Java tutorial
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(); }