Add bounds check before signature length read

This commit is contained in:
Krzysztof Stachowiak 2018-03-13 11:28:49 +01:00
parent 469b882947
commit a1098f81c2

View File

@ -2478,6 +2478,14 @@ static int ssl_parse_server_key_exchange( mbedtls_ssl_context *ssl )
/*
* Read signature
*/
if( p > end - 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
sig_len = ( p[0] << 8 ) | p[1];
p += 2;