001    /**
002     *  Licensed to the Apache Software Foundation (ASF) under one or more
003     *  contributor license agreements.  See the NOTICE file distributed with
004     *  this work for additional information regarding copyright ownership.
005     *  The ASF licenses this file to You under the Apache License, Version 2.0
006     *  (the "License"); you may not use this file except in compliance with
007     *  the License.  You may obtain a copy of the License at
008     *
009     *     http://www.apache.org/licenses/LICENSE-2.0
010     *
011     *  Unless required by applicable law or agreed to in writing, software
012     *  distributed under the License is distributed on an "AS IS" BASIS,
013     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     *  See the License for the specific language governing permissions and
015     *  limitations under the License.
016     */
017    
018    package org.apache.geronimo.util.crypto;
019    
020    
021    /**
022     * Block cipher engines are expected to conform to this interface.
023     */
024    public interface BlockCipher
025    {
026        /**
027         * Initialise the cipher.
028         *
029         * @param forEncryption if true the cipher is initialised for
030         *  encryption, if false for decryption.
031         * @param params the key and other data required by the cipher.
032         * @exception IllegalArgumentException if the params argument is
033         * inappropriate.
034         */
035        public void init(boolean forEncryption, CipherParameters params)
036            throws IllegalArgumentException;
037    
038        /**
039         * Return the name of the algorithm the cipher implements.
040         *
041         * @return the name of the algorithm the cipher implements.
042         */
043        public String getAlgorithmName();
044    
045        /**
046         * Return the block size for this cipher (in bytes).
047         *
048         * @return the block size for this cipher in bytes.
049         */
050        public int getBlockSize();
051    
052        /**
053         * Process one block of input from the array in and write it to
054         * the out array.
055         *
056         * @param in the array containing the input data.
057         * @param inOff offset into the in array the data starts at.
058         * @param out the array the output data will be copied into.
059         * @param outOff the offset into the out array the output will start at.
060         * @exception DataLengthException if there isn't enough data in in, or
061         * space in out.
062         * @exception IllegalStateException if the cipher isn't initialised.
063         * @return the number of bytes processed and produced.
064         */
065        public int processBlock(byte[] in, int inOff, byte[] out, int outOff)
066            throws DataLengthException, IllegalStateException;
067    
068        /**
069         * Reset the cipher. After resetting the cipher is in the same state
070         * as it was after the last init (if there was one).
071         */
072        public void reset();
073    }