JEP 244: TLS Application-Layer Protocol Negotiation Extension

Xuelei Fan xuelei.fan at oracle.com
Mon Apr 13 23:51:38 UTC 2015


On 4/14/2015 2:25 AM, Thomas Lußnig wrote:
> Hi,
> 
> i checked the CipherSuites in JDK and found that in the JDK there is and
> mistake i think.
> In CipherSuite the method add set the PRF to NONE only if obsoleted less
> than TLSv1.2.
> But if the suite is forbidden / obsoleted in TLSv1.2 the check must be
> <= (less or equal)
Can you explain more about this point?

Xuelei

> if i am correct.
> 
> http://grepcode.com/file_/repository.grepcode.com/java/root/jdk/openjdk/8-b132/sun/security/ssl/CipherSuite.java/?v=source
> 
>     /*
>      * Use this method when there is no lower protocol limit where this
>      * suite can be used, and the PRF is P_SHA256.  That is, the
>      * existing ciphersuites.  From RFC 5246:
>      *
>      *     All cipher suites in this document use P_SHA256.
>      */
>     private static void add(String name, int id, int priority,
>             KeyExchange keyExchange, BulkCipher cipher,
>             boolean allowed, int obsoleted) {
>         // If this is an obsoleted suite, then don't let the TLS 1.2
>         // protocol have a valid PRF value.
>         PRF prf = P_SHA256;
>         if (obsoleted < ProtocolVersion.TLS12.v) {
>             prf = P_NONE;
>         }
> 
>         add(name, id, priority, keyExchange, cipher, allowed, obsoleted,
>             ProtocolVersion.LIMIT_MIN_VALUE, prf);
>     }
> 
> Gruß Thomas
> 



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