pki: Use constant for minimal RSA key size in FIPS

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

.clang-format

@@ -22,8 +22,8 @@ BinPackArguments: false
 BinPackParameters: false
 AllowAllArgumentsOnNextLine: false
 AllowShortFunctionsOnASingleLine: Empty
-# TODO with Clang 19, replace the below with
-# BreakAfterReturnType: ExceptShortType
+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

@@ -3,6 +3,7 @@ variables:
   BUILD_IMAGES_PROJECT: libssh/build-images
   CENTOS8_BUILD: buildenv-c8s
   CENTOS9_BUILD: buildenv-c9s
+  CENTOS10_BUILD: buildenv-c10s
   FEDORA_BUILD: buildenv-fedora
   MINGW_BUILD: buildenv-mingw
   TUMBLEWEED_BUILD: buildenv-tumbleweed
@@ -26,13 +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
@@ -74,8 +79,6 @@ workflow:
 .fedora:
   extends: .tests
   image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$FEDORA_BUILD
-  variables:
-    CMAKE_ADDITIONAL_OPTIONS: -DWITH_PKCS11_URI=ON
 
 .tumbleweed:
   extends: .tests
@@ -107,7 +110,7 @@ review:
   image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$FEDORA_BUILD
   script:
     - ERROR=0
-      codespell --ignore-words-list=keypair,sorce,ned,nd,ue || ERROR=1;
+      codespell --ignore-words-list=keypair,sorce,ned,nd,ue,pendin || ERROR=1;
       ./.gitlab-ci/clang-format-check.sh || ERROR=1;
       ./.gitlab-ci/git-check-signoff-trailer.sh ${CI_MERGE_REQUEST_DIFF_BASE_SHA} || ERROR=1;
       ./.gitlab-ci/shellcheck.sh || ERROR=1;
@@ -122,7 +125,29 @@ review:
 ###############################################################################
 #                               CentOS builds                                 #
 ###############################################################################
-centos9s/openssl_3.0.x/x86_64:
+centos10s/openssl_3.5.x/x86_64:
+  image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$CENTOS10_BUILD
+  extends: .tests
+  variables:
+    CMAKE_ADDITIONAL_OPTIONS: -DWITH_PKCS11_URI=ON -DWITH_PKCS11_PROVIDER=ON
+  script:
+    - export OPENSSL_ENABLE_SHA1_SIGNATURES=1
+    - cmake $CMAKE_OPTIONS $CMAKE_ADDITIONAL_OPTIONS .. &&
+      make -j$(nproc) &&
+      ctest --output-on-failure
+
+centos10s/openssl_3.5.x/x86_64/fips:
+  extends: .fips
+  image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$CENTOS10_BUILD
+  variables:
+    CMAKE_ADDITIONAL_OPTIONS: -DWITH_PKCS11_URI=ON -DWITH_PKCS11_PROVIDER=ON
+  script:
+    - export OPENSSL_ENABLE_SHA1_SIGNATURES=1
+    - cmake $CMAKE_OPTIONS $CMAKE_ADDITIONAL_OPTIONS .. &&
+      make -j$(nproc) &&
+      OPENSSL_FORCE_FIPS_MODE=1 ctest --output-on-failure
+
+centos9s/openssl_3.5.x/x86_64:
   image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$CENTOS9_BUILD
   extends: .tests
   variables:
@@ -139,7 +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:
@@ -204,15 +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:
@@ -328,7 +353,7 @@ fedora/mingw64:
       -DWITH_PCAP=ON
       -DUNIT_TESTING=ON .. &&
       make -j$(nproc) &&
-      ctest --output-on-failure
+      ctest --output-on-failure -E torture_rand
 
 # Unit testing only, no client and pkd testing, because cwrap is not available
 # for MinGW
@@ -345,7 +370,7 @@ fedora/mingw32:
       -DWITH_PCAP=ON
       -DUNIT_TESTING=ON .. &&
       make -j$(nproc) &&
-      ctest --output-on-failure
+      ctest --output-on-failure -E torture_rand
 
 
 ###############################################################################
@@ -384,7 +409,7 @@ fedora/mingw32:
     paths:
       - obj-csbuild/
 
-fedora/csbuild/openssl_3.0.x:
+fedora/csbuild/openssl_3.x:
   extends: .csbuild
   script:
     - csbuild
@@ -414,6 +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                                 #
@@ -426,7 +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:
@@ -443,10 +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
@@ -459,12 +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
@@ -476,7 +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++"
@@ -486,6 +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
@@ -547,9 +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:
@@ -641,3 +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

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.12.0)
+cmake_minimum_required(VERSION 3.14.0)
 
 # Specify search path for CMake modules to be loaded by include()
 # and find_package()
@@ -9,7 +9,7 @@ list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules")
 include(DefineCMakeDefaults)
 include(DefineCompilerFlags)
 
-project(libssh VERSION 0.11.00 LANGUAGES C CXX)
+project(libssh VERSION 0.11.00 LANGUAGES C)
 
 # global needed variable
 set(APPLICATION_NAME ${PROJECT_NAME})
@@ -41,6 +41,8 @@ macro_ensure_out_of_source_build("${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)
@@ -190,12 +193,13 @@ endif (WITH_SYMBOL_VERSIONING AND ABIMAP_FOUND)
 
 # Coverage
 if (WITH_COVERAGE)
+    ENABLE_LANGUAGE(CXX)
     include(CodeCoverage)
     setup_target_for_coverage_lcov(
         NAME "coverage"
         EXECUTABLE make test
         DEPENDENCIES ssh tests)
-    set(GCOVR_ADDITIONAL_ARGS --xml-pretty --exclude-unreachable-branches --print-summary)
+    set(GCOVR_ADDITIONAL_ARGS --xml-pretty --exclude-unreachable-branches --print-summary --gcov-ignore-parse-errors)
     setup_target_for_coverage_gcovr_xml(
         NAME "coverage_xml"
         EXECUTABLE make test
@@ -248,9 +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!
 

CPackConfig.cmake

@@ -10,7 +10,7 @@ set(CPACK_PACKAGE_VERSION ${PROJECT_VERSION})
 
 # SOURCE GENERATOR
 set(CPACK_SOURCE_GENERATOR "TXZ")
-set(CPACK_SOURCE_IGNORE_FILES "~$;[.]swp$;/[.]git/;/[.]clangd/;/[.]cache/;.gitignore;/build*;/obj*;tags;cscope.*;compile_commands.json;.*\.patch")
+set(CPACK_SOURCE_IGNORE_FILES "~$;[.]swp$;/[.]bare/;/[.]git/;/[.]git;/[.]clangd/;/[.]cache/;.gitignore;/build*;/obj*;tags;cscope.*;compile_commands.json;.*\.patch")
 set(CPACK_SOURCE_PACKAGE_FILE_NAME "${CPACK_PACKAGE_NAME}-${CPACK_PACKAGE_VERSION}")
 
 ### NSIS INSTALLER

CompilerChecks.cmake

@@ -16,7 +16,6 @@ if (UNIX)
         endif()
     endif()
 
-    add_c_compiler_flag("-std=gnu99" SUPPORTED_COMPILER_FLAGS)
     add_c_compiler_flag("-Wpedantic" SUPPORTED_COMPILER_FLAGS)
     add_c_compiler_flag("-Wall" SUPPORTED_COMPILER_FLAGS)
     add_c_compiler_flag("-Wshadow" SUPPORTED_COMPILER_FLAGS)
@@ -49,6 +48,7 @@ if (UNIX)
     add_c_compiler_flag("-Werror=implicit-int" SUPPORTED_COMPILER_FLAGS)
     add_c_compiler_flag("-Wint-conversion" SUPPORTED_COMPILER_FLAGS)
     add_c_compiler_flag("-Werror=int-conversion" SUPPORTED_COMPILER_FLAGS)
+    add_c_compiler_flag("-Werror=unused-variable" SUPPORTED_COMPILER_FLAGS)
 
     check_c_compiler_flag("-Wformat" REQUIRED_FLAGS_WFORMAT)
     if (REQUIRED_FLAGS_WFORMAT)
@@ -92,9 +92,12 @@ if (UNIX)
     endif (WITH_STACK_PROTECTOR_STRONG)
 
     if (NOT WINDOWS AND NOT CYGWIN)
-        check_c_compiler_flag_ssp("-fstack-clash-protection" WITH_STACK_CLASH_PROTECTION)
-        if (WITH_STACK_CLASH_PROTECTION)
-            list(APPEND SUPPORTED_COMPILER_FLAGS "-fstack-clash-protection")
+        # apple m* chips do not support this option
+        if (NOT ${CMAKE_SYSTEM_PROCESSOR} STREQUAL arm64)
+            check_c_compiler_flag_ssp("-fstack-clash-protection" WITH_STACK_CLASH_PROTECTION)
+            if (WITH_STACK_CLASH_PROTECTION)
+                list(APPEND SUPPORTED_COMPILER_FLAGS "-fstack-clash-protection")
+            endif()
         endif()
     endif()
 

ConfigureChecks.cmake

@@ -64,6 +64,7 @@ check_include_file(arpa/inet.h HAVE_ARPA_INET_H)
 check_include_file(byteswap.h HAVE_BYTESWAP_H)
 check_include_file(glob.h HAVE_GLOB_H)
 check_include_file(valgrind/valgrind.h HAVE_VALGRIND_VALGRIND_H)
+check_include_file(ifaddrs.h HAVE_IFADDRS_H)
 
 if (WIN32)
   check_include_file(io.h HAVE_IO_H)
@@ -103,6 +104,11 @@ if (OPENSSL_FOUND)
     check_function_exists(RAND_priv_bytes HAVE_OPENSSL_RAND_PRIV_BYTES)
     check_function_exists(EVP_chacha20 HAVE_OPENSSL_EVP_CHACHA20)
 
+    # Check for ML-KEM768 availability (OpenSSL 3.5+)
+    if (OPENSSL_VERSION VERSION_GREATER_EQUAL "3.5.0")
+        set(HAVE_MLKEM 1)
+    endif ()
+
     unset(CMAKE_REQUIRED_INCLUDES)
     unset(CMAKE_REQUIRED_LIBRARIES)
 endif()
@@ -225,6 +231,7 @@ 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)
 
@@ -235,6 +242,13 @@ 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/AddCMockaTest.cmake

@@ -117,6 +117,7 @@ function(ADD_CMOCKA_TEST _TARGET_NAME)
         ${TARGET_SYSTEM_EMULATOR} ${_TARGET_NAME}
     )
     if (WITH_COVERAGE)
+        ENABLE_LANGUAGE(CXX)
         include(CodeCoverage)
         append_coverage_compiler_flags_to_target(${_TARGET_NAME})
     endif (WITH_COVERAGE)

cmake/Modules/FindGCrypt.cmake

@@ -39,6 +39,15 @@ find_path(GCRYPT_INCLUDE_DIR
         include
 )
 
+find_path(GCRYPT_ERROR_INCLUDE_DIR
+    NAMES
+        gpg-error.h
+    HINTS
+        ${_GCRYPT_ROOT_HINTS_AND_PATHS}
+    PATH_SUFFIXES
+        include
+)
+
 find_library(GCRYPT_LIBRARY
     NAMES
         gcrypt
@@ -56,8 +65,10 @@ find_library(GCRYPT_ERROR_LIBRARY
         libgpg-error6-0
     HINTS
         ${_GCRYPT_ROOT_HINTS_AND_PATHS}
+    PATH_SUFFIXES
+        lib        
 )
-set(GCRYPT_LIBRARIES ${GCRYPT_LIBRARY}  ${GCRYPT_ERROR_LIBRARY})
+set(GCRYPT_LIBRARIES ${GCRYPT_ERROR_LIBRARY} ${GCRYPT_LIBRARY})
 
 if (GCRYPT_INCLUDE_DIR)
     file(STRINGS "${GCRYPT_INCLUDE_DIR}/gcrypt.h" _gcrypt_version_str REGEX "^#define GCRYPT_VERSION \"[0-9]+\\.[0-9]+\\.[0-9]")
@@ -83,5 +94,25 @@ else (GCRYPT_VERSION)
         GCRYPT_LIBRARIES)
 endif (GCRYPT_VERSION)
 
-# show the GCRYPT_INCLUDE_DIRS and GCRYPT_LIBRARIES variables only in the advanced view
-mark_as_advanced(GCRYPT_INCLUDE_DIR GCRYPT_LIBRARIES)
+# show the GCRYPT_INCLUDE_DIRS, GCRYPT_LIBRARIES and GCRYPT_ERROR_INCLUDE_DIR variables only in the advanced view
+mark_as_advanced(GCRYPT_INCLUDE_DIR GCRYPT_ERROR_INCLUDE_DIR GCRYPT_LIBRARIES)
+
+if(GCRYPT_FOUND)
+  if(NOT TARGET libgcrypt::libgcrypt)
+      add_library(libgcrypt::libgcrypt UNKNOWN IMPORTED)
+      set_target_properties(libgcrypt::libgcrypt PROPERTIES
+                            INTERFACE_INCLUDE_DIRECTORIES "${GCRYPT_INCLUDE_DIR}"
+                            INTERFACE_LINK_LIBRARIES libgcrypt::libgcrypt
+                            IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+                            IMPORTED_LOCATION "${GCRYPT_LIBRARY}")
+  endif()
+  
+  if(NOT TARGET libgpg-error::libgpg-error)
+      add_library(libgpg-error::libgpg-error UNKNOWN IMPORTED)
+      set_target_properties(libgpg-error::libgpg-error PROPERTIES
+                            INTERFACE_INCLUDE_DIRECTORIES "${GCRYPT_ERROR_INCLUDE_DIR}"
+                            INTERFACE_LINK_LIBRARIES libgpg-error::libgpg-error
+                            IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+                            IMPORTED_LOCATION "${GCRYPT_ERROR_LIBRARY}")
+  endif()
+endif()

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)
@@ -110,3 +112,32 @@ endif (MBEDTLS_VERSION)
 
 # show the MBEDTLS_INCLUDE_DIRS and MBEDTLS_LIBRARIES variables only in the advanced view
 mark_as_advanced(MBEDTLS_INCLUDE_DIR MBEDTLS_LIBRARIES)
+
+if(MBEDTLS_FOUND)
+  if(NOT TARGET MbedTLS::mbedcrypto)
+      add_library(MbedTLS::mbedcrypto UNKNOWN IMPORTED)
+      set_target_properties(MbedTLS::mbedcrypto PROPERTIES
+                            INTERFACE_INCLUDE_DIRECTORIES "${MBEDTLS_INCLUDE_DIR}"
+                            INTERFACE_LINK_LIBRARIES MbedTLS::mbedcrypto
+                            IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+                            IMPORTED_LOCATION "${MBEDTLS_CRYPTO_LIBRARY}")
+  endif()
+
+  if(NOT TARGET MbedTLS::mbedx509)
+      add_library(MbedTLS::mbedx509 UNKNOWN IMPORTED)
+      set_target_properties(MbedTLS::mbedx509 PROPERTIES
+                            INTERFACE_INCLUDE_DIRECTORIES "${MBEDTLS_INCLUDE_DIR}"
+                            INTERFACE_LINK_LIBRARIES MbedTLS::mbedx509
+                            IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+                            IMPORTED_LOCATION "${MBEDTLS_X509_LIBRARY}")
+  endif()
+
+  if(NOT TARGET MbedTLS::mbedtls)
+      add_library(MbedTLS::mbedtls UNKNOWN IMPORTED)
+      set_target_properties(MbedTLS::mbedtls PROPERTIES
+                            INTERFACE_INCLUDE_DIRECTORIES "${MBEDTLS_INCLUDE_DIR}"
+                            INTERFACE_LINK_LIBRARIES MbedTLS::mbedtls
+                            IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+                            IMPORTED_LOCATION "${MBEDTLS_LIBRARY}")
+  endif()
+endif()

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 *************************/
@@ -58,6 +60,9 @@
 /* Define to 1 if you have the <stdint.h> header file. */
 #cmakedefine HAVE_STDINT_H 1
 
+/* Define to 1 if you have the <ifaddrs.h> header file. */
+#cmakedefine HAVE_IFADDRS_H 1
+
 /* Define to 1 if you have the <openssl/aes.h> header file. */
 #cmakedefine HAVE_OPENSSL_AES_H 1
 
@@ -82,6 +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
 
@@ -94,6 +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. */
@@ -180,6 +191,9 @@
 /* Define to 1 if we have support for blowfish */
 #cmakedefine HAVE_BLOWFISH 1
 
+/* Define to 1 if we have support for ML-KEM */
+#cmakedefine HAVE_MLKEM 1
+
 /*************************** LIBRARIES ***************************/
 
 /* Define to 1 if you have the `crypto' library (-lcrypto). */

doc/authentication.dox

@@ -105,7 +105,7 @@ Here is a small example of password authentication:
 @code
 int authenticate_password(ssh_session session)
 {
-  char *password;
+  char *password = NULL;
   int rc;
 
   password = getpass("Enter your password: ");
@@ -218,7 +218,7 @@ int authenticate_kbdint(ssh_session session)
   rc = ssh_userauth_kbdint(session, NULL, NULL);
   while (rc == SSH_AUTH_INFO)
   {
-    const char *name, *instruction;
+    const char *name = NULL, *instruction = NULL;
     int nprompts, iprompt;
 
     name = ssh_userauth_kbdint_getname(session);
@@ -231,7 +231,7 @@ int authenticate_kbdint(ssh_session session)
       printf("%s\n", instruction);
     for (iprompt = 0; iprompt < nprompts; iprompt++)
     {
-      const char *prompt;
+      const char *prompt = NULL;
       char echo;
 
       prompt = ssh_userauth_kbdint_getprompt(session, iprompt, &echo);
@@ -251,7 +251,7 @@ int authenticate_kbdint(ssh_session session)
       }
       else
       {
-        char *ptr;
+        char *ptr = NULL;
 
         ptr = getpass(prompt);
         if (ssh_userauth_kbdint_setanswer(session, iprompt, ptr) < 0)
@@ -354,7 +354,7 @@ The following example shows how to retrieve and dispose the issue banner:
 int display_banner(ssh_session session)
 {
   int rc;
-  char *banner;
+  char *banner = NULL;
 
 /*
  *** Does not work without calling ssh_userauth_none() first ***

doc/command.dox

@@ -22,7 +22,7 @@ a SSH session that uses this channel:
 @code
 int show_remote_files(ssh_session session)
 {
-  ssh_channel channel;
+  ssh_channel channel = NULL;
   int rc;
 
   channel = ssh_channel_new(session);
@@ -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/forwarding.dox

@@ -100,7 +100,7 @@ used to retrieve google's home page from the remote SSH server.
 @code
 int direct_forwarding(ssh_session session)
 {
-  ssh_channel forwarding_channel;
+  ssh_channel forwarding_channel = NULL;
   int rc = SSH_ERROR;
   char *http_get = "GET / HTTP/1.1\nHost: www.google.com\n\n";
   int nbytes, nwritten;
@@ -161,7 +161,7 @@ local libssh application, which handles them:
 int web_server(ssh_session session)
 {
   int rc;
-  ssh_channel channel;
+  ssh_channel channel = NULL;
   char buffer[256];
   int nbytes, nwritten;
   int port = 0;

doc/guided_tour.dox

@@ -79,7 +79,7 @@ Here is a small example of how to use it:
 
 int main()
 {
-  ssh_session my_ssh_session;
+  ssh_session my_ssh_session = NULL;
   int verbosity = SSH_LOG_PROTOCOL;
   int port = 22;
 
@@ -126,7 +126,7 @@ Here's an example:
 
 int main()
 {
-  ssh_session my_ssh_session;
+  ssh_session my_ssh_session = NULL;
   int rc;
 
   my_ssh_session = ssh_new();
@@ -190,8 +190,8 @@ int verify_knownhost(ssh_session session)
     ssh_key srv_pubkey = NULL;
     size_t hlen;
     char buf[10];
-    char *hexa;
-    char *p;
+    char *hexa = NULL;
+    char *p = NULL;
     int cmp;
     int rc;
 
@@ -317,9 +317,9 @@ The example below shows an authentication with password:
 
 int main()
 {
-  ssh_session my_ssh_session;
+  ssh_session my_ssh_session = NULL;
   int rc;
-  char *password;
+  char *password = NULL;
 
   // Open session and set options
   my_ssh_session = ssh_new();
@@ -380,7 +380,7 @@ The example below shows how to execute a remote command:
 @code
 int show_remote_processes(ssh_session session)
 {
-  ssh_channel channel;
+  ssh_channel channel = NULL;
   int rc;
   char buffer[256];
   int nbytes;

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, sntrup761x25519-sha512@openssh.com, mlkem768x25519-sha256, 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/pkcs11.dox

@@ -81,10 +81,6 @@ We recommend the users to provide a specific PKCS #11 URI so that it matches onl
 If the engine discovers multiple slots that could potentially contain the private keys referenced
 by the provided PKCS #11 URI, the engine will not try to authenticate.
 
-For testing, the SoftHSM PKCS#11 library is used. But it has some issues with
-OpenSSL initialization/cleanup when used with OpenSSL 3.0 so we are using it
-indirectly through a p11-kit remoting as described in the following article:
-
-https://p11-glue.github.io/p11-glue/p11-kit/manual/remoting.html
+For testing, the SoftHSM PKCS#11 library is used.
 
 */

doc/shell.dox

@@ -26,7 +26,7 @@ The code sample below achieves these tasks:
 @code
 int shell_session(ssh_session session)
 {
-  ssh_channel channel;
+  ssh_channel channel = NULL;
   int rc;
 
   channel = ssh_channel_new(session);

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/CMakeLists.txt

@@ -30,9 +30,11 @@ if (UNIX AND NOT WIN32)
         target_compile_options(samplesftp PRIVATE ${DEFAULT_C_COMPILE_FLAGS})
         target_link_libraries(samplesftp ssh::ssh)
 
-        add_executable(sample_sftpserver sample_sftpserver.c ${examples_SRCS})
-        target_compile_options(sample_sftpserver PRIVATE ${DEFAULT_C_COMPILE_FLAGS})
-        target_link_libraries(sample_sftpserver ssh::ssh ${ARGP_LIBRARIES})
+        if (WITH_SERVER)
+            add_executable(sample_sftpserver sample_sftpserver.c ${examples_SRCS})
+            target_compile_options(sample_sftpserver PRIVATE ${DEFAULT_C_COMPILE_FLAGS})
+            target_link_libraries(sample_sftpserver ssh::ssh ${ARGP_LIBRARIES})
+        endif (WITH_SERVER)
     endif (WITH_SFTP)
 
     add_executable(ssh-client ssh_client.c ${examples_SRCS})

examples/authentication.c

@@ -30,8 +30,8 @@ int authenticate_kbdint(ssh_session session, const char *password)
 
     err = ssh_userauth_kbdint(session, NULL, NULL);
     while (err == SSH_AUTH_INFO) {
-        const char *instruction;
-        const char *name;
+        const char *instruction = NULL;
+        const char *name = NULL;
         char buffer[128];
         int i, n;
 
@@ -48,8 +48,8 @@ int authenticate_kbdint(ssh_session session, const char *password)
         }
 
         for (i = 0; i < n; i++) {
-            const char *answer;
-            const char *prompt;
+            const char *answer = NULL;
+            const char *prompt = NULL;
             char echo;
 
             prompt = ssh_userauth_kbdint_getprompt(session, i, &echo);
@@ -58,7 +58,7 @@ int authenticate_kbdint(ssh_session session, const char *password)
             }
 
             if (echo) {
-                char *p;
+                char *p = NULL;
 
                 printf("%s", prompt);
 
@@ -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;
@@ -143,11 +142,11 @@ int authenticate_console(ssh_session session)
     int rc;
     int method;
     char password[128] = {0};
-    char *banner;
+    char *banner = NULL;
 
     // 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 +21,57 @@ 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;
-  int auth=0;
+ssh_session connect_ssh(const char *host, const char *port, 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 (port != NULL) {
+        if (ssh_options_set(session, SSH_OPTIONS_PORT_STR, port) < 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

@@ -16,11 +16,11 @@ 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);
 int verify_knownhost(ssh_session session);
-ssh_session connect_ssh(const char *hostname, const char *user, int verbosity);
+ssh_session connect_ssh(const char *hostname, const char *port, const char *user, int verbosity);
 
 #endif /* EXAMPLES_COMMON_H_ */

examples/exec.c

@@ -5,13 +5,13 @@
 #include "examples_common.h"
 
 int main(void) {
-    ssh_session session;
-    ssh_channel channel;
+    ssh_session session = NULL;
+    ssh_channel channel = NULL;
     char buffer[256];
     int rbytes, wbytes, total = 0;
     int rc;
 
-    session = connect_ssh("localhost", NULL, 0);
+    session = connect_ssh("localhost", NULL, NULL, 0);
     if (session == NULL) {
         ssh_finalize();
         return 1;

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/knownhosts.c

@@ -38,7 +38,7 @@ int verify_knownhost(ssh_session session)
     char buf[10];
     unsigned char *hash = NULL;
     size_t hlen;
-    ssh_key srv_pubkey;
+    ssh_key srv_pubkey = NULL;
     int rc;
 
     rc = ssh_get_server_publickey(session, &srv_pubkey);

examples/libssh_scp.c

@@ -26,10 +26,11 @@ program.
 #define BUF_SIZE 16384
 #endif
 
-static char **sources;
+static char **sources = NULL;
 static int nsources;
-static char *destination;
+static char *destination = NULL;
 static int verbosity = 0;
+static char *port = NULL;
 
 struct location {
     int is_ssh;
@@ -49,9 +50,10 @@ enum {
 static void usage(const char *argv0) {
     fprintf(stderr, "Usage : %s [options] [[user@]host1:]file1 ... \n"
             "                               [[user@]host2:]destination\n"
-            "sample scp client - libssh-%s\n",
-            //      "Options :\n",
-            //      "  -r : use RSA to verify host public key\n",
+            "sample scp client - libssh-%s\n"
+            "Options :\n"
+            "  -P : use port to connect to remote host\n"
+            "  -v : increase verbosity of libssh. Can be used multiple times\n",
             argv0,
             ssh_version(0));
     exit(0);
@@ -60,11 +62,14 @@ static void usage(const char *argv0) {
 static int opts(int argc, char **argv) {
     int i;
 
-    while((i = getopt(argc, argv, "v")) != -1) {
+    while((i = getopt(argc, argv, "P:v")) != -1) {
         switch(i) {
         case 'v':
             verbosity++;
             break;
+        case 'P':
+            port = optarg;
+            break;
         default:
             fprintf(stderr, "unknown option %c\n", optopt);
             usage(argv[0]);
@@ -114,9 +119,14 @@ static void location_free(struct location *loc)
     }
 }
 
-static struct location *parse_location(char *loc) {
-    struct location *location;
-    char *ptr;
+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) {
@@ -178,7 +188,7 @@ static void close_location(struct location *loc) {
 
 static int open_location(struct location *loc, int flag) {
     if (loc->is_ssh && flag == WRITE) {
-        loc->session = connect_ssh(loc->host, loc->user, verbosity);
+        loc->session = connect_ssh(loc->host, port, loc->user, verbosity);
         if (!loc->session) {
             fprintf(stderr, "Couldn't connect to %s\n", loc->host);
             return -1;
@@ -204,7 +214,7 @@ static int open_location(struct location *loc, int flag) {
         }
         return 0;
     } else if (loc->is_ssh && flag == READ) {
-        loc->session = connect_ssh(loc->host, loc->user, verbosity);
+        loc->session = connect_ssh(loc->host, port, loc->user, verbosity);
         if (!loc->session) {
             fprintf(stderr, "Couldn't connect to %s\n", loc->host);
             return -1;

examples/proxy.c

@@ -35,8 +35,8 @@ clients must be made or how a client should react.
 static int authenticated=0;
 static int tries = 0;
 static int error = 0;
-static ssh_channel chan=NULL;
-static char *username;
+static ssh_channel chan = NULL;
+static char *username = NULL;
 static ssh_gssapi_creds client_creds = NULL;
 
 static int auth_password(ssh_session session, const char *user,
@@ -204,11 +204,12 @@ static error_t parse_opt (int key, char *arg, struct argp_state *state) {
 static struct argp argp = {options, parse_opt, args_doc, doc, NULL, NULL, NULL};
 #endif /* HAVE_ARGP_H */
 
-int main(int argc, char **argv){
-    ssh_session session;
-    ssh_bind sshbind;
-    ssh_event mainloop;
-    ssh_session client_session;
+int main(int argc, char **argv)
+{
+    ssh_session session = NULL;
+    ssh_bind sshbind = NULL;
+    ssh_event mainloop = NULL;
+    ssh_session client_session = NULL;
 
     struct ssh_server_callbacks_struct cb = {
         .userdata = NULL,
@@ -219,7 +220,7 @@ int main(int argc, char **argv){
 
     char buf[BUF_SIZE];
     char host[128]="";
-    char *ptr;
+    char *ptr = NULL;
     int i,r, rc;
 
     sshbind=ssh_bind_new();
@@ -336,4 +337,3 @@ int main(int argc, char **argv){
     ssh_finalize();
     return 0;
 }
-

examples/sample_sftpserver.c

@@ -148,6 +148,7 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state)
     ssh_bind sshbind = state->input;
     static int no_default_keys = 0;
     static int rsa_already_set = 0, ecdsa_already_set = 0;
+    static int verbosity = 0;
 
     switch (key)
     {
@@ -176,8 +177,10 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state)
         strncpy(authorizedkeys, arg, DEF_STR_SIZE - 1);
         break;
     case 'v':
-        ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_LOG_VERBOSITY_STR,
-                             "3");
+        verbosity++;
+        ssh_bind_options_set(sshbind,
+                             SSH_BIND_OPTIONS_LOG_VERBOSITY,
+                             &verbosity);
         break;
     case ARGP_KEY_ARG:
         if (state->arg_num >= 1)
@@ -213,10 +216,7 @@ static struct argp argp = {options, parse_opt, args_doc, doc, NULL, NULL, NULL};
 #endif /* HAVE_ARGP_H */
 
 /* A userdata struct for channel. */
-struct channel_data_struct
-{
-    /* Event which is used to poll the above descriptors. */
-    ssh_event event;
+struct channel_data_struct {
     sftp_session sftp;
 };
 
@@ -378,18 +378,11 @@ static void handle_session(ssh_event event, ssh_session session)
     do {
         /* Poll the main event which takes care of the session, the channel and
          * even our child process's stdout/stderr (once it's started). */
-        if (ssh_event_dopoll(event, -1) == SSH_ERROR) {
+        if (ssh_event_dopoll(event, 100) == SSH_ERROR) {
             ssh_channel_close(sdata.channel);
         }
-
-        /* If child process's stdout/stderr has been registered with the event,
-         * or the child process hasn't started yet, continue. */
-        if (cdata.event != NULL) {
-            continue;
-        }
-        /* FIXME The server keeps hanging in the poll above when the client
-         * closes the channel */
-    } while (ssh_channel_is_open(sdata.channel));
+    } while (ssh_channel_is_open(sdata.channel) &&
+             !ssh_channel_is_eof(sdata.channel));
 
     ssh_channel_send_eof(sdata.channel);
     ssh_channel_close(sdata.channel);

examples/samplesshd-cb.c

@@ -244,10 +244,11 @@ static error_t parse_opt (int key, char *arg, struct argp_state *state) {
 static struct argp argp = {options, parse_opt, args_doc, doc, NULL, NULL, NULL};
 #endif /* HAVE_ARGP_H */
 
-int main(int argc, char **argv){
-    ssh_session session;
-    ssh_bind sshbind;
-    ssh_event mainloop;
+int main(int argc, char **argv)
+{
+    ssh_session session = NULL;
+    ssh_bind sshbind = NULL;
+    ssh_event mainloop = NULL;
     struct ssh_server_callbacks_struct cb = {
         .userdata = NULL,
         .auth_none_function = auth_none,
@@ -339,4 +340,3 @@ int main(int argc, char **argv){
     ssh_finalize();
     return 0;
 }
-

examples/samplesshd-kbdint.c

@@ -174,8 +174,8 @@ static error_t parse_opt (int key, char *arg, struct argp_state *state) {
 static struct argp argp = {options, parse_opt, args_doc, doc, NULL, NULL, NULL};
 #endif /* HAVE_ARGP_H */
 
-static const char *name;
-static const char *instruction;
+static const char *name = NULL;
+static const char *instruction = NULL;
 static const char *prompts[2];
 static char echo[] = { 1, 0 };
 
@@ -279,11 +279,12 @@ static int authenticate(ssh_session session) {
     return 0;
 }
 
-int main(int argc, char **argv){
-    ssh_session session;
-    ssh_bind sshbind;
-    ssh_message message;
-    ssh_channel chan=0;
+int main(int argc, char **argv)
+{
+    ssh_session session = NULL;
+    ssh_bind sshbind = NULL;
+    ssh_message message = NULL;
+    ssh_channel chan = NULL;
     char buf[BUF_SIZE];
     int auth=0;
     int shell=0;
@@ -411,4 +412,3 @@ int main(int argc, char **argv){
     ssh_finalize();
     return 0;
 }
-

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;
-  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;
-  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, 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;
-  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, 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_X11_client.c

@@ -70,6 +70,7 @@
 
 #include <errno.h>
 #include <fcntl.h>
+#include <inttypes.h>
 #include <poll.h>
 #include <pthread.h>
 #include <stddef.h>
@@ -231,7 +232,7 @@ static void _logging_callback(int priority, const char *function,
 
     milliseconds = _current_timestamp();
 
-    fprintf(fp, "[%s.%jd, %d] %s: %s\n", buf, milliseconds, priority,
+    fprintf(fp, "[%s.%" PRId64 ", %d] %s: %s\n", buf, milliseconds, priority,
             function, buffer);
     fclose(fp);
 }

examples/ssh_client.c

@@ -39,8 +39,6 @@
 
 #include <libssh/callbacks.h>
 #include <libssh/libssh.h>
-#include <libssh/sftp.h>
-
 
 #include "examples_common.h"
 #define MAXCMD 10
@@ -53,7 +51,7 @@ static struct termios terminal;
 
 static char *pcap_file = NULL;
 
-static char *proxycommand;
+static char *proxycommand = NULL;
 
 static int auth_callback(const char *prompt,
                          char *buf,
@@ -112,8 +110,8 @@ static int opts(int argc, char **argv)
 {
     int i;
 
-    while((i = getopt(argc,argv,"T:P:F:")) != -1) {
-        switch(i){
+    while ((i = getopt(argc, argv, "T:P:F:")) != -1) {
+        switch (i) {
         case 'P':
             pcap_file = optarg;
             break;
@@ -159,16 +157,14 @@ static void cfmakeraw(struct termios *termios_p)
 
 static void do_cleanup(int i)
 {
-  /* unused variable */
-  (void) i;
+    (void)i;
 
-  tcsetattr(0, TCSANOW, &terminal);
+    tcsetattr(0, TCSANOW, &terminal);
 }
 
 static void do_exit(int i)
 {
-    /* unused variable */
-    (void) i;
+    (void)i;
 
     do_cleanup(0);
     exit(0);
@@ -179,7 +175,7 @@ static int signal_delayed = 0;
 #ifdef SIGWINCH
 static void sigwindowchanged(int i)
 {
-    (void) i;
+    (void)i;
     signal_delayed = 1;
 }
 #endif
@@ -213,18 +209,18 @@ static void select_loop(ssh_session session,ssh_channel channel)
     /* stdin */
     connector_in = ssh_connector_new(session);
     ssh_connector_set_out_channel(connector_in, channel, SSH_CONNECTOR_STDINOUT);
-    ssh_connector_set_in_fd(connector_in, 0);
+    ssh_connector_set_in_fd(connector_in, STDIN_FILENO);
     ssh_event_add_connector(event, connector_in);
 
     /* stdout */
     connector_out = ssh_connector_new(session);
-    ssh_connector_set_out_fd(connector_out, 1);
+    ssh_connector_set_out_fd(connector_out, STDOUT_FILENO);
     ssh_connector_set_in_channel(connector_out, channel, SSH_CONNECTOR_STDINOUT);
     ssh_event_add_connector(event, connector_out);
 
     /* stderr */
     connector_err = ssh_connector_new(session);
-    ssh_connector_set_out_fd(connector_err, 2);
+    ssh_connector_set_out_fd(connector_err, STDERR_FILENO);
     ssh_connector_set_in_channel(connector_err, channel, SSH_CONNECTOR_STDERR);
     ssh_event_add_connector(event, connector_err);
 
@@ -251,9 +247,9 @@ static void select_loop(ssh_session session,ssh_channel channel)
 
 static void shell(ssh_session session)
 {
-    ssh_channel channel;
+    ssh_channel channel = NULL;
     struct termios terminal_local;
-    int interactive=isatty(0);
+    int interactive = isatty(0);
 
     channel = ssh_channel_new(session);
     if (channel == NULL) {
@@ -339,7 +335,7 @@ static void batch_shell(ssh_session session)
 static int client(ssh_session session)
 {
     int auth = 0;
-    char *banner;
+    char *banner = NULL;
     int state;
 
     if (user) {
@@ -423,7 +419,7 @@ static void cleanup_pcap(void)
 
 int main(int argc, char **argv)
 {
-    ssh_session session;
+    ssh_session session = NULL;
 
     ssh_init();
     session = ssh_new();

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/sshd_direct-tcpip.c

@@ -361,7 +361,7 @@ my_fd_data_function(UNUSED_PARAM(socket_t fd),
 {
     struct event_fd_data_struct *event_fd_data = (struct event_fd_data_struct *)userdata;
     ssh_channel channel = event_fd_data->channel;
-    ssh_session session;
+    ssh_session session = NULL;
     int len, i, wr;
     char buf[BUF_SIZE];
     int blocking;
@@ -455,8 +455,8 @@ open_tcp_socket(ssh_message msg)
 {
     struct sockaddr_in sin;
     int forwardsock = -1;
-    struct hostent *host;
-    const char *dest_hostname;
+    struct hostent *host = NULL;
+    const char *dest_hostname = NULL;
     int dest_port;
 
     forwardsock = socket(AF_INET, SOCK_STREAM, 0);
@@ -499,8 +499,8 @@ message_callback(UNUSED_PARAM(ssh_session session),
                  UNUSED_PARAM(void *userdata))
 {
     ssh_channel channel;
-    int socket_fd, *pFd;
-    struct ssh_channel_callbacks_struct *cb_chan;
+    int socket_fd, *pFd = NULL;
+    struct ssh_channel_callbacks_struct *cb_chan = NULL;
     struct event_fd_data_struct *event_fd_data;
 
     _ssh_log(SSH_LOG_PACKET, "=== message_callback", "Message type: %d",
@@ -655,8 +655,8 @@ static struct argp argp = {options, parse_opt, args_doc, doc, NULL, NULL, NULL};
 int
 main(int argc, char **argv)
 {
-    ssh_session session;
-    ssh_bind sshbind;
+    ssh_session session = NULL;
+    ssh_bind sshbind = NULL;
     struct ssh_server_callbacks_struct cb = {
         .userdata = NULL,
         .auth_password_function = auth_password,

examples/sshnetcat.c

@@ -39,223 +39,237 @@ clients must be made or how a client should react.
 #define BUF_SIZE 4096
 #endif
 
-char *host;
-const char *desthost="localhost";
-const char *port="22";
+char *host = NULL;
+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;
-  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){
-    ssh_session session;
+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/bind_config.h

@@ -52,6 +52,7 @@ enum ssh_bind_config_opcode_e {
     BIND_CFG_MATCH,
     BIND_CFG_PUBKEY_ACCEPTED_KEY_TYPES,
     BIND_CFG_HOSTKEY_ALGORITHMS,
+    BIND_CFG_REQUIRED_RSA_SIZE,
 
     BIND_CFG_MAX /* Keep this one last in the list */
 };

include/libssh/buffer.h

@@ -74,6 +74,8 @@ ssh_string ssh_buffer_get_ssh_string(ssh_buffer buffer);
 uint32_t ssh_buffer_pass_bytes_end(ssh_buffer buffer, uint32_t len);
 uint32_t ssh_buffer_pass_bytes(ssh_buffer buffer, uint32_t len);
 
+ssh_buffer ssh_buffer_dup(const ssh_buffer buffer);
+
 #ifdef __cplusplus
 }
 #endif

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/config.h

@@ -66,6 +66,7 @@ enum ssh_config_opcode_e {
     SOC_CONTROLMASTER,
     SOC_CONTROLPATH,
     SOC_CERTIFICATE,
+    SOC_REQUIRED_RSA_SIZE,
 
     SOC_MAX /* Keep this one last in the list */
 };

include/libssh/crypto.h

@@ -45,10 +45,14 @@
 #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"
+#ifdef HAVE_MLKEM
+#include "libssh/mlkem768.h"
+#endif
 
 #define DIGEST_MAX_LEN 64
 
@@ -56,32 +60,40 @@
 #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,
+    /* sntrup761x25519-sha512 */
+    SSH_KEX_SNTRUP761X25519_SHA512,
+#ifdef HAVE_MLKEM
+    /* mlkem768x25519-sha256 */
+    SSH_KEX_MLKEM768X25519_SHA256,
+#endif /* HAVE_MLKEM */
 };
 
 enum ssh_cipher_e {
@@ -125,9 +137,25 @@ 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_MLKEM
+    ssh_mlkem768_privkey mlkem768_client_privkey;
+    ssh_mlkem768_pubkey mlkem768_client_pubkey;
+    ssh_mlkem768_ciphertext mlkem768_ciphertext;
+#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 +251,8 @@ 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);
 
 #ifdef __cplusplus
 }

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

@@ -1,7 +1,7 @@
 /*
  * This file is part of the SSH Library
  *
- * Copyright (c) 2003-2024 by Aris Adamantiadis and the libssh team
+ * Copyright (c) 2003-2025 by Aris Adamantiadis and the libssh team
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -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;
@@ -843,6 +844,7 @@ LIBSSH_API int ssh_string_fill(ssh_string str, const void *data, size_t len);
     do { if ((x) != NULL) { ssh_string_free(x); x = NULL; } } while(0)
 LIBSSH_API void ssh_string_free(ssh_string str);
 LIBSSH_API ssh_string ssh_string_from_char(const char *what);
+LIBSSH_API ssh_string ssh_string_from_data(const void *data, size_t len);
 LIBSSH_API size_t ssh_string_len(ssh_string str);
 LIBSSH_API ssh_string ssh_string_new(size_t size);
 LIBSSH_API const char *ssh_string_get_char(ssh_string str);
@@ -850,6 +852,7 @@ 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 +877,7 @@ 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 +890,27 @@ 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/mlkem768.h

@@ -0,0 +1,63 @@
+/*
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2025 by Red Hat, Inc.
+ *
+ * Author: Sahana Prasad <sahana@redhat.com>
+ * Author: Claude (Anthropic)
+ *
+ * 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; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * 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 MLKEM768_H_
+#define MLKEM768_H_
+
+#include "config.h"
+
+/* ML-KEM768 key and ciphertext sizes as defined in FIPS 203 */
+#define MLKEM768_PUBLICKEY_SIZE   1184
+#define MLKEM768_SECRETKEY_SIZE   2400
+#define MLKEM768_CIPHERTEXT_SIZE  1088
+#define MLKEM768_SHARED_SECRET_SIZE 32
+
+/* Hybrid ML-KEM768x25519 combined sizes */
+#define MLKEM768X25519_CLIENT_PUBKEY_SIZE \
+    (MLKEM768_PUBLICKEY_SIZE + CURVE25519_PUBKEY_SIZE)
+#define MLKEM768X25519_SERVER_RESPONSE_SIZE \
+    (MLKEM768_CIPHERTEXT_SIZE + CURVE25519_PUBKEY_SIZE)
+#define MLKEM768X25519_SHARED_SECRET_SIZE \
+    (MLKEM768_SHARED_SECRET_SIZE + CURVE25519_PUBKEY_SIZE)
+
+typedef unsigned char ssh_mlkem768_pubkey[MLKEM768_PUBLICKEY_SIZE];
+typedef unsigned char ssh_mlkem768_privkey[MLKEM768_SECRETKEY_SIZE];
+typedef unsigned char ssh_mlkem768_ciphertext[MLKEM768_CIPHERTEXT_SIZE];
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* ML-KEM768x25519 key exchange functions */
+int ssh_client_mlkem768x25519_init(ssh_session session);
+void ssh_client_mlkem768x25519_remove_callbacks(ssh_session session);
+
+#ifdef WITH_SERVER
+void ssh_server_mlkem768x25519_init(ssh_session session);
+#endif /* WITH_SERVER */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* MLKEM768_H_ */

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/packet.h

@@ -58,6 +58,7 @@ extern "C" {
 SSH_PACKET_CALLBACK(ssh_packet_unimplemented);
 SSH_PACKET_CALLBACK(ssh_packet_disconnect_callback);
 SSH_PACKET_CALLBACK(ssh_packet_ignore_callback);
+SSH_PACKET_CALLBACK(ssh_packet_debug_callback);
 SSH_PACKET_CALLBACK(ssh_packet_dh_reply);
 SSH_PACKET_CALLBACK(ssh_packet_newkeys);
 SSH_PACKET_CALLBACK(ssh_packet_service_accept);

include/libssh/pki.h

@@ -46,11 +46,24 @@
 #define MAX_PUBKEY_SIZE 0x100000 /* 1M */
 #define MAX_PRIVKEY_SIZE 0x400000 /* 4M */
 
+#define RSA_MIN_KEY_SIZE      1024
+#define RSA_MIN_FIPS_KEY_SIZE 2048
+#define RSA_DEFAULT_KEY_SIZE  3072
+
 #define SSH_KEY_FLAG_EMPTY   0x0
 #define SSH_KEY_FLAG_PUBLIC  0x0001
 #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 +76,12 @@ 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 +90,11 @@ 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 +146,11 @@ 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 +164,16 @@ 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);
+int pki_sk_signature_buffer_prepare(const ssh_key key,
+                                    const ssh_signature sig,
+                                    const unsigned char *input,
+                                    size_t input_len,
+                                    ssh_buffer *sk_buffer_out);
+
 #ifdef __cplusplus
 }
 #endif

include/libssh/poll.h

@@ -157,6 +157,7 @@ void ssh_poll_ctx_free(ssh_poll_ctx ctx);
 int ssh_poll_ctx_add(ssh_poll_ctx ctx, ssh_poll_handle p);
 int ssh_poll_ctx_add_socket (ssh_poll_ctx ctx, struct ssh_socket_struct *s);
 void ssh_poll_ctx_remove(ssh_poll_ctx ctx, ssh_poll_handle p);
+bool ssh_poll_is_locked(ssh_poll_handle p);
 int ssh_poll_ctx_dopoll(ssh_poll_ctx ctx, int timeout);
 ssh_poll_ctx ssh_poll_get_default_ctx(ssh_session session);
 int ssh_event_add_poll(ssh_event event, ssh_poll_handle p);

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
@@ -384,6 +399,7 @@ void explicit_bzero(void *s, size_t n);
  */
 #define discard_const_p(type, ptr) ((type *)discard_const(ptr))
 
+#ifndef __VA_NARG__
 /**
  * Get the argument count of variadic arguments
  */
@@ -415,6 +431,7 @@ void explicit_bzero(void *s, size_t n);
         29, 28, 27, 26, 25, 24, 23, 22, 21, 20, \
         19, 18, 17, 16, 15, 14, 13, 12, 11, 10, \
          9,  8,  7,  6,  5,  4,  3,  2,  1,  0
+#endif
 
 #define CLOSE_SOCKET(s) do { if ((s) != SSH_INVALID_SOCKET) { _XCLOSESOCKET(s); (s) = SSH_INVALID_SOCKET;} } while(0)
 

include/libssh/session.h

@@ -89,6 +89,9 @@ enum ssh_pending_call_e {
 #define SSH_SESSION_FLAG_KEX_STRICT 0x0010
 /* Unexpected packets have been sent while the session was still unencrypted */
 #define SSH_SESSION_FLAG_KEX_TAINTED 0x0020
+/* The scp on server can not handle quoted paths. Skip the mitigation for
+ * CVE-2019-14889 when using scp */
+#define SSH_SESSION_FLAG_SCP_QUOTING_BROKEN 0x0040
 
 /* codes to use with ssh_handle_packets*() */
 /* Infinite timeout */
@@ -120,6 +123,8 @@ 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/sftpserver.h

@@ -29,6 +29,10 @@ extern "C" {
 #endif
 
 #include <stdint.h>
+
+#include "libssh/libssh.h"
+#include "libssh/sftp.h"
+
 /**
  * @defgroup libssh_sftp_server The libssh SFTP server API
  *

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/ssh2.h

@@ -16,8 +16,8 @@
 #define SSH2_MSG_KEXDH_REPLY 31
 #define SSH2_MSG_KEX_ECDH_INIT 30
 #define SSH2_MSG_KEX_ECDH_REPLY 31
-#define SSH2_MSG_ECMQV_INIT 30
-#define SSH2_MSG_ECMQV_REPLY 31
+#define SSH2_MSG_KEX_HYBRID_INIT 30
+#define SSH2_MSG_KEX_HYBRID_REPLY 31
 
 #define SSH2_MSG_KEX_DH_GEX_REQUEST_OLD 30
 #define SSH2_MSG_KEX_DH_GEX_GROUP 31

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/CMakeLists.txt

@@ -1,6 +1,7 @@
 set(LIBSSH_PUBLIC_INCLUDE_DIRS ${libssh_SOURCE_DIR}/include)
 
 set(LIBSSH_PRIVATE_INCLUDE_DIRS
+  ${libssh_BINARY_DIR}/include
   ${libssh_BINARY_DIR}
 )
 
@@ -12,27 +13,13 @@ if (TARGET OpenSSL::Crypto)
   list(APPEND LIBSSH_LINK_LIBRARIES OpenSSL::Crypto)
 endif ()
 
-if (MBEDTLS_CRYPTO_LIBRARY)
-    set(LIBSSH_PRIVATE_INCLUDE_DIRS
-      ${LIBSSH_PRIVATE_INCLUDE_DIRS}
-      ${MBEDTLS_INCLUDE_DIR}
-    )
-  set(LIBSSH_LINK_LIBRARIES
-    ${LIBSSH_LINK_LIBRARIES}
-    ${MBEDTLS_CRYPTO_LIBRARY}
-  )
-endif (MBEDTLS_CRYPTO_LIBRARY)
+if (TARGET MbedTLS::mbedcrypto)
+  list(APPEND LIBSSH_LINK_LIBRARIES MbedTLS::mbedcrypto)
+endif ()
 
-if (GCRYPT_LIBRARIES)
-  set(LIBSSH_PRIVATE_INCLUDE_DIRS
-    ${LIBSSH_PRIVATE_INCLUDE_DIRS}
-    ${GCRYPT_INCLUDE_DIR}
-  )
-
-  set(LIBSSH_LINK_LIBRARIES
-    ${LIBSSH_LINK_LIBRARIES}
-    ${GCRYPT_LIBRARIES})
-endif()
+if (TARGET libgcrypt::libgcrypt)
+  list(APPEND LIBSSH_LINK_LIBRARIES ${GCRYPT_LIBRARIES})
+endif ()
 
 if (WITH_ZLIB)
   list(APPEND LIBSSH_LINK_LIBRARIES ZLIB::ZLIB)
@@ -100,10 +87,12 @@ set(libssh_SRCS
   connector.c
   crypto_common.c
   curve25519.c
+  sntrup761.c
   dh.c
   ecdh.c
   error.c
   getpass.c
+  gzip.c
   init.c
   kdf.c
   kex.c
@@ -186,6 +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}
@@ -202,6 +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
@@ -211,17 +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
@@ -265,13 +269,6 @@ if (WITH_GEX)
   )
 endif (WITH_GEX)
 
-if (WITH_ZLIB)
-  set(libssh_SRCS
-    ${libssh_SRCS}
-    gzip.c
-  )
-endif(WITH_ZLIB)
-
 if (WITH_GSSAPI AND GSSAPI_FOUND)
   set(libssh_SRCS
     ${libssh_SRCS}
@@ -280,14 +277,22 @@ 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()
 endif (NOT WITH_NACL)
 
+if (HAVE_MLKEM)
+  set(libssh_SRCS
+    ${libssh_SRCS}
+    mlkem768.c
+  )
+endif (HAVE_MLKEM)
+
 # Set the path to the default map file
 set(MAP_PATH "${CMAKE_CURRENT_SOURCE_DIR}/${PROJECT_NAME}.map")
 
@@ -355,6 +360,8 @@ endif (WITH_SYMBOL_VERSIONING AND HAVE_LD_VERSION_SCRIPT)
 
 set_target_properties(ssh
     PROPERTIES
+      C_STANDARD
+        99
       VERSION
         ${LIBRARY_VERSION}
       SOVERSION

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)
@@ -422,8 +445,9 @@ ssh_key ssh_agent_get_first_ident(struct ssh_session_struct *session,
 
 /* caller has to free comment */
 ssh_key ssh_agent_get_next_ident(struct ssh_session_struct *session,
-    char **comment) {
-    struct ssh_key_struct *key;
+                                 char **comment)
+{
+    struct ssh_key_struct *key = NULL;
     struct ssh_string_struct *blob = NULL;
     struct ssh_string_struct *tmp = NULL;
     int rc;
@@ -470,35 +494,37 @@ 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,
                                const ssh_key pubkey,
                                struct ssh_buffer_struct *data)
 {
-    ssh_buffer request;
-    ssh_buffer reply;
-    ssh_string key_blob;
-    ssh_string sig_blob;
+    ssh_buffer request = NULL;
+    ssh_buffer reply = NULL;
+    ssh_string key_blob = NULL;
+    ssh_string sig_blob = NULL;
     unsigned int type = 0;
     unsigned int flags = 0;
     uint32_t dlen;
+    size_t request_len;
     int rc;
 
     request = ssh_buffer_new();
@@ -524,11 +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

@@ -195,8 +195,9 @@ static int ssh_userauth_get_response(ssh_session session)
  *
  * This banner should be shown to user prior to authentication
  */
-SSH_PACKET_CALLBACK(ssh_packet_userauth_banner) {
-    ssh_string banner;
+SSH_PACKET_CALLBACK(ssh_packet_userauth_banner)
+{
+    ssh_string banner = NULL;
     (void)type;
     (void)user;
 
@@ -462,6 +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.
  *
@@ -508,29 +611,42 @@ 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
+     * compatibility to make sure the possible EXT_INFO packet is processed,
+     * extensions recorded and the right signature type is used below
+     */
+    rc = ssh_userauth_request_service(session);
+    if (rc == SSH_AGAIN) {
+        return SSH_AUTH_AGAIN;
+    } else if (rc == SSH_ERROR) {
+        return SSH_AUTH_ERROR;
     }
 
     /* 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);
@@ -538,19 +654,15 @@ 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;
     }
 
-    rc = ssh_userauth_request_service(session);
-    if (rc == SSH_AGAIN) {
-        return SSH_AUTH_AGAIN;
-    } else if (rc == SSH_ERROR) {
-        return SSH_AUTH_ERROR;
-    }
-
     /* public key */
     rc = ssh_pki_export_pubkey_blob(pubkey, &pubkey_s);
     if (rc < 0) {
@@ -558,20 +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;
@@ -640,16 +742,28 @@ 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
+     * compatibility to make sure the possible EXT_INFO packet is processed,
+     * extensions recorded and the right signature type is used below
+     */
+    rc = ssh_userauth_request_service(session);
+    if (rc == SSH_AGAIN) {
+        return SSH_AUTH_AGAIN;
+    } else if (rc == SSH_ERROR) {
+        return SSH_AUTH_ERROR;
     }
 
     /* Cert auth requires presenting the cert type name (*-cert@openssh.com) */
@@ -658,13 +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);
@@ -672,19 +788,15 @@ 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;
     }
 
-    rc = ssh_userauth_request_service(session);
-    if (rc == SSH_AGAIN) {
-        return SSH_AUTH_AGAIN;
-    } else if (rc == SSH_ERROR) {
-        return SSH_AUTH_ERROR;
-    }
-
     /* get public key or cert */
     rc = ssh_pki_export_pubkey_blob(privkey, &str);
     if (rc < 0) {
@@ -692,16 +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;
     }
@@ -769,6 +872,10 @@ static int ssh_userauth_agent_publickey(ssh_session session,
         return SSH_ERROR;
     }
 
+    /* Note, that this is intentionally before checking the signature type
+     * compatibility to make sure the possible EXT_INFO packet is processed,
+     * extensions recorded and the right signature type is used below
+     */
     rc = ssh_userauth_request_service(session);
     if (rc == SSH_AGAIN) {
         return SSH_AUTH_AGAIN;
@@ -785,14 +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);
@@ -801,27 +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);
@@ -879,7 +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);
     }
 }
 
@@ -905,8 +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;
@@ -925,12 +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;
     }
 
@@ -1682,7 +1783,7 @@ int ssh_userauth_agent_pubkey(ssh_session session,
                               const char *username,
                               ssh_public_key publickey)
 {
-    ssh_key key;
+    ssh_key key = NULL;
     int rc;
 
     key = ssh_key_new();

src/base64.c

@@ -29,6 +29,9 @@
 #include "libssh/priv.h"
 #include "libssh/buffer.h"
 
+/* Do not allow encoding more than 256MB of data */
+#define BASE64_MAX_INPUT_LEN 256 * 1024 * 1024
+
 static
 const uint8_t alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                          "abcdefghijklmnopqrstuvwxyz"
@@ -183,7 +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) {
@@ -278,7 +281,15 @@ uint8_t *bin_to_base64(const uint8_t *source, size_t len)
 {
     uint8_t *base64 = NULL;
     uint8_t *ptr = NULL;
-    size_t flen = len + (3 - (len % 3)); /* round to upper 3 multiple */
+    size_t flen = 0;
+
+    /* Set the artificial upper limit for the input. Otherwise on 32b arch, the
+     * following line could overflow for sizes larger than SIZE_MAX / 4 */
+    if (len > BASE64_MAX_INPUT_LEN) {
+        return NULL;
+    }
+
+    flen = len + (3 - (len % 3)); /* round to upper 3 multiple */
     flen = (4 * flen) / 3 + 1;
 
     base64 = malloc(flen);

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

@@ -74,7 +74,7 @@
 static socket_t bind_socket(ssh_bind sshbind, const char *hostname,
     int port) {
     char port_c[6];
-    struct addrinfo *ai;
+    struct addrinfo *ai = NULL;
     struct addrinfo hints;
     int opt = 1;
     socket_t s;
@@ -132,8 +132,9 @@ static socket_t bind_socket(ssh_bind sshbind, const char *hostname,
     return s;
 }
 
-ssh_bind ssh_bind_new(void) {
-    ssh_bind ptr;
+ssh_bind ssh_bind_new(void)
+{
+    ssh_bind ptr = NULL;
 
     ptr = calloc(1, sizeof(struct ssh_bind_struct));
     if (ptr == NULL) {
@@ -217,28 +218,12 @@ static int ssh_bind_import_keys(ssh_bind sshbind) {
   return SSH_OK;
 }
 
-int ssh_bind_listen(ssh_bind sshbind) {
-    const char *host;
+int ssh_bind_listen(ssh_bind sshbind)
+{
+    const char *host = NULL;
     socket_t fd;
     int rc;
 
-    /* Apply global bind configurations, if it hasn't been applied before */
-    rc = ssh_bind_options_parse_config(sshbind, NULL);
-    if (rc != 0) {
-        ssh_set_error(sshbind, SSH_FATAL,"Could not parse global config");
-        return SSH_ERROR;
-    }
-
-    /* Set default hostkey paths if no hostkey was found before */
-    if (sshbind->ecdsakey == NULL &&
-        sshbind->rsakey == NULL &&
-        sshbind->ed25519key == NULL) {
-
-        sshbind->ecdsakey = strdup("/etc/ssh/ssh_host_ecdsa_key");
-        sshbind->rsakey = strdup("/etc/ssh/ssh_host_rsa_key");
-        sshbind->ed25519key = strdup("/etc/ssh/ssh_host_ed25519_key");
-    }
-
     /* Apply global bind configurations, if it hasn't been applied before */
     rc = ssh_bind_options_parse_config(sshbind, NULL);
     if (rc != 0) {
@@ -288,10 +273,10 @@ int ssh_bind_listen(ssh_bind sshbind) {
         }
 
         sshbind->bindfd = fd;
-  } else {
-      SSH_LOG(SSH_LOG_DEBUG, "Using app-provided bind socket");
-  }
-  return 0;
+    } else {
+        SSH_LOG(SSH_LOG_DEBUG, "Using app-provided bind socket");
+    }
+    return 0;
 }
 
 int ssh_bind_set_callbacks(ssh_bind sshbind, ssh_bind_callbacks callbacks, void *userdata)
@@ -462,7 +447,7 @@ int ssh_bind_accept_fd(ssh_bind sshbind, ssh_session session, socket_t fd)
                 return SSH_ERROR;
             }
         } else {
-            char *p;
+            char *p = NULL;
             /* If something was set to the session prior to calling this
              * function, keep only what is allowed by the options set in
              * sshbind */
@@ -504,7 +489,10 @@ 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

@@ -104,6 +104,11 @@ ssh_bind_config_keyword_table[] = {
         .opcode = BIND_CFG_HOSTKEY_ALGORITHMS,
         .allowed_in_match = true
     },
+    {
+        .name   = "requiredrsasize",
+        .opcode = BIND_CFG_REQUIRED_RSA_SIZE,
+        .allowed_in_match = true
+    },
     {
         .opcode = BIND_CFG_UNKNOWN,
     }
@@ -200,7 +205,7 @@ local_parse_file(ssh_bind bind,
                  uint8_t *seen,
                  unsigned int depth)
 {
-    FILE *f;
+    FILE *f = NULL;
     char line[MAX_LINE_SIZE] = {0};
     unsigned int count = 0;
     int rv;
@@ -293,6 +298,7 @@ ssh_bind_config_parse_line(ssh_bind bind,
     const char *p = NULL;
     char *s = NULL, *x = NULL;
     char *keyword = NULL;
+    long l;
     size_t len;
 
     int rc = 0;
@@ -594,6 +600,18 @@ ssh_bind_config_parse_line(ssh_bind bind,
             }
         }
         break;
+    case BIND_CFG_REQUIRED_RSA_SIZE:
+        l = ssh_config_get_long(&s, -1);
+        if (l >= 0 && (*parser_flags & PARSING)) {
+            rc = ssh_bind_options_set(bind, SSH_BIND_OPTIONS_RSA_MIN_SIZE, &l);
+            if (rc != 0) {
+                SSH_LOG(SSH_LOG_TRACE,
+                        "line %d: Failed to set RequiredRSASize value '%ld'",
+                        count,
+                        l);
+            }
+        }
+        break;
     case BIND_CFG_NOT_ALLOWED_IN_MATCH:
         SSH_LOG(SSH_LOG_DEBUG, "Option not allowed in Match block: %s, line: %d",
                 keyword, count);
@@ -626,7 +644,7 @@ int ssh_bind_config_parse_file(ssh_bind bind, const char *filename)
 {
     char line[MAX_LINE_SIZE] = {0};
     unsigned int count = 0;
-    FILE *f;
+    FILE *f = NULL;
     uint32_t parser_flags;
     int rv;
 
@@ -669,7 +687,8 @@ 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 +717,10 @@ 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

@@ -371,7 +371,8 @@ int ssh_buffer_allocate_size(struct ssh_buffer_struct *buffer,
  */
 void *ssh_buffer_allocate(struct ssh_buffer_struct *buffer, uint32_t len)
 {
-    void *ptr;
+    void *ptr = NULL;
+
     buffer_verify(buffer);
 
     if (buffer->used + len < len) {
@@ -406,20 +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;
 }
 
 /**
@@ -610,6 +617,53 @@ uint32_t ssh_buffer_get_len(struct ssh_buffer_struct *buffer){
   return buffer->used - buffer->pos;
 }
 
+/**
+ * @internal
+ *
+ * @brief Duplicate an existing buffer.
+ *
+ * Creates a new ssh_buffer and copies all data from the source buffer.
+ * The new buffer preserves the secure flag setting of the source.
+ *
+ * @param[in]  buffer   The buffer to duplicate. Can be NULL.
+ *
+ * @return              A new buffer containing a copy of the data on success,
+ *                      NULL on failure or if buffer is NULL.
+ *
+ * @see ssh_buffer_free()
+ */
+ssh_buffer ssh_buffer_dup(const ssh_buffer buffer)
+{
+    ssh_buffer new_buffer = NULL;
+    int rc;
+
+    if (buffer == NULL) {
+        return NULL;
+    }
+
+    buffer_verify(buffer);
+
+    new_buffer = ssh_buffer_new();
+    if (new_buffer == NULL) {
+        return NULL;
+    }
+
+    new_buffer->secure = buffer->secure;
+
+    if (ssh_buffer_get_len(buffer) > 0) {
+        rc = ssh_buffer_add_data(new_buffer,
+                                 ssh_buffer_get(buffer),
+                                 ssh_buffer_get_len(buffer));
+        if (rc != SSH_OK) {
+            ssh_buffer_free(new_buffer);
+            return NULL;
+        }
+    }
+
+    buffer_verify(new_buffer);
+    return new_buffer;
+}
+
 /**
  * @internal
  *
@@ -822,6 +876,7 @@ 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;
@@ -852,7 +907,7 @@ static int ssh_buffer_pack_allocate_va(struct ssh_buffer_struct *buffer,
             break;
         case 'S':
             string = va_arg(ap, ssh_string);
-            needed_size += 4 + ssh_string_len(string);
+            needed_size += sizeof(uint32_t) + ssh_string_len(string);
             string = NULL;
             break;
         case 's':
@@ -866,13 +921,18 @@ 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 *);
@@ -926,7 +986,7 @@ ssh_buffer_pack_va(struct ssh_buffer_struct *buffer,
                    va_list ap)
 {
     int rc = SSH_ERROR;
-    const char *p;
+    const char *p = NULL;
     union {
         uint8_t byte;
         uint16_t word;
@@ -935,7 +995,7 @@ ssh_buffer_pack_va(struct ssh_buffer_struct *buffer,
         ssh_string string;
         void *data;
     } o;
-    char *cstring;
+    char *cstring = NULL;
     bignum b;
     size_t len;
     size_t count;
@@ -978,24 +1038,40 @@ 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;
@@ -1006,7 +1082,11 @@ 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:
@@ -1047,6 +1127,8 @@ 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
@@ -1094,7 +1176,7 @@ int ssh_buffer_unpack_va(struct ssh_buffer_struct *buffer,
                          va_list ap)
 {
     int rc = SSH_ERROR;
-    const char *p = format, *last;
+    const char *p = format, *last = NULL;
     union {
         uint8_t *byte;
         uint16_t *word;
@@ -1186,28 +1268,28 @@ 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;
@@ -1232,7 +1314,7 @@ 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;
         }
@@ -122,14 +122,14 @@ int ssh_add_channel_callbacks(ssh_channel channel, ssh_channel_callbacks cb)
 
 int ssh_remove_channel_callbacks(ssh_channel channel, ssh_channel_callbacks cb)
 {
-    struct ssh_iterator *it;
+    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/chachapoly.c

@@ -42,7 +42,7 @@ static int chacha20_set_encrypt_key(struct ssh_cipher_struct *cipher,
                                     void *key,
                                     void *IV)
 {
-    struct chacha20_poly1305_keysched *sched;
+    struct chacha20_poly1305_keysched *sched = NULL;
     uint8_t *u8key = key;
     (void)IV;
 

src/client.c

@@ -46,6 +46,15 @@
 #include "libssh/misc.h"
 #include "libssh/pki.h"
 #include "libssh/kex.h"
+#ifdef HAVE_MLKEM
+#include "libssh/mlkem768.h"
+#endif
+
+#ifndef _WIN32
+#ifdef HAVE_PTHREAD
+extern int proxy_disconnect;
+#endif /* HAVE_PTHREAD */
+#endif /* _WIN32 */
 
 #define set_status(session, status) do {\
         if (session->common.callbacks && session->common.callbacks->connect_status_function) \
@@ -220,7 +229,7 @@ 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;
     }
@@ -229,8 +238,8 @@ 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
 
@@ -248,45 +257,58 @@ 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:
+        case SSH_KEX_SNTRUP761X25519_SHA512_OPENSSH_COM:
+            rc = ssh_client_sntrup761x25519_init(session);
+            break;
+#endif
+#ifdef HAVE_MLKEM
+        case SSH_KEX_MLKEM768X25519_SHA256:
+            rc = ssh_client_mlkem768x25519_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;
@@ -294,15 +316,17 @@ 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)
@@ -587,8 +611,7 @@ 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() &&
@@ -765,8 +788,6 @@ ssh_session_set_disconnect_message(ssh_session session, const char *message)
     return SSH_OK;
 }
 
-extern int proxy_disconnect;
-
 /**
  * @brief Disconnect from a session (client or server).
  *
@@ -781,7 +802,7 @@ extern int proxy_disconnect;
 void
 ssh_disconnect(ssh_session session)
 {
-    struct ssh_iterator *it;
+    struct ssh_iterator *it = NULL;
     int rc;
 
     if (session == NULL) {
@@ -789,12 +810,14 @@ ssh_disconnect(ssh_session session)
     }
 
 #ifndef _WIN32
+#ifdef HAVE_PTHREAD
     /* Only send the disconnect to all other threads when the root session calls
      * ssh_disconnect() */
     if (session->proxy_root) {
         proxy_disconnect = 1;
     }
-#endif
+#endif /* HAVE_PTHREAD */
+#endif /* _WIN32 */
 
     if (session->disconnect_message == NULL) {
         session->disconnect_message = strdup("Bye Bye") ;
@@ -830,6 +853,7 @@ error:
     session->opts.fd = SSH_INVALID_SOCKET;
     session->session_state = SSH_SESSION_STATE_DISCONNECTED;
     session->pending_call_state = SSH_PENDING_CALL_NONE;
+    session->packet_state = PACKET_STATE_INIT;
 
     while ((it = ssh_list_get_iterator(session->channels)) != NULL) {
         ssh_channel_do_free(ssh_iterator_value(ssh_channel, it));
@@ -889,7 +913,7 @@ error:
  */
 const char *ssh_copyright(void)
 {
-    return SSH_STRINGIFY(LIBSSH_VERSION) " (c) 2003-2024 "
+    return SSH_STRINGIFY(LIBSSH_VERSION) " (c) 2003-2025 "
            "Aris Adamantiadis, Andreas Schneider "
            "and libssh contributors. "
            "Distributed under the LGPL, please refer to COPYING "

src/config.c

@@ -39,10 +39,12 @@
 # include <errno.h>
 # include <signal.h>
 # include <sys/wait.h>
-# include <ifaddrs.h>
 # include <net/if.h>
 # include <netinet/in.h>
 #endif
+#ifdef HAVE_IFADDRS_H
+#include <ifaddrs.h>
+#endif
 
 #include "libssh/config_parser.h"
 #include "libssh/config.h"
@@ -130,9 +132,9 @@ static struct ssh_config_keyword_table_s ssh_config_keyword_table[] = {
   { "verifyhostkeydns", SOC_UNSUPPORTED},
   { "visualhostkey", SOC_UNSUPPORTED},
   { "clearallforwardings", SOC_NA},
-  { "controlmaster", SOC_CONTROLMASTER},
+  { "controlmaster", SOC_NA},
   { "controlpersist", SOC_NA},
-  { "controlpath", SOC_CONTROLPATH},
+  { "controlpath", SOC_NA},
   { "dynamicforward", SOC_NA},
   { "escapechar", SOC_NA},
   { "exitonforwardfailure", SOC_NA},
@@ -151,6 +153,7 @@ static struct ssh_config_keyword_table_s ssh_config_keyword_table[] = {
   { "tunneldevice", SOC_NA},
   { "xauthlocation", SOC_NA},
   { "pubkeyacceptedkeytypes", SOC_PUBKEYACCEPTEDKEYTYPES},
+  { "requiredrsasize", SOC_REQUIRED_RSA_SIZE},
   { NULL, SOC_UNKNOWN }
 };
 
@@ -209,7 +212,7 @@ local_parse_file(ssh_session session,
                  unsigned int depth,
                  bool global)
 {
-    FILE *f;
+    FILE *f = NULL;
     char line[MAX_LINE_SIZE] = {0};
     unsigned int count = 0;
     int rv;
@@ -639,7 +642,7 @@ ssh_config_make_absolute(ssh_session session,
     return out;
 }
 
-#ifndef _WIN32
+#ifdef HAVE_IFADDRS_H
 /**
  * @brief Checks if host address matches the local network specified.
  *
@@ -730,7 +733,7 @@ ssh_match_localnetwork(const char *addrlist, bool negate)
 
     return (found == (negate ? 0 : 1));
 }
-#endif
+#endif /* HAVE_IFADDRS_H */
 
 static int
 ssh_config_parse_line(ssh_session session,
@@ -892,9 +895,11 @@ ssh_config_parse_line(ssh_session session,
                 /* Here we match only one argument */
                 p = ssh_config_get_str_tok(&s, NULL);
                 if (p == NULL || p[0] == '\0') {
-                    ssh_set_error(session, SSH_FATAL,
-                                  "line %d: ERROR - Match user keyword "
-                                  "requires argument", count);
+                    ssh_set_error(session,
+                                  SSH_FATAL,
+                                  "line %d: ERROR - Match localuser keyword "
+                                  "requires argument",
+                                  count);
                     SAFE_FREE(x);
                     return -1;
                 }
@@ -955,7 +960,6 @@ ssh_config_parse_line(ssh_session session,
                 args++;
                 break;
 
-#ifndef _WIN32
             case MATCH_LOCALNETWORK:
                 /* Here we match only one argument */
                 p = ssh_config_get_str_tok(&s, NULL);
@@ -968,6 +972,7 @@ ssh_config_parse_line(ssh_session session,
                     SAFE_FREE(x);
                     return -1;
                 }
+#ifdef HAVE_IFADDRS_H
                 rv = match_cidr_address_list(NULL, p, -1);
                 if (rv == -1) {
                     ssh_set_error(session,
@@ -992,23 +997,31 @@ ssh_config_parse_line(ssh_session session,
                 }
 
                 result &= rv;
+#else /* HAVE_IFADDRS_H */
+                ssh_set_error(session,
+                              SSH_FATAL,
+                              "line %d: ERROR - match localnetwork "
+                              "not supported on this platform",
+                              count);
+                SAFE_FREE(x);
+                return -1;
+#endif /* HAVE_IFADDRS_H */
                 args++;
                 break;
-#endif
 
             case MATCH_UNKNOWN:
             default:
-                ssh_set_error(session, SSH_FATAL,
-                              "ERROR - Unknown argument '%s' for Match keyword", p);
-                SAFE_FREE(x);
-                return -1;
+                SSH_LOG(SSH_LOG_WARN,
+                        "Unknown argument '%s' for Match keyword. Not matching",
+                        p);
+                result = 0;
+                break;
             }
         } while (p != NULL && p[0] != '\0');
         if (args == 0) {
-            ssh_set_error(session, SSH_FATAL,
-                          "ERROR - Match keyword requires an argument");
-            SAFE_FREE(x);
-            return -1;
+            SSH_LOG(SSH_LOG_WARN,
+                    "ERROR - Match keyword requires an argument. Not matching");
+            result = 0;
         }
         *parsing = result;
         break;
@@ -1427,6 +1440,12 @@ ssh_config_parse_line(ssh_session session,
             ssh_options_set(session, SSH_OPTIONS_CERTIFICATE, p);
         }
         break;
+    case SOC_REQUIRED_RSA_SIZE:
+        l = ssh_config_get_long(&s, -1);
+        if (l >= 0 && *parsing) {
+            ssh_options_set(session, SSH_OPTIONS_RSA_MIN_SIZE, &l);
+        }
+        break;
     default:
       ssh_set_error(session, SSH_FATAL, "ERROR - unimplemented opcode: %d",
               opcode);
@@ -1439,6 +1458,32 @@ 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
@@ -1448,36 +1493,32 @@ 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;
-    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
@@ -1492,7 +1533,8 @@ 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:");
@@ -1514,8 +1556,10 @@ 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/config_parser.c

@@ -39,8 +39,8 @@
  */
 char *ssh_config_get_cmd(char **str)
 {
-    register char *c;
-    char *r;
+    register char *c = NULL;
+    char *r = NULL;
 
     /* Ignore leading spaces */
     for (c = *str; *c; c++) {
@@ -67,7 +67,7 @@ out:
  */
 char *ssh_config_get_token(char **str)
 {
-    register char *c;
+    register char *c = NULL;
     bool had_equal = false;
     char *r = NULL;
 
@@ -82,6 +82,13 @@ char *ssh_config_get_token(char **str)
     if (*c == '\"') {
         for (r = ++c; *c; c++) {
             if (*c == '\"' || *c == '\n') {
+                if (*c == '\"' && r != c && *(c - 1) == '\\') {
+                    /* Escaped quote: Move the remaining one char left */
+                    int remaining_len = strlen(c);
+                    memmove(c - 1, c, remaining_len);
+                    c[remaining_len - 1] = '\0';
+                    continue;
+                }
                 *c = '\0';
                 c++;
                 break;
@@ -116,7 +123,7 @@ out:
 
 long ssh_config_get_long(char **str, long notfound)
 {
-    char *p, *endp;
+    char *p = NULL, *endp = NULL;
     long i;
 
     p = ssh_config_get_token(str);
@@ -133,7 +140,7 @@ long ssh_config_get_long(char **str, long notfound)
 
 const char *ssh_config_get_str_tok(char **str, const char *def)
 {
-    char *p;
+    char *p = NULL;
 
     p = ssh_config_get_token(str);
     if (p && *p) {
@@ -145,7 +152,7 @@ const char *ssh_config_get_str_tok(char **str, const char *def)
 
 int ssh_config_get_yesno(char **str, int notfound)
 {
-    const char *p;
+    const char *p = NULL;
 
     p = ssh_config_get_str_tok(str, NULL);
     if (p == NULL) {

src/connect.c

@@ -189,8 +189,8 @@ socket_t ssh_connect_host_nonblocking(ssh_session session, const char *host,
         }
 
         if (bind_addr) {
-            struct addrinfo *bind_ai;
-            struct addrinfo *bind_itr;
+            struct addrinfo *bind_ai = NULL;
+            struct addrinfo *bind_itr = NULL;
 
             SSH_LOG(SSH_LOG_PACKET, "Resolving %s", bind_addr);
 
@@ -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

@@ -166,7 +166,7 @@ int ssh_connector_set_out_channel(ssh_connector connector,
 
     /* Fallback to default value for invalid flags */
     if (!(flags & SSH_CONNECTOR_STDOUT) && !(flags & SSH_CONNECTOR_STDERR)) {
-        connector->in_flags = SSH_CONNECTOR_STDOUT;
+        connector->out_flags = SSH_CONNECTOR_STDOUT;
     }
 
     return ssh_add_channel_callbacks(channel, &connector->out_channel_cb);
@@ -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;
@@ -381,15 +382,13 @@ ssh_connector_fd_out_cb(ssh_connector connector)
  *
  * @returns 0
  */
-static int ssh_connector_fd_cb(ssh_poll_handle p,
+static int ssh_connector_fd_cb(UNUSED_PARAM(ssh_poll_handle p),
                                socket_t fd,
                                int revents,
                                void *userdata)
 {
     ssh_connector connector = userdata;
 
-    (void)p;
-
     if (revents & POLLERR) {
         ssh_connector_except(connector, fd);
     } else if((revents & (POLLIN|POLLHUP)) && fd == connector->in_fd) {
@@ -408,6 +407,10 @@ static int ssh_connector_fd_cb(ssh_poll_handle p,
  *
  * @brief Callback called when data is received on channel.
  *
+ * @param[in] session The SSH session
+ *
+ * @param[in] channel The channel data came from
+ *
  * @param[in] data Pointer to the data
  *
  * @param[in] len Length of data
@@ -419,7 +422,7 @@ static int ssh_connector_fd_cb(ssh_poll_handle p,
  * @returns Amount of data bytes consumed
  */
 static int ssh_connector_channel_data_cb(ssh_session session,
-                                         ssh_channel channel,
+                                         UNUSED_PARAM(ssh_channel channel),
                                          void *data,
                                          uint32_t len,
                                          int is_stderr,
@@ -429,11 +432,11 @@ static int ssh_connector_channel_data_cb(ssh_session session,
     int w;
     uint32_t window;
 
-    (void) session;
-    (void) channel;
-    (void) is_stderr;
-
-    SSH_LOG(SSH_LOG_TRACE,"connector data on channel");
+    SSH_LOG(SSH_LOG_TRACE,
+            "Received data (%" PRIu32 ") on channel (%" PRIu32 ":%" PRIu32 ")",
+            len,
+            channel->local_channel,
+            channel->remote_channel);
 
     if (is_stderr && !(connector->in_flags & SSH_CONNECTOR_STDERR)) {
         /* ignore stderr */
@@ -447,6 +450,7 @@ static int ssh_connector_channel_data_cb(ssh_session session,
     }
 
     if (connector->out_wontblock) {
+        SSH_LOG(SSH_LOG_TRACE, "Writing won't block");
         if (connector->out_channel != NULL) {
             uint32_t window_len;
 
@@ -476,9 +480,11 @@ 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;
@@ -493,6 +499,7 @@ static int ssh_connector_channel_data_cb(ssh_session session,
 
         return w;
     } else {
+        SSH_LOG(SSH_LOG_TRACE, "Writing would block: wait?");
         connector->in_available = 1;
 
         return 0;
@@ -510,10 +517,11 @@ static int ssh_connector_channel_data_cb(ssh_session session,
  *
  * @returns Amount of data bytes consumed
  */
-static int ssh_connector_channel_write_wontblock_cb(ssh_session session,
-                                                    ssh_channel channel,
-                                                    uint32_t bytes,
-                                                    void *userdata)
+static int
+ssh_connector_channel_write_wontblock_cb(ssh_session session,
+                                         UNUSED_PARAM(ssh_channel channel),
+                                         uint32_t bytes,
+                                         void *userdata)
 {
     ssh_connector connector = userdata;
     uint8_t buffer[CHUNKSIZE];
@@ -521,7 +529,12 @@ static int ssh_connector_channel_write_wontblock_cb(ssh_session session,
 
     (void) channel;
 
-    SSH_LOG(SSH_LOG_TRACE, "Channel write won't block");
+    SSH_LOG(SSH_LOG_TRACE,
+            "Write won't block (%" PRIu32 ") on channel (%" PRIu32 ":%" PRIu32 ")",
+            bytes,
+            channel->local_channel,
+            channel->remote_channel);
+
     if (connector->in_available) {
         if (connector->in_channel != NULL) {
             uint32_t len = MIN(CHUNKSIZE, bytes);
@@ -532,7 +545,7 @@ static int ssh_connector_channel_write_wontblock_cb(ssh_session session,
                                              0);
             if (r == SSH_ERROR) {
                 ssh_connector_except_channel(connector, connector->in_channel);
-            } else if(r == 0 && ssh_channel_is_eof(connector->in_channel)){
+            } else if (r == 0 && ssh_channel_is_eof(connector->in_channel)) {
                 ssh_channel_send_eof(connector->out_channel);
             } else if (r > 0) {
                 w = ssh_channel_write(connector->out_channel, buffer, r);
@@ -603,15 +616,15 @@ int ssh_connector_set_event(ssh_connector connector, ssh_event event)
         }
     }
     if (connector->in_channel != NULL) {
-        rc = ssh_event_add_session(event,
-                ssh_channel_get_session(connector->in_channel));
+        ssh_session session = ssh_channel_get_session(connector->in_channel);
+        rc = ssh_event_add_session(event, session);
         if (rc != SSH_OK)
             goto error;
         if (ssh_channel_poll_timeout(connector->in_channel, 0, 0) > 0){
             connector->in_available = 1;
         }
     }
-    if(connector->out_channel != NULL) {
+    if (connector->out_channel != NULL) {
         ssh_session session = ssh_channel_get_session(connector->out_channel);
 
         rc =  ssh_event_add_session(event, session);
@@ -627,8 +640,9 @@ error:
     return rc;
 }
 
-int ssh_connector_remove_event(ssh_connector connector) {
-    ssh_session session;
+int ssh_connector_remove_event(ssh_connector connector)
+{
+    ssh_session session = NULL;
 
     if (connector->in_poll != NULL) {
         ssh_event_remove_poll(connector->event, connector->in_poll);

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 +1,164 @@
+/*
+ * 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;
+    }
+
+    /* Free any previously allocated privkey */
+    if (session->next_crypto->curve25519_privkey != NULL) {
+        EVP_PKEY_free(session->next_crypto->curve25519_privkey);
+        session->next_crypto->curve25519_privkey = NULL;
+    }
+
+    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 +1,205 @@
+/*
+ * 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);
+
+    /* Free any previously allocated privkey */
+    if (session->next_crypto->curve25519_privkey != NULL) {
+        gcry_sexp_release(session->next_crypto->curve25519_privkey);
+        session->next_crypto->curve25519_privkey = NULL;
+    }
+
+    /* 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;
         }
 
@@ -571,12 +577,12 @@ error:
 static SSH_PACKET_CALLBACK(ssh_packet_server_dhgex_request);
 static SSH_PACKET_CALLBACK(ssh_packet_server_dhgex_init);
 
-static ssh_packet_callback dhgex_server_callbacks[]= {
-    NULL, /* SSH_MSG_KEX_DH_GEX_REQUEST_OLD */
-    NULL, /* SSH_MSG_KEX_DH_GEX_GROUP */
+static ssh_packet_callback dhgex_server_callbacks[] = {
+    NULL,                           /* SSH_MSG_KEX_DH_GEX_REQUEST_OLD */
+    NULL,                           /* SSH_MSG_KEX_DH_GEX_GROUP */
     ssh_packet_server_dhgex_init,   /* SSH_MSG_KEX_DH_GEX_INIT */
     NULL,                           /* SSH_MSG_KEX_DH_GEX_REPLY */
-    ssh_packet_server_dhgex_request /* SSH_MSG_GEX_DH_GEX_REQUEST */
+    ssh_packet_server_dhgex_request /* SSH_MSG_KEX_DH_GEX_REQUEST */
 
 };
 

src/dh_crypto.c

@@ -404,9 +404,14 @@ done:
  */
 int ssh_dh_init_common(struct ssh_crypto_struct *crypto)
 {
-    struct dh_ctx *ctx;
+    struct dh_ctx *ctx = NULL;
     int rc;
 
+    /* Cleanup any previously allocated dh_ctx */
+    if (crypto->dh_ctx != NULL) {
+        ssh_dh_cleanup(crypto);
+    }
+
     ctx = calloc(1, sizeof(*ctx));
     if (ctx == NULL) {
         return SSH_ERROR;
@@ -592,7 +597,7 @@ 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/dh_key.c

@@ -237,6 +237,11 @@ int ssh_dh_init_common(struct ssh_crypto_struct *crypto)
     struct dh_ctx *ctx = NULL;
     int rc;
 
+    /* Cleanup any previously allocated dh_ctx */
+    if (crypto->dh_ctx != NULL) {
+        ssh_dh_cleanup(crypto);
+    }
+
     ctx = calloc(1, sizeof(*ctx));
     if (ctx == NULL) {
         return SSH_ERROR;

src/ecdh_crypto.c

@@ -191,6 +191,17 @@ static ssh_string ssh_ecdh_generate(ssh_session session)
 #endif /* OPENSSL_VERSION_NUMBER */
         return NULL;
     }
+
+    /* Free any previously allocated privkey */
+    if (session->next_crypto->ecdh_privkey != NULL) {
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+        EC_KEY_free(session->next_crypto->ecdh_privkey);
+#else
+        EVP_PKEY_free(session->next_crypto->ecdh_privkey);
+#endif
+        session->next_crypto->ecdh_privkey = NULL;
+    }
+
     session->next_crypto->ecdh_privkey = key;
     return pubkey_string;
 }
@@ -219,6 +230,7 @@ int ssh_client_ecdh_init(ssh_session session)
         return SSH_ERROR;
     }
 
+    ssh_string_free(session->next_crypto->ecdh_client_pubkey);
     session->next_crypto->ecdh_client_pubkey = client_pubkey;
 
     /* register the packet callbacks */
@@ -444,7 +456,7 @@ SSH_PACKET_CALLBACK(ssh_packet_server_ecdh_init)
     ssh_string q_c_string = NULL;
     ssh_string q_s_string = NULL;
     /* SSH host keys (rsa, ed25519 and ecdsa) */
-    ssh_key privkey;
+    ssh_key privkey = NULL;
     enum ssh_digest_e digest = SSH_DIGEST_AUTO;
     ssh_string sig_blob = NULL;
     ssh_string pubkey_blob = NULL;

src/ecdh_gcrypt.c

@@ -101,8 +101,15 @@ int ssh_client_ecdh_init(ssh_session session)
         goto out;
     }
 
+    /* Free any previously allocated privkey */
+    if (session->next_crypto->ecdh_privkey != NULL) {
+        gcry_sexp_release(session->next_crypto->ecdh_privkey);
+        session->next_crypto->ecdh_privkey = NULL;
+    }
     session->next_crypto->ecdh_privkey = key;
     key = NULL;
+
+    SSH_STRING_FREE(session->next_crypto->ecdh_client_pubkey);
     session->next_crypto->ecdh_client_pubkey = client_pubkey;
     client_pubkey = NULL;
 
@@ -132,9 +139,9 @@ int ecdh_build_k(ssh_session session)
 #else
     size_t k_len = 0;
     enum ssh_key_exchange_e kex_type = session->next_crypto->kex_type;
-    ssh_string s;
+    ssh_string s = NULL;
 #endif
-    ssh_string pubkey_raw;
+    ssh_string pubkey_raw = NULL;
     gcry_sexp_t pubkey = NULL;
     ssh_string privkey = NULL;
     int rc = SSH_ERROR;
@@ -267,12 +274,12 @@ int ecdh_build_k(ssh_session session)
 SSH_PACKET_CALLBACK(ssh_packet_server_ecdh_init){
     gpg_error_t err;
     /* ECDH keys */
-    ssh_string q_c_string;
-    ssh_string q_s_string;
+    ssh_string q_c_string = NULL;
+    ssh_string q_s_string = NULL;
     gcry_sexp_t param = NULL;
     gcry_sexp_t key = NULL;
     /* SSH host keys (rsa, ed25519 and ecdsa) */
-    ssh_key privkey;
+    ssh_key privkey = NULL;
     enum ssh_digest_e digest = SSH_DIGEST_AUTO;
     ssh_string sig_blob = NULL;
     ssh_string pubkey_blob = NULL;

src/ecdh_mbedcrypto.c

@@ -70,6 +70,12 @@ int ssh_client_ecdh_init(ssh_session session)
         return SSH_ERROR;
     }
 
+    /* Free any previously allocated privkey */
+    if (session->next_crypto->ecdh_privkey != NULL) {
+        mbedtls_ecp_keypair_free(session->next_crypto->ecdh_privkey);
+        SAFE_FREE(session->next_crypto->ecdh_privkey);
+    }
+
     session->next_crypto->ecdh_privkey = malloc(sizeof(mbedtls_ecp_keypair));
     if (session->next_crypto->ecdh_privkey == NULL) {
         return SSH_ERROR;
@@ -110,6 +116,7 @@ int ssh_client_ecdh_init(ssh_session session)
         goto out;
     }
 
+    SSH_STRING_FREE(session->next_crypto->ecdh_client_pubkey);
     session->next_crypto->ecdh_client_pubkey = client_pubkey;
     client_pubkey = NULL;
 

src/gcrypt_missing.c

@@ -47,7 +47,7 @@ int ssh_gcry_dec2bn(bignum *bn, const char *data) {
 
 char *ssh_gcry_bn2dec(bignum bn) {
   bignum bndup, num, ten;
-  char *ret;
+  char *ret = NULL;
   int count, count2;
   int size, rsize;
   char decnum;