Merge remote-tracking branch 'upstream-restricted/pr/461' into development-restricted-proposed

This commit is contained in:
Gilles Peskine 2018-04-19 17:41:39 +02:00
commit f2b76cd45c
2 changed files with 51 additions and 10 deletions
library

View file

@ -2673,10 +2673,27 @@ static int ssl_parse_certificate_request( mbedtls_ssl_context *ssl )
buf = ssl->in_msg;
/* certificate_types */
if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
}
cert_type_len = buf[mbedtls_ssl_hs_hdr_len( ssl )];
n = cert_type_len;
if( ssl->in_hslen < mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n )
/*
* In the subsequent code there are two paths that read from buf:
* * the length of the signature algorithms field (if minor version of
* SSL is 3),
* * distinguished name length otherwise.
* Both reach at most the index:
* ...hdr_len + 2 + n,
* therefore the buffer length at this point must be greater than that
* regardless of the actual code path.
*/
if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
@ -2691,9 +2708,32 @@ static int ssl_parse_certificate_request( mbedtls_ssl_context *ssl )
size_t sig_alg_len = ( ( buf[mbedtls_ssl_hs_hdr_len( ssl ) + 1 + n] << 8 )
| ( buf[mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n] ) );
#if defined(MBEDTLS_DEBUG_C)
unsigned char* sig_alg = buf + mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n;
unsigned char* sig_alg;
size_t i;
#endif
/*
* The furthest access in buf is in the loop few lines below:
* sig_alg[i + 1],
* where:
* sig_alg = buf + ...hdr_len + 3 + n,
* max(i) = sig_alg_len - 1.
* Therefore the furthest access is:
* buf[...hdr_len + 3 + n + sig_alg_len - 1 + 1],
* which reduces to:
* buf[...hdr_len + 3 + n + sig_alg_len],
* which is one less than we need the buf to be.
*/
if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n + sig_alg_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
}
#if defined(MBEDTLS_DEBUG_C)
sig_alg = buf + mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n;
for( i = 0; i < sig_alg_len; i += 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Supported Signature Algorithm found: %d"
@ -2702,14 +2742,6 @@ static int ssl_parse_certificate_request( mbedtls_ssl_context *ssl )
#endif
n += 2 + sig_alg_len;
if( ssl->in_hslen < mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
}
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */