Fix potential overflow in CertificateRequest

This commit is contained in:
Manuel Pégourié-Gonnard 2015-10-02 11:16:47 +02:00
parent c7e61a2e3f
commit de9c8a5734
2 changed files with 12 additions and 3 deletions

View file

@ -21,6 +21,10 @@ Security
* Fix possible heap buffer overflow in base64_encode() when the input
buffer is 512MB or larger on 32-bit platforms.
Found by Guido Vranken. Not trigerrable remotely in TLS.
* Fix potential heap buffer overflow in servers that perform client
authentication against a crafted CA cert. Cannot be triggered remotely
unless you allow third parties to pick trust CAs for client auth.
Found by Guido Vranken.
= mbed TLS 1.3.13 released 2015-09-17

View file

@ -2300,6 +2300,7 @@ static int ssl_write_certificate_request( ssl_context *ssl )
size_t ct_len, sa_len; /* including length bytes */
unsigned char *buf, *p;
const x509_crt *crt;
const unsigned char * const end = ssl->out_msg + SSL_MAX_CONTENT_LEN;
SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) );
@ -2406,10 +2407,14 @@ static int ssl_write_certificate_request( ssl_context *ssl )
total_dn_size = 0;
while( crt != NULL && crt->version != 0 )
{
if( p - buf > 4096 )
break;
dn_size = crt->subject_raw.len;
if( end < p || (size_t)( end - p ) < 2 + dn_size )
{
SSL_DEBUG_MSG( 1, ( "skipping CAs: buffer too short" ) );
break;
}
*p++ = (unsigned char)( dn_size >> 8 );
*p++ = (unsigned char)( dn_size );
memcpy( p, crt->subject_raw.p, dn_size );