BlockCipher.java revision e6bf3e8dfa2804891a82075cb469b736321b4827 
1package org.bouncycastle.crypto;
2
3
4/**
5 * Block cipher engines are expected to conform to this interface.
6 */
7public interface BlockCipher
8{
9    /**
10     * Initialise the cipher.
11     *
12     * @param forEncryption if true the cipher is initialised for
13     *  encryption, if false for decryption.
14     * @param params the key and other data required by the cipher.
15     * @exception IllegalArgumentException if the params argument is
16     * inappropriate.
17     */
18    public void init(boolean forEncryption, CipherParameters params)
19        throws IllegalArgumentException;
20
21    /**
22     * Return the name of the algorithm the cipher implements.
23     *
24     * @return the name of the algorithm the cipher implements.
25     */
26    public String getAlgorithmName();
27
28    /**
29     * Return the block size for this cipher (in bytes).
30     *
31     * @return the block size for this cipher in bytes.
32     */
33    public int getBlockSize();
34
35    /**
36     * Process one block of input from the array in and write it to
37     * the out array.
38     *
39     * @param in the array containing the input data.
40     * @param inOff offset into the in array the data starts at.
41     * @param out the array the output data will be copied into.
42     * @param outOff the offset into the out array the output will start at.
43     * @exception DataLengthException if there isn't enough data in in, or
44     * space in out.
45     * @exception IllegalStateException if the cipher isn't initialised.
46     * @return the number of bytes processed and produced.
47     */
48    public int processBlock(byte[] in, int inOff, byte[] out, int outOff)
49        throws DataLengthException, IllegalStateException;
50
51    /**
52     * Reset the cipher. After resetting the cipher is in the same state
53     * as it was after the last init (if there was one).
54     */
55    public void reset();
56}
57