package org.bouncycastle.crypto;/** * Block cipher engines are expected to conform to this interface. */public interface BlockCipher{    /**     * Initialise the cipher.     *     * @param forEncryption if true the cipher is initialised for     *  encryption, if false for decryption.     * @param params the key and other data required by the cipher.     * @exception IllegalArgumentException if the params argument is     * inappropriate.     */    public void init(boolean forEncryption, CipherParameters params)        throws IllegalArgumentException;    /**     * Return the name of the algorithm the cipher implements.     *     * @return the name of the algorithm the cipher implements.     */    public String getAlgorithmName();    /**     * Return the block size for this cipher (in bytes).     *     * @return the block size for this cipher in bytes.     */    public int getBlockSize();    /**     * Process one block of input from the array in and write it to     * the out array.     *     * @param in the array containing the input data.     * @param inOff offset into the in array the data starts at.     * @param out the array the output data will be copied into.     * @param outOff the offset into the out array the output will start at.     * @exception DataLengthException if there isn't enough data in in, or     * space in out.     * @exception IllegalStateException if the cipher isn't initialised.     * @return the number of bytes processed and produced.     */    public int processBlock(byte[] in, int inOff, byte[] out, int outOff)        throws DataLengthException, IllegalStateException;    /**     * Reset the cipher. After resetting the cipher is in the same state     * as it was after the last init (if there was one).     */    public void reset();}