JEP 244: TLS Application-Layer Protocol Negotiation Extension

Thomas Lußnig openjdk at
Mon Apr 13 18:25:40 UTC 2015


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)
if i am correct.

     * 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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