1 /* 2 * Copyright (c) 1997, 2007, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.crypto.provider; 27 28 import java.security.InvalidKeyException; 29 30 /** 31 * This abstract class represents the core of all block ciphers. It allows to 32 * intialize the cipher and encrypt/decrypt single blocks. Larger quantities 33 * are handled by modes, which are subclasses of FeedbackCipher. 34 * 35 * @author Gigi Ankeny 36 * @author Jan Luehe 37 * 38 * 39 * @see AESCrypt 40 * @see DESCrypt 41 * @see DESedeCrypt 42 * @see BlowfishCrypt 43 * @see FeedbackCipher 44 */ 45 abstract class SymmetricCipher { 46 SymmetricCipher()47 SymmetricCipher() { 48 // empty 49 } 50 51 /** 52 * Retrieves this cipher's block size. 53 * 54 * @return the block size of this cipher 55 */ getBlockSize()56 abstract int getBlockSize(); 57 58 /** 59 * Initializes the cipher in the specified mode with the given key. 60 * 61 * @param decrypting flag indicating encryption or decryption 62 * @param algorithm the algorithm name 63 * @param key the key 64 * 65 * @exception InvalidKeyException if the given key is inappropriate for 66 * initializing this cipher 67 */ init(boolean decrypting, String algorithm, byte[] key)68 abstract void init(boolean decrypting, String algorithm, byte[] key) 69 throws InvalidKeyException; 70 71 /** 72 * Encrypt one cipher block. 73 * 74 * <p>The input <code>plain</code>, starting at <code>plainOffset</code> 75 * and ending at <code>(plainOffset+blockSize-1)</code>, is encrypted. 76 * The result is stored in <code>cipher</code>, starting at 77 * <code>cipherOffset</code>. 78 * 79 * @param plain the input buffer with the data to be encrypted 80 * @param plainOffset the offset in <code>plain</code> 81 * @param cipher the buffer for the encryption result 82 * @param cipherOffset the offset in <code>cipher</code> 83 */ encryptBlock(byte[] plain, int plainOffset, byte[] cipher, int cipherOffset)84 abstract void encryptBlock(byte[] plain, int plainOffset, 85 byte[] cipher, int cipherOffset); 86 87 /** 88 * Decrypt one cipher block. 89 * 90 * <p>The input <code>cipher</code>, starting at <code>cipherOffset</code> 91 * and ending at <code>(cipherOffset+blockSize-1)</code>, is decrypted. 92 * The result is stored in <code>plain</code>, starting at 93 * <code>plainOffset</code>. 94 * 95 * @param cipher the input buffer with the data to be decrypted 96 * @param cipherOffset the offset in <code>cipher</code> 97 * @param plain the buffer for the decryption result 98 * @param plainOffset the offset in <code>plain</code> 99 */ decryptBlock(byte[] cipher, int cipherOffset, byte[] plain, int plainOffset)100 abstract void decryptBlock(byte[] cipher, int cipherOffset, 101 byte[] plain, int plainOffset); 102 } 103