAMS(X)  X.MBEDTLS_PRIVATE(ctx).MBEDTLS_PRIVATE(mbed_ecdh)
+typedef mbedtls_ecdh_context_mbed mbedtls_ecdh_params;
+#endif /* HAVE_MBEDTLS_CURVE25519 */
+
 #endif /* MBEDTLS_VERSION_MAJOR < 3 */
-#else  /* MBEDTLS_VERSION_MAJOR */
-#include <mbedtls/build_info.h>
-#if MBEDTLS_VERSION_MAJOR < 3
-#define MBEDTLS_PRIVATE(X) X
-#endif /* MBEDTLS_VERSION_MAJOR < 3 */
-#endif /* MBEDTLS_VERSION_MAJOR */
 #endif /* MBEDCRYPTO_COMPAT_H */

src/messages.c

@@ -204,8 +204,35 @@ static int ssh_execute_server_request(ssh_session session, ssh_message msg)
                     ssh_message_reply_default(msg);
                 }
 
+                return SSH_OK;
+#define CB channel_open_request_direct_tcpip_function
+            } else if (msg->channel_request_open.type == SSH_CHANNEL_DIRECT_TCPIP &&
+                       ssh_callbacks_exists(session->server_callbacks, CB)) {
+                struct ssh_channel_request_open *rq = &msg->channel_request_open;
+                channel = session->server_callbacks->CB(session,
+                                                        rq->destination,
+                                                        rq->destination_port,
+                                                        rq->originator,
+                                                        rq->originator_port,
+                                                        session->server_callbacks->userdata);
+#undef CB
+                if (channel != NULL) {
+                    rc = ssh_message_channel_request_open_reply_accept_channel(
+                        msg,
+                        channel);
+                    if (rc != SSH_OK) {
+                        SSH_LOG(SSH_LOG_TRACE,
+                                "Failed to send reply for accepting a channel "
+                                "open");
+                    }
+                    return SSH_OK;
+                } else {
+                    ssh_message_reply_default(msg);
+                }
+
                 return SSH_OK;
             }
+
             break;
         case SSH_REQUEST_CHANNEL:
             channel = msg->channel_request.channel;
@@ -519,30 +546,36 @@ static void ssh_message_queue(ssh_session session, ssh_message message)
  *
  * @returns             The head message or NULL if it doesn't exist.
  */
-ssh_message ssh_message_pop_head(ssh_session session){
-  ssh_message msg=NULL;
-  struct ssh_iterator *i = NULL;
-  if(session->ssh_message_list == NULL)
-    return NULL;
-  i=ssh_list_get_iterator(session->ssh_message_list);
-  if(i != NULL){
-    msg=ssh_iterator_value(ssh_message,i);
-    ssh_list_remove(session->ssh_message_list,i);
-  }
-  return msg;
+ssh_message ssh_message_pop_head(ssh_session session)
+{
+    ssh_message msg = NULL;
+    struct ssh_iterator *i = NULL;
+
+    if (session->ssh_message_list == NULL)
+        return NULL;
+
+    i = ssh_list_get_iterator(session->ssh_message_list);
+    if (i != NULL) {
+        msg = ssh_iterator_value(ssh_message, i);
+        ssh_list_remove(session->ssh_message_list, i);
+    }
+    return msg;
 }
 
 /* Returns 1 if there is a message available */
-static int ssh_message_termination(void *s){
-  ssh_session session = s;
-  struct ssh_iterator *it = NULL;
-  if(session->session_state == SSH_SESSION_STATE_ERROR)
-    return 1;
-  it = ssh_list_get_iterator(session->ssh_message_list);
-  if(!it)
-    return 0;
-  else
-    return 1;
+static int ssh_message_termination(void *s)
+{
+    ssh_session session = s;
+    struct ssh_iterator *it = NULL;
+
+    if (session->session_state == SSH_SESSION_STATE_ERROR)
+        return 1;
+
+    it = ssh_list_get_iterator(session->ssh_message_list);
+    if (!it)
+        return 0;
+    else
+        return 1;
 }
 /**
  * @brief Retrieve a SSH message from a SSH session.
@@ -642,6 +675,7 @@ void ssh_message_free(ssh_message msg){
         SAFE_FREE(msg->auth_request.password);
       }
       ssh_key_free(msg->auth_request.pubkey);
+      ssh_key_free(msg->auth_request.server_pubkey);
       break;
     case SSH_REQUEST_CHANNEL_OPEN:
       SAFE_FREE(msg->channel_request_open.originator);
@@ -733,11 +767,12 @@ error:
 static ssh_buffer ssh_msg_userauth_build_digest(ssh_session session,
                                                 ssh_message msg,
                                                 const char *service,
-                                                ssh_string algo)
+                                                ssh_string algo,
+                                                const char *method)
 {
     struct ssh_crypto_struct *crypto = NULL;
     ssh_buffer buffer = NULL;
-    ssh_string str=NULL;
+    ssh_string str = NULL;
     int rc;
 
     crypto = ssh_packet_get_current_crypto(session, SSH_DIRECTION_IN);
@@ -763,10 +798,10 @@ static ssh_buffer ssh_msg_userauth_build_digest(ssh_session session,
                          SSH2_MSG_USERAUTH_REQUEST, /* type */
                          msg->auth_request.username,
                          service,
-                         "publickey", /* method */
+                         method,
                          1, /* has to be signed (true) */
                          ssh_string_get_char(algo), /* pubkey algorithm */
-                         str); /* public key as a blob */
+                         str);                      /* public key as a blob */
 
     SSH_STRING_FREE(str);
     if (rc != SSH_OK) {
@@ -775,6 +810,25 @@ static ssh_buffer ssh_msg_userauth_build_digest(ssh_session session,
         return NULL;
     }
 
+    /* Add server public key for hostbound extension */
+    if (strcmp(method, "publickey-hostbound-v00@openssh.com") == 0 &&
+        msg->auth_request.server_pubkey != NULL) {
+
+        rc = ssh_pki_export_pubkey_blob(msg->auth_request.server_pubkey, &str);
+        if (rc < 0) {
+            SSH_BUFFER_FREE(buffer);
+            return NULL;
+        }
+
+        rc = ssh_buffer_add_ssh_string(buffer, str);
+        SSH_STRING_FREE(str);
+        if (rc < 0) {
+            ssh_set_error_oom(session);
+            SSH_BUFFER_FREE(buffer);
+            return NULL;
+        }
+    }
+
     return buffer;
 }
 
@@ -784,263 +838,334 @@ static ssh_buffer ssh_msg_userauth_build_digest(ssh_session session,
  * @brief Handle a SSH_MSG_MSG_USERAUTH_REQUEST packet and queue a
  * SSH Message
  */
-SSH_PACKET_CALLBACK(ssh_packet_userauth_request){
-  ssh_message msg = NULL;
-  ssh_signature sig = NULL;
-  char *service = NULL;
-  char *method = NULL;
-  int cmp;
-  int rc;
+SSH_PACKET_CALLBACK(ssh_packet_userauth_request)
+{
+    ssh_message msg = NULL;
+    ssh_signature sig = NULL;
+    char *service = NULL;
+    char *method = NULL;
+    int cmp;
+    int rc;
 
-  (void)user;
-  (void)type;
+    (void)user;
+    (void)type;
 
-  msg = ssh_message_new(session);
-  if (msg == NULL) {
-    ssh_set_error_oom(session);
-    goto error;
-  }
-  msg->type = SSH_REQUEST_AUTH;
-  rc = ssh_buffer_unpack(packet,
-                         "sss",
-                         &msg->auth_request.username,
-                         &service,
-                         &method);
-
-  if (rc != SSH_OK) {
-      goto error;
-  }
-
-  SSH_LOG(SSH_LOG_PACKET,
-      "Auth request for service %s, method %s for user '%s'",
-      service, method,
-      msg->auth_request.username);
-
-  cmp = strcmp(service, "ssh-connection");
-  if (cmp != 0) {
-      SSH_LOG(SSH_LOG_TRACE,
-              "Invalid service request: %s",
-              service);
-      goto end;
-  }
-
-  if (strcmp(method, "none") == 0) {
-    msg->auth_request.method = SSH_AUTH_METHOD_NONE;
-    goto end;
-  }
-
-  if (strcmp(method, "password") == 0) {
-    uint8_t tmp;
-
-    msg->auth_request.method = SSH_AUTH_METHOD_PASSWORD;
-    rc = ssh_buffer_unpack(packet, "bs", &tmp, &msg->auth_request.password);
-    if (rc != SSH_OK) {
-      goto error;
-    }
-    goto end;
-  }
-
-  if (strcmp(method, "keyboard-interactive") == 0) {
-    ssh_string lang = NULL;
-    ssh_string submethods = NULL;
-
-    msg->auth_request.method = SSH_AUTH_METHOD_INTERACTIVE;
-    lang = ssh_buffer_get_ssh_string(packet);
-    if (lang == NULL) {
-      goto error;
-    }
-    /* from the RFC 4256
-     * 3.1.  Initial Exchange
-     * "The language tag is deprecated and SHOULD be the empty string."
-     */
-    SSH_STRING_FREE(lang);
-
-    submethods = ssh_buffer_get_ssh_string(packet);
-    if (submethods == NULL) {
-      goto error;
-    }
-    /* from the RFC 4256
-     * 3.1.  Initial Exchange
-     * "One possible implementation strategy of the submethods field on the
-     *  server is that, unless the user may use multiple different
-     *  submethods, the server ignores this field."
-     */
-    SSH_STRING_FREE(submethods);
-
-    goto end;
-  }
-
-  if (strcmp(method, "publickey") == 0) {
-    ssh_string algo = NULL;
-    ssh_string pubkey_blob = NULL;
-    uint8_t has_sign;
-
-    msg->auth_request.method = SSH_AUTH_METHOD_PUBLICKEY;
-    SAFE_FREE(method);
-    rc = ssh_buffer_unpack(packet, "bSS",
-            &has_sign,
-            &algo,
-            &pubkey_blob
-            );
-
-    if (rc != SSH_OK) {
-      goto error;
-    }
-
-    rc = ssh_pki_import_pubkey_blob(pubkey_blob, &msg->auth_request.pubkey);
-    SSH_STRING_FREE(pubkey_blob);
-    pubkey_blob = NULL;
-    if (rc < 0) {
-        SSH_STRING_FREE(algo);
-        algo = NULL;
+    msg = ssh_message_new(session);
+    if (msg == NULL) {
+        ssh_set_error_oom(session);
         goto error;
     }
-    msg->auth_request.signature_state = SSH_PUBLICKEY_STATE_NONE;
-    msg->auth_request.sigtype = strdup(ssh_string_get_char(algo));
-    if (msg->auth_request.sigtype == NULL) {
-        msg->auth_request.signature_state = SSH_PUBLICKEY_STATE_ERROR;
-        SSH_STRING_FREE(algo);
-        algo = NULL;
+    msg->type = SSH_REQUEST_AUTH;
+    rc = ssh_buffer_unpack(packet,
+                           "sss",
+                           &msg->auth_request.username,
+                           &service,
+                           &method);
+
+    if (rc != SSH_OK) {
         goto error;
     }
 
-    // has a valid signature ?
-    if(has_sign) {
-        ssh_string sig_blob = NULL;
-        ssh_buffer digest = NULL;
+    SSH_LOG(SSH_LOG_PACKET,
+            "Auth request for service %s, method %s for user '%s'",
+            service,
+            method,
+            msg->auth_request.username);
 
-        sig_blob = ssh_buffer_get_ssh_string(packet);
-        if(sig_blob == NULL) {
-            SSH_LOG(SSH_LOG_PACKET, "Invalid signature packet from peer");
+    cmp = strcmp(service, "ssh-connection");
+    if (cmp != 0) {
+        SSH_LOG(SSH_LOG_TRACE, "Invalid service request: %s", service);
+        goto end;
+    }
+
+    if (strcmp(method, "none") == 0) {
+        msg->auth_request.method = SSH_AUTH_METHOD_NONE;
+        goto end;
+    }
+
+    if (strcmp(method, "password") == 0) {
+        uint8_t tmp;
+
+        msg->auth_request.method = SSH_AUTH_METHOD_PASSWORD;
+        rc = ssh_buffer_unpack(packet, "bs", &tmp, &msg->auth_request.password);
+        if (rc != SSH_OK) {
+            goto error;
+        }
+        goto end;
+    }
+
+    if (strcmp(method, "keyboard-interactive") == 0) {
+        ssh_string lang = NULL;
+        ssh_string submethods = NULL;
+
+        msg->auth_request.method = SSH_AUTH_METHOD_INTERACTIVE;
+        lang = ssh_buffer_get_ssh_string(packet);
+        if (lang == NULL) {
+            goto error;
+        }
+        /* from the RFC 4256
+         * 3.1.  Initial Exchange
+         * "The language tag is deprecated and SHOULD be the empty string."
+         */
+        SSH_STRING_FREE(lang);
+
+        submethods = ssh_buffer_get_ssh_string(packet);
+        if (submethods == NULL) {
+            goto error;
+        }
+        /* from the RFC 4256
+         * 3.1.  Initial Exchange
+         * "One possible implementation strategy of the submethods field on the
+         *  server is that, unless the user may use multiple different
+         *  submethods, the server ignores this field."
+         */
+        SSH_STRING_FREE(submethods);
+
+        goto end;
+    }
+
+    if (strcmp(method, "publickey") == 0 ||
+        strcmp(method, "publickey-hostbound-v00@openssh.com") == 0) {
+        ssh_string algo = NULL;
+        ssh_string pubkey_blob = NULL;
+        ssh_string server_pubkey_blob = NULL;
+        uint8_t has_sign;
+
+        msg->auth_request.method = SSH_AUTH_METHOD_PUBLICKEY;
+
+        rc = ssh_buffer_unpack(packet, "bSS", &has_sign, &algo, &pubkey_blob);
+
+        if (rc != SSH_OK) {
+            goto error;
+        }
+
+        cmp = strcmp(method, "publickey-hostbound-v00@openssh.com");
+        if (cmp == 0) {
+            server_pubkey_blob = ssh_buffer_get_ssh_string(packet);
+            if (server_pubkey_blob == NULL) {
+                SSH_STRING_FREE(pubkey_blob);
+                SSH_STRING_FREE(algo);
+                goto error;
+            }
+
+            rc = ssh_pki_import_pubkey_blob(server_pubkey_blob,
+                                            &msg->auth_request.server_pubkey);
+            SSH_STRING_FREE(server_pubkey_blob);
+
+            if (rc < 0) {
+                SSH_STRING_FREE(pubkey_blob);
+                SSH_STRING_FREE(algo);
+                goto error;
+            }
+        }
+
+        rc = ssh_pki_import_pubkey_blob(pubkey_blob, &msg->auth_request.pubkey);
+        SSH_STRING_FREE(pubkey_blob);
+        pubkey_blob = NULL;
+        if (rc < 0) {
+            SSH_STRING_FREE(algo);
+            algo = NULL;
+            goto error;
+        }
+        msg->auth_request.signature_state = SSH_PUBLICKEY_STATE_NONE;
+        msg->auth_request.sigtype = strdup(ssh_string_get_char(algo));
+        if (msg->auth_request.sigtype == NULL) {
             msg->auth_request.signature_state = SSH_PUBLICKEY_STATE_ERROR;
             SSH_STRING_FREE(algo);
             algo = NULL;
             goto error;
         }
 
-        digest = ssh_msg_userauth_build_digest(session, msg, service, algo);
-        SSH_STRING_FREE(algo);
-        algo = NULL;
-        if (digest == NULL) {
-            SSH_STRING_FREE(sig_blob);
-            SSH_LOG(SSH_LOG_PACKET, "Failed to get digest");
-            msg->auth_request.signature_state = SSH_PUBLICKEY_STATE_WRONG;
-            goto error;
-        }
+        // has a valid signature ?
+        if (has_sign) {
+            ssh_string sig_blob = NULL;
+            ssh_buffer digest = NULL;
 
-        rc = ssh_pki_import_signature_blob(sig_blob,
-                                           msg->auth_request.pubkey,
-                                           &sig);
-        if (rc == SSH_OK) {
-            /* Check if the signature from client matches server preferences */
-            if (session->opts.pubkey_accepted_types) {
-                cmp = match_group(session->opts.pubkey_accepted_types,
-                                  sig->type_c);
-                if (cmp != 1) {
-                    ssh_set_error(session,
+            sig_blob = ssh_buffer_get_ssh_string(packet);
+            if (sig_blob == NULL) {
+                SSH_LOG(SSH_LOG_PACKET, "Invalid signature packet from peer");
+                msg->auth_request.signature_state = SSH_PUBLICKEY_STATE_ERROR;
+                SSH_STRING_FREE(algo);
+                algo = NULL;
+                goto error;
+            }
+
+            digest = ssh_msg_userauth_build_digest(session,
+                                                   msg,
+                                                   service,
+                                                   algo,
+                                                   method);
+            SSH_STRING_FREE(algo);
+            algo = NULL;
+            if (digest == NULL) {
+                SSH_STRING_FREE(sig_blob);
+                SSH_LOG(SSH_LOG_PACKET, "Failed to get digest");
+                msg->auth_request.signature_state = SSH_PUBLICKEY_STATE_WRONG;
+                goto error;
+            }
+
+            rc = ssh_pki_import_signature_blob(sig_blob,
+                                               msg->auth_request.pubkey,
+                                               &sig);
+            if (rc == SSH_OK) {
+                /* Check if the signature from client matches server preferences
+                 */
+                if (session->opts.pubkey_accepted_types) {
+                    cmp = match_group(session->opts.pubkey_accepted_types,
+                                      sig->type_c);
+                    if (cmp != 1) {
+                        ssh_set_error(
+                            session,
                             SSH_FATAL,
                             "Public key from client (%s) doesn't match server "
                             "preference (%s)",
                             sig->type_c,
                             session->opts.pubkey_accepted_types);
-                    rc = SSH_ERROR;
+                        rc = SSH_ERROR;
+                    }
+                }
+
+                if (rc == SSH_OK) {
+                    rc = ssh_pki_signature_verify(session,
+                                                  sig,
+                                                  msg->auth_request.pubkey,
+                                                  ssh_buffer_get(digest),
+                                                  ssh_buffer_get_len(digest));
                 }
             }
-
-            if (rc == SSH_OK) {
-                rc = ssh_pki_signature_verify(session,
-                                              sig,
-                                              msg->auth_request.pubkey,
-                                              ssh_buffer_get(digest),
-                                              ssh_buffer_get_len(digest));
+            SSH_STRING_FREE(sig_blob);
+            SSH_BUFFER_FREE(digest);
+            ssh_signature_free(sig);
+            if (rc < 0) {
+                SSH_LOG(SSH_LOG_PACKET,
+                        "Received an invalid signature from peer");
+                msg->auth_request.signature_state = SSH_PUBLICKEY_STATE_WRONG;
+                goto error;
             }
+
+            SSH_LOG(SSH_LOG_PACKET, "Valid signature received");
+
+            cmp = strcmp(method, "publickey-hostbound-v00@openssh.com");
+            if (cmp == 0) {
+                ssh_key server_key = NULL;
+
+                if (msg->auth_request.server_pubkey == NULL) {
+                    SSH_LOG(SSH_LOG_PACKET,
+                            "Server public key not provided by client");
+                    msg->auth_request.signature_state =
+                        SSH_PUBLICKEY_STATE_WRONG;
+                    goto error;
+                }
+
+                rc = ssh_get_server_publickey(session, &server_key);
+                if (rc != SSH_OK) {
+                    SSH_LOG(SSH_LOG_PACKET,
+                            "Failed to get server public key for hostbound "
+                            "verification");
+                    msg->auth_request.signature_state =
+                        SSH_PUBLICKEY_STATE_ERROR;
+                    ssh_key_free(server_key);
+                    goto error;
+                }
+
+                if (ssh_key_cmp(server_key,
+                                msg->auth_request.server_pubkey,
+                                SSH_KEY_CMP_PUBLIC) != 0) {
+                    SSH_LOG(SSH_LOG_PACKET,
+                            "Server public key doesn't match the one provided "
+                            "by client");
+                    msg->auth_request.signature_state =
+                        SSH_PUBLICKEY_STATE_WRONG;
+                    ssh_key_free(server_key);
+                    goto error;
+                }
+                ssh_key_free(server_key);
+            }
+
+            msg->auth_request.signature_state = SSH_PUBLICKEY_STATE_VALID;
         }
-        SSH_STRING_FREE(sig_blob);
-        SSH_BUFFER_FREE(digest);
-        ssh_signature_free(sig);
-        if (rc < 0) {
-            SSH_LOG(
-                    SSH_LOG_PACKET,
-                    "Received an invalid signature from peer");
-            msg->auth_request.signature_state = SSH_PUBLICKEY_STATE_WRONG;
+
+        SAFE_FREE(method);
+        SSH_STRING_FREE(algo);
+        goto end;
+    }
+#ifdef WITH_GSSAPI
+    if (strcmp(method, "gssapi-with-mic") == 0) {
+        uint32_t n_oid;
+        ssh_string *oids = NULL;
+        ssh_string oid = NULL;
+        char *hexa = NULL;
+        int i;
+        ssh_buffer_get_u32(packet, &n_oid);
+        n_oid = ntohl(n_oid);
+        if (n_oid > 100) {
+            ssh_set_error(
+                session,
+                SSH_FATAL,
+                "USERAUTH_REQUEST: gssapi-with-mic OID count too big (%d)",
+                n_oid);
             goto error;
         }
+        SSH_LOG(SSH_LOG_PACKET, "gssapi: %d OIDs", n_oid);
+        oids = calloc(n_oid, sizeof(ssh_string));
+        if (oids == NULL) {
+            ssh_set_error_oom(session);
+            goto error;
+        }
+        for (i = 0; i < (int)n_oid; ++i) {
+            oid = ssh_buffer_get_ssh_string(packet);
+            if (oid == NULL) {
+                for (i = i - 1; i >= 0; --i) {
+                    SAFE_FREE(oids[i]);
+                }
+                SAFE_FREE(oids);
+                ssh_set_error(session,
+                              SSH_LOG_PACKET,
+                              "USERAUTH_REQUEST: gssapi-with-mic missing OID");
+                goto error;
+            }
+            oids[i] = oid;
+            if (session->common.log_verbosity >= SSH_LOG_PACKET) {
+                hexa = ssh_get_hexa(ssh_string_data(oid), ssh_string_len(oid));
+                SSH_LOG(SSH_LOG_PACKET, "gssapi: OID %d: %s", i, hexa);
+                SAFE_FREE(hexa);
+            }
+        }
+        ssh_gssapi_handle_userauth(session,
+                                   msg->auth_request.username,
+                                   n_oid,
+                                   oids);
 
-        SSH_LOG(SSH_LOG_PACKET, "Valid signature received");
+        for (i = 0; i < (int)n_oid; ++i) {
+            SAFE_FREE(oids[i]);
+        }
+        SAFE_FREE(oids);
+        /* bypass the message queue thing */
+        SAFE_FREE(service);
+        SAFE_FREE(method);
+        SSH_MESSAGE_FREE(msg);
 
-        msg->auth_request.signature_state = SSH_PUBLICKEY_STATE_VALID;
+        return SSH_PACKET_USED;
     }
-    SSH_STRING_FREE(algo);
-    goto end;
-  }
-#ifdef WITH_GSSAPI
-  if (strcmp(method, "gssapi-with-mic") == 0) {
-     uint32_t n_oid;
-     ssh_string *oids = NULL;
-     ssh_string oid = NULL;
-     char *hexa = NULL;
-     int i;
-     ssh_buffer_get_u32(packet, &n_oid);
-     n_oid=ntohl(n_oid);
-     if(n_oid > 100){
-    	 ssh_set_error(session, SSH_FATAL, "USERAUTH_REQUEST: gssapi-with-mic OID count too big (%d)",n_oid);
-    	 goto error;
-     }
-     SSH_LOG(SSH_LOG_PACKET, "gssapi: %d OIDs", n_oid);
-     oids = calloc(n_oid, sizeof(ssh_string));
-     if (oids == NULL){
-    	 ssh_set_error_oom(session);
-    	 goto error;
-     }
-     for (i=0;i<(int) n_oid;++i){
-    	 oid=ssh_buffer_get_ssh_string(packet);
-    	 if(oid == NULL){
-    		 for(i=i-1;i>=0;--i){
-    			 SAFE_FREE(oids[i]);
-    		 }
-    		 SAFE_FREE(oids);
-    		 ssh_set_error(session, SSH_LOG_PACKET, "USERAUTH_REQUEST: gssapi-with-mic missing OID");
-    		 goto error;
-    	 }
-    	 oids[i] = oid;
-    	 if(session->common.log_verbosity >= SSH_LOG_PACKET){
-    		 hexa = ssh_get_hexa(ssh_string_data(oid), ssh_string_len(oid));
-    		 SSH_LOG(SSH_LOG_PACKET,"gssapi: OID %d: %s",i, hexa);
-    		 SAFE_FREE(hexa);
-    	 }
-     }
-     ssh_gssapi_handle_userauth(session, msg->auth_request.username, n_oid, oids);
-
-     for(i=0;i<(int)n_oid;++i){
-         SAFE_FREE(oids[i]);
-     }
-     SAFE_FREE(oids);
-     /* bypass the message queue thing */
-     SAFE_FREE(service);
-     SAFE_FREE(method);
-     SSH_MESSAGE_FREE(msg);
-
-     return SSH_PACKET_USED;
-  }
 #endif
 
-  msg->auth_request.method = SSH_AUTH_METHOD_UNKNOWN;
-  SAFE_FREE(method);
-  goto end;
+    msg->auth_request.method = SSH_AUTH_METHOD_UNKNOWN;
+    SAFE_FREE(method);
+    goto end;
 error:
-  SAFE_FREE(service);
-  SAFE_FREE(method);
+    SAFE_FREE(service);
+    SAFE_FREE(method);
 
-  SSH_MESSAGE_FREE(msg);
+    SSH_MESSAGE_FREE(msg);
 
-  return SSH_PACKET_USED;
+    return SSH_PACKET_USED;
 end:
-  SAFE_FREE(service);
-  SAFE_FREE(method);
+    SAFE_FREE(service);
+    SAFE_FREE(method);
 
-  ssh_message_queue(session,msg);
+    ssh_message_queue(session, msg);
 
-  return SSH_PACKET_USED;
+    return SSH_PACKET_USED;
 }
 
 #endif /* WITH_SERVER */
@@ -1301,7 +1426,9 @@ end:
  *
  * @returns             SSH_OK on success, SSH_ERROR if an error occurred.
  */
-int ssh_message_channel_request_open_reply_accept_channel(ssh_message msg, ssh_channel chan) {
+int ssh_message_channel_request_open_reply_accept_channel(ssh_message msg,
+                                                          ssh_channel chan)
+{
     ssh_session session = NULL;
     int rc;
 
@@ -1352,25 +1479,25 @@ int ssh_message_channel_request_open_reply_accept_channel(ssh_message msg, ssh_c
  *
  * @returns NULL in case of error
  */
-ssh_channel ssh_message_channel_request_open_reply_accept(ssh_message msg) {
-	ssh_channel chan = NULL;
-	int rc;
+ssh_channel ssh_message_channel_request_open_reply_accept(ssh_message msg)
+{
+    ssh_channel chan = NULL;
+    int rc;
 
-	if (msg == NULL) {
-	    return NULL;
-	}
-
-	chan = ssh_channel_new(msg->session);
-	if (chan == NULL) {
-		return NULL;
-	}
-	rc = ssh_message_channel_request_open_reply_accept_channel(msg, chan);
-	if (rc < 0) {
-		ssh_channel_free(chan);
-		chan = NULL;
-	}
-	return chan;
+    if (msg == NULL) {
+        return NULL;
+    }
 
+    chan = ssh_channel_new(msg->session);
+    if (chan == NULL) {
+        return NULL;
+    }
+    rc = ssh_message_channel_request_open_reply_accept_channel(msg, chan);
+    if (rc < 0) {
+        ssh_channel_free(chan);
+        chan = NULL;
+    }
+    return chan;
 }
 
 /**

src/misc.c

@@ -178,6 +178,35 @@ int ssh_gettimeofday(struct timeval *__p, void *__t)
   return (0);
 }
 
+/**
+ * @internal
+ *
+ * @brief Convert time in seconds since the Epoch to broken-down local time
+ *
+ * This is a helper used to provide localtime_r() like function interface
+ * on Windows.
+ *
+ * @param timer    Pointer to a location storing the time_t which
+ *                 represents the time in seconds since the Epoch.
+ *
+ * @param result   Pointer to a location where the broken-down time
+ *                 (expressed as local time) should be stored.
+ *
+ * @returns        A pointer to the structure pointed to by the parameter
+ *                 <tt>result</tt> on success, NULL on error with the errno
+ *                 set to indicate the error.
+ */
+struct tm *ssh_localtime(const time_t *timer, struct tm *result)
+{
+    errno_t rc;
+    rc = localtime_s(result, timer);
+    if (rc != 0) {
+        return NULL;
+    }
+
+    return result;
+}
+
 char *ssh_get_local_username(void)
 {
     DWORD size = 0;
@@ -401,22 +430,22 @@ int ssh_is_ipaddr(const char *str)
 
 char *ssh_lowercase(const char* str)
 {
-  char *new = NULL, *p = NULL;
+    char *new = NULL, *p = NULL;
 
-  if (str == NULL) {
-    return NULL;
-  }
+    if (str == NULL) {
+        return NULL;
+    }
 
-  new = strdup(str);
-  if (new == NULL) {
-    return NULL;
-  }
+    new = strdup(str);
+    if (new == NULL) {
+        return NULL;
+    }
 
-  for (p = new; *p; p++) {
-    *p = tolower(*p);
-  }
+    for (p = new; *p; p++) {
+        *p = tolower(*p);
+    }
 
-  return new;
+    return new;
 }
 
 char *ssh_hostport(const char *host, int port)
@@ -836,32 +865,32 @@ int ssh_list_prepend(struct ssh_list *list, const void *data)
 
 void ssh_list_remove(struct ssh_list *list, struct ssh_iterator *iterator)
 {
-  struct ssh_iterator *ptr = NULL, *prev = NULL;
+    struct ssh_iterator *ptr = NULL, *prev = NULL;
 
-  if (list == NULL) {
-      return;
-  }
+    if (list == NULL) {
+        return;
+    }
 
-  prev=NULL;
-  ptr=list->root;
-  while(ptr && ptr != iterator){
-    prev=ptr;
-    ptr=ptr->next;
-  }
-  if(!ptr){
-    /* we did not find the element */
-    return;
-  }
-  /* unlink it */
-  if(prev)
-    prev->next=ptr->next;
-  /* if iterator was the head */
-  if(list->root == iterator)
-    list->root=iterator->next;
-  /* if iterator was the tail */
-  if(list->end == iterator)
-    list->end = prev;
-  SAFE_FREE(iterator);
+    prev = NULL;
+    ptr = list->root;
+    while (ptr && ptr != iterator) {
+        prev = ptr;
+        ptr = ptr->next;
+    }
+    if (!ptr) {
+        /* we did not find the element */
+        return;
+    }
+    /* unlink it */
+    if (prev)
+        prev->next = ptr->next;
+    /* if iterator was the head */
+    if (list->root == iterator)
+        list->root = iterator->next;
+    /* if iterator was the tail */
+    if (list->end == iterator)
+        list->end = prev;
+    SAFE_FREE(iterator);
 }
 
 /**
@@ -1590,6 +1619,27 @@ void explicit_bzero(void *s, size_t n)
 }
 #endif /* !HAVE_EXPLICIT_BZERO */
 
+/**
+ * @brief Securely free memory by overwriting it before deallocation
+ *
+ * Overwrites the memory region with zeros before calling free() to prevent
+ * sensitive data from remaining in memory after deallocation.
+ *
+ * @param[in] ptr Pointer to the memory region to securely free.
+ *                Can be NULL (no operation performed).
+ * @param[in] len Length of the memory region in bytes.
+ *
+ */
+void burn_free(void *ptr, size_t len)
+{
+    if (ptr == NULL || len == 0) {
+        return;
+    }
+
+    explicit_bzero(ptr, len);
+    free(ptr);
+}
+
 #if !defined(HAVE_STRNDUP)
 char *strndup(const char *s, size_t n)
 {
@@ -1802,7 +1852,7 @@ int ssh_quote_file_name(const char *file_name, char *buf, size_t buf_len)
     /* Put the string terminator */
     *dst = '\0';
 
-    return dst - buf;
+    return (int)(dst - buf);
 
 error:
     return SSH_ERROR;
@@ -1848,7 +1898,7 @@ int ssh_newline_vis(const char *string, char *buf, size_t buf_len)
     }
     *out = '\0';
 
-    return out - buf;
+    return (int)(out - buf);
 }
 
 /**

src/options.c

@@ -1814,6 +1814,8 @@ int ssh_options_getopt(ssh_session session, int *argcptr, char **argv)
  *
  * @param  filename     The options file to use, if NULL the default
  *                      ~/.ssh/config and /etc/ssh/ssh_config will be used.
+ *                      If complied with support for hermetic-usr,
+ *                      /usr/etc/ssh/ssh_config will be used last.
  *
  * @return 0 on success, < 0 on error.
  *
@@ -1821,48 +1823,63 @@ int ssh_options_getopt(ssh_session session, int *argcptr, char **argv)
  */
 int ssh_options_parse_config(ssh_session session, const char *filename)
 {
-  char *expanded_filename = NULL;
-  int r;
+    char *expanded_filename = NULL;
+    int r;
+    FILE *fp = NULL;
 
-  if (session == NULL) {
-    return -1;
-  }
-  if (session->opts.host == NULL) {
-    ssh_set_error_invalid(session);
-    return -1;
-  }
+    if (session == NULL) {
+        return -1;
+    }
+    if (session->opts.host == NULL) {
+        ssh_set_error_invalid(session);
+        return -1;
+    }
 
-  if (session->opts.sshdir == NULL) {
-      r = ssh_options_set(session, SSH_OPTIONS_SSH_DIR, NULL);
-      if (r < 0) {
-          ssh_set_error_oom(session);
-          return -1;
-      }
-  }
+    if (session->opts.sshdir == NULL) {
+        r = ssh_options_set(session, SSH_OPTIONS_SSH_DIR, NULL);
+        if (r < 0) {
+            ssh_set_error_oom(session);
+            return -1;
+        }
+    }
 
-  /* set default filename */
-  if (filename == NULL) {
-    expanded_filename = ssh_path_expand_escape(session, "%d/config");
-  } else {
-    expanded_filename = ssh_path_expand_escape(session, filename);
-  }
-  if (expanded_filename == NULL) {
-    return -1;
-  }
+    /* set default filename */
+    if (filename == NULL) {
+        expanded_filename = ssh_path_expand_escape(session, "%d/config");
+    } else {
+        expanded_filename = ssh_path_expand_escape(session, filename);
+    }
+    if (expanded_filename == NULL) {
+        return -1;
+    }
 
-  r = ssh_config_parse_file(session, expanded_filename);
-  if (r < 0) {
-      goto out;
-  }
-  if (filename == NULL) {
-      r = ssh_config_parse_file(session, GLOBAL_CLIENT_CONFIG);
-  }
+    r = ssh_config_parse_file(session, expanded_filename);
+    if (r < 0) {
+        goto out;
+    }
+    if (filename == NULL) {
+        if ((fp = fopen(GLOBAL_CLIENT_CONFIG, "r")) != NULL) {
+            filename = GLOBAL_CLIENT_CONFIG;
+#ifdef USR_GLOBAL_CLIENT_CONFIG
+        } else if ((fp = fopen(USR_GLOBAL_CLIENT_CONFIG, "r")) != NULL) {
+            filename = USR_GLOBAL_CLIENT_CONFIG;
+#endif
+        }
 
-  /* Do not process the default configuration as part of connection again */
-  session->opts.config_processed = true;
+        if (fp) {
+            SSH_LOG(SSH_LOG_PACKET,
+                    "Reading configuration data from %s",
+                    filename);
+            r = ssh_config_parse(session, fp, true);
+            fclose(fp);
+        }
+    }
+
+    /* Do not process the default configuration as part of connection again */
+    session->opts.config_processed = true;
 out:
-  free(expanded_filename);
-  return r;
+    free(expanded_filename);
+    return r;
 }
 
 int ssh_options_apply(ssh_session session)
@@ -1968,10 +1985,10 @@ int ssh_options_apply(ssh_session session)
              * it with ssh expansion of ssh escape characters.
              */
             tmp = ssh_path_expand_escape(session, id);
+            free(id);
             if (tmp == NULL) {
                 return -1;
             }
-            free(id);
         }
 
         /* use append to keep the order at first call and use prepend
@@ -1982,6 +1999,7 @@ int ssh_options_apply(ssh_session session)
             rc = ssh_list_append(session->opts.identity, tmp);
         }
         if (rc != SSH_OK) {
+            free(tmp);
             return -1;
         }
     }
@@ -1993,13 +2011,14 @@ int ssh_options_apply(ssh_session session)
         char *id = tmp;
 
         tmp = ssh_path_expand_escape(session, id);
+        free(id);
         if (tmp == NULL) {
             return -1;
         }
-        free(id);
 
         rc = ssh_list_append(session->opts.certificate, tmp);
         if (rc != SSH_OK) {
+            free(tmp);
             return -1;
         }
     }
@@ -2268,6 +2287,9 @@ ssh_bind_options_set(ssh_bind sshbind,
                               SSH_FATAL,
                               "The host key size %d is too small.",
                               ssh_key_size(key));
+                if (type != SSH_BIND_OPTIONS_IMPORT_KEY) {
+                    SSH_KEY_FREE(key);
+                }
                 return -1;
             }
             key_type = ssh_key_type(key);
@@ -2313,6 +2335,11 @@ ssh_bind_options_set(ssh_bind sshbind,
                     ssh_key_free(key);
                     return -1;
                 }
+            } else if (type == SSH_BIND_OPTIONS_IMPORT_KEY_STR) {
+                if (bind_key_loc == NULL) {
+                    ssh_key_free(key);
+                    return -1;
+                }
             } else {
                 if (bind_key_loc == NULL) {
                     return -1;
@@ -2706,7 +2733,13 @@ int ssh_bind_options_parse_config(ssh_bind sshbind, const char *filename)
     /* If the global default configuration hasn't been processed yet, process it
      * before the provided configuration. */
     if (!(sshbind->config_processed)) {
-        rc = ssh_bind_config_parse_file(sshbind, GLOBAL_BIND_CONFIG);
+        if (ssh_file_readaccess_ok(GLOBAL_BIND_CONFIG)) {
+            rc = ssh_bind_config_parse_file(sshbind, GLOBAL_BIND_CONFIG);
+#ifdef USR_GLOBAL_BIND_CONFIG
+        } else {
+            rc = ssh_bind_config_parse_file(sshbind, USR_GLOBAL_BIND_CONFIG);
+#endif
+        }
         if (rc != 0) {
             return rc;
         }

src/packet.c

@@ -1158,7 +1158,7 @@ ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user)
     uint32_t lenfield_blocksize = 8;
     size_t current_macsize = 0;
     uint8_t *ptr = NULL;
-    long to_be_read;
+    ssize_t to_be_read;
     int rc;
     uint8_t *cleartext_packet = NULL;
     uint8_t *packet_second_block = NULL;
@@ -1268,7 +1268,7 @@ ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user)
                 /* remote sshd sends invalid sizes? */
                 ssh_set_error(session,
                               SSH_FATAL,
-                              "Given numbers of bytes left to be read < 0 (%ld)!",
+                              "Given numbers of bytes left to be read < 0 (%zd)!",
                               to_be_read);
                 goto error;
             }
@@ -1286,7 +1286,7 @@ ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user)
                     /* give up, not enough data in buffer */
                     SSH_LOG(SSH_LOG_PACKET,
                             "packet: partial packet (read len) "
-                            "[len=%" PRIu32 ", receivedlen=%zu, to_be_read=%ld]",
+                            "[len=%" PRIu32 ", receivedlen=%zu, to_be_read=%zd]",
                             packet_len,
                             receivedlen,
                             to_be_read);
@@ -1300,7 +1300,7 @@ ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user)
             /* remaining encrypted bytes from the packet, MAC not included */
             packet_remaining = packet_len - (packet_offset - sizeof(uint32_t));
             cleartext_packet = ssh_buffer_allocate(session->in_buffer,
-                                                   packet_remaining);
+                                                   (uint32_t)packet_remaining);
             if (cleartext_packet == NULL) {
                 goto error;
             }
@@ -1476,6 +1476,7 @@ ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user)
 
             session->packet_state = PACKET_STATE_INIT;
             if (processed < receivedlen) {
+                size_t num;
                 /* Handle a potential packet left in socket buffer */
                 SSH_LOG(SSH_LOG_PACKET,
                         "Processing %zu bytes left in socket buffer",
@@ -1483,9 +1484,10 @@ ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user)
 
                 ptr = ((uint8_t*)data) + processed;
 
-                rc = ssh_packet_socket_callback(ptr, receivedlen - processed,
-                                                user);
-                processed += rc;
+                num = ssh_packet_socket_callback(ptr,
+                                                 receivedlen - processed,
+                                                 user);
+                processed += num;
             }
 
             ok = ssh_packet_need_rekey(session, 0);
@@ -1854,7 +1856,7 @@ static int packet_send2(ssh_session session)
     if (hmac != NULL) {
         rc = ssh_buffer_add_data(session->out_buffer,
                                  hmac,
-                                 hmac_digest_len(hmac_type));
+                                 (uint32_t)hmac_digest_len(hmac_type));
         if (rc < 0) {
             goto error;
         }

src/packet_cb.c

@@ -291,7 +291,6 @@ SSH_PACKET_CALLBACK(ssh_packet_ext_info)
     for (i = 0; i < nr_extensions; i++) {
         char *name = NULL;
         char *value = NULL;
-        int cmp;
 
         rc = ssh_buffer_unpack(packet, "ss", &name, &value);
         if (rc != SSH_OK) {
@@ -299,8 +298,7 @@ SSH_PACKET_CALLBACK(ssh_packet_ext_info)
             return SSH_PACKET_USED;
         }
 
-        cmp = strcmp(name, "server-sig-algs");
-        if (cmp == 0) {
+        if (strcmp(name, "server-sig-algs") == 0) {
             /* TODO check for NULL bytes */
             SSH_LOG(SSH_LOG_PACKET, "Extension: %s=<%s>", name, value);
 
@@ -313,6 +311,9 @@ SSH_PACKET_CALLBACK(ssh_packet_ext_info)
             if (rc == 1) {
                 session->extensions |= SSH_EXT_SIG_RSA_SHA256;
             }
+        } else if (strcmp(name, "publickey-hostbound@openssh.com") == 0) {
+            SSH_LOG(SSH_LOG_PACKET, "Extension: %s=<%s>", name, value);
+            session->extensions |= SSH_EXT_PUBLICKEY_HOSTBOUND;
         } else {
             SSH_LOG(SSH_LOG_PACKET, "Unknown extension: %s", name);
         }

src/pcap.c

@@ -126,11 +126,10 @@ ssh_pcap_file ssh_pcap_file_new(void)
 {
     struct ssh_pcap_file_struct *pcap = NULL;
 
-    pcap = malloc(sizeof(struct ssh_pcap_file_struct));
+    pcap = calloc(1, sizeof(struct ssh_pcap_file_struct));
     if (pcap == NULL) {
         return NULL;
     }
-    ZERO_STRUCTP(pcap);
 
     return pcap;
 }
@@ -296,12 +295,13 @@ void ssh_pcap_file_free(ssh_pcap_file pcap)
  */
 ssh_pcap_context ssh_pcap_context_new(ssh_session session)
 {
-    ssh_pcap_context ctx = (struct ssh_pcap_context_struct *)malloc(sizeof(struct ssh_pcap_context_struct));
+    ssh_pcap_context ctx = NULL;
+
+    ctx = calloc(1, sizeof(struct ssh_pcap_context_struct));
     if (ctx == NULL) {
         ssh_set_error_oom(session);
         return NULL;
     }
-    ZERO_STRUCTP(ctx);
     ctx->session = session;
     return ctx;
 }

src/pki_container_openssh.c

@@ -155,7 +155,7 @@ static int pki_private_key_decrypt(ssh_string blob,
     }
     rc = ssh_buffer_add_data(buffer,
                              ssh_string_data(kdfoptions),
-                             ssh_string_len(kdfoptions));
+                             (uint32_t)ssh_string_len(kdfoptions));
     if (rc != SSH_ERROR){
         rc = ssh_buffer_unpack(buffer, "Sd", &salt, &rounds);
     }
@@ -339,7 +339,7 @@ ssh_pki_openssh_import(const char *text_key,
     ssh_buffer_set_secure(privkey_buffer);
     ssh_buffer_add_data(privkey_buffer,
                         ssh_string_data(privkeys),
-                        ssh_string_len(privkeys));
+                        (uint32_t)ssh_string_len(privkeys));
 
     rc = ssh_buffer_unpack(privkey_buffer, "dd", &checkint1, &checkint2);
     if (rc == SSH_ERROR || checkint1 != checkint2) {

src/pki_ed25519.c

@@ -28,6 +28,205 @@
 #include "libssh/ed25519.h"
 #include "libssh/buffer.h"
 
+int pki_pubkey_build_ed25519(ssh_key key, ssh_string pubkey)
+{
+    if (ssh_string_len(pubkey) != ED25519_KEY_LEN) {
+        SSH_LOG(SSH_LOG_TRACE, "Invalid ed25519 key len");
+        return SSH_ERROR;
+    }
+
+    key->ed25519_pubkey = malloc(ED25519_KEY_LEN);
+    if (key->ed25519_pubkey == NULL) {
+        return SSH_ERROR;
+    }
+
+    memcpy(key->ed25519_pubkey, ssh_string_data(pubkey), ED25519_KEY_LEN);
+
+    return SSH_OK;
+}
+
+int pki_privkey_build_ed25519(ssh_key key,
+                              ssh_string pubkey,
+                              ssh_string privkey)
+{
+    if (ssh_string_len(pubkey) != ED25519_KEY_LEN ||
+        ssh_string_len(privkey) != (2 * ED25519_KEY_LEN)) {
+        SSH_LOG(SSH_LOG_TRACE, "Invalid ed25519 key len");
+        return SSH_ERROR;
+    }
+
+    /* In the internal implementation, the private key is the concatenation of
+     * the private seed with the public key. */
+    key->ed25519_privkey = malloc(2 * ED25519_KEY_LEN);
+    if (key->ed25519_privkey == NULL) {
+        goto error;
+    }
+
+    key->ed25519_pubkey = malloc(ED25519_KEY_LEN);
+    if (key->ed25519_pubkey == NULL) {
+        goto error;
+    }
+
+    memcpy(key->ed25519_privkey, ssh_string_data(privkey), 2 * ED25519_KEY_LEN);
+    memcpy(key->ed25519_pubkey, ssh_string_data(pubkey), ED25519_KEY_LEN);
+
+    return SSH_OK;
+
+error:
+    SAFE_FREE(key->ed25519_privkey);
+    SAFE_FREE(key->ed25519_pubkey);
+
+    return SSH_ERROR;
+}
+
+/**
+ * @internal
+ *
+ * @brief Compare ed25519 keys if they are equal.
+ *
+ * @param[in] k1        The first key to compare.
+ *
+ * @param[in] k2        The second key to compare.
+ *
+ * @param[in] what      What part or type of the key do you want to compare.
+ *
+ * @return              0 if equal, 1 if not.
+ */
+int
+pki_ed25519_key_cmp(const ssh_key k1, const ssh_key k2, enum ssh_keycmp_e what)
+{
+    int cmp;
+
+    switch (what) {
+    case SSH_KEY_CMP_PRIVATE:
+        if (k1->ed25519_privkey == NULL || k2->ed25519_privkey == NULL) {
+            return 1;
+        }
+        /* In the internal implementation, the private key is the concatenation
+         * of the private seed with the public key. */
+        cmp = memcmp(k1->ed25519_privkey,
+                     k2->ed25519_privkey,
+                     2 * ED25519_KEY_LEN);
+        if (cmp != 0) {
+            return 1;
+        }
+        FALL_THROUGH;
+    case SSH_KEY_CMP_PUBLIC:
+        if (k1->ed25519_pubkey == NULL || k2->ed25519_pubkey == NULL) {
+            return 1;
+        }
+        cmp = memcmp(k1->ed25519_pubkey, k2->ed25519_pubkey, ED25519_KEY_LEN);
+        if (cmp != 0) {
+            return 1;
+        }
+        break;
+    case SSH_KEY_CMP_CERTIFICATE:
+        /* handled globally */
+        return 1;
+    }
+
+    return 0;
+}
+
+/**
+ * @internal
+ *
+ * @brief Duplicate an Ed25519 key
+ *
+ * @param[out] new Pre-initialized ssh_key structure
+ *
+ * @param[in] key Key to copy
+ *
+ * @return SSH_ERROR on error, SSH_OK on success
+ */
+int pki_ed25519_key_dup(ssh_key new_key, const ssh_key key)
+{
+    if (key->ed25519_privkey == NULL && key->ed25519_pubkey == NULL) {
+        return SSH_ERROR;
+    }
+
+    if (key->ed25519_privkey != NULL) {
+        /* In the internal implementation, the private key is the concatenation
+         * of the private seed with the public key. */
+        new_key->ed25519_privkey = malloc(2 * ED25519_KEY_LEN);
+        if (new_key->ed25519_privkey == NULL) {
+            return SSH_ERROR;
+        }
+        memcpy(new_key->ed25519_privkey,
+               key->ed25519_privkey,
+               2 * ED25519_KEY_LEN);
+    }
+
+    if (key->ed25519_pubkey != NULL) {
+        new_key->ed25519_pubkey = malloc(ED25519_KEY_LEN);
+        if (new_key->ed25519_pubkey == NULL) {
+            SAFE_FREE(new_key->ed25519_privkey);
+            return SSH_ERROR;
+        }
+        memcpy(new_key->ed25519_pubkey, key->ed25519_pubkey, ED25519_KEY_LEN);
+    }
+
+    return SSH_OK;
+}
+
+/**
+ * @internal
+ *
+ * @brief Outputs an Ed25519 public key in a blob buffer.
+ *
+ * @param[out] buffer Output buffer
+ *
+ * @param[in] key Key to output
+ *
+ * @return SSH_ERROR on error, SSH_OK on success
+ */
+int pki_ed25519_public_key_to_blob(ssh_buffer buffer, ssh_key key)
+{
+    int rc;
+
+    if (key->ed25519_pubkey == NULL) {
+        return SSH_ERROR;
+    }
+
+    rc = ssh_buffer_pack(buffer,
+                         "dP",
+                         (uint32_t)ED25519_KEY_LEN,
+                         (size_t)ED25519_KEY_LEN,
+                         key->ed25519_pubkey);
+
+    return rc;
+}
+
+/** @internal
+ * @brief exports a ed25519 private key to a string blob.
+ * @param[in] privkey private key to convert
+ * @param[out] buffer buffer to write the blob in.
+ * @returns SSH_OK on success
+ */
+int pki_ed25519_private_key_to_blob(ssh_buffer buffer, const ssh_key privkey)
+{
+    int rc;
+
+    if (privkey->type != SSH_KEYTYPE_ED25519) {
+        SSH_LOG(SSH_LOG_TRACE, "Type %s not supported", privkey->type_c);
+        return SSH_ERROR;
+    }
+    if (privkey->ed25519_privkey == NULL || privkey->ed25519_pubkey == NULL) {
+        return SSH_ERROR;
+    }
+    rc = ssh_buffer_pack(buffer,
+                         "dPdPP",
+                         (uint32_t)ED25519_KEY_LEN,
+                         (size_t)ED25519_KEY_LEN,
+                         privkey->ed25519_pubkey,
+                         (uint32_t)(2 * ED25519_KEY_LEN),
+                         (size_t)ED25519_KEY_LEN,
+                         privkey->ed25519_privkey,
+                         (size_t)ED25519_KEY_LEN,
+                         privkey->ed25519_pubkey);
+    return rc;
+}
+
 int pki_key_generate_ed25519(ssh_key key)
 {
     int rc;

src/pki_ed25519_common.c

@@ -27,213 +27,6 @@
 #include "libssh/pki_priv.h"
 #include "libssh/buffer.h"
 
-int pki_privkey_build_ed25519(ssh_key key,
-                              ssh_string pubkey,
-                              ssh_string privkey)
-{
-    if (ssh_string_len(pubkey) != ED25519_KEY_LEN ||
-        ssh_string_len(privkey) != (2 * ED25519_KEY_LEN))
-    {
-        SSH_LOG(SSH_LOG_TRACE, "Invalid ed25519 key len");
-        return SSH_ERROR;
-    }
-
-#ifdef HAVE_LIBCRYPTO
-    /* In OpenSSL implementation, the private key is the original private seed,
-     * without the public key. */
-    key->ed25519_privkey = malloc(ED25519_KEY_LEN);
-#else
-    /* In the internal implementation, the private key is the concatenation of
-     * the private seed with the public key. */
-    key->ed25519_privkey = malloc(2 * ED25519_KEY_LEN);
-#endif
-    if (key->ed25519_privkey == NULL) {
-        goto error;
-    }
-
-    key->ed25519_pubkey = malloc(ED25519_KEY_LEN);
-    if (key->ed25519_pubkey == NULL) {
-        goto error;
-    }
-
-#ifdef HAVE_LIBCRYPTO
-    memcpy(key->ed25519_privkey, ssh_string_data(privkey),
-           ED25519_KEY_LEN);
-#else
-    memcpy(key->ed25519_privkey, ssh_string_data(privkey),
-           2 * ED25519_KEY_LEN);
-#endif
-    memcpy(key->ed25519_pubkey, ssh_string_data(pubkey),
-           ED25519_KEY_LEN);
-
-    return SSH_OK;
-
-error:
-    SAFE_FREE(key->ed25519_privkey);
-    SAFE_FREE(key->ed25519_pubkey);
-
-    return SSH_ERROR;
-}
-
-/**
- * @internal
- *
- * @brief Compare ed25519 keys if they are equal.
- *
- * @param[in] k1        The first key to compare.
- *
- * @param[in] k2        The second key to compare.
- *
- * @param[in] what      What part or type of the key do you want to compare.
- *
- * @return              0 if equal, 1 if not.
- */
-int pki_ed25519_key_cmp(const ssh_key k1,
-                        const ssh_key k2,
-                        enum ssh_keycmp_e what)
-{
-    int cmp;
-
-    switch(what) {
-    case SSH_KEY_CMP_PRIVATE:
-        if (k1->ed25519_privkey == NULL || k2->ed25519_privkey == NULL) {
-            return 1;
-        }
-#ifdef HAVE_LIBCRYPTO
-        /* In OpenSSL implementation, the private key is the original private
-         * seed, without the public key. */
-        cmp = memcmp(k1->ed25519_privkey, k2->ed25519_privkey, ED25519_KEY_LEN);
-#else
-        /* In the internal implementation, the private key is the concatenation
-         * of the private seed with the public key. */
-        cmp = memcmp(k1->ed25519_privkey, k2->ed25519_privkey,
-                     2 * ED25519_KEY_LEN);
-#endif
-        if (cmp != 0) {
-            return 1;
-        }
-        FALL_THROUGH;
-    case SSH_KEY_CMP_PUBLIC:
-        if (k1->ed25519_pubkey == NULL || k2->ed25519_pubkey == NULL) {
-            return 1;
-        }
-        cmp = memcmp(k1->ed25519_pubkey, k2->ed25519_pubkey, ED25519_KEY_LEN);
-        if (cmp != 0) {
-            return 1;
-        }
-        break;
-    case SSH_KEY_CMP_CERTIFICATE:
-        /* handled globally */
-        return 1;
-    }
-
-    return 0;
-}
-
-/**
- * @internal
- *
- * @brief Duplicate an Ed25519 key
- *
- * @param[out] new Pre-initialized ssh_key structure
- *
- * @param[in] key Key to copy
- *
- * @return SSH_ERROR on error, SSH_OK on success
- */
-int pki_ed25519_key_dup(ssh_key new_key, const ssh_key key)
-{
-    if (key->ed25519_privkey == NULL && key->ed25519_pubkey == NULL) {
-        return SSH_ERROR;
-    }
-
-    if (key->ed25519_privkey != NULL) {
-#ifdef HAVE_LIBCRYPTO
-        /* In OpenSSL implementation, the private key is the original private
-         * seed, without the public key. */
-        new_key->ed25519_privkey = malloc(ED25519_KEY_LEN);
-#else
-        /* In the internal implementation, the private key is the concatenation
-         * of the private seed with the public key. */
-        new_key->ed25519_privkey = malloc(2 * ED25519_KEY_LEN);
-#endif
-        if (new_key->ed25519_privkey == NULL) {
-            return SSH_ERROR;
-        }
-#ifdef HAVE_LIBCRYPTO
-        memcpy(new_key->ed25519_privkey, key->ed25519_privkey, ED25519_KEY_LEN);
-#else
-        memcpy(new_key->ed25519_privkey, key->ed25519_privkey, 2 * ED25519_KEY_LEN);
-#endif
-    }
-
-    if (key->ed25519_pubkey != NULL) {
-        new_key->ed25519_pubkey = malloc(ED25519_KEY_LEN);
-        if (new_key->ed25519_pubkey == NULL) {
-            SAFE_FREE(new_key->ed25519_privkey);
-            return SSH_ERROR;
-        }
-        memcpy(new_key->ed25519_pubkey, key->ed25519_pubkey, ED25519_KEY_LEN);
-    }
-
-    return SSH_OK;
-}
-
-/**
- * @internal
- *
- * @brief Outputs an Ed25519 public key in a blob buffer.
- *
- * @param[out] buffer Output buffer
- *
- * @param[in] key Key to output
- *
- * @return SSH_ERROR on error, SSH_OK on success
- */
-int pki_ed25519_public_key_to_blob(ssh_buffer buffer, ssh_key key)
-{
-    int rc;
-
-    if (key->ed25519_pubkey == NULL){
-        return SSH_ERROR;
-    }
-
-    rc = ssh_buffer_pack(buffer,
-                         "dP",
-                         (uint32_t)ED25519_KEY_LEN,
-                         (size_t)ED25519_KEY_LEN, key->ed25519_pubkey);
-
-    return rc;
-}
-
-/** @internal
- * @brief exports a ed25519 private key to a string blob.
- * @param[in] privkey private key to convert
- * @param[out] buffer buffer to write the blob in.
- * @returns SSH_OK on success
- */
-int pki_ed25519_private_key_to_blob(ssh_buffer buffer, const ssh_key privkey)
-{
-    int rc;
-
-    if (privkey->type != SSH_KEYTYPE_ED25519) {
-        SSH_LOG(SSH_LOG_TRACE, "Type %s not supported", privkey->type_c);
-        return SSH_ERROR;
-    }
-    if (privkey->ed25519_privkey == NULL ||
-        privkey->ed25519_pubkey == NULL) {
-        return SSH_ERROR;
-    }
-    rc = ssh_buffer_pack(buffer,
-                         "dPdPP",
-                         (uint32_t)ED25519_KEY_LEN,
-                         (size_t)ED25519_KEY_LEN, privkey->ed25519_pubkey,
-                         (uint32_t)(2 * ED25519_KEY_LEN),
-                         (size_t)ED25519_KEY_LEN, privkey->ed25519_privkey,
-                         (size_t)ED25519_KEY_LEN, privkey->ed25519_pubkey);
-    return rc;
-}
-
 /**
  * @internal
  *

src/pki_mbedcrypto.c

@@ -380,19 +380,11 @@ ssh_key pki_key_dup(const ssh_key key, int demote)
     mbedtls_mpi Q;
 #endif
 
-    new = ssh_key_new();
+    new = pki_key_dup_common_init(key, demote);
     if (new == NULL) {
         return NULL;
     }
 
-    new->type = key->type;
-    new->type_c = key->type_c;
-    if (demote) {
-        new->flags = SSH_KEY_FLAG_PUBLIC;
-    } else {
-        new->flags = key->flags;
-    }
-
 #if MBEDTLS_VERSION_MAJOR > 2
     mbedtls_mpi_init(&N);
     mbedtls_mpi_init(&E);
@@ -512,6 +504,7 @@ ssh_key pki_key_dup(const ssh_key key, int demote)
         case SSH_KEYTYPE_ECDSA_P256:
         case SSH_KEYTYPE_ECDSA_P384:
         case SSH_KEYTYPE_ECDSA_P521:
+        case SSH_KEYTYPE_SK_ECDSA:
             new->ecdsa_nid = key->ecdsa_nid;
 
             new->ecdsa = malloc(sizeof(mbedtls_ecdsa_context));
@@ -522,7 +515,8 @@ ssh_key pki_key_dup(const ssh_key key, int demote)
 
             mbedtls_ecdsa_init(new->ecdsa);
 
-            if (demote && ssh_key_is_private(key)) {
+            if ((demote && ssh_key_is_private(key)) ||
+                is_sk_key_type(key->type)) {
                 rc = mbedtls_ecp_copy(&new->ecdsa->MBEDTLS_PRIVATE(Q),
                                 &key->ecdsa->MBEDTLS_PRIVATE(Q));
                 if (rc != 0) {
@@ -540,6 +534,7 @@ ssh_key pki_key_dup(const ssh_key key, int demote)
 
             break;
         case SSH_KEYTYPE_ED25519:
+        case SSH_KEYTYPE_SK_ED25519:
             rc = pki_ed25519_key_dup(new, key);
             if (rc != SSH_OK) {
                 goto fail;
@@ -768,7 +763,8 @@ int pki_key_compare(const ssh_key k1, const ssh_key k2, enum ssh_keycmp_e what)
                 goto cleanup;
             }
 
-            if (what == SSH_KEY_CMP_PRIVATE) {
+            if (what == SSH_KEY_CMP_PRIVATE &&
+                k1->type != SSH_KEYTYPE_SK_ECDSA) {
                 if (mbedtls_mpi_cmp_mpi(&ecdsa1->MBEDTLS_PRIVATE(d),
                     &ecdsa2->MBEDTLS_PRIVATE(d)))
                 {
@@ -864,7 +860,12 @@ ssh_string pki_key_to_blob(const ssh_key key, enum ssh_key_e type)
     ssh_string type_s = NULL;
     ssh_string e = NULL;
     ssh_string n = NULL;
+    ssh_string p = NULL;
+    ssh_string q = NULL;
+    ssh_string d = NULL;
+    ssh_string iqmp = NULL;
     ssh_string str = NULL;
+    int rc;
 #if MBEDTLS_VERSION_MAJOR > 2
     mbedtls_mpi E = {0};
     mbedtls_mpi N = {0};
@@ -872,18 +873,21 @@ ssh_string pki_key_to_blob(const ssh_key key, enum ssh_key_e type)
     mbedtls_mpi IQMP = {0};
     mbedtls_mpi P = {0};
     mbedtls_mpi Q = {0};
-#endif
-    int rc;
 
-#if MBEDTLS_VERSION_MAJOR > 2
     mbedtls_mpi_init(&E);
     mbedtls_mpi_init(&N);
+    mbedtls_mpi_init(&D);
+    mbedtls_mpi_init(&IQMP);
+    mbedtls_mpi_init(&P);
+    mbedtls_mpi_init(&Q);
 #endif
 
     buffer = ssh_buffer_new();
     if (buffer == NULL) {
         return NULL;
     }
+    /* The buffer will contain sensitive information. Make sure it is erased */
+    ssh_buffer_set_secure(buffer);
 
     if (key->cert != NULL) {
         rc = ssh_buffer_add_buffer(buffer, key->cert);
@@ -909,279 +913,260 @@ ssh_string pki_key_to_blob(const ssh_key key, enum ssh_key_e type)
     }
 
     switch (key->type) {
-        case SSH_KEYTYPE_RSA: {
-            mbedtls_rsa_context *rsa;
-            if (mbedtls_pk_can_do(key->pk, MBEDTLS_PK_RSA) == 0) {
-                SSH_BUFFER_FREE(buffer);
-                return NULL;
-            }
+    case SSH_KEYTYPE_RSA: {
+        mbedtls_rsa_context *rsa = NULL;
+        mbedtls_mpi *E_ptr = NULL, *N_ptr = NULL;
 
-            rsa = mbedtls_pk_rsa(*key->pk);
-
-#if MBEDTLS_VERSION_MAJOR > 2
-            rc = mbedtls_rsa_export(rsa, &N, NULL, NULL, NULL, &E);
-            if (rc != 0) {
-                goto fail;
-            }
-
-            e = ssh_make_bignum_string(&E);
-            if (e == NULL) {
-                goto fail;
-            }
-
-            n = ssh_make_bignum_string(&N);
-            if (n == NULL) {
-                goto fail;
-            }
-#else
-            e = ssh_make_bignum_string(&rsa->E);
-            if (e == NULL) {
-                goto fail;
-            }
-
-            n = ssh_make_bignum_string(&rsa->N);
-            if (n == NULL) {
-                goto fail;
-            }
-#endif
-
-            if (type == SSH_KEY_PUBLIC) {
-                /* The N and E parts are swapped in the public key export ! */
-                rc = ssh_buffer_add_ssh_string(buffer, e);
-                if (rc < 0) {
-                    goto fail;
-                }
-
-                rc = ssh_buffer_add_ssh_string(buffer, n);
-                if (rc < 0) {
-                    goto fail;
-                }
-            } else if (type == SSH_KEY_PRIVATE) {
-                ssh_string p = NULL;
-                ssh_string q = NULL;
-                ssh_string d = NULL;
-                ssh_string iqmp = NULL;
-
-                rc = ssh_buffer_add_ssh_string(buffer, n);
-                if (rc < 0) {
-                    goto fail;
-                }
-
-                rc = ssh_buffer_add_ssh_string(buffer, e);
-                if (rc < 0) {
-                    goto fail;
-                }
-
-#if MBEDTLS_VERSION_MAJOR > 2
-                rc = mbedtls_rsa_export(rsa, NULL, &P, &Q, &D, NULL);
-                if (rc != 0) {
-                    goto fail;
-                }
-
-                p = ssh_make_bignum_string(&P);
-                if (p == NULL) {
-                    goto fail;
-                }
-
-                q = ssh_make_bignum_string(&Q);
-                if (q == NULL) {
-                    goto fail;
-                }
-
-                d = ssh_make_bignum_string(&D);
-                if (d == NULL) {
-                    goto fail;
-                }
-                rc = mbedtls_rsa_export_crt(rsa, NULL, NULL, &IQMP);
-                if (rc != 0) {
-                    goto fail;
-                }
-
-                iqmp = ssh_make_bignum_string(&IQMP);
-                if (iqmp == NULL) {
-                    goto fail;
-                }
-
-#else
-                p = ssh_make_bignum_string(&rsa->P);
-                if (p == NULL) {
-                    goto fail;
-                }
-
-                q = ssh_make_bignum_string(&rsa->Q);
-                if (q == NULL) {
-                    goto fail;
-                }
-
-                d = ssh_make_bignum_string(&rsa->D);
-                if (d == NULL) {
-                    goto fail;
-                }
-
-                iqmp = ssh_make_bignum_string(&rsa->QP);
-                if (iqmp == NULL) {
-                    goto fail;
-                }
-#endif
-
-                rc = ssh_buffer_add_ssh_string(buffer, d);
-                if (rc < 0) {
-                    goto fail;
-                }
-
-                rc = ssh_buffer_add_ssh_string(buffer, iqmp);
-                if (rc < 0) {
-                    goto fail;
-                }
-
-                rc = ssh_buffer_add_ssh_string(buffer, p);
-                if (rc < 0) {
-                    goto fail;
-                }
-
-                rc = ssh_buffer_add_ssh_string(buffer, q);
-                if (rc < 0) {
-                    goto fail;
-                }
-
-                ssh_string_burn(d);
-                SSH_STRING_FREE(d);
-                d = NULL;
-                ssh_string_burn(iqmp);
-                SSH_STRING_FREE(iqmp);
-                iqmp = NULL;
-                ssh_string_burn(p);
-                SSH_STRING_FREE(p);
-                p = NULL;
-                ssh_string_burn(q);
-                SSH_STRING_FREE(q);
-                q = NULL;
-            }
-            ssh_string_burn(e);
-            SSH_STRING_FREE(e);
-            e = NULL;
-            ssh_string_burn(n);
-            SSH_STRING_FREE(n);
-            n = NULL;
-            break;
+        if (mbedtls_pk_can_do(key->pk, MBEDTLS_PK_RSA) == 0) {
+            SSH_BUFFER_FREE(buffer);
+            return NULL;
         }
-        case SSH_KEYTYPE_ECDSA_P256:
-        case SSH_KEYTYPE_ECDSA_P384:
-        case SSH_KEYTYPE_ECDSA_P521:
-        case SSH_KEYTYPE_SK_ECDSA:
-            type_s =
-                ssh_string_from_char(pki_key_ecdsa_nid_to_char(key->ecdsa_nid));
-            if (type_s == NULL) {
-                SSH_BUFFER_FREE(buffer);
-                return NULL;
-            }
 
-            rc = ssh_buffer_add_ssh_string(buffer, type_s);
-            SSH_STRING_FREE(type_s);
+        rsa = mbedtls_pk_rsa(*key->pk);
+#if MBEDTLS_VERSION_MAJOR > 2
+        rc = mbedtls_rsa_export(rsa, &N, NULL, NULL, NULL, &E);
+        if (rc != 0) {
+            goto out;
+        }
+
+        E_ptr = &E;
+        N_ptr = &N;
+#else
+        E_ptr = &rsa->E;
+        N_ptr = &rsa->N;
+#endif
+
+        e = ssh_make_bignum_string(E_ptr);
+        if (e == NULL) {
+            goto out;
+        }
+
+        n = ssh_make_bignum_string(N_ptr);
+        if (n == NULL) {
+            goto out;
+        }
+
+        if (type == SSH_KEY_PUBLIC) {
+            /* The N and E parts are swapped in the public key export ! */
+            rc = ssh_buffer_add_ssh_string(buffer, e);
             if (rc < 0) {
-                SSH_BUFFER_FREE(buffer);
-                return NULL;
+                goto out;
             }
 
-            e = make_ecpoint_string(&key->ecdsa->MBEDTLS_PRIVATE(grp),
-                            &key->ecdsa->MBEDTLS_PRIVATE(Q));
+            rc = ssh_buffer_add_ssh_string(buffer, n);
+            if (rc < 0) {
+                goto out;
+            }
+        } else if (type == SSH_KEY_PRIVATE) {
+            mbedtls_mpi *P_ptr = NULL, *Q_ptr = NULL, *D_ptr = NULL;
+            mbedtls_mpi *IQMP_ptr = NULL;
 
-            if (e == NULL) {
-                SSH_BUFFER_FREE(buffer);
-                return NULL;
+            rc = ssh_buffer_add_ssh_string(buffer, n);
+            if (rc < 0) {
+                goto out;
             }
 
             rc = ssh_buffer_add_ssh_string(buffer, e);
             if (rc < 0) {
-                goto fail;
+                goto out;
             }
 
-            ssh_string_burn(e);
-            SSH_STRING_FREE(e);
-            e = NULL;
+#if MBEDTLS_VERSION_MAJOR > 2
+            rc = mbedtls_rsa_export(rsa, NULL, &P, &Q, &D, NULL);
+            if (rc != 0) {
+                goto out;
+            }
 
-            if (type == SSH_KEY_PRIVATE) {
-                ssh_string d = NULL;
-                d = ssh_make_bignum_string(&key->ecdsa->MBEDTLS_PRIVATE(d));
+            rc = mbedtls_rsa_export_crt(rsa, NULL, NULL, &IQMP);
+            if (rc != 0) {
+                goto out;
+            }
 
-                if (d == NULL) {
-                    SSH_BUFFER_FREE(buffer);
-                    return NULL;
-                }
+            P_ptr = &P;
+            Q_ptr = &Q;
+            D_ptr = &D;
+            IQMP_ptr = &IQMP;
+#else
+            P_ptr = &rsa->P;
+            Q_ptr = &rsa->Q;
+            D_ptr = &rsa->D;
+            IQMP_ptr = &rsa->QP;
+#endif
 
-                rc = ssh_buffer_add_ssh_string(buffer, d);
-                if (rc < 0) {
-                    goto fail;
-                }
+            p = ssh_make_bignum_string(P_ptr);
+            if (p == NULL) {
+                goto out;
+            }
 
-                ssh_string_burn(d);
-                SSH_STRING_FREE(d);
-                d = NULL;
-            } else if (key->type == SSH_KEYTYPE_SK_ECDSA) {
-                /* public key can contain certificate sk information */
+            q = ssh_make_bignum_string(Q_ptr);
+            if (q == NULL) {
+                goto out;
+            }
+
+            d = ssh_make_bignum_string(D_ptr);
+            if (d == NULL) {
+                goto out;
+            }
+
+            iqmp = ssh_make_bignum_string(IQMP_ptr);
+            if (iqmp == NULL) {
+                goto out;
+            }
+
+            rc = ssh_buffer_add_ssh_string(buffer, d);
+            if (rc < 0) {
+                goto out;
+            }
+
+            rc = ssh_buffer_add_ssh_string(buffer, iqmp);
+            if (rc < 0) {
+                goto out;
+            }
+
+            rc = ssh_buffer_add_ssh_string(buffer, p);
+            if (rc < 0) {
+                goto out;
+            }
+
+            rc = ssh_buffer_add_ssh_string(buffer, q);
+            if (rc < 0) {
+                goto out;
+            }
+        }
+        break;
+    }
+    case SSH_KEYTYPE_ECDSA_P256:
+    case SSH_KEYTYPE_ECDSA_P384:
+    case SSH_KEYTYPE_ECDSA_P521:
+    case SSH_KEYTYPE_SK_ECDSA:
+        type_s =
+            ssh_string_from_char(pki_key_ecdsa_nid_to_char(key->ecdsa_nid));
+        if (type_s == NULL) {
+            SSH_BUFFER_FREE(buffer);
+            return NULL;
+        }
+
+        rc = ssh_buffer_add_ssh_string(buffer, type_s);
+        SSH_STRING_FREE(type_s);
+        if (rc < 0) {
+            SSH_BUFFER_FREE(buffer);
+            return NULL;
+        }
+
+        e = make_ecpoint_string(&key->ecdsa->MBEDTLS_PRIVATE(grp),
+                                &key->ecdsa->MBEDTLS_PRIVATE(Q));
+
+        if (e == NULL) {
+            SSH_BUFFER_FREE(buffer);
+            return NULL;
+        }
+
+        rc = ssh_buffer_add_ssh_string(buffer, e);
+        if (rc < 0) {
+            goto out;
+        }
+
+        if (type == SSH_KEY_PRIVATE && key->type != SSH_KEYTYPE_SK_ECDSA) {
+            d = ssh_make_bignum_string(&key->ecdsa->MBEDTLS_PRIVATE(d));
+
+            if (d == NULL) {
+                SSH_BUFFER_FREE(buffer);
+                goto out;
+            }
+
+            rc = ssh_buffer_add_ssh_string(buffer, d);
+            if (rc < 0) {
+                goto out;
+            }
+        } else if (type == SSH_KEY_PRIVATE &&
+                   key->type == SSH_KEYTYPE_SK_ECDSA) {
+            rc = pki_buffer_pack_sk_priv_data(buffer, key);
+            if (rc != SSH_OK) {
+                goto out;
+            }
+        } else if (type == SSH_KEY_PUBLIC &&
+                   key->type == SSH_KEYTYPE_SK_ECDSA) {
+            /* public key can contain certificate sk information */
+            rc = ssh_buffer_add_ssh_string(buffer, key->sk_application);
+            if (rc < 0) {
+                goto out;
+            }
+        }
+        break;
+    case SSH_KEYTYPE_ED25519:
+    case SSH_KEYTYPE_SK_ED25519:
+        if (type == SSH_KEY_PUBLIC) {
+            rc = pki_ed25519_public_key_to_blob(buffer, key);
+            if (rc == SSH_ERROR) {
+                goto out;
+            }
+            /* public key can contain certificate sk information */
+            if (key->type == SSH_KEYTYPE_SK_ED25519) {
                 rc = ssh_buffer_add_ssh_string(buffer, key->sk_application);
                 if (rc < 0) {
-                    goto fail;
+                    goto out;
                 }
-
             }
-            break;
-        case SSH_KEYTYPE_ED25519:
-        case SSH_KEYTYPE_SK_ED25519:
-            if (type == SSH_KEY_PUBLIC) {
+        } else {
+            if (key->type == SSH_KEYTYPE_SK_ED25519) {
                 rc = pki_ed25519_public_key_to_blob(buffer, key);
                 if (rc == SSH_ERROR) {
-                    goto fail;
+                    goto out;
                 }
-                /* public key can contain certificate sk information */
-                if (key->type == SSH_KEYTYPE_SK_ED25519) {
-                    rc = ssh_buffer_add_ssh_string(buffer, key->sk_application);
-                    if (rc < 0) {
-                        goto fail;
-                    }
+
+                rc = pki_buffer_pack_sk_priv_data(buffer, key);
+                if (rc == SSH_ERROR) {
+                    goto out;
                 }
             } else {
                 rc = pki_ed25519_private_key_to_blob(buffer, key);
                 if (rc == SSH_ERROR) {
-                    goto fail;
+                    goto out;
                 }
             }
-            break;
-        default:
-            goto fail;
+        }
+        break;
+    default:
+        goto out;
     }
 makestring:
     str = ssh_string_new(ssh_buffer_get_len(buffer));
     if (str == NULL) {
-        goto fail;
+        goto out;
     }
 
-    rc = ssh_string_fill(str, ssh_buffer_get(buffer),
-            ssh_buffer_get_len(buffer));
+    rc = ssh_string_fill(str,
+                         ssh_buffer_get(buffer),
+                         ssh_buffer_get_len(buffer));
     if (rc < 0) {
-        goto fail;
+        ssh_string_burn(str);
+        SSH_STRING_FREE(str);
     }
 
+out:
     SSH_BUFFER_FREE(buffer);
-#if MBEDTLS_VERSION_MAJOR > 2
-    mbedtls_mpi_free(&N);
-    mbedtls_mpi_free(&E);
-#endif
-    return str;
-fail:
-    SSH_BUFFER_FREE(buffer);
-    ssh_string_burn(str);
-    SSH_STRING_FREE(str);
     ssh_string_burn(e);
     SSH_STRING_FREE(e);
     ssh_string_burn(n);
     SSH_STRING_FREE(n);
+    ssh_string_burn(d);
+    SSH_STRING_FREE(d);
+    ssh_string_burn(iqmp);
+    SSH_STRING_FREE(iqmp);
+    ssh_string_burn(p);
+    SSH_STRING_FREE(p);
+    ssh_string_burn(q);
+    SSH_STRING_FREE(q);
 #if MBEDTLS_VERSION_MAJOR > 2
     mbedtls_mpi_free(&N);
     mbedtls_mpi_free(&E);
+    mbedtls_mpi_free(&D);
+    mbedtls_mpi_free(&IQMP);
+    mbedtls_mpi_free(&P);
+    mbedtls_mpi_free(&Q);
 #endif
 
-    return NULL;
+    return str;
 }
 
 ssh_string pki_signature_to_blob(const ssh_signature sig)
@@ -1249,6 +1234,11 @@ ssh_string pki_signature_to_blob(const ssh_signature sig)
         case SSH_KEYTYPE_ED25519:
             sig_blob = pki_ed25519_signature_to_blob(sig);
             break;
+        case SSH_KEYTYPE_SK_ECDSA:
+        case SSH_KEYTYPE_SK_ED25519:
+            /* For SK keys, signature data is already in raw_sig */
+            sig_blob = ssh_string_copy(sig->raw_sig);
+            break;
         default:
             SSH_LOG(SSH_LOG_TRACE, "Unknown signature key type: %s",
                     sig->type_c);
@@ -1832,7 +1822,6 @@ int pki_privkey_build_ecdsa(ssh_key key, int nid, ssh_string e, ssh_string exp)
     mbedtls_ecp_point Q;
 
     key->ecdsa_nid = nid;
-    key->type_c = pki_key_ecdsa_nid_to_name(nid);
 
     key->ecdsa = malloc(sizeof(mbedtls_ecdsa_context));
     if (key->ecdsa == NULL) {
@@ -1900,7 +1889,6 @@ int pki_pubkey_build_ecdsa(ssh_key key, int nid, ssh_string e)
     mbedtls_ecp_point Q;
 
     key->ecdsa_nid = nid;
-    key->type_c = pki_key_ecdsa_nid_to_name(nid);
 
     key->ecdsa = malloc(sizeof(mbedtls_ecdsa_context));
     if (key->ecdsa == NULL) {

src/poll.c

@@ -61,24 +61,24 @@
  */
 
 struct ssh_poll_handle_struct {
-  ssh_poll_ctx ctx;
-  ssh_session session;
-  union {
-    socket_t fd;
-    size_t idx;
-  } x;
-  short events;
-  uint32_t lock_cnt;
-  ssh_poll_callback cb;
-  void *cb_data;
+    ssh_poll_ctx ctx;
+    ssh_session session;
+    union {
+        socket_t fd;
+        size_t idx;
+    } x;
+    short events;
+    uint32_t lock_cnt;
+    ssh_poll_callback cb;
+    void *cb_data;
 };
 
 struct ssh_poll_ctx_struct {
-  ssh_poll_handle *pollptrs;
-  ssh_pollfd_t *pollfds;
-  size_t polls_allocated;
-  size_t polls_used;
-  size_t chunk_size;
+    ssh_poll_handle *pollptrs;
+    ssh_pollfd_t *pollfds;
+    size_t polls_allocated;
+    size_t polls_used;
+    size_t chunk_size;
 };
 
 #ifdef HAVE_POLL
@@ -96,7 +96,7 @@ void ssh_poll_cleanup(void)
 
 int ssh_poll(ssh_pollfd_t *fds, nfds_t nfds, int timeout)
 {
-  return poll((struct pollfd *) fds, nfds, timeout);
+    return poll((struct pollfd *)fds, nfds, timeout);
 }
 
 #else /* HAVE_POLL */
@@ -249,14 +249,15 @@ static int bsd_poll(ssh_pollfd_t *fds, nfds_t nfds, int timeout)
         }
 #endif
 
-        // we use the readfds to get POLLHUP and POLLERR, which are provided even when not requested
-        FD_SET (fds[i].fd, &readfds);
+        // we use the readfds to get POLLHUP and POLLERR, which are provided
+        // even when not requested
+        FD_SET(fds[i].fd, &readfds);
 
         if (fds[i].events & (POLLOUT | POLLWRNORM | POLLWRBAND)) {
-            FD_SET (fds[i].fd, &writefds);
+            FD_SET(fds[i].fd, &writefds);
         }
         if (fds[i].events & (POLLPRI | POLLRDBAND)) {
-            FD_SET (fds[i].fd, &exceptfds);
+            FD_SET(fds[i].fd, &exceptfds);
         }
 
         if (fds[i].fd > max_fd) {
@@ -297,11 +298,12 @@ static int bsd_poll(ssh_pollfd_t *fds, nfds_t nfds, int timeout)
             fds[i].revents = 0;
 
             if (FD_ISSET(fds[i].fd, &readfds)) {
-                fds[i].revents = bsd_socket_compute_revents(fds[i].fd,
-                                                            fds[i].events);
+                fds[i].revents =
+                    bsd_socket_compute_revents(fds[i].fd, fds[i].events);
             }
             if (FD_ISSET(fds[i].fd, &writefds)) {
-                fds[i].revents |= fds[i].events & (POLLOUT | POLLWRNORM | POLLWRBAND);
+                fds[i].revents |=
+                    fds[i].events & (POLLOUT | POLLWRNORM | POLLWRBAND);
             }
 
             if (FD_ISSET(fds[i].fd, &exceptfds)) {
@@ -319,22 +321,26 @@ static int bsd_poll(ssh_pollfd_t *fds, nfds_t nfds, int timeout)
     return rc;
 }
 
-void ssh_poll_init(void) {
+void ssh_poll_init(void)
+{
     ssh_poll_emu = bsd_poll;
 }
 
-void ssh_poll_cleanup(void) {
+void ssh_poll_cleanup(void)
+{
     ssh_poll_emu = bsd_poll;
 }
 
-int ssh_poll(ssh_pollfd_t *fds, nfds_t nfds, int timeout) {
+int ssh_poll(ssh_pollfd_t *fds, nfds_t nfds, int timeout)
+{
     return (ssh_poll_emu)(fds, nfds, timeout);
 }
 
 #endif /* HAVE_POLL */
 
 /**
- * @brief  Allocate a new poll object, which could be used within a poll context.
+ * @brief  Allocate a new poll object, which could be used within a poll
+ * context.
  *
  * @param[in]  fd           Socket that will be polled.
  * @param[in]  events       Poll events that will be monitored for the socket.
@@ -354,7 +360,7 @@ int ssh_poll(ssh_pollfd_t *fds, nfds_t nfds, int timeout) {
 ssh_poll_handle
 ssh_poll_new(socket_t fd, short events, ssh_poll_callback cb, void *userdata)
 {
-    ssh_poll_handle p;
+    ssh_poll_handle p = NULL;
 
     p = malloc(sizeof(struct ssh_poll_handle_struct));
     if (p == NULL) {
@@ -370,7 +376,6 @@ ssh_poll_new(socket_t fd, short events, ssh_poll_callback cb, void *userdata)
     return p;
 }
 
-
 /**
  * @brief  Free a poll object.
  *
@@ -433,8 +438,8 @@ void ssh_poll_set_events(ssh_poll_handle p, short events)
 }
 
 /**
- * @brief  Set the file descriptor of a poll object. The FD will also be propagated
- *         to an associated poll context.
+ * @brief  Set the file descriptor of a poll object. The FD will also be
+ * propagated to an associated poll context.
  *
  * @param  p            Pointer to an already allocated poll object.
  * @param  fd       New file descriptor.
@@ -496,7 +501,9 @@ socket_t ssh_poll_get_fd(ssh_poll_handle p)
  * @param  userdata     Userdata to be passed to the callback function. NULL if
  *                      not needed.
  */
-void ssh_poll_set_callback(ssh_poll_handle p, ssh_poll_callback cb, void *userdata)
+void ssh_poll_set_callback(ssh_poll_handle p,
+                           ssh_poll_callback cb,
+                           void *userdata)
 {
     if (cb != NULL) {
         p->cb = cb;
@@ -542,7 +549,7 @@ ssh_poll_ctx ssh_poll_ctx_new(size_t chunk_size)
 void ssh_poll_ctx_free(ssh_poll_ctx ctx)
 {
     if (ctx->polls_allocated > 0) {
-        while (ctx->polls_used > 0){
+        while (ctx->polls_used > 0) {
             ssh_poll_handle p = ctx->pollptrs[0];
             /*
              * The free function calls ssh_poll_ctx_remove() and decrements
@@ -560,29 +567,38 @@ void ssh_poll_ctx_free(ssh_poll_ctx ctx)
 
 static int ssh_poll_ctx_resize(ssh_poll_ctx ctx, size_t new_size)
 {
-  ssh_poll_handle *pollptrs = NULL;
-  ssh_pollfd_t *pollfds = NULL;
+    ssh_poll_handle *pollptrs = NULL;
+    ssh_pollfd_t *pollfds = NULL;
 
-  pollptrs = realloc(ctx->pollptrs, sizeof(ssh_poll_handle) * new_size);
-  if (pollptrs == NULL) {
-    return -1;
-  }
-  ctx->pollptrs = pollptrs;
-
-  pollfds = realloc(ctx->pollfds, sizeof(ssh_pollfd_t) * new_size);
-  if (pollfds == NULL) {
-    pollptrs = realloc(ctx->pollptrs, sizeof(ssh_poll_handle) * ctx->polls_allocated);
+    pollptrs = realloc(ctx->pollptrs, sizeof(ssh_poll_handle) * new_size);
     if (pollptrs == NULL) {
-        return -1;
+        /* Fail, but keep the old value to be freed later */
+        return SSH_ERROR;
     }
     ctx->pollptrs = pollptrs;
-    return -1;
-  }
 
-  ctx->pollfds = pollfds;
-  ctx->polls_allocated = new_size;
+    pollfds = realloc(ctx->pollfds, sizeof(ssh_pollfd_t) * new_size);
+    if (pollfds == NULL) {
+        if (ctx->polls_allocated == 0) {
+            /* This was initial allocation -- just free what we allocated above
+             * and fail */
+            SAFE_FREE(ctx->pollptrs);
+            return SSH_ERROR;
+        }
+        /* Try to realloc the pollptrs back to the original size */
+        pollptrs = realloc(ctx->pollptrs,
+                           sizeof(ssh_poll_handle) * ctx->polls_allocated);
+        if (pollptrs == NULL) {
+            return SSH_ERROR;
+        }
+        ctx->pollptrs = pollptrs;
+        return SSH_ERROR;
+    }
 
-  return 0;
+    ctx->pollfds = pollfds;
+    ctx->polls_allocated = new_size;
+
+    return SSH_OK;
 }
 
 /**
@@ -595,27 +611,27 @@ static int ssh_poll_ctx_resize(ssh_poll_ctx ctx, size_t new_size)
  */
 int ssh_poll_ctx_add(ssh_poll_ctx ctx, ssh_poll_handle p)
 {
-  socket_t fd;
+    socket_t fd;
 
-  if (p->ctx != NULL) {
-    /* already attached to a context */
-    return -1;
-  }
+    if (p->ctx != NULL) {
+        /* already attached to a context */
+        return -1;
+    }
 
-  if (ctx->polls_used == ctx->polls_allocated &&
-      ssh_poll_ctx_resize(ctx, ctx->polls_allocated + ctx->chunk_size) < 0) {
-    return -1;
-  }
+    if (ctx->polls_used == ctx->polls_allocated &&
+        ssh_poll_ctx_resize(ctx, ctx->polls_allocated + ctx->chunk_size) < 0) {
+        return -1;
+    }
 
-  fd = p->x.fd;
-  p->x.idx = ctx->polls_used++;
-  ctx->pollptrs[p->x.idx] = p;
-  ctx->pollfds[p->x.idx].fd = fd;
-  ctx->pollfds[p->x.idx].events = p->events;
-  ctx->pollfds[p->x.idx].revents = 0;
-  p->ctx = ctx;
+    fd = p->x.fd;
+    p->x.idx = ctx->polls_used++;
+    ctx->pollptrs[p->x.idx] = p;
+    ctx->pollfds[p->x.idx].fd = fd;
+    ctx->pollfds[p->x.idx].events = p->events;
+    ctx->pollfds[p->x.idx].revents = 0;
+    p->ctx = ctx;
 
-  return 0;
+    return 0;
 }
 
 /**
@@ -626,20 +642,17 @@ int ssh_poll_ctx_add(ssh_poll_ctx ctx, ssh_poll_handle p)
  *
  * @return              0 on success, < 0 on error
  */
-int ssh_poll_ctx_add_socket (ssh_poll_ctx ctx, ssh_socket s)
+int ssh_poll_ctx_add_socket(ssh_poll_ctx ctx, ssh_socket s)
 {
     ssh_poll_handle p = NULL;
-    int ret;
 
     p = ssh_socket_get_poll_handle(s);
     if (p == NULL) {
         return -1;
     }
-    ret = ssh_poll_ctx_add(ctx,p);
-    return ret;
+    return ssh_poll_ctx_add(ctx, p);
 }
 
-
 /**
  * @brief  Remove a poll object from a poll context.
  *
@@ -648,25 +661,25 @@ int ssh_poll_ctx_add_socket (ssh_poll_ctx ctx, ssh_socket s)
  */
 void ssh_poll_ctx_remove(ssh_poll_ctx ctx, ssh_poll_handle p)
 {
-  size_t i;
+    size_t i;
 
-  i = p->x.idx;
-  p->x.fd = ctx->pollfds[i].fd;
-  p->ctx = NULL;
+    i = p->x.idx;
+    p->x.fd = ctx->pollfds[i].fd;
+    p->ctx = NULL;
 
-  ctx->polls_used--;
+    ctx->polls_used--;
 
-  /* fill the empty poll slot with the last one */
-  if (ctx->polls_used > 0 && ctx->polls_used != i) {
-    ctx->pollfds[i] = ctx->pollfds[ctx->polls_used];
-    ctx->pollptrs[i] = ctx->pollptrs[ctx->polls_used];
-    ctx->pollptrs[i]->x.idx = i;
-  }
+    /* fill the empty poll slot with the last one */
+    if (ctx->polls_used > 0 && ctx->polls_used != i) {
+        ctx->pollfds[i] = ctx->pollfds[ctx->polls_used];
+        ctx->pollptrs[i] = ctx->pollptrs[ctx->polls_used];
+        ctx->pollptrs[i]->x.idx = i;
+    }
 
-  /* this will always leave at least chunk_size polls allocated */
-  if (ctx->polls_allocated - ctx->polls_used > ctx->chunk_size) {
-    ssh_poll_ctx_resize(ctx, ctx->polls_allocated - ctx->chunk_size);
-  }
+    /* this will always leave at least chunk_size polls allocated */
+    if (ctx->polls_allocated - ctx->polls_used > ctx->chunk_size) {
+        ssh_poll_ctx_resize(ctx, ctx->polls_allocated - ctx->chunk_size);
+    }
 }
 
 /**
@@ -689,7 +702,7 @@ int ssh_poll_ctx_dopoll(ssh_poll_ctx ctx, int timeout)
 {
     int rc;
     size_t i, used;
-    ssh_poll_handle p;
+    ssh_poll_handle p = NULL;
     socket_t fd;
     int revents;
     struct ssh_timestamp ts;
@@ -744,7 +757,8 @@ int ssh_poll_ctx_dopoll(ssh_poll_ctx ctx, int timeout)
                 if (ret == -2) {
                     return -1;
                 }
-                /* the poll was removed, reload the used counter and start again */
+                /* the poll was removed, reload the used counter and start again
+                 */
                 used = ctx->polls_used;
                 i = 0;
             } else {
@@ -770,8 +784,9 @@ int ssh_poll_ctx_dopoll(ssh_poll_ctx ctx, int timeout)
  */
 ssh_poll_ctx ssh_poll_get_default_ctx(ssh_session session)
 {
-    if(session->default_poll_ctx != NULL)
+    if (session->default_poll_ctx != NULL) {
         return session->default_poll_ctx;
+    }
     /* 2 is enough for the default one */
     session->default_poll_ctx = ssh_poll_ctx_new(2);
     return session->default_poll_ctx;
@@ -781,7 +796,7 @@ ssh_poll_ctx ssh_poll_get_default_ctx(ssh_session session)
 
 struct ssh_event_fd_wrapper {
     ssh_event_callback cb;
-    void * userdata;
+    void *userdata;
 };
 
 struct ssh_event_struct {
@@ -810,14 +825,14 @@ ssh_event ssh_event_new(void)
     ZERO_STRUCTP(event);
 
     event->ctx = ssh_poll_ctx_new(2);
-    if(event->ctx == NULL) {
+    if (event->ctx == NULL) {
         free(event);
         return NULL;
     }
 
 #ifdef WITH_SERVER
     event->sessions = ssh_list_new();
-    if(event->sessions == NULL) {
+    if (event->sessions == NULL) {
         ssh_poll_ctx_free(event->ctx);
         free(event);
         return NULL;
@@ -827,9 +842,10 @@ ssh_event ssh_event_new(void)
     return event;
 }
 
-static int
-ssh_event_fd_wrapper_callback(ssh_poll_handle p, socket_t fd, int revents,
-                              void *userdata)
+static int ssh_event_fd_wrapper_callback(ssh_poll_handle p,
+                                         socket_t fd,
+                                         int revents,
+                                         void *userdata)
 {
     struct ssh_event_fd_wrapper *pw = (struct ssh_event_fd_wrapper *)userdata;
 
@@ -857,19 +873,22 @@ ssh_event_fd_wrapper_callback(ssh_poll_handle p, socket_t fd, int revents,
  * @returns SSH_OK      on success
  *          SSH_ERROR   on failure
  */
-int
-ssh_event_add_fd(ssh_event event, socket_t fd, short events,
-                 ssh_event_callback cb, void *userdata)
+int ssh_event_add_fd(ssh_event event,
+                     socket_t fd,
+                     short events,
+                     ssh_event_callback cb,
+                     void *userdata)
 {
-    ssh_poll_handle p;
+    ssh_poll_handle p = NULL;
     struct ssh_event_fd_wrapper *pw = NULL;
+    int rc;
 
-    if(event == NULL || event->ctx == NULL || cb == NULL
-                                           || fd == SSH_INVALID_SOCKET) {
+    if (event == NULL || event->ctx == NULL || cb == NULL ||
+        fd == SSH_INVALID_SOCKET) {
         return SSH_ERROR;
     }
     pw = malloc(sizeof(struct ssh_event_fd_wrapper));
-    if(pw == NULL) {
+    if (pw == NULL) {
         return SSH_ERROR;
     }
 
@@ -878,12 +897,13 @@ ssh_event_add_fd(ssh_event event, socket_t fd, short events,
 
     /* pw is freed by ssh_event_remove_fd */
     p = ssh_poll_new(fd, events, ssh_event_fd_wrapper_callback, pw);
-    if(p == NULL) {
+    if (p == NULL) {
         free(pw);
         return SSH_ERROR;
     }
 
-    if(ssh_poll_ctx_add(event->ctx, p) < 0) {
+    rc = ssh_poll_ctx_add(event->ctx, p);
+    if (rc < 0) {
         free(pw);
         ssh_poll_free(p);
         return SSH_ERROR;
@@ -915,7 +935,7 @@ int ssh_event_add_poll(ssh_event event, ssh_poll_handle p)
  */
 void ssh_event_remove_poll(ssh_event event, ssh_poll_handle p)
 {
-    ssh_poll_ctx_remove(event->ctx,p);
+    ssh_poll_ctx_remove(event->ctx, p);
 }
 
 /**
@@ -930,15 +950,16 @@ void ssh_event_remove_poll(ssh_event event, ssh_poll_handle p)
  */
 int ssh_event_add_session(ssh_event event, ssh_session session)
 {
-    ssh_poll_handle p;
+    ssh_poll_handle p = NULL;
 #ifdef WITH_SERVER
     struct ssh_iterator *iterator = NULL;
 #endif
+    int rc;
 
-    if(event == NULL || event->ctx == NULL || session == NULL) {
+    if (event == NULL || event->ctx == NULL || session == NULL) {
         return SSH_ERROR;
     }
-    if(session->default_poll_ctx == NULL) {
+    if (session->default_poll_ctx == NULL) {
         return SSH_ERROR;
     }
     while (session->default_poll_ctx->polls_used > 0) {
@@ -948,7 +969,10 @@ int ssh_event_add_session(ssh_event event, ssh_session session)
          * session->default_poll_ctx->polls_used
          */
         ssh_poll_ctx_remove(session->default_poll_ctx, p);
-        ssh_poll_ctx_add(event->ctx, p);
+        rc = ssh_poll_ctx_add(event->ctx, p);
+        if (rc != SSH_OK) {
+            return rc;
+        }
         /* associate the pollhandler with a session so we can put it back
          * at ssh_event_free()
          */
@@ -956,14 +980,14 @@ int ssh_event_add_session(ssh_event event, ssh_session session)
     }
 #ifdef WITH_SERVER
     iterator = ssh_list_get_iterator(event->sessions);
-    while(iterator != NULL) {
-        if((ssh_session)iterator->data == session) {
+    while (iterator != NULL) {
+        if ((ssh_session)iterator->data == session) {
             /* allow only one instance of this session */
             return SSH_OK;
         }
         iterator = iterator->next;
     }
-    if(ssh_list_append(event->sessions, session) == SSH_ERROR) {
+    if (ssh_list_append(event->sessions, session) == SSH_ERROR) {
         return SSH_ERROR;
     }
 #endif
@@ -1031,17 +1055,17 @@ int ssh_event_remove_fd(ssh_event event, socket_t fd)
     register size_t i, used;
     int rc = SSH_ERROR;
 
-    if(event == NULL || event->ctx == NULL) {
+    if (event == NULL || event->ctx == NULL) {
         return SSH_ERROR;
     }
 
     used = event->ctx->polls_used;
     for (i = 0; i < used; i++) {
-        if(fd == event->ctx->pollfds[i].fd) {
+        if (fd == event->ctx->pollfds[i].fd) {
             ssh_poll_handle p = event->ctx->pollptrs[i];
-            if (p->session != NULL){
-            	/* we cannot free that handle, it's owned by its session */
-            	continue;
+            if (p->session != NULL) {
+                /* we cannot free that handle, it's owned by its session */
+                continue;
             }
             if (p->cb == ssh_event_fd_wrapper_callback) {
                 struct ssh_event_fd_wrapper *pw = p->cb_data;
@@ -1075,7 +1099,7 @@ int ssh_event_remove_fd(ssh_event event, socket_t fd)
  */
 int ssh_event_remove_session(ssh_event event, ssh_session session)
 {
-    ssh_poll_handle p;
+    ssh_poll_handle p = NULL;
     register size_t i, used;
     int rc = SSH_ERROR;
 #ifdef WITH_SERVER
@@ -1096,7 +1120,10 @@ int ssh_event_remove_session(ssh_event event, ssh_session session)
              */
             ssh_poll_ctx_remove(event->ctx, p);
             p->session = NULL;
-            ssh_poll_ctx_add(session->default_poll_ctx, p);
+            rc = ssh_poll_ctx_add(session->default_poll_ctx, p);
+            if (rc != SSH_OK) {
+                return rc;
+            }
             rc = SSH_OK;
             /*
              * Restart the loop!
@@ -1104,7 +1131,6 @@ int ssh_event_remove_session(ssh_event event, ssh_session session)
              */
             used = event->ctx->polls_used;
             i = 0;
-
         }
     }
 #ifdef WITH_SERVER
@@ -1145,7 +1171,7 @@ int ssh_event_remove_connector(ssh_event event, ssh_connector connector)
 void ssh_event_free(ssh_event event)
 {
     size_t used, i;
-    ssh_poll_handle p;
+    ssh_poll_handle p = NULL;
 
     if (event == NULL) {
         return;

src/server.c

@@ -230,11 +230,13 @@ static int ssh_server_send_extensions(ssh_session session)
     }
 
     rc = ssh_buffer_pack(session->out_buffer,
-                         "bdss",
+                         "bdssss",
                          SSH2_MSG_EXT_INFO,
-                         1, /* nr. of extensions */
+                         2, /* nr. of extensions */
                          "server-sig-algs",
-                         hostkey_algorithms);
+                         hostkey_algorithms,
+                         "publickey-hostbound@openssh.com",
+                         "0");
     if (rc != SSH_OK) {
         goto error;
     }
@@ -483,8 +485,8 @@ static size_t callback_receive_banner(const void *data, size_t len, void *user)
             ssh_pcap_context_write(session->pcap_ctx,
                                    SSH_PCAP_DIR_IN,
                                    buffer,
-                                   i + 1,
-                                   i + 1);
+                                   (uint32_t)(i + 1),
+                                   (uint32_t)(i + 1));
         }
 #endif
         if (buffer[i] == '\r') {
@@ -523,6 +525,7 @@ static int ssh_server_kex_termination(void *s){
   ssh_session session = s;
   if (session->session_state != SSH_SESSION_STATE_ERROR &&
       session->session_state != SSH_SESSION_STATE_AUTHENTICATING &&
+      session->session_state != SSH_SESSION_STATE_AUTHENTICATED &&
       session->session_state != SSH_SESSION_STATE_DISCONNECTED)
     return 0;
   else

src/session.c

@@ -26,6 +26,10 @@
 #include <string.h>
 #include <stdlib.h>
 
+#ifdef _WIN32
+#include <winsock2.h>
+#endif
+
 #include "libssh/priv.h"
 #include "libssh/libssh.h"
 #include "libssh/crypto.h"
@@ -409,10 +413,10 @@ const char* ssh_get_clientbanner(ssh_session session) {
  * @return Returns the server banner string or NULL.
  */
 const char* ssh_get_serverbanner(ssh_session session) {
-	if(!session) {
-		return NULL;
-	}
-	return session->serverbanner;
+    if (!session) {
+        return NULL;
+    }
+    return session->serverbanner;
 }
 
 /**
@@ -429,28 +433,34 @@ const char* ssh_get_kex_algo(ssh_session session) {
     }
 
     switch (session->current_crypto->kex_type) {
-        case SSH_KEX_DH_GROUP1_SHA1:
-            return "diffie-hellman-group1-sha1";
-        case SSH_KEX_DH_GROUP14_SHA1:
-            return "diffie-hellman-group14-sha1";
-        case SSH_KEX_DH_GROUP14_SHA256:
-            return "diffie-hellman-group14-sha256";
-        case SSH_KEX_DH_GROUP16_SHA512:
-            return "diffie-hellman-group16-sha512";
-        case SSH_KEX_DH_GROUP18_SHA512:
-            return "diffie-hellman-group18-sha512";
-        case SSH_KEX_ECDH_SHA2_NISTP256:
-            return "ecdh-sha2-nistp256";
-        case SSH_KEX_ECDH_SHA2_NISTP384:
-            return "ecdh-sha2-nistp384";
-        case SSH_KEX_ECDH_SHA2_NISTP521:
-            return "ecdh-sha2-nistp521";
-        case SSH_KEX_CURVE25519_SHA256:
-           return "curve25519-sha256";
-        case SSH_KEX_CURVE25519_SHA256_LIBSSH_ORG:
-            return "curve25519-sha256@libssh.org";
-        default:
-            break;
+    case SSH_KEX_DH_GROUP1_SHA1:
+        return "diffie-hellman-group1-sha1";
+    case SSH_KEX_DH_GROUP14_SHA1:
+        return "diffie-hellman-group14-sha1";
+    case SSH_KEX_DH_GROUP14_SHA256:
+        return "diffie-hellman-group14-sha256";
+    case SSH_KEX_DH_GROUP16_SHA512:
+        return "diffie-hellman-group16-sha512";
+    case SSH_KEX_DH_GROUP18_SHA512:
+        return "diffie-hellman-group18-sha512";
+    case SSH_KEX_ECDH_SHA2_NISTP256:
+        return "ecdh-sha2-nistp256";
+    case SSH_KEX_ECDH_SHA2_NISTP384:
+        return "ecdh-sha2-nistp384";
+    case SSH_KEX_ECDH_SHA2_NISTP521:
+        return "ecdh-sha2-nistp521";
+    case SSH_KEX_CURVE25519_SHA256:
+        return "curve25519-sha256";
+    case SSH_KEX_CURVE25519_SHA256_LIBSSH_ORG:
+        return "curve25519-sha256@libssh.org";
+    case SSH_KEX_SNTRUP761X25519_SHA512_OPENSSH_COM:
+        return "sntrup761x25519-sha512@openssh.com";
+#ifdef WITH_GEX
+    case SSH_KEX_DH_GEX_SHA1:
+        return "diffie-hellman-group-exchange-sha1";
+    case SSH_KEX_DH_GEX_SHA256:
+        return "diffie-hellman-group-exchange-sha256";
+#endif /* WITH_GEX */
     }
 
     return NULL;
@@ -734,7 +744,10 @@ int ssh_handle_packets(ssh_session session, int timeout)
             ssh_set_error_oom(session);
             return SSH_ERROR;
         }
-        ssh_poll_ctx_add(ctx, spoll);
+        rc = ssh_poll_ctx_add(ctx, spoll);
+        if (rc != SSH_OK) {
+            return SSH_ERROR;
+        }
     }
 
     if (timeout == SSH_TIMEOUT_USER) {
@@ -936,16 +949,41 @@ int ssh_get_version(ssh_session session) {
  * @param user is a pointer to session
  */
 void ssh_socket_exception_callback(int code, int errno_code, void *user){
-    ssh_session session=(ssh_session)user;
+    ssh_session session = (ssh_session)user;
 
-    SSH_LOG(SSH_LOG_RARE,"Socket exception callback: %d (%d)",code, errno_code);
+    SSH_LOG(SSH_LOG_RARE,
+            "Socket exception callback: %d (%d)",
+            code,
+            errno_code);
     session->session_state = SSH_SESSION_STATE_ERROR;
     if (errno_code == 0 && code == SSH_SOCKET_EXCEPTION_EOF) {
         ssh_set_error(session, SSH_FATAL, "Socket error: disconnected");
+#ifdef _WIN32
+    } else if (errno_code == WSAENETDOWN) {
+        ssh_set_error(session, SSH_FATAL, "Socket error: network down");
+    } else if (errno_code == WSAENETUNREACH) {
+        ssh_set_error(session, SSH_FATAL, "Socket error: network unreachable");
+    } else if (errno_code == WSAENETRESET) {
+        ssh_set_error(session, SSH_FATAL, "Socket error: network reset");
+    } else if (errno_code == WSAECONNABORTED) {
+        ssh_set_error(session, SSH_FATAL, "Socket error: connection aborted");
+    } else if (errno_code == WSAECONNRESET) {
+        ssh_set_error(session,
+                      SSH_FATAL,
+                      "Socket error: connection reset by peer");
+    } else if (errno_code == WSAETIMEDOUT) {
+        ssh_set_error(session, SSH_FATAL, "Socket error: connection timed out");
+    } else if (errno_code == WSAECONNREFUSED) {
+        ssh_set_error(session, SSH_FATAL, "Socket error: connection refused");
+    } else if (errno_code == WSAEHOSTUNREACH) {
+        ssh_set_error(session, SSH_FATAL, "Socket error: host unreachable");
+#endif
     } else {
         char err_msg[SSH_ERRNO_MSG_MAX] = {0};
-        ssh_set_error(session, SSH_FATAL, "Socket error: %s",
-                ssh_strerror(errno_code, err_msg, SSH_ERRNO_MSG_MAX));
+        ssh_set_error(session,
+                      SSH_FATAL,
+                      "Socket error: %s",
+                      ssh_strerror(errno_code, err_msg, SSH_ERRNO_MSG_MAX));
     }
 
     session->ssh_connection_callback(session);
@@ -1232,110 +1270,108 @@ int ssh_get_publickey_hash(const ssh_key key,
     }
 
     switch (type) {
-    case SSH_PUBLICKEY_HASH_SHA1:
-        {
-            SHACTX ctx = NULL;
+    case SSH_PUBLICKEY_HASH_SHA1: {
+        SHACTX ctx = NULL;
 
-            h = calloc(1, SHA_DIGEST_LEN);
-            if (h == NULL) {
-                rc = -1;
-                goto out;
-            }
-
-            ctx = sha1_init();
-            if (ctx == NULL) {
-                free(h);
-                rc = -1;
-                goto out;
-            }
-
-            rc = sha1_update(ctx, ssh_string_data(blob), ssh_string_len(blob));
-            if (rc != SSH_OK) {
-                free(h);
-                sha1_ctx_free(ctx);
-                goto out;
-            }
-            rc = sha1_final(h, ctx);
-            if (rc != SSH_OK) {
-                free(h);
-                goto out;
-            }
-
-            *hlen = SHA_DIGEST_LEN;
+        h = calloc(1, SHA_DIGEST_LEN);
+        if (h == NULL) {
+            rc = -1;
+            goto out;
         }
-        break;
-    case SSH_PUBLICKEY_HASH_SHA256:
-        {
-            SHA256CTX ctx = NULL;
 
-            h = calloc(1, SHA256_DIGEST_LEN);
-            if (h == NULL) {
-                rc = -1;
-                goto out;
-            }
-
-            ctx = sha256_init();
-            if (ctx == NULL) {
-                free(h);
-                rc = -1;
-                goto out;
-            }
-
-            rc = sha256_update(ctx, ssh_string_data(blob), ssh_string_len(blob));
-            if (rc != SSH_OK) {
-                free(h);
-                sha256_ctx_free(ctx);
-                goto out;
-            }
-            rc = sha256_final(h, ctx);
-            if (rc != SSH_OK) {
-                free(h);
-                goto out;
-            }
-
-            *hlen = SHA256_DIGEST_LEN;
+        ctx = sha1_init();
+        if (ctx == NULL) {
+            free(h);
+            rc = -1;
+            goto out;
         }
-        break;
-    case SSH_PUBLICKEY_HASH_MD5:
-        {
-            MD5CTX ctx = NULL;
 
-            /* In FIPS mode, we cannot use MD5 */
-            if (ssh_fips_mode()) {
-                SSH_LOG(SSH_LOG_TRACE, "In FIPS mode MD5 is not allowed."
-                                       "Try using SSH_PUBLICKEY_HASH_SHA256");
-                rc = SSH_ERROR;
-                goto out;
-            }
-
-            h = calloc(1, MD5_DIGEST_LEN);
-            if (h == NULL) {
-                rc = -1;
-                goto out;
-            }
-
-            ctx = md5_init();
-            if (ctx == NULL) {
-                free(h);
-                rc = -1;
-                goto out;
-            }
-
-            rc = md5_update(ctx, ssh_string_data(blob), ssh_string_len(blob));
-            if (rc != SSH_OK) {
-                free(h);
-                md5_ctx_free(ctx);
-                goto out;
-            }
-            rc = md5_final(h, ctx);
-            if (rc != SSH_OK) {
-                free(h);
-                goto out;
-            }
-
-            *hlen = MD5_DIGEST_LEN;
+        rc = sha1_update(ctx, ssh_string_data(blob), ssh_string_len(blob));
+        if (rc != SSH_OK) {
+            free(h);
+            sha1_ctx_free(ctx);
+            goto out;
         }
+        rc = sha1_final(h, ctx);
+        if (rc != SSH_OK) {
+            free(h);
+            goto out;
+        }
+
+        *hlen = SHA_DIGEST_LEN;
         break;
+    }
+    case SSH_PUBLICKEY_HASH_SHA256: {
+        SHA256CTX ctx = NULL;
+
+        h = calloc(1, SHA256_DIGEST_LEN);
+        if (h == NULL) {
+            rc = -1;
+            goto out;
+        }
+
+        ctx = sha256_init();
+        if (ctx == NULL) {
+            free(h);
+            rc = -1;
+            goto out;
+        }
+
+        rc = sha256_update(ctx, ssh_string_data(blob), ssh_string_len(blob));
+        if (rc != SSH_OK) {
+            free(h);
+            sha256_ctx_free(ctx);
+            goto out;
+        }
+        rc = sha256_final(h, ctx);
+        if (rc != SSH_OK) {
+            free(h);
+            goto out;
+        }
+
+        *hlen = SHA256_DIGEST_LEN;
+        break;
+    }
+    case SSH_PUBLICKEY_HASH_MD5: {
+        MD5CTX ctx = NULL;
+
+        /* In FIPS mode, we cannot use MD5 */
+        if (ssh_fips_mode()) {
+            SSH_LOG(SSH_LOG_TRACE,
+                    "In FIPS mode MD5 is not allowed."
+                    "Try using SSH_PUBLICKEY_HASH_SHA256");
+            rc = SSH_ERROR;
+            goto out;
+        }
+
+        h = calloc(1, MD5_DIGEST_LEN);
+        if (h == NULL) {
+            rc = -1;
+            goto out;
+        }
+
+        ctx = md5_init();
+        if (ctx == NULL) {
+            free(h);
+            rc = -1;
+            goto out;
+        }
+
+        rc = md5_update(ctx, ssh_string_data(blob), ssh_string_len(blob));
+        if (rc != SSH_OK) {
+            free(h);
+            md5_ctx_free(ctx);
+            goto out;
+        }
+        rc = md5_final(h, ctx);
+        if (rc != SSH_OK) {
+            free(h);
+            goto out;
+        }
+
+        *hlen = MD5_DIGEST_LEN;
+        break;
+    }
     default:
         rc = -1;
         goto out;

src/sftp_aio.c

@@ -55,7 +55,7 @@ ssize_t sftp_aio_begin_read(sftp_file file, size_t len, sftp_aio *aio)
     sftp_session sftp = NULL;
     ssh_buffer buffer = NULL;
     sftp_aio aio_handle = NULL;
-    uint32_t id;
+    uint32_t id, read_len;
     int rc;
 
     if (file == NULL ||
@@ -73,10 +73,12 @@ ssize_t sftp_aio_begin_read(sftp_file file, size_t len, sftp_aio *aio)
         return SSH_ERROR;
     }
 
-    /* Apply a cap on the length a user is allowed to read */
-    if (len > sftp->limits->max_read_length) {
-        len = sftp->limits->max_read_length;
-    }
+    /* Apply a cap on the length a user is allowed to read
+     *
+     * The limits are in theory uint64, but packet contain data length in uint32
+     * so in practice, the limit will never be larger than UINT32_MAX
+     */
+    read_len = (uint32_t)MIN(sftp->limits->max_read_length, len);
 
     if (aio == NULL) {
         ssh_set_error(sftp->session, SSH_FATAL,
@@ -100,7 +102,7 @@ ssize_t sftp_aio_begin_read(sftp_file file, size_t len, sftp_aio *aio)
                          id,
                          file->handle,
                          file->offset,
-                         len);
+                         read_len);
 
     if (rc != SSH_OK) {
         ssh_set_error_oom(sftp->session);
@@ -119,7 +121,7 @@ ssize_t sftp_aio_begin_read(sftp_file file, size_t len, sftp_aio *aio)
 
     aio_handle->file = file;
     aio_handle->id = id;
-    aio_handle->len = len;
+    aio_handle->len = read_len;
 
     rc = sftp_packet_write(sftp, SSH_FXP_READ, buffer);
     SSH_BUFFER_FREE(buffer);
@@ -129,9 +131,9 @@ ssize_t sftp_aio_begin_read(sftp_file file, size_t len, sftp_aio *aio)
     }
 
     /* Assume we read len bytes from the file */
-    file->offset += len;
+    file->offset += read_len;
     *aio = aio_handle;
-    return len;
+    return read_len;
 }
 
 ssize_t sftp_aio_wait_read(sftp_aio *aio,
@@ -202,21 +204,15 @@ ssize_t sftp_aio_wait_read(sftp_aio *aio,
     }
 
     /* handle an existing request */
-    while (msg == NULL) {
-        if (file->nonblocking) {
-            if (ssh_channel_poll(sftp->channel, 0) == 0) {
-                /* we cannot block */
-                return SSH_AGAIN;
-            }
-        }
+    rc = sftp_recv_response_msg(sftp, (*aio)->id, !file->nonblocking, &msg);
+    if (rc == SSH_ERROR) {
+        SFTP_AIO_FREE(*aio);
+        return SSH_ERROR;
+    }
 
-        if (sftp_read_and_dispatch(sftp) < 0) {
-            /* something nasty has happened */
-            SFTP_AIO_FREE(*aio);
-            return SSH_ERROR;
-        }
-
-        msg = sftp_dequeue(sftp, (*aio)->id);
+    if (rc == SSH_AGAIN) {
+        /* return without freeing the (*aio) */
+        return SSH_AGAIN;
     }
 
     /*
@@ -315,7 +311,7 @@ ssize_t sftp_aio_begin_write(sftp_file file,
     sftp_session sftp = NULL;
     ssh_buffer buffer = NULL;
     sftp_aio aio_handle = NULL;
-    uint32_t id;
+    uint32_t id, write_len;
     int rc;
 
     if (file == NULL ||
@@ -341,10 +337,12 @@ ssize_t sftp_aio_begin_write(sftp_file file,
         return SSH_ERROR;
     }
 
-    /* Apply a cap on the length a user is allowed to write */
-    if (len > sftp->limits->max_write_length) {
-        len = sftp->limits->max_write_length;
-    }
+    /* Apply a cap on the length a user is allowed to write
+     *
+     * The limits are in theory uint64, but packet contain data length in uint32
+     * so in practice, the limit will never be larger than UINT32_MAX
+     */
+    write_len = (uint32_t)MIN(sftp->limits->max_write_length, len);
 
     if (aio == NULL) {
         ssh_set_error(sftp->session, SSH_FATAL,
@@ -367,8 +365,9 @@ ssize_t sftp_aio_begin_write(sftp_file file,
                          id,
                          file->handle,
                          file->offset,
-                         len, /* len of datastring */
-                         len, buf);
+                         write_len, /* len of datastring */
+                         (size_t)write_len,
+                         buf);
 
     if (rc != SSH_OK) {
         ssh_set_error_oom(sftp->session);
@@ -387,7 +386,7 @@ ssize_t sftp_aio_begin_write(sftp_file file,
 
     aio_handle->file = file;
     aio_handle->id = id;
-    aio_handle->len = len;
+    aio_handle->len = write_len;
 
     rc = sftp_packet_write(sftp, SSH_FXP_WRITE, buffer);
     SSH_BUFFER_FREE(buffer);
@@ -397,9 +396,9 @@ ssize_t sftp_aio_begin_write(sftp_file file,
     }
 
     /* Assume we wrote len bytes to the file */
-    file->offset += len;
+    file->offset += write_len;
     *aio = aio_handle;
-    return len;
+    return write_len;
 }
 
 ssize_t sftp_aio_wait_write(sftp_aio *aio)
@@ -410,6 +409,7 @@ ssize_t sftp_aio_wait_write(sftp_aio *aio)
     sftp_session sftp = NULL;
     sftp_message msg = NULL;
     sftp_status_message status = NULL;
+    int rc;
 
     /*
      * This function releases the memory of the structure
@@ -446,21 +446,15 @@ ssize_t sftp_aio_wait_write(sftp_aio *aio)
         return SSH_ERROR;
     }
 
-    while (msg == NULL) {
-        if (file->nonblocking) {
-            if (ssh_channel_poll(sftp->channel, 0) == 0) {
-                /* we cannot block */
-                return SSH_AGAIN;
-            }
-        }
+    rc = sftp_recv_response_msg(sftp, (*aio)->id, !file->nonblocking, &msg);
+    if (rc == SSH_ERROR) {
+        SFTP_AIO_FREE(*aio);
+        return SSH_ERROR;
+    }
 
-        if (sftp_read_and_dispatch(sftp) < 0) {
-            /* something nasty has happened */
-            SFTP_AIO_FREE(*aio);
-            return SSH_ERROR;
-        }
-
-        msg = sftp_dequeue(sftp, (*aio)->id);
+    if (rc == SSH_AGAIN) {
+        /* Return without freeing the (*aio) */
+        return SSH_AGAIN;
     }
 
     /*

src/sftp_common.c

@@ -418,6 +418,9 @@ static sftp_attributes sftp_parse_attr_4(sftp_session sftp,
                    (attr->extended_type = ssh_buffer_get_ssh_string(buf)) &&
                    (attr->extended_data = ssh_buffer_get_ssh_string(buf))) {
                 attr->extended_count--;
+                /* just ignore the extensions -- we can't interpret them */
+                SSH_STRING_FREE(attr->extended_type);
+                SSH_STRING_FREE(attr->extended_data);
             }
 
             if (attr->extended_count) {
@@ -859,6 +862,94 @@ int sftp_read_and_dispatch(sftp_session sftp)
     return 0;
 }
 
+int sftp_recv_response_msg(sftp_session sftp,
+                           uint32_t id,
+                           bool blocking,
+                           sftp_message *msg_ptr)
+{
+    sftp_message msg = NULL;
+    int rc;
+
+    if (sftp == NULL) {
+        return SSH_ERROR;
+    }
+
+    if (msg_ptr == NULL) {
+        ssh_set_error_invalid(sftp->session);
+        sftp_set_error(sftp, SSH_FX_FAILURE);
+        return SSH_ERROR;
+    }
+
+    SSH_LOG(SSH_LOG_PACKET,
+            "Trying to receive response of request id %" PRIu32 " in %s mode",
+            id,
+            blocking ? "blocking" : "non-blocking");
+
+    /*
+     * We deliberately check the queue first for the response before
+     * polling/blocking on the channel. The reason for this approach is
+     * explained by the following example (And a similar scenario can occur when
+     * the async sftp aio API is used, because it provides the control of which
+     * responses to receive (and in what order) to the user via the
+     * sftp_aio_wait_*() functions)
+     *
+     * Its possible that while this function is trying to receive some
+     * specific response (based on request id), other responses have already
+     * arrived (or may arrive) before that specific response on the channel. In
+     * that case, this function would collect those other responses from the
+     * channel, add them to the sftp response queue (using
+     * sftp_read_and_dipatch()) and finally provide the caller with the
+     * required specific response.
+     *
+     * Now, whenever the caller will call this function again to get one of
+     * those other responses, it won't be on the channel, instead it would be
+     * present in the queue.
+     *
+     * Assuming that no new response ever comes on the channel, if we don't
+     * check the queue first and instead:
+     * - (In non blocking mode) poll on the channel, then we'd always get 0
+     *    bytes of data and return SSH_AGAIN.
+     * - (In blocking mode) wait on the channel, then
+     *   sftp_read_and_dispatch() would block infinitely by default if the
+     *   user has not set any timeout.
+     *
+     * Hence checking the queue for the response first and if not found there,
+     * polling/blocking on the channel is advised.
+     */
+    while (msg == NULL) {
+        /*
+         * Before trying to poll/block on the channel for data, probe the queue
+         * to check whether the response is already present in it.
+         */
+        msg = sftp_dequeue(sftp, id);
+        if (msg != NULL) {
+            break;
+        }
+
+        if (!blocking) {
+            rc = ssh_channel_poll(sftp->channel, 0);
+            if (rc == SSH_ERROR) {
+                sftp_set_error(sftp, SSH_FX_FAILURE);
+                return SSH_ERROR;
+            }
+
+            if (rc == 0) {
+                /* nothing available and we cannot block */
+                return SSH_AGAIN;
+            }
+        }
+
+        rc = sftp_read_and_dispatch(sftp);
+        if (rc == -1) {
+            /* something nasty has happened */
+            return SSH_ERROR;
+        }
+    }
+
+    *msg_ptr = msg;
+    return SSH_OK;
+}
+
 sftp_status_message parse_status_msg(sftp_message msg)
 {
     sftp_status_message status = NULL;

src/sftpserver.c

@@ -787,8 +787,8 @@ stat_to_filexfer_attrib(const struct stat *z_st, struct sftp_attributes_struct *
     z_attr->permissions = z_st->st_mode;
 
     z_attr->flags |= (uint32_t)SSH_FILEXFER_ATTR_ACMODTIME;
-    z_attr->atime = z_st->st_atime;
-    z_attr->mtime = z_st->st_mtime;
+    z_attr->atime = (uint32_t)z_st->st_atime;
+    z_attr->mtime = (uint32_t)z_st->st_mtime;
 }
 
 static void
@@ -820,7 +820,7 @@ struct sftp_handle
     char *name;
 };
 
-SSH_SFTP_CALLBACK(process_unsupposed);
+SSH_SFTP_CALLBACK(process_unsupported);
 SSH_SFTP_CALLBACK(process_open);
 SSH_SFTP_CALLBACK(process_read);
 SSH_SFTP_CALLBACK(process_write);
@@ -844,9 +844,9 @@ const struct sftp_message_handler message_handlers[] = {
     {"read", NULL, SSH_FXP_READ, process_read},
     {"write", NULL, SSH_FXP_WRITE, process_write},
     {"lstat", NULL, SSH_FXP_LSTAT, process_lstat},
-    {"fstat", NULL, SSH_FXP_FSTAT, process_unsupposed},
+    {"fstat", NULL, SSH_FXP_FSTAT, process_unsupported},
     {"setstat", NULL, SSH_FXP_SETSTAT, process_setstat},
-    {"fsetstat", NULL, SSH_FXP_FSETSTAT, process_unsupposed},
+    {"fsetstat", NULL, SSH_FXP_FSETSTAT, process_unsupported},
     {"opendir", NULL, SSH_FXP_OPENDIR, process_opendir},
     {"readdir", NULL, SSH_FXP_READDIR, process_readdir},
     {"remove", NULL, SSH_FXP_REMOVE, process_remove},
@@ -854,7 +854,7 @@ const struct sftp_message_handler message_handlers[] = {
     {"rmdir", NULL, SSH_FXP_RMDIR, process_rmdir},
     {"realpath", NULL, SSH_FXP_REALPATH, process_realpath},
     {"stat", NULL, SSH_FXP_STAT, process_stat},
-    {"rename", NULL, SSH_FXP_RENAME, process_unsupposed},
+    {"rename", NULL, SSH_FXP_RENAME, process_unsupported},
     {"readlink", NULL, SSH_FXP_READLINK, process_readlink},
     {"symlink", NULL, SSH_FXP_SYMLINK, process_symlink},
     {"init", NULL, SSH_FXP_INIT, sftp_reply_version},
@@ -882,17 +882,26 @@ process_open(sftp_client_message client_msg)
     SSH_LOG(SSH_LOG_PROTOCOL, "Processing open: filename %s, mode=0%o" PRIu32,
             filename, mode);
 
-    if (((msg_flag & (uint32_t)SSH_FXF_READ) == SSH_FXF_READ) &&
-        ((msg_flag & (uint32_t)SSH_FXF_WRITE) == SSH_FXF_WRITE)) {
-        file_flag = O_RDWR; // file must exist
-        if ((msg_flag & (uint32_t)SSH_FXF_CREAT) == SSH_FXF_CREAT)
-            file_flag |= O_CREAT;
-    } else if ((msg_flag & (uint32_t)SSH_FXF_WRITE) == SSH_FXF_WRITE) {
-        file_flag = O_WRONLY;
-        if ((msg_flag & (uint32_t)SSH_FXF_APPEND) == SSH_FXF_APPEND)
+    if ((msg_flag & (uint32_t)SSH_FXF_WRITE) == SSH_FXF_WRITE) {
+        if ((msg_flag & (uint32_t)SSH_FXF_READ) == SSH_FXF_READ) {
+            /* Both read and write */
+            file_flag = O_RDWR;
+        } else {
+            /* Only write */
+            file_flag = O_WRONLY;
+        }
+
+        if ((msg_flag & (uint32_t)SSH_FXF_APPEND) == SSH_FXF_APPEND) {
             file_flag |= O_APPEND;
-        if ((msg_flag & (uint32_t)SSH_FXF_CREAT) == SSH_FXF_CREAT)
+        }
+
+        if ((msg_flag & (uint32_t)SSH_FXF_CREAT) == SSH_FXF_CREAT) {
             file_flag |= O_CREAT;
+        }
+
+        if ((msg_flag & (uint32_t)SSH_FXF_TRUNC) == SSH_FXF_TRUNC) {
+            file_flag |= O_TRUNC;
+        }
     } else if ((msg_flag & (uint32_t)SSH_FXF_READ) == SSH_FXF_READ) {
         file_flag = O_RDONLY;
     } else {
@@ -1632,7 +1641,7 @@ process_remove(sftp_client_message client_msg)
 }
 
 static int
-process_unsupposed(sftp_client_message client_msg)
+process_unsupported(sftp_client_message client_msg)
 {
     sftp_reply_status(client_msg, SSH_FX_OP_UNSUPPORTED,
                       "Operation not supported");

src/sntrup761.c

@@ -0,0 +1,522 @@
+/*
+ * sntrup761.c - SNTRUP761x25519 ECDH functions for key exchange
+ * sntrup761x25519-sha512@openssh.com - based on curve25519.c.
+ *
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2013      by Aris Adamantiadis <aris@badcode.be>
+ * Copyright (c) 2023 Simon Josefsson <simon@josefsson.org>
+ * Copyright (c) 2025 Jakub Jelen <jjelen@redhat.com>
+ *
+ * The SSH Library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, version 2.1 of the License.
+ *
+ * The SSH Library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the SSH Library; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#include "config.h"
+
+#include "libssh/sntrup761.h"
+#ifdef HAVE_SNTRUP761
+
+#include "libssh/bignum.h"
+#include "libssh/buffer.h"
+#include "libssh/crypto.h"
+#include "libssh/dh.h"
+#include "libssh/pki.h"
+#include "libssh/priv.h"
+#include "libssh/session.h"
+#include "libssh/ssh2.h"
+
+void crypto_hash_sha512(unsigned char *out,
+                        const unsigned char *in,
+                        unsigned long long inlen)
+{
+    sha512(in, inlen, out);
+}
+
+#ifndef HAVE_LIBGCRYPT
+static void crypto_random(void *ctx, size_t length, uint8_t *dst)
+{
+    int *err = ctx;
+    *err = ssh_get_random(dst, length, 1);
+}
+#endif /* HAVE_LIBGCRYPT */
+
+static SSH_PACKET_CALLBACK(ssh_packet_client_sntrup761x25519_reply);
+
+static ssh_packet_callback dh_client_callbacks[] = {
+    ssh_packet_client_sntrup761x25519_reply,
+};
+
+static struct ssh_packet_callbacks_struct ssh_sntrup761x25519_client_callbacks =
+    {
+        .start = SSH2_MSG_KEX_ECDH_REPLY,
+        .n_callbacks = 1,
+        .callbacks = dh_client_callbacks,
+        .user = NULL,
+};
+
+static int ssh_sntrup761x25519_init(ssh_session session)
+{
+    int rc;
+
+    rc = ssh_curve25519_init(session);
+    if (rc != SSH_OK) {
+        return rc;
+    }
+
+    if (!session->server) {
+#ifdef HAVE_LIBGCRYPT
+        gcry_error_t err;
+
+        err = gcry_kem_keypair(GCRY_KEM_SNTRUP761,
+                               session->next_crypto->sntrup761_client_pubkey,
+                               SNTRUP761_PUBLICKEY_SIZE,
+                               session->next_crypto->sntrup761_privkey,
+                               SNTRUP761_SECRETKEY_SIZE);
+        if (err) {
+            SSH_LOG(SSH_LOG_TRACE,
+                    "Failed to generate sntrup761 key: %s",
+                    gpg_strerror(err));
+            return SSH_ERROR;
+        }
+#else
+        sntrup761_keypair(session->next_crypto->sntrup761_client_pubkey,
+                          session->next_crypto->sntrup761_privkey,
+                          &rc,
+                          crypto_random);
+        if (rc != 1) {
+            SSH_LOG(SSH_LOG_TRACE,
+                    "Failed to generate sntrup761 key: PRNG failure");
+            return SSH_ERROR;
+        }
+#endif /* HAVE_LIBGCRYPT */
+    }
+
+    return SSH_OK;
+}
+
+/** @internal
+ * @brief Starts sntrup761x25519-sha512@openssh.com key exchange
+ */
+int ssh_client_sntrup761x25519_init(ssh_session session)
+{
+    int rc;
+
+    rc = ssh_sntrup761x25519_init(session);
+    if (rc != SSH_OK) {
+        return rc;
+    }
+
+    rc = ssh_buffer_pack(session->out_buffer,
+                         "bdPP",
+                         SSH2_MSG_KEX_ECDH_INIT,
+                         CURVE25519_PUBKEY_SIZE + SNTRUP761_PUBLICKEY_SIZE,
+                         (size_t)SNTRUP761_PUBLICKEY_SIZE,
+                         session->next_crypto->sntrup761_client_pubkey,
+                         (size_t)CURVE25519_PUBKEY_SIZE,
+                         session->next_crypto->curve25519_client_pubkey);
+    if (rc != SSH_OK) {
+        ssh_set_error_oom(session);
+        return SSH_ERROR;
+    }
+
+    /* register the packet callbacks */
+    ssh_packet_set_callbacks(session, &ssh_sntrup761x25519_client_callbacks);
+    session->dh_handshake_state = DH_STATE_INIT_SENT;
+    rc = ssh_packet_send(session);
+
+    return rc;
+}
+
+void ssh_client_sntrup761x25519_remove_callbacks(ssh_session session)
+{
+    ssh_packet_remove_callbacks(session, &ssh_sntrup761x25519_client_callbacks);
+}
+
+static int ssh_sntrup761x25519_build_k(ssh_session session)
+{
+    unsigned char ssk[SNTRUP761_SIZE + CURVE25519_PUBKEY_SIZE];
+    unsigned char *k = ssk + SNTRUP761_SIZE;
+    unsigned char hss[SHA512_DIGEST_LEN];
+    int rc;
+
+    rc = ssh_curve25519_create_k(session, k);
+    if (rc != SSH_OK) {
+        return SSH_ERROR;
+    }
+
+#ifdef DEBUG_CRYPTO
+    ssh_log_hexdump("Curve25519 shared secret", k, CURVE25519_PUBKEY_SIZE);
+#endif
+
+#ifdef HAVE_LIBGCRYPT
+    if (session->server) {
+        gcry_error_t err;
+        err = gcry_kem_encap(GCRY_KEM_SNTRUP761,
+                             session->next_crypto->sntrup761_client_pubkey,
+                             SNTRUP761_PUBLICKEY_SIZE,
+                             session->next_crypto->sntrup761_ciphertext,
+                             SNTRUP761_CIPHERTEXT_SIZE,
+                             ssk,
+                             SNTRUP761_SIZE,
+                             NULL,
+                             0);
+        if (err) {
+            SSH_LOG(SSH_LOG_TRACE,
+                    "Failed to encapsulate sntrup761 shared secret: %s",
+                    gpg_strerror(err));
+            return SSH_ERROR;
+        }
+    } else {
+        gcry_error_t err;
+        err = gcry_kem_decap(GCRY_KEM_SNTRUP761,
+                             session->next_crypto->sntrup761_privkey,
+                             SNTRUP761_SECRETKEY_SIZE,
+                             session->next_crypto->sntrup761_ciphertext,
+                             SNTRUP761_CIPHERTEXT_SIZE,
+                             ssk,
+                             SNTRUP761_SIZE,
+                             NULL,
+                             0);
+        if (err) {
+            SSH_LOG(SSH_LOG_TRACE,
+                    "Failed to decapsulate sntrup761 shared secret: %s",
+                    gpg_strerror(err));
+            return SSH_ERROR;
+        }
+    }
+#else
+    if (session->server) {
+        sntrup761_enc(session->next_crypto->sntrup761_ciphertext,
+                      ssk,
+                      session->next_crypto->sntrup761_client_pubkey,
+                      &rc,
+                      crypto_random);
+        if (rc != 1) {
+            return SSH_ERROR;
+        }
+    } else {
+        sntrup761_dec(ssk,
+                      session->next_crypto->sntrup761_ciphertext,
+                      session->next_crypto->sntrup761_privkey);
+    }
+#endif /* HAVE_LIBGCRYPT */
+
+#ifdef DEBUG_CRYPTO
+    ssh_log_hexdump("server cipher text",
+                    session->next_crypto->sntrup761_ciphertext,
+                    SNTRUP761_CIPHERTEXT_SIZE);
+    ssh_log_hexdump("kem key", ssk, SNTRUP761_SIZE);
+#endif
+
+    sha512(ssk, sizeof ssk, hss);
+
+    bignum_bin2bn(hss, sizeof hss, &session->next_crypto->shared_secret);
+    if (session->next_crypto->shared_secret == NULL) {
+        return SSH_ERROR;
+    }
+
+#ifdef DEBUG_CRYPTO
+    ssh_print_bignum("Shared secret key", session->next_crypto->shared_secret);
+#endif
+
+    return 0;
+}
+
+/** @internal
+ * @brief parses a SSH_MSG_KEX_ECDH_REPLY packet and sends back
+ * a SSH_MSG_NEWKEYS
+ */
+static SSH_PACKET_CALLBACK(ssh_packet_client_sntrup761x25519_reply)
+{
+    ssh_string q_s_string = NULL;
+    ssh_string pubkey_blob = NULL;
+    ssh_string signature = NULL;
+    int rc;
+    (void)type;
+    (void)user;
+
+    ssh_client_sntrup761x25519_remove_callbacks(session);
+
+    pubkey_blob = ssh_buffer_get_ssh_string(packet);
+    if (pubkey_blob == NULL) {
+        ssh_set_error(session, SSH_FATAL, "No public key in packet");
+        goto error;
+    }
+
+    rc = ssh_dh_import_next_pubkey_blob(session, pubkey_blob);
+    SSH_STRING_FREE(pubkey_blob);
+    if (rc != 0) {
+        ssh_set_error(session, SSH_FATAL, "Failed to import next public key");
+        goto error;
+    }
+
+    q_s_string = ssh_buffer_get_ssh_string(packet);
+    if (q_s_string == NULL) {
+        ssh_set_error(session, SSH_FATAL, "No sntrup761x25519 Q_S in packet");
+        goto error;
+    }
+    if (ssh_string_len(q_s_string) != (SNTRUP761_CIPHERTEXT_SIZE + CURVE25519_PUBKEY_SIZE)) {
+        ssh_set_error(session,
+                      SSH_FATAL,
+                      "Incorrect size for server sntrup761x25519 ciphertext+key: %d",
+                      (int)ssh_string_len(q_s_string));
+        SSH_STRING_FREE(q_s_string);
+        goto error;
+    }
+    memcpy(session->next_crypto->sntrup761_ciphertext,
+           ssh_string_data(q_s_string),
+           SNTRUP761_CIPHERTEXT_SIZE);
+    memcpy(session->next_crypto->curve25519_server_pubkey,
+           (char *)ssh_string_data(q_s_string) + SNTRUP761_CIPHERTEXT_SIZE,
+           CURVE25519_PUBKEY_SIZE);
+    SSH_STRING_FREE(q_s_string);
+
+    signature = ssh_buffer_get_ssh_string(packet);
+    if (signature == NULL) {
+        ssh_set_error(session, SSH_FATAL, "No signature in packet");
+        goto error;
+    }
+    session->next_crypto->dh_server_signature = signature;
+    signature = NULL; /* ownership changed */
+    /* TODO: verify signature now instead of waiting for NEWKEYS */
+    if (ssh_sntrup761x25519_build_k(session) < 0) {
+        ssh_set_error(session, SSH_FATAL, "Cannot build k number");
+        goto error;
+    }
+
+    /* Send the MSG_NEWKEYS */
+    if (ssh_buffer_add_u8(session->out_buffer, SSH2_MSG_NEWKEYS) < 0) {
+        goto error;
+    }
+
+    rc = ssh_packet_send(session);
+    if (rc == SSH_ERROR) {
+        goto error;
+    }
+
+    SSH_LOG(SSH_LOG_DEBUG, "SSH_MSG_NEWKEYS sent");
+    session->dh_handshake_state = DH_STATE_NEWKEYS_SENT;
+
+    return SSH_PACKET_USED;
+
+error:
+    session->session_state = SSH_SESSION_STATE_ERROR;
+    return SSH_PACKET_USED;
+}
+
+#ifdef WITH_SERVER
+
+static SSH_PACKET_CALLBACK(ssh_packet_server_sntrup761x25519_init);
+
+static ssh_packet_callback dh_server_callbacks[] = {
+    ssh_packet_server_sntrup761x25519_init,
+};
+
+static struct ssh_packet_callbacks_struct ssh_sntrup761x25519_server_callbacks =
+    {
+        .start = SSH2_MSG_KEX_ECDH_INIT,
+        .n_callbacks = 1,
+        .callbacks = dh_server_callbacks,
+        .user = NULL,
+};
+
+/** @internal
+ * @brief sets up the sntrup761x25519-sha512@openssh.com kex callbacks
+ */
+void ssh_server_sntrup761x25519_init(ssh_session session)
+{
+    /* register the packet callbacks */
+    ssh_packet_set_callbacks(session, &ssh_sntrup761x25519_server_callbacks);
+}
+
+/** @brief Parse a SSH_MSG_KEXDH_INIT packet (server) and send a
+ * SSH_MSG_KEXDH_REPLY
+ */
+static SSH_PACKET_CALLBACK(ssh_packet_server_sntrup761x25519_init)
+{
+    /* ECDH/SNTRUP761 keys */
+    ssh_string q_c_string = NULL;
+    ssh_string q_s_string = NULL;
+    ssh_string server_pubkey_blob = NULL;
+
+    /* SSH host keys (rsa, ed25519 and ecdsa) */
+    ssh_key privkey = NULL;
+    enum ssh_digest_e digest = SSH_DIGEST_AUTO;
+    ssh_string sig_blob = NULL;
+    int rc;
+    (void)type;
+    (void)user;
+
+    ssh_packet_remove_callbacks(session, &ssh_sntrup761x25519_server_callbacks);
+
+    /* Extract the client pubkey from the init packet */
+    q_c_string = ssh_buffer_get_ssh_string(packet);
+    if (q_c_string == NULL) {
+        ssh_set_error(session, SSH_FATAL, "No sntrup761x25519 Q_C in packet");
+        goto error;
+    }
+    if (ssh_string_len(q_c_string) != (SNTRUP761_PUBLICKEY_SIZE + CURVE25519_PUBKEY_SIZE)) {
+        ssh_set_error(session,
+                      SSH_FATAL,
+                      "Incorrect size for server sntrup761x25519 public key: %zu",
+                      ssh_string_len(q_c_string));
+        goto error;
+    }
+
+    memcpy(session->next_crypto->sntrup761_client_pubkey,
+           ssh_string_data(q_c_string),
+           SNTRUP761_PUBLICKEY_SIZE);
+    memcpy(session->next_crypto->curve25519_client_pubkey,
+           ((char *)ssh_string_data(q_c_string)) + SNTRUP761_PUBLICKEY_SIZE,
+           CURVE25519_PUBKEY_SIZE);
+    SSH_STRING_FREE(q_c_string);
+
+#ifdef DEBUG_CRYPTO
+    ssh_log_hexdump("client public key sntrup761",
+                    session->next_crypto->sntrup761_client_pubkey,
+                    SNTRUP761_PUBLICKEY_SIZE);
+    ssh_log_hexdump("client public key c25519",
+                    session->next_crypto->curve25519_client_pubkey,
+                    CURVE25519_PUBKEY_SIZE);
+#endif
+
+    /* Build server's key pair */
+    rc = ssh_sntrup761x25519_init(session);
+    if (rc != SSH_OK) {
+        ssh_set_error(session, SSH_FATAL, "Failed to generate sntrup761 keys");
+        goto error;
+    }
+
+    rc = ssh_buffer_add_u8(session->out_buffer, SSH2_MSG_KEX_ECDH_REPLY);
+    if (rc < 0) {
+        ssh_set_error_oom(session);
+        goto error;
+    }
+
+    /* build k and session_id */
+    rc = ssh_sntrup761x25519_build_k(session);
+    if (rc < 0) {
+        ssh_set_error(session, SSH_FATAL, "Cannot build k number");
+        goto error;
+    }
+
+    /* privkey is not allocated */
+    rc = ssh_get_key_params(session, &privkey, &digest);
+    if (rc == SSH_ERROR) {
+        goto error;
+    }
+
+    rc = ssh_make_sessionid(session);
+    if (rc != SSH_OK) {
+        ssh_set_error(session, SSH_FATAL, "Could not create a session id");
+        goto error;
+    }
+
+    rc = ssh_dh_get_next_server_publickey_blob(session, &server_pubkey_blob);
+    if (rc != 0) {
+        ssh_set_error(session, SSH_FATAL, "Could not export server public key");
+        goto error;
+    }
+
+    /* add host's public key */
+    rc = ssh_buffer_add_ssh_string(session->out_buffer, server_pubkey_blob);
+    SSH_STRING_FREE(server_pubkey_blob);
+    if (rc < 0) {
+        ssh_set_error_oom(session);
+        goto error;
+    }
+
+    /* add ecdh public key */
+    rc = ssh_buffer_add_u32(session->out_buffer,
+                            ntohl(SNTRUP761_CIPHERTEXT_SIZE
+                                  + CURVE25519_PUBKEY_SIZE));
+    if (rc < 0) {
+        ssh_set_error_oom(session);
+        goto error;
+    }
+
+    rc = ssh_buffer_add_data(session->out_buffer,
+                             session->next_crypto->sntrup761_ciphertext,
+                             SNTRUP761_CIPHERTEXT_SIZE);
+    if (rc < 0) {
+        ssh_set_error_oom(session);
+        goto error;
+    }
+
+    rc = ssh_buffer_add_data(session->out_buffer,
+                             session->next_crypto->curve25519_server_pubkey,
+                             CURVE25519_PUBKEY_SIZE);
+    if (rc < 0) {
+        ssh_set_error_oom(session);
+        goto error;
+    }
+
+#ifdef DEBUG_CRYPTO
+    ssh_log_hexdump("server public key c25519",
+                    session->next_crypto->curve25519_server_pubkey,
+                    CURVE25519_PUBKEY_SIZE);
+#endif
+
+    /* add signature blob */
+    sig_blob = ssh_srv_pki_do_sign_sessionid(session, privkey, digest);
+    if (sig_blob == NULL) {
+        ssh_set_error(session, SSH_FATAL, "Could not sign the session id");
+        goto error;
+    }
+
+    rc = ssh_buffer_add_ssh_string(session->out_buffer, sig_blob);
+    SSH_STRING_FREE(sig_blob);
+    if (rc < 0) {
+        ssh_set_error_oom(session);
+        goto error;
+    }
+
+#ifdef DEBUG_CRYPTO
+    ssh_log_hexdump("ECDH_REPLY:",
+                    ssh_buffer_get(session->out_buffer),
+                    ssh_buffer_get_len(session->out_buffer));
+#endif
+
+    SSH_LOG(SSH_LOG_DEBUG, "SSH_MSG_KEX_ECDH_REPLY sent");
+    rc = ssh_packet_send(session);
+    if (rc == SSH_ERROR) {
+        return SSH_ERROR;
+    }
+
+    /* Send the MSG_NEWKEYS */
+    rc = ssh_buffer_add_u8(session->out_buffer, SSH2_MSG_NEWKEYS);
+    if (rc < 0) {
+        goto error;
+    }
+
+    session->dh_handshake_state = DH_STATE_NEWKEYS_SENT;
+    rc = ssh_packet_send(session);
+    if (rc == SSH_ERROR) {
+        goto error;
+    }
+    SSH_LOG(SSH_LOG_DEBUG, "SSH_MSG_NEWKEYS sent");
+
+    return SSH_PACKET_USED;
+error:
+    SSH_STRING_FREE(q_c_string);
+    SSH_STRING_FREE(q_s_string);
+    ssh_buffer_reinit(session->out_buffer);
+    session->session_state = SSH_SESSION_STATE_ERROR;
+    return SSH_PACKET_USED;
+}
+
+#endif /* WITH_SERVER */
+
+#endif /* HAVE_SNTRUP761 */