1 package org.bouncycastle.crypto; 2 3 4 /** 5 * Block cipher engines are expected to conform to this interface. 6 */ 7 public 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
