Commit c6dab2b0 authored by Janos Follath's avatar Janos Follath Committed by Simon Butcher

Fix non compliance SSLv3 in server extension handling.

The server code parses the client hello extensions even when the
protocol is SSLv3 and this behaviour is non compliant with rfc6101.
Also the server sends extensions in the server hello and omitting
them may prevent interoperability problems.
parent 00efff74
......@@ -34,6 +34,8 @@ Changes
* Disabled SSLv3 in the default configuration.
* Optimized mbedtls_mpi_zeroize() for MPI integer size. (Fix by Alexey
Skalozub).
* Fix non-compliance server extension handling. Extensions for SSLv3 are now
ignored, as required by RFC6101.
= mbed TLS 2.2.1 released 2016-01-05
......
......@@ -1507,6 +1507,12 @@ read_record_header:
ssl->session_negotiate->compression = MBEDTLS_SSL_COMPRESS_NULL;
#endif
/* Do not parse the extensions if the protocol is SSLv3 */
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( ( ssl->major_ver != 3 ) || ( ssl->minor_ver != 0 ) )
{
#endif
/*
* Check the extension length
*/
......@@ -1692,8 +1698,13 @@ read_record_header:
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
}
#if defined(MBEDTLS_SSL_PROTO_SSL3)
}
#endif
#if defined(MBEDTLS_SSL_FALLBACK_SCSV)
for( i = 0, p = buf + 41 + sess_len; i < ciph_len; i += 2, p += 2 )
{
......@@ -2363,6 +2374,12 @@ static int ssl_write_server_hello( mbedtls_ssl_context *ssl )
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: 0x%02X",
ssl->session_negotiate->compression ) );
/* Do not write the extensions if the protocol is SSLv3 */
#if defined(MBEDTLS_SSL_PROTO_SSL3)
if( ( ssl->major_ver != 3 ) || ( ssl->minor_ver != 0 ) )
{
#endif
/*
* First write extensions, then the total length
*/
......@@ -2419,6 +2436,10 @@ static int ssl_write_server_hello( mbedtls_ssl_context *ssl )
p += ext_len;
}
#if defined(MBEDTLS_SSL_PROTO_SSL3)
}
#endif
ssl->out_msglen = p - buf;
ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = MBEDTLS_SSL_HS_SERVER_HELLO;
......
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