Fix potential integer overflow parsing DER CRT

This patch prevents a potential signed integer overflow during the
certificate version verification checks.
This commit is contained in:
Andres AG 2017-03-09 16:46:14 +00:00 committed by Simon Butcher
parent 26124be17a
commit 47f3059780
2 changed files with 6 additions and 3 deletions

View file

@ -17,6 +17,9 @@ Bugfix
encoded X509 CRLs. The overflow would enable maliciously constructed CRLs
to bypass the version verification check. Found by Peng Li/Yueh-Hsun Lin,
KNOX Security, Samsung Research America
* Fix a potential integer overflow in the version verification for DER
encoded X509 certificates. The overflow would enable maliciously
constructed certificates to bypass the certificate verification check.
= mbed TLS 1.3.20 branch released 2017-06-21

View file

@ -619,14 +619,14 @@ static int x509_crt_parse_der_core( x509_crt *crt, const unsigned char *buf,
return( ret );
}
crt->version++;
if( crt->version > 3 )
if( crt->version < 0 || crt->version > 2 )
{
x509_crt_free( crt );
return( POLARSSL_ERR_X509_UNKNOWN_VERSION );
}
crt->version++;
if( ( ret = x509_get_sig_alg( &crt->sig_oid1, &sig_params1,
&crt->sig_md, &crt->sig_pk,
&crt->sig_opts ) ) != 0 )