001    /**
002     *
003     *  Licensed to the Apache Software Foundation (ASF) under one or more
004     *  contributor license agreements.  See the NOTICE file distributed with
005     *  this work for additional information regarding copyright ownership.
006     *  The ASF licenses this file to You under the Apache License, Version 2.0
007     *  (the "License"); you may not use this file except in compliance with
008     *  the License.  You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     *  Unless required by applicable law or agreed to in writing, software
013     *  distributed under the License is distributed on an "AS IS" BASIS,
014     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     *  See the License for the specific language governing permissions and
016     *  limitations under the License.
017     */
018    
019    package org.apache.geronimo.util.crypto;
020    
021    
022    /**
023     * Block cipher engines are expected to conform to this interface.
024     */
025    public interface BlockCipher
026    {
027        /**
028         * Initialise the cipher.
029         *
030         * @param forEncryption if true the cipher is initialised for
031         *  encryption, if false for decryption.
032         * @param params the key and other data required by the cipher.
033         * @exception IllegalArgumentException if the params argument is
034         * inappropriate.
035         */
036        public void init(boolean forEncryption, CipherParameters params)
037            throws IllegalArgumentException;
038    
039        /**
040         * Return the name of the algorithm the cipher implements.
041         *
042         * @return the name of the algorithm the cipher implements.
043         */
044        public String getAlgorithmName();
045    
046        /**
047         * Return the block size for this cipher (in bytes).
048         *
049         * @return the block size for this cipher in bytes.
050         */
051        public int getBlockSize();
052    
053        /**
054         * Process one block of input from the array in and write it to
055         * the out array.
056         *
057         * @param in the array containing the input data.
058         * @param inOff offset into the in array the data starts at.
059         * @param out the array the output data will be copied into.
060         * @param outOff the offset into the out array the output will start at.
061         * @exception DataLengthException if there isn't enough data in in, or
062         * space in out.
063         * @exception IllegalStateException if the cipher isn't initialised.
064         * @return the number of bytes processed and produced.
065         */
066        public int processBlock(byte[] in, int inOff, byte[] out, int outOff)
067            throws DataLengthException, IllegalStateException;
068    
069        /**
070         * Reset the cipher. After resetting the cipher is in the same state
071         * as it was after the last init (if there was one).
072         */
073        public void reset();
074    }