Merge pull request #5428 from gstrauss/mbedtls_ssl_ciphersuite

Add accessors for ciphersuite info

ChangeLog.d/mbedtls_ssl_get_ciphersuite_id.txt

@@ -0,0 +1,3 @@
+Features
+   * Add accessor to obtain ciphersuite id from ssl context.
+   * Add accessors to get members from ciphersuite info.

include/mbedtls/ssl.h

@@ -3888,6 +3888,15 @@ size_t mbedtls_ssl_get_bytes_avail( const mbedtls_ssl_context *ssl );
  */
 uint32_t mbedtls_ssl_get_verify_result( const mbedtls_ssl_context *ssl );
 
+/**
+ * \brief          Return the id of the current ciphersuite
+ *
+ * \param ssl      SSL context
+ *
+ * \return         a ciphersuite id
+ */
+int mbedtls_ssl_get_ciphersuite_id_from_ssl( const mbedtls_ssl_context *ssl );
+
 /**
  * \brief          Return the name of the current ciphersuite
  *

include/mbedtls/ssl_ciphersuites.h

@@ -394,6 +394,13 @@ mbedtls_pk_type_t mbedtls_ssl_get_ciphersuite_sig_alg( const mbedtls_ssl_ciphers
 int mbedtls_ssl_ciphersuite_uses_ec( const mbedtls_ssl_ciphersuite_t *info );
 int mbedtls_ssl_ciphersuite_uses_psk( const mbedtls_ssl_ciphersuite_t *info );
 
+static inline const char *mbedtls_ssl_ciphersuite_get_name( const mbedtls_ssl_ciphersuite_t *info )
+{
+    return info->MBEDTLS_PRIVATE(name);
+}
+
+size_t mbedtls_ssl_ciphersuite_get_cipher_key_bitlen( const mbedtls_ssl_ciphersuite_t *info );
+
 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PFS_ENABLED)
 static inline int mbedtls_ssl_ciphersuite_has_pfs( const mbedtls_ssl_ciphersuite_t *info )
 {

library/ssl_ciphersuites.c

@@ -2064,6 +2064,19 @@ int mbedtls_ssl_get_ciphersuite_id( const char *ciphersuite_name )
     return( cur->id );
 }
 
+size_t mbedtls_ssl_ciphersuite_get_cipher_key_bitlen( const mbedtls_ssl_ciphersuite_t *info )
+{
+#if defined(MBEDTLS_CIPHER_C)
+    const mbedtls_cipher_info_t * const cipher_info =
+      mbedtls_cipher_info_from_type( info->cipher );
+
+    return( mbedtls_cipher_info_get_key_bitlen( cipher_info ) );
+#else
+    (void)info;
+    return( 0 );
+#endif
+}
+
 #if defined(MBEDTLS_PK_C)
 mbedtls_pk_type_t mbedtls_ssl_get_ciphersuite_sig_pk_alg( const mbedtls_ssl_ciphersuite_t *info )
 {

library/ssl_tls.c

@@ -4364,6 +4364,14 @@ uint32_t mbedtls_ssl_get_verify_result( const mbedtls_ssl_context *ssl )
     return( 0xFFFFFFFF );
 }
 
+int mbedtls_ssl_get_ciphersuite_id_from_ssl( const mbedtls_ssl_context *ssl )
+{
+    if( ssl == NULL || ssl->session == NULL )
+        return( 0 );
+
+    return( ssl->session->ciphersuite );
+}
+
 const char *mbedtls_ssl_get_ciphersuite( const mbedtls_ssl_context *ssl )
 {
     if( ssl == NULL || ssl->session == NULL )

programs/ssl/ssl_client2.c

@@ -2144,9 +2144,19 @@ int main( int argc, char *argv[] )
         }
     }
 
-    mbedtls_printf( " ok\n    [ Protocol is %s ]\n    [ Ciphersuite is %s ]\n",
-                    mbedtls_ssl_get_version( &ssl ),
-                    mbedtls_ssl_get_ciphersuite( &ssl ) );
+    {
+        int suite_id = mbedtls_ssl_get_ciphersuite_id_from_ssl( &ssl );
+        const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
+        ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( suite_id );
+
+        mbedtls_printf( " ok\n    [ Protocol is %s ]\n"
+                             "    [ Ciphersuite is %s ]\n"
+                             "    [ Key size is %u ]\n",
+          mbedtls_ssl_get_version( &ssl ),
+          mbedtls_ssl_ciphersuite_get_name( ciphersuite_info ),
+          (unsigned int)
+            mbedtls_ssl_ciphersuite_get_cipher_key_bitlen( ciphersuite_info ) );
+    }
 
     if( ( ret = mbedtls_ssl_get_record_expansion( &ssl ) ) >= 0 )
         mbedtls_printf( "    [ Record expansion is %d ]\n", ret );

programs/ssl/ssl_server2.c

@@ -3243,8 +3243,17 @@ handshake:
     }
     else /* ret == 0 */
     {
-        mbedtls_printf( " ok\n    [ Protocol is %s ]\n    [ Ciphersuite is %s ]\n",
-                mbedtls_ssl_get_version( &ssl ), mbedtls_ssl_get_ciphersuite( &ssl ) );
+        int suite_id = mbedtls_ssl_get_ciphersuite_id_from_ssl( &ssl );
+        const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
+        ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( suite_id );
+
+        mbedtls_printf( " ok\n    [ Protocol is %s ]\n"
+                             "    [ Ciphersuite is %s ]\n"
+                             "    [ Key size is %u ]\n",
+          mbedtls_ssl_get_version( &ssl ),
+          mbedtls_ssl_ciphersuite_get_name( ciphersuite_info ),
+          (unsigned int)
+            mbedtls_ssl_ciphersuite_get_cipher_key_bitlen( ciphersuite_info ) );
     }
 
     if( ( ret = mbedtls_ssl_get_record_expansion( &ssl ) ) >= 0 )

programs/ssl/ssl_test_lib.h

@@ -70,6 +70,7 @@
 
 #include "mbedtls/net_sockets.h"
 #include "mbedtls/ssl.h"
+#include "mbedtls/ssl_ciphersuites.h"
 #include "mbedtls/entropy.h"
 #include "mbedtls/ctr_drbg.h"
 #include "mbedtls/hmac_drbg.h"

tests/ssl-opt.sh

@@ -1475,6 +1475,20 @@ run_test    "TLS client auth: required" \
             0 \
             -s "Verifying peer X.509 certificate... ok"
 
+run_test    "key size: TLS-ECDHE-ECDSA-WITH-CHACHA20-POLY1305-SHA256" \
+            "$P_SRV" \
+            "$P_CLI force_ciphersuite=TLS-ECDHE-ECDSA-WITH-CHACHA20-POLY1305-SHA256" \
+            0 \
+            -c "Ciphersuite is TLS-ECDHE-ECDSA-WITH-CHACHA20-POLY1305-SHA256" \
+            -c "Key size is 256"
+
+run_test    "key size: TLS-ECDHE-ECDSA-WITH-AES-128-CCM-8" \
+            "$P_SRV" \
+            "$P_CLI force_ciphersuite=TLS-ECDHE-ECDSA-WITH-AES-128-CCM-8" \
+            0 \
+            -c "Ciphersuite is TLS-ECDHE-ECDSA-WITH-AES-128-CCM-8" \
+            -c "Key size is 128"
+
 requires_config_enabled MBEDTLS_X509_CRT_PARSE_C
 requires_config_enabled MBEDTLS_ECDSA_C
 requires_config_enabled MBEDTLS_SHA256_C