Avoid seemingly-possible overflow

By looking just at that test, it looks like 2 + dn_size could overflow. In
fact that can't happen as that would mean we've read a CA cert of size is too
big to be represented by a size_t.

However, it's best for code to be more obviously free of overflow without
having to reason about the bigger picture.
This commit is contained in:
Simon Butcher 2015-12-22 23:53:04 +00:00
parent 15f0bbef2d
commit c23bf6e23c

View file

@ -990,7 +990,9 @@ static int ssl_write_certificate_request( ssl_context *ssl )
{
dn_size = crt->subject_raw.len;
if( end < p || (size_t)( end - p ) < 2 + dn_size )
if( end < p ||
(size_t)( end - p ) < dn_size ||
(size_t)( end - p ) < 2 + dn_size )
{
SSL_DEBUG_MSG( 1, ( "skipping CAs: buffer too short" ) );
break;