Merge pull request #330 from hannestschofenig/hannestschofenig-patch-7

Accepting records with a v1.1 version number

library/mps/layer2.c

@@ -1867,6 +1867,17 @@ MBEDTLS_MPS_ALWAYS_INLINE
 int l2_version_wire_matches_logical( uint8_t wire_version,
                                      int logical_version )
 {
+
+    /* TODO: Since MBEDTLS_MPS_L2_VERSION_UNSPECIFIED is not 
+     * yet implemented we include this special handling.
+     */
+    if( wire_version == MBEDTLS_SSL_MINOR_VERSION_1 )
+    { 
+        /* Backwards compatibility case */
+        MBEDTLS_MPS_TRACE_COMMENT( "Record with TLS 1.1 version number received" );
+        return( 1 );
+    }
+
     switch( logical_version )
     {
         case MBEDTLS_MPS_L2_VERSION_UNSPECIFIED:
@@ -1956,6 +1967,8 @@ int l2_in_fetch_protected_record_tls( mbedtls_mps_l2 *ctx, mps_rec *rec )
      * MBEDTLS_MPS_L2_VERSION_UNSPECIFIED.
      *
      * Also, for TLS 1.3, the wire-version is still TLS 1.2.
+     * For backwards compatibility reasons, the wire-version may also be set 
+     * to TLS 1.1 for the ClientHello.     
      *
      * We capture both special cases in a helper function checking whether the
      * wire-version matches the configured logical version. */