package org.bouncycastle.crypto;/** * Generic signer interface for hash based and message recovery signers. */public interface Signer {    /**     * Initialise the signer for signing or verification.     *      * @param forSigning true if for signing, false otherwise     * @param param necessary parameters.     */    public void init(boolean forSigning, CipherParameters param);    /**     * update the internal digest with the byte b     */    public void update(byte b);    /**     * update the internal digest with the byte array in     */    public void update(byte[] in, int off, int len);    /**     * generate a signature for the message we've been loaded with using     * the key we were initialised with.     */    public byte[] generateSignature()        throws CryptoException, DataLengthException;    /**     * return true if the internal state represents the signature described     * in the passed in array.     */    public boolean verifySignature(byte[] signature);        /**     * reset the internal state     */    public void reset();}