http://www.bouncycastle.org/java.html: The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for JDK 1.5 to JDK 1.8.
  • The Legion of the Bouncy Castle Inc. 
package org.bouncycastle.crypto.tls;

import org.bouncycastle.crypto.Digest;

public interface TlsHandshakeHash
    extends Digest
{
    void init(TlsContext context);

    TlsHandshakeHash notifyPRFDetermined();

    void trackHashAlgorithm(short hashAlgorithm);

    void sealHashAlgorithms();

    TlsHandshakeHash stopTracking();

    Digest forkPRFHash();

    byte[] getFinalHash(short hashAlgorithm);
}