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1: /* MacSpi.java -- The MAC service provider interface. 2: Copyright (C) 2004 Free Software Foundation, Inc. 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: 39: package javax.crypto; 40: 41: import java.security.InvalidAlgorithmParameterException; 42: import java.security.InvalidKeyException; 43: import java.security.Key; 44: import java.security.spec.AlgorithmParameterSpec; 45: 46: /** 47: * This is the <i>Service Provider Interface</i> (<b>SPI</b>) for the 48: * {@link Mac} class. 49: * 50: * <p>Providers wishing to implement a Mac must subclass this class and 51: * provide appropriate implementations of all its abstract methods, 52: * then provide an entry pointing to this implementation in the master 53: * {@link java.security.Provider} class. 54: * 55: * <p>Implementations may optionally implement the {@link 56: * java.lang.Cloneable} interface. 57: * 58: * @author Casey Marshall (csm@gnu.org) 59: * @since 1.4 60: */ 61: public abstract class MacSpi 62: { 63: 64: // Constructor. 65: // ------------------------------------------------------------------------ 66: 67: /** 68: * Create a new MacSpi instance. 69: */ 70: public MacSpi() 71: { 72: } 73: 74: // Instance methods. 75: // ------------------------------------------------------------------------ 76: 77: /** 78: * Returns a clone of this instance if cloning is supported. 79: * 80: * @return A clone of this instance. 81: * @throws java.lang.CloneNotSupportedException If this instance does 82: * not support cloneing. 83: */ 84: public Object clone() throws CloneNotSupportedException 85: { 86: return super.clone(); 87: } 88: 89: // Abstract instance methods. 90: // ------------------------------------------------------------------------ 91: 92: /** 93: * Finalize the computation of this MAC and return the result as a 94: * byte array. 95: * 96: * @return The MAC. 97: */ 98: protected abstract byte[] engineDoFinal(); 99: 100: /** 101: * Return the total length, in bytes, of the computed MAC (the length 102: * of the byte array returned by {@link #doFinal()}. 103: * 104: * @return The MAC length. 105: */ 106: protected abstract int engineGetMacLength(); 107: 108: /** 109: * Initialize (or re-initialize) this instance. 110: * 111: * @param key The key to use. 112: * @param params The parameters to use. 113: * @throws java.security.InvalidAlgorithmParameterException If this 114: * instance rejects the specified parameters. 115: * @throws java.security.InvalidKeyException If this instance rejects 116: * the specified key. 117: */ 118: protected abstract void engineInit(Key key, AlgorithmParameterSpec params) 119: throws InvalidAlgorithmParameterException, InvalidKeyException; 120: 121: /** 122: * Reset this instance. After this method succeeds, the state of this 123: * instance should be the same as it was before any data was input 124: * (possibly after a call to {@link 125: * #init(java.security.Key,java.security.spec.AlgorithmParameterSpec)}, 126: * possibly not). 127: */ 128: protected abstract void engineReset(); 129: 130: /** 131: * Update this MAC with a single byte. 132: * 133: * @param input The next byte. 134: */ 135: protected abstract void engineUpdate(byte input); 136: 137: /** 138: * Update this MAC with a portion of a byte array. 139: * 140: * @param input The next bytes. 141: * @param offset The index in <code>input</code> at which to start. 142: * @param length The number of bytes to update. 143: */ 144: protected abstract void engineUpdate(byte[] input, int offset, int length); 145: }
GNU Classpath (0.20) |