tests: Add dh-group-exchange algorithm tests

Signed-off-by: Aris Adamantiadis <aris@0xbadc0de.be>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

tests/client/torture_algorithms.c

@@ -438,6 +438,26 @@ static void torture_algorithms_dh_group18(void **state) {
     test_algorithm(s->ssh.session, "diffie-hellman-group18-sha512", NULL/*cipher*/, NULL/*hmac*/);
 }
 
+static void torture_algorithms_dh_gex_sha1(void **state)
+{
+    struct torture_state *s = *state;
+
+    test_algorithm(s->ssh.session,
+                   "diffie-hellman-group-exchange-sha1",
+                   NULL,  /* cipher */
+                   NULL); /* hmac */
+}
+
+static void torture_algorithms_dh_gex_sha256(void **state)
+{
+    struct torture_state *s = *state;
+
+    test_algorithm(s->ssh.session,
+                   "diffie-hellman-group-exchange-sha256",
+                   NULL, /* cipher */
+                   NULL); /* hmac */
+}
+
 int torture_run_tests(void) {
     int rc;
     struct CMUnitTest tests[] = {
@@ -544,6 +564,12 @@ int torture_run_tests(void) {
         cmocka_unit_test_setup_teardown(torture_algorithms_dh_group18,
                                         session_setup,
                                         session_teardown),
+        cmocka_unit_test_setup_teardown(torture_algorithms_dh_gex_sha1,
+                                        session_setup,
+                                        session_teardown),
+        cmocka_unit_test_setup_teardown(torture_algorithms_dh_gex_sha256,
+                                        session_setup,
+                                        session_teardown),
 #if ((OPENSSH_VERSION_MAJOR == 7 && OPENSSH_VERSION_MINOR >= 3) || OPENSSH_VERSION_MAJOR > 7)
         cmocka_unit_test_setup_teardown(torture_algorithms_ecdh_curve25519_sha256,
                                         session_setup,

tests/torture.c

@@ -626,7 +626,8 @@ static void torture_setup_create_sshd_config(void **state, bool pam)
 # else /* OPENSSH_VERSION 7.0 - 7.5 */
              "Ciphers +3des-cbc,aes128-cbc,aes192-cbc,aes256-cbc\n"
 # endif /* OPENSSH_VERSION 7.0 - 7.6 */
-             "KexAlgorithms +diffie-hellman-group1-sha1"
+             "KexAlgorithms +diffie-hellman-group1-sha1,"
+             "diffie-hellman-group-exchange-sha1"
 #else /* OPENSSH_VERSION >= 6.7 */
              "Ciphers 3des-cbc,aes128-cbc,aes192-cbc,aes256-cbc,aes128-ctr,"
                      "aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,"