public Delegate(MessageDigestSpi digestSpi,
    String algorithm) 
{
            super(algorithm);
            this.digestSpi = digestSpi;
}

 public Object clone() throws CloneNotSupportedException 
{
            if (digestSpi instanceof Cloneable) {
                MessageDigestSpi digestSpiClone =
                    (MessageDigestSpi)digestSpi.clone();
                // Because 'algorithm', 'provider', and 'state' are private
                // members of our supertype, we must perform a cast to
                // access them.
                MessageDigest that =
                    new Delegate(digestSpiClone,
                                 ((MessageDigest)this).algorithm);
                that.provider = ((MessageDigest)this).provider;
                that.state = ((MessageDigest)this).state;
                return that;
            } else {
                throw new CloneNotSupportedException();
            }
}

Returns a clone if the delegate is cloneable.

 protected byte[] engineDigest() 
{
            return digestSpi.engineDigest();
}

 protected int engineDigest(byte[] buf,
    int offset,
    int len) throws DigestException 
{
                return digestSpi.engineDigest(buf, offset, len);
}

 protected int engineGetDigestLength() 
{
            return digestSpi.engineGetDigestLength();
}

 protected  void engineReset() 
{
            digestSpi.engineReset();
}

 protected  void engineUpdate(byte input) 
{
            digestSpi.engineUpdate(input);
}

 protected  void engineUpdate(ByteBuffer input) 
{
            digestSpi.engineUpdate(input);
}

 protected  void engineUpdate(byte[] input,
    int offset,
    int len) 
{
            digestSpi.engineUpdate(input, offset, len);
}