BlockCipher.java

/**
 *
 * Copyright 2003-2004 The Apache Software Foundation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.apache.geronimo.util.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();
}