Encrypted Extensions: Change extensions length check
@@ -1432,7 +1432,7 @@ static int ssl_tls13_process_encrypted_extensions( mbedtls_ssl_context *ssl )
/* Process the message contents */
MBEDTLS_SSL_PROC_CHK(
- ssl_tls13_parse_encrypted_extensions( ssl, buf, ( buf + buf_len ) ) );
+ ssl_tls13_parse_encrypted_extensions( ssl, buf, buf + buf_len ) );
mbedtls_ssl_tls1_3_add_hs_msg_to_checksum(
ssl, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSION, buf, buf_len );
@@ -1458,14 +1458,17 @@ static int ssl_tls13_parse_encrypted_extensions( mbedtls_ssl_context *ssl,
int ret = 0;
size_t extensions_len;
const unsigned char *p = buf;
+ const unsigned char *extensions_end;
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
extensions_len = MBEDTLS_GET_UINT16_BE( p, 0 );
p += 2;
MBEDTLS_SSL_DEBUG_BUF( 3, "encrypted extensions", p, extensions_len );
+ extensions_end = p + extensions_len;
+ MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, extensions_len );
- while( p < end )
+ while( p < extensions_end )
{
unsigned int extension_type;
size_t extension_data_len;
@@ -1476,12 +1479,12 @@ static int ssl_tls13_parse_encrypted_extensions( mbedtls_ssl_context *ssl,
* opaque extension_data<0..2^16-1>;
* } Extension;
*/
- MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 4 );
+ MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, 4 );
extension_type = MBEDTLS_GET_UINT16_BE( p, 0 );
extension_data_len = MBEDTLS_GET_UINT16_BE( p, 2 );
p += 4;
- MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, extension_data_len );
+ MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, extension_data_len );
/* The client MUST check EncryptedExtensions for the
* presence of any forbidden extensions and if any are found MUST abort
@@ -1501,18 +1504,17 @@ static int ssl_tls13_parse_encrypted_extensions( mbedtls_ssl_context *ssl,
MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT, \
MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION );
return ( MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION );
- break;
}
p += extension_data_len;
}
/* Check that we consumed all the message. */
- if( p != end )
+ if( p != extensions_end )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "EncryptedExtension lengths misaligned" ) );
- MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, \
- MBEDTLS_ERR_SSL_DECODE_ERROR );
+ MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER, \
+ MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_DECODE_ERROR );
}
