Ability to specify allowed ciphersuites based on the protocol version.

The ciphersuites parameter in the ssl_session structure changed from
'int *' to 'int **' and is now malloced in ssl_init() and freed in
ssl_free().

The new function ssl_set_ciphersuite_for_version() sets specific entries
inside this array. ssl_set_ciphersuite() sets all entries to the same
value.

ChangeLog

@@ -1,6 +1,9 @@
 PolarSSL ChangeLog
 
 = Branch 1.2
+Features
+   * Ability to specify allowed ciphersuites based on the protocol version.
+
 Bugfix
    * Fix for MPI assembly for ARM
 

include/polarssl/ssl.h

@@ -491,7 +491,7 @@ struct _ssl_context
     int verify_result;                  /*!<  verification result     */
     int disable_renegotiation;          /*!<  enable/disable renegotiation   */
     int allow_legacy_renegotiation;     /*!<  allow legacy renegotiation     */
-    const int *ciphersuites;            /*!<  allowed ciphersuites    */
+    const int **ciphersuites;           /*!<  allowed ciphersuites / version */
 
 #if defined(POLARSSL_DHM_C)
     mpi dhm_P;                          /*!<  prime modulus for DHM   */
@@ -718,12 +718,30 @@ void ssl_set_session( ssl_context *ssl, const ssl_session *session );
 
 /**
  * \brief               Set the list of allowed ciphersuites
+ *                      (Overrides all version specific lists)
  *
  * \param ssl           SSL context
  * \param ciphersuites  0-terminated list of allowed ciphersuites
  */
 void ssl_set_ciphersuites( ssl_context *ssl, const int *ciphersuites );
 
+/**
+ * \brief               Set the list of allowed ciphersuites for a specific
+ *                      version of the protocol.
+ *                      (Only useful on the server side)
+ *
+ * \param ssl           SSL context
+ * \param ciphersuites  0-terminated list of allowed ciphersuites
+ * \param major         Major version number (only SSL_MAJOR_VERSION_3
+ *                      supported)
+ * \param minor         Minor version number (SSL_MINOR_VERSION_0,
+ *                      SSL_MINOR_VERSION_1 and SSL_MINOR_VERSION_2,
+ *                      SSL_MINOR_VERSION_3 supported)
+ */
+void ssl_set_ciphersuites_for_version( ssl_context *ssl,
+                                       const int *ciphersuites,
+                                       int major, int minor );
+
 /**
  * \brief          Set the data required to verify peer certificate
  *

library/ssl_cli.c

@@ -119,7 +119,7 @@ static int ssl_write_client_hello( ssl_context *ssl )
     SSL_DEBUG_MSG( 3, ( "client hello, session id len.: %d", n ) );
     SSL_DEBUG_BUF( 3,   "client hello, session id", buf + 39, n );
 
-    for( n = 0; ssl->ciphersuites[n] != 0; n++ );
+    for( n = 0; ssl->ciphersuites[ssl->minor_ver][n] != 0; n++ );
     if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE ) n++;
     *p++ = (unsigned char)( n >> 7 );
     *p++ = (unsigned char)( n << 1 );
@@ -139,10 +139,10 @@ static int ssl_write_client_hello( ssl_context *ssl )
     for( i = 0; i < n; i++ )
     {
         SSL_DEBUG_MSG( 3, ( "client hello, add ciphersuite: %2d",
-                       ssl->ciphersuites[i] ) );
+                       ssl->ciphersuites[ssl->minor_ver][i] ) );
 
-        *p++ = (unsigned char)( ssl->ciphersuites[i] >> 8 );
+        *p++ = (unsigned char)( ssl->ciphersuites[ssl->minor_ver][i] >> 8 );
-        *p++ = (unsigned char)( ssl->ciphersuites[i]      );
+        *p++ = (unsigned char)( ssl->ciphersuites[ssl->minor_ver][i]      );
     }
 
 #if defined(POLARSSL_ZLIB_SUPPORT)
@@ -515,13 +515,13 @@ static int ssl_parse_server_hello( ssl_context *ssl )
     i = 0;
     while( 1 )
     {
-        if( ssl->ciphersuites[i] == 0 )
+        if( ssl->ciphersuites[ssl->minor_ver][i] == 0 )
         {
             SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
             return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
         }
 
-        if( ssl->ciphersuites[i++] == ssl->session_negotiate->ciphersuite )
+        if( ssl->ciphersuites[ssl->minor_ver][i++] == ssl->session_negotiate->ciphersuite )
             break;
     }
 

library/ssl_srv.c

@@ -359,13 +359,13 @@ static int ssl_parse_client_hello_v2( ssl_context *ssl )
         }
     }
 
-    for( i = 0; ssl->ciphersuites[i] != 0; i++ )
+    for( i = 0; ssl->ciphersuites[ssl->minor_ver][i] != 0; i++ )
     {
         for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 )
         {
             if( p[0] == 0 &&
                 p[1] == 0 &&
-                p[2] == ssl->ciphersuites[i] )
+                p[2] == ssl->ciphersuites[ssl->minor_ver][i] )
                 goto have_ciphersuite_v2;
         }
     }
@@ -375,7 +375,7 @@ static int ssl_parse_client_hello_v2( ssl_context *ssl )
     return( POLARSSL_ERR_SSL_NO_CIPHER_CHOSEN );
 
 have_ciphersuite_v2:
-    ssl->session_negotiate->ciphersuite = ssl->ciphersuites[i];
+    ssl->session_negotiate->ciphersuite = ssl->ciphersuites[ssl->minor_ver][i];
     ssl_optimize_checksum( ssl, ssl->session_negotiate->ciphersuite );
 
     /*
@@ -642,12 +642,12 @@ static int ssl_parse_client_hello( ssl_context *ssl )
     /*
      * Search for a matching ciphersuite
      */
-    for( i = 0; ssl->ciphersuites[i] != 0; i++ )
+    for( i = 0; ssl->ciphersuites[ssl->minor_ver][i] != 0; i++ )
     {
         for( j = 0, p = buf + 41 + sess_len; j < ciph_len;
             j += 2, p += 2 )
         {
-            if( p[0] == 0 && p[1] == ssl->ciphersuites[i] )
+            if( p[0] == 0 && p[1] == ssl->ciphersuites[ssl->minor_ver][i] )
                 goto have_ciphersuite;
         }
     }
@@ -657,7 +657,7 @@ static int ssl_parse_client_hello( ssl_context *ssl )
     return( POLARSSL_ERR_SSL_NO_CIPHER_CHOSEN );
 
 have_ciphersuite:
-    ssl->session_negotiate->ciphersuite = ssl->ciphersuites[i];
+    ssl->session_negotiate->ciphersuite = ssl->ciphersuites[ssl->minor_ver][i];
     ssl_optimize_checksum( ssl, ssl->session_negotiate->ciphersuite );
 
     ext = buf + 44 + sess_len + ciph_len + comp_len;

library/ssl_tls.c

@@ -2952,7 +2952,8 @@ int ssl_init( ssl_context *ssl )
     ssl->min_major_ver = SSL_MAJOR_VERSION_3;
     ssl->min_minor_ver = SSL_MINOR_VERSION_0;
 
-    ssl->ciphersuites = ssl_default_ciphersuites;
+    ssl->ciphersuites = malloc( sizeof(int *) * 4 );
+    ssl_set_ciphersuites( ssl, ssl_default_ciphersuites );
 
 #if defined(POLARSSL_DHM_C)
     if( ( ret = mpi_read_string( &ssl->dhm_P, 16,
@@ -3133,7 +3134,22 @@ void ssl_set_session( ssl_context *ssl, const ssl_session *session )
 
 void ssl_set_ciphersuites( ssl_context *ssl, const int *ciphersuites )
 {
-    ssl->ciphersuites    = ciphersuites;
+    ssl->ciphersuites[SSL_MINOR_VERSION_0] = ciphersuites;
+    ssl->ciphersuites[SSL_MINOR_VERSION_1] = ciphersuites;
+    ssl->ciphersuites[SSL_MINOR_VERSION_2] = ciphersuites;
+    ssl->ciphersuites[SSL_MINOR_VERSION_3] = ciphersuites;
+}
+
+void ssl_set_ciphersuites_for_version( ssl_context *ssl, const int *ciphersuites,
+                                       int major, int minor )
+{
+    if( major != SSL_MAJOR_VERSION_3 )
+        return;
+
+    if( minor < SSL_MINOR_VERSION_0 || minor > SSL_MINOR_VERSION_3 )
+        return;
+
+    ssl->ciphersuites[minor] = ciphersuites;
 }
 
 void ssl_set_ca_chain( ssl_context *ssl, x509_cert *ca_chain,
@@ -3897,6 +3913,8 @@ void ssl_free( ssl_context *ssl )
 {
     SSL_DEBUG_MSG( 2, ( "=> free" ) );
 
+    free( ssl->ciphersuites );
+
     if( ssl->out_ctr != NULL )
     {
         memset( ssl->out_ctr, 0, SSL_BUFFER_LEN );