RandomCookie.java (was Re: Code Review Request: TLS 1.3 Implementation)

[Weijun Wang]

RandomCookie.java:

+    private boolean isT12Downgrade() {
+        return Arrays.equals(randomBytes, 24, 31, t12Protection, 0, 7);
+    }
+
+    private boolean isT11Downgrade() {
+        return Arrays.equals(randomBytes, 24, 31, t11Protection, 0, 7);
+    }

The "to" in Arrays::equals is exclusive, so please update 31 -> 32, 7 -> 8.

Also, at the end of https://tools.ietf.org/html/draft-ietf-tls-tls13-28#section-4.1.3

   RFC EDITOR: PLEASE REMOVE THE FOLLOWING PARAGRAPH Implementations of
   draft versions (see Section 4.2.1.1) of this specification SHOULD NOT
   implement this mechanism on either client and server.  A pre-RFC
   client connecting to RFC servers, or vice versa, will appear to
   downgrade to TLS 1.2.  With the mechanism enabled, this will cause an
   interoperability failure.

Has the current implementation implemented (and turned on) this mechanism?

Thanks
Max

> 
> 
>>>> On Jun 5, 2018, at 12:12 PM, Xuelei Fan <xuelei.fan at oracle.com> wrote:
>>>> 
>>>>> http://cr.openjdk.java.net/~xuelei/8196584/webrev-full.01
>