mbedtls: Prevent bounds check bypass through overflow in PSK identity parsing

This is a patch for CVE-2017-18187.
Cherry-picked from 83c9f495ff
Ref. https://github.com/espressif/esp-idf/issues/1730
This commit is contained in:
Ivan Grokhotkov 2018-04-19 11:42:56 +08:00
parent 0a97cb62ef
commit 67ba85650d

View file

@ -3436,7 +3436,7 @@ static int ssl_parse_client_psk_identity( mbedtls_ssl_context *ssl, unsigned cha
/*
* Receive client pre-shared key identity name
*/
if( *p + 2 > end )
if( end - *p < 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
@ -3445,7 +3445,7 @@ static int ssl_parse_client_psk_identity( mbedtls_ssl_context *ssl, unsigned cha
n = ( (*p)[0] << 8 ) | (*p)[1];
*p += 2;
if( n < 1 || n > 65535 || *p + n > end )
if( n < 1 || n > 65535 || n > (size_t) ( end - *p ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );