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.
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 9afd399..6b5b461 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -2584,7 +2584,9 @@
{
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 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "skipping CAs: buffer too short" ) );
break;
