Don't attempt to add a zero length padding extension
authorMatt Caswell <matt@openssl.org>
Mon, 4 Sep 2017 07:44:02 +0000 (08:44 +0100)
committerMatt Caswell <matt@openssl.org>
Mon, 4 Sep 2017 14:15:30 +0000 (15:15 +0100)
The padding extension should always be at least 1 byte long

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/4331)

ssl/statem/extensions_clnt.c

index 2c72dea..bffe7ac 100644 (file)
@@ -843,7 +843,7 @@ EXT_RETURN tls_construct_ctos_padding(SSL *s, WPACKET *pkt,
          * 1 byte long so as not to have an empty extension last (WebSphere 7.x,
          * 8.x are intolerant of that condition)
          */
-        if (hlen >= 4)
+        if (hlen > 4)
             hlen -= 4;
         else
             hlen = 1;