Stricter check on SSL ClientHello internal sizes compared to actual packet size

This commit is contained in:
Paul Bakker 2014-05-22 15:12:19 +02:00
parent dff3139cc8
commit 0f651c7422
2 changed files with 9 additions and 5 deletions

View file

@ -5,6 +5,8 @@ Bugfix
* Fix in debug_print_msg() * Fix in debug_print_msg()
* Enforce alignment in the buffer allocator even if buffer is not alligned * Enforce alignment in the buffer allocator even if buffer is not alligned
* Remove less-than-zero checks on unsigned numbers * Remove less-than-zero checks on unsigned numbers
* Stricter check on SSL ClientHello internal sizes compared to actual packet
size (found by TrustInSoft)
= PolarSSL 1.3.7 released on 2014-05-02 = PolarSSL 1.3.7 released on 2014-05-02
Features Features

View file

@ -1209,8 +1209,9 @@ static int ssl_parse_client_hello( ssl_context *ssl )
* 38 . 38 session id length * 38 . 38 session id length
* 39 . 38+x session id * 39 . 38+x session id
* 39+x . 40+x ciphersuitelist length * 39+x . 40+x ciphersuitelist length
* 41+x . .. ciphersuitelist * 41+x . 40+y ciphersuitelist
* .. . .. compression alg. * 41+y . 41+y compression alg length
* 42+y . 41+z compression algs
* .. . .. extensions * .. . .. extensions
*/ */
SSL_DEBUG_BUF( 4, "record contents", buf, n ); SSL_DEBUG_BUF( 4, "record contents", buf, n );
@ -1275,7 +1276,7 @@ static int ssl_parse_client_hello( ssl_context *ssl )
*/ */
sess_len = buf[38]; sess_len = buf[38];
if( sess_len > 32 ) if( sess_len > 32 || sess_len > n - 42 )
{ {
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
@ -1293,7 +1294,7 @@ static int ssl_parse_client_hello( ssl_context *ssl )
ciph_len = ( buf[39 + sess_len] << 8 ) ciph_len = ( buf[39 + sess_len] << 8 )
| ( buf[40 + sess_len] ); | ( buf[40 + sess_len] );
if( ciph_len < 2 || ( ciph_len % 2 ) != 0 ) if( ciph_len < 2 || ( ciph_len % 2 ) != 0 || ciph_len > n - 42 - sess_len )
{ {
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
@ -1304,7 +1305,8 @@ static int ssl_parse_client_hello( ssl_context *ssl )
*/ */
comp_len = buf[41 + sess_len + ciph_len]; comp_len = buf[41 + sess_len + ciph_len];
if( comp_len < 1 || comp_len > 16 ) if( comp_len < 1 || comp_len > 16 ||
comp_len > n - 42 - sess_len - ciph_len )
{ {
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );