Add key_opaque option to ssl_server2.c + test

Signed-off-by: Przemyslaw Stekiel <przemyslaw.stekiel@mobica.com>

programs/ssl/ssl_server2.c

@@ -80,6 +80,7 @@ int main( void )
 #define DFL_CA_PATH             ""
 #define DFL_CRT_FILE            ""
 #define DFL_KEY_FILE            ""
+#define DFL_KEY_OPAQUE          0
 #define DFL_KEY_PWD             ""
 #define DFL_CRT_FILE2           ""
 #define DFL_KEY_FILE2           ""
@@ -200,6 +201,13 @@ int main( void )
 #else
 #define USAGE_IO ""
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
+#if defined(MBEDTLS_USE_PSA_CRYPTO) && defined(MBEDTLS_X509_CRT_PARSE_C)
+#define USAGE_KEY_OPAQUE \
+    "    key_opaque=%%d       Handle your private key as if it were opaque\n" \
+    "                        default: 0 (disabled)\n"
+#else
+#define USAGE_KEY_OPAQUE ""
+#endif
 
 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
 #define USAGE_SSL_ASYNC \
@@ -483,6 +491,7 @@ int main( void )
     "    cert_req_ca_list=%%d default: 1 (send ca list)\n"  \
     "                        options: 1 (send ca list), 0 (don't send)\n" \
     USAGE_IO                                                \
+    USAGE_KEY_OPAQUE                                        \
     "\n"                                                    \
     USAGE_PSK                                               \
     USAGE_CA_CALLBACK                                       \
@@ -567,6 +576,7 @@ struct options
     const char *ca_path;        /* the path with the CA certificate(s) reside */
     const char *crt_file;       /* the file with the server certificate     */
     const char *key_file;       /* the file with the server key             */
+    int key_opaque;             /* handle private key as if it were opaque  */
     const char *key_pwd;        /* the password for the server key          */
     const char *crt_file2;      /* the file with the 2nd server certificate */
     const char *key_file2;      /* the file with the 2nd server key         */
@@ -1315,6 +1325,9 @@ int main( int argc, char *argv[] )
     mbedtls_pk_context pkey;
     mbedtls_x509_crt srvcert2;
     mbedtls_pk_context pkey2;
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    psa_key_id_t key_slot = 0; /* invalid key slot */
+#endif
     int key_cert_init = 0, key_cert_init2 = 0;
 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
     ssl_async_key_context_t ssl_async_keys;
@@ -1491,6 +1504,7 @@ int main( int argc, char *argv[] )
     opt.ca_path             = DFL_CA_PATH;
     opt.crt_file            = DFL_CRT_FILE;
     opt.key_file            = DFL_KEY_FILE;
+    opt.key_opaque          = DFL_KEY_OPAQUE;
     opt.key_pwd             = DFL_KEY_PWD;
     opt.crt_file2           = DFL_CRT_FILE2;
     opt.key_file2           = DFL_KEY_FILE2;
@@ -1622,6 +1636,10 @@ int main( int argc, char *argv[] )
             opt.key_file = q;
         else if( strcmp( p, "key_pwd" ) == 0 )
             opt.key_pwd = q;
+#if defined(MBEDTLS_USE_PSA_CRYPTO) && defined(MBEDTLS_X509_CRT_PARSE_C)
+        else if( strcmp( p, "key_opaque" ) == 0 )
+            opt.key_opaque = atoi( q );
+#endif
         else if( strcmp( p, "crt_file2" ) == 0 )
             opt.crt_file2 = q;
         else if( strcmp( p, "key_file2" ) == 0 )
@@ -2473,11 +2491,23 @@ int main( int argc, char *argv[] )
                             (unsigned int) -ret );
             goto exit;
         }
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    if( opt.key_opaque != 0 )
+    {
+        if( ( ret = mbedtls_pk_wrap_as_opaque( &pkey2, &key_slot,
+                                               PSA_ALG_SHA_256 ) ) != 0 )
+        {
+            mbedtls_printf( " failed\n  !  "
+                            "mbedtls_pk_wrap_as_opaque returned -0x%x\n\n", (unsigned int)  -ret );
+            goto exit;
+        }
+    }
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
         key_cert_init2 = 2;
 #endif /* MBEDTLS_ECDSA_C */
     }
 
-    mbedtls_printf( " ok\n" );
+    mbedtls_printf( " ok (key type: %s)\n", mbedtls_pk_get_name( &pkey2 ) );
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
 #if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_FS_IO)

tests/ssl-opt.sh

@@ -1444,6 +1444,21 @@ run_test    "Opaque key for client authentication" \
             -S "error" \
             -C "error"
 
+# Test using an opaque private key for server authentication
+requires_config_enabled MBEDTLS_USE_PSA_CRYPTO
+requires_config_enabled MBEDTLS_X509_CRT_PARSE_C
+requires_config_enabled MBEDTLS_ECDSA_C
+requires_config_enabled MBEDTLS_SHA256_C
+run_test    "Opaque key for server authentication" \
+            "$P_SRV auth_mode=required key_opaque=1" \
+            "$P_CLI crt_file=data_files/server5.crt \
+             key_file=data_files/server5.key" \
+            0 \
+            -c "Verifying peer X.509 certificate... ok" \
+            -s "key type: Opaque" \
+            -S "error" \
+            -C "error"
+
 # Test ciphersuites which we expect to be fully supported by PSA Crypto
 # and check that we don't fall back to Mbed TLS' internal crypto primitives.
 run_test_psa TLS-ECDHE-ECDSA-WITH-AES-128-CCM