gssapi: enable gssapi-keyex in FIPS mode

All gssapi-keyex tests have to be disabled in Centos Stream 8
because the KEX is not allowed in FIPS. In Centos Stream 9,
only tests against OpenSSH have to be disabled because
OpenSSH only enables gssapi-keyex since Centos Stream 10.

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

.gitlab-ci.yml

@@ -201,9 +201,11 @@ centos9s/openssl_3.5.x/x86_64/fips:
   variables:
     OPENSSL_ENABLE_SHA1_SIGNATURES: 1
   script:
+    # torture_gssapi_key_exchange_* tests are excluded because gssapi-keyex is disabled
+    # by OpenSSH in FIPS mode in RHEL 9
     - cmake $CMAKE_OPTIONS $CMAKE_ADDITIONAL_OPTIONS .. &&
       make -j$(nproc) &&
-      OPENSSL_FORCE_FIPS_MODE=1 ctest --output-on-failure
+      OPENSSL_FORCE_FIPS_MODE=1 ctest --output-on-failure -E "^torture_gssapi_key_exchange.*"
 
 centos8s/openssl_1.1.1/x86_64:
   image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$CENTOS8_BUILD
@@ -219,9 +221,11 @@ centos8s/openssl_1.1.1/x86_64/fips:
   extends: .fips
   image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$CENTOS8_BUILD
   script:
+    # torture_gssapi_key_exchange_* and torture_gssapi_server_key_exchange_* tests are excluded
+    # because gssapi-keyex is not allowed in FIPS mode in RHEL 8
     - cmake $CMAKE_OPTIONS $CMAKE_ADDITIONAL_OPTIONS .. &&
       make -j$(nproc) &&
-      OPENSSL_FORCE_FIPS_MODE=1 ctest --output-on-failure
+      OPENSSL_FORCE_FIPS_MODE=1 ctest --output-on-failure -E "^torture_gssapi.*key_exchange.*"
 
 ###############################################################################
 #                               Fedora builds                                 #

src/gssapi.c

@@ -672,7 +672,6 @@ fail:
  */
 char *ssh_gssapi_oid_hash(ssh_string oid)
 {
-    MD5CTX ctx = NULL;
     unsigned char *h = NULL;
     int rc;
     char *base64 = NULL;
@@ -682,19 +681,7 @@ char *ssh_gssapi_oid_hash(ssh_string oid)
         return NULL;
     }
 
-    ctx = md5_init();
+    rc = md5(ssh_string_data(oid), ssh_string_len(oid), h);
-    if (ctx == NULL) {
-        SAFE_FREE(h);
-        return NULL;
-    }
-
-    rc = md5_update(ctx, ssh_string_data(oid), ssh_string_len(oid));
-    if (rc != SSH_OK) {
-        SAFE_FREE(h);
-        md5_ctx_free(ctx);
-        return NULL;
-    }
-    rc = md5_final(h, ctx);
     if (rc != SSH_OK) {
         SAFE_FREE(h);
         return NULL;

src/kex.c

@@ -811,7 +811,7 @@ int ssh_set_client_kex(ssh_session session)
         return SSH_ERROR;
     }
 #ifdef WITH_GSSAPI
-    if (session->opts.gssapi_key_exchange && !ssh_fips_mode()) {
+    if (session->opts.gssapi_key_exchange) {
         char *gssapi_algs = NULL;
 
         ok = ssh_gssapi_init(session);
@@ -831,9 +831,15 @@ int ssh_set_client_kex(ssh_session session)
         }
 
         /* Prefix the default algorithms with gsskex algs */
+        if (ssh_fips_mode()) {
+            session->opts.wanted_methods[SSH_KEX] =
+                ssh_prefix_without_duplicates(fips_methods[SSH_KEX],
+                                              gssapi_algs);
+        } else {
             session->opts.wanted_methods[SSH_KEX] =
                 ssh_prefix_without_duplicates(default_methods[SSH_KEX],
                                               gssapi_algs);
+        }
 
         gssapi_null_alg = true;
 

src/server.c

@@ -172,7 +172,7 @@ int server_set_kex(ssh_session session)
         }
     }
 #ifdef WITH_GSSAPI
-    if (session->opts.gssapi_key_exchange && !ssh_fips_mode()) {
+    if (session->opts.gssapi_key_exchange) {
         ok = ssh_gssapi_init(session);
         if (ok != SSH_OK) {
             ssh_set_error_oom(session);

tests/client/torture_gssapi_key_exchange.c

@@ -78,11 +78,6 @@ static void torture_gssapi_key_exchange(void **state)
     int rc;
     bool t = true;
 
-    /* Skip test if in FIPS mode */
-    if (ssh_fips_mode()) {
-        skip();
-    }
-
     /* Valid */
     torture_setup_kdc_server(
         state,
@@ -108,11 +103,6 @@ static void torture_gssapi_key_exchange_no_tgt(void **state)
     int rc;
     bool t = true;
 
-    /* Skip test if in FIPS mode */
-    if (ssh_fips_mode()) {
-        skip();
-    }
-
     /* Don't run kinit */
     torture_setup_kdc_server(
         state,
@@ -144,11 +134,6 @@ static void torture_gssapi_key_exchange_alg(void **state,
     int rc;
     bool t = true;
 
-    /* Skip test if in FIPS mode */
-    if (ssh_fips_mode()) {
-        skip();
-    }
-
     /* Valid */
     torture_setup_kdc_server(
         state,
@@ -213,11 +198,6 @@ static void torture_gssapi_key_exchange_auth(void **state)
     int rc;
     bool t = true;
 
-    /* Skip test if in FIPS mode */
-    if (ssh_fips_mode()) {
-        skip();
-    }
-
     /* Valid */
     torture_setup_kdc_server(
         state,
@@ -247,11 +227,6 @@ static void torture_gssapi_key_exchange_no_auth(void **state)
     int rc;
     bool f = false;
 
-    /* Skip test if in FIPS mode */
-    if (ssh_fips_mode()) {
-        skip();
-    }
-
     /* Valid */
     torture_setup_kdc_server(
         state,

tests/client/torture_gssapi_key_exchange_null.c

@@ -18,8 +18,6 @@ static int sshd_setup(void **state)
     s = *state;
     s->disable_hostkeys = true;
 
-    if (!ssh_fips_mode()) {
-        /* Temporary kerberos server */
     torture_setup_kdc_server(
         state,
         "kadmin.local addprinc -randkey host/server.libssh.site \n"
@@ -34,7 +32,7 @@ static int sshd_setup(void **state)
                                "GSSAPIKeyExchange yes\n");
 
     torture_teardown_kdc_server(state);
-    }
+
     return 0;
 }
 
@@ -95,11 +93,6 @@ static void torture_gssapi_key_exchange_null(void **state)
     int rc;
     bool t = true;
 
-    /* Skip test if in FIPS mode */
-    if (ssh_fips_mode()) {
-        skip();
-    }
-
     /* Valid */
     torture_setup_kdc_server(
         state,

tests/server/torture_gssapi_server_key_exchange.c

@@ -281,11 +281,6 @@ static void torture_gssapi_server_key_exchange(void **state)
     int rc;
     bool t = true;
 
-    /* Skip test if in FIPS mode */
-    if (ssh_fips_mode()) {
-        skip();
-    }
-
     assert_non_null(tss);
 
     s = tss->state;
@@ -321,10 +316,6 @@ static void torture_gssapi_server_key_exchange_no_tgt(void **state)
     int rc;
     bool t = true;
 
-    /* Skip test if in FIPS mode */
-    if (ssh_fips_mode()) {
-        skip();
-    }
 
     assert_non_null(tss);
 
@@ -366,11 +357,6 @@ static void torture_gssapi_server_key_exchange_alg(void **state,
     int rc;
     bool t = true;
 
-    /* Skip test if in FIPS mode */
-    if (ssh_fips_mode()) {
-        skip();
-    }
-
     assert_non_null(tss);
 
     s = tss->state;
@@ -444,11 +430,6 @@ static void torture_gssapi_server_key_exchange_auth(void **state)
     int rc;
     bool t = true;
 
-    /* Skip test if in FIPS mode */
-    if (ssh_fips_mode()) {
-        skip();
-    }
-
     assert_non_null(tss);
 
     s = tss->state;
@@ -487,11 +468,6 @@ static void torture_gssapi_server_key_exchange_no_auth(void **state)
     int rc;
     bool f = false;
 
-    /* Skip test if in FIPS mode */
-    if (ssh_fips_mode()) {
-        skip();
-    }
-
     assert_non_null(tss);
 
     s = tss->state;

tests/server/torture_gssapi_server_key_exchange_fallback.c

@@ -278,11 +278,6 @@ static void torture_gssapi_server_key_exchange_fallback(void **state)
     int rc;
     bool t = true;
 
-    /* Skip test if in FIPS mode */
-    if (ssh_fips_mode()) {
-        skip();
-    }
-
     assert_non_null(tss);
 
     s = tss->state;

tests/server/torture_gssapi_server_key_exchange_null.c

@@ -250,11 +250,6 @@ static void torture_gssapi_server_key_exchange_null(void **state)
     int rc;
     bool t = true;
 
-    /* Skip test if in FIPS mode */
-    if (ssh_fips_mode()) {
-        skip();
-    }
-
     assert_non_null(tss);
 
     s = tss->state;
@@ -293,10 +288,6 @@ static void torture_gssapi_server_key_exchange_no_tgt(void **state)
     int rc;
     bool t = true;
 
-    /* Skip test if in FIPS mode */
-    if (ssh_fips_mode()) {
-        skip();
-    }
 
     assert_non_null(tss);
 

tests/torture.c

@@ -999,10 +999,8 @@ torture_setup_create_sshd_config(void **state, bool pam, bool second_sshd)
                  fips_config_string,
                  second_sshd ? TORTURE_SSHD_SRV1_IPV4 : TORTURE_SSHD_SRV_IPV4,
                  second_sshd ? TORTURE_SSHD_SRV1_IPV6 : TORTURE_SSHD_SRV_IPV6,
-                 "HostKey",
+                 s->disable_hostkeys ? "" : "HostKey", s->disable_hostkeys ? "" : rsa_hostkey,
-                 rsa_hostkey,
+                 s->disable_hostkeys ? "" : "HostKey", s->disable_hostkeys ? "" : ecdsa_hostkey,
-                 "HostKey",
-                 ecdsa_hostkey,
                  trusted_ca_pubkey,
                  sftp_server,
                  usepam,