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1: /* Stage.java -- 2: Copyright (C) 2003, 2006 Free Software Foundation, Inc. 3: 4: This file is a 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 of the License, or (at 9: your option) 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; if not, write to the Free Software 18: Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 19: 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 gnu.javax.crypto.assembly; 40: 41: import gnu.javax.crypto.mode.IMode; 42: 43: import java.security.InvalidKeyException; 44: import java.util.Map; 45: import java.util.Set; 46: 47: /** 48: * A <i>Stage</i> in a Cascade Cipher. 49: * <p> 50: * Each stage may be either an implementation of a Block Cipher Mode of 51: * Operation ({@link IMode}) or another Cascade Cipher ({@link Cascade}). 52: * Each stage has also a <i>natural</i> operational direction when constructed 53: * for inclusion within a {@link Cascade}. This <i>natural</i> direction 54: * dictates how data flows from one stage into another when stages are chained 55: * together in a cascade. One can think of a stage and its natural direction as 56: * the specification of how to wire the stage into the chain. The following 57: * diagrams may help understand the paradigme. The first shows two stages 58: * chained each with a {@link Direction#FORWARD} direction. 59: * 60: * <pre> 61: * FORWARD FORWARD 62: * +------+ +-------+ 63: * | | | | 64: * | +--in --+ | +--in --+ 65: * ---+ | Stage | | | Stage | +--- 66: * +--out--+ | +--out--+ | 67: * | | | | 68: * +-------+ +------+ 69: * </pre> 70: * 71: * <p> 72: * The second diagram shows two stages, one in a {@link Direction#FORWARD} 73: * direction, while the other is wired in a {@link Direction#REVERSED} 74: * direction. 75: * 76: * <pre> 77: * FORWARD REVERSED 78: * +------+ +------+ 79: * | | | | 80: * | +--in --+ +--in --+ | 81: * ---+ | Stage | | Stage | +--- 82: * +--out--+ +--out--+ 83: * | | 84: * +---------------+ 85: * </pre> 86: * 87: * @see ModeStage 88: * @see CascadeStage 89: */ 90: public abstract class Stage 91: { 92: public static final String DIRECTION = "gnu.crypto.assembly.stage.direction"; 93: 94: protected Direction forward; 95: 96: protected Direction wired; 97: 98: protected Stage(Direction forwardDirection) 99: { 100: super(); 101: 102: this.forward = forwardDirection; 103: this.wired = null; 104: } 105: 106: public static final Stage getInstance(IMode mode, Direction forwardDirection) 107: { 108: return new ModeStage(mode, forwardDirection); 109: } 110: 111: public static final Stage getInstance(Cascade cascade, 112: Direction forwardDirection) 113: { 114: return new CascadeStage(cascade, forwardDirection); 115: } 116: 117: /** 118: * Returns the {@link Set} of supported block sizes for this 119: * <code>Stage</code>. Each element in the returned {@link Set} is an 120: * instance of {@link Integer}. 121: * 122: * @return a {@link Set} of supported block sizes. 123: */ 124: public abstract Set blockSizes(); 125: 126: /** 127: * Initialises the stage for operation with specific characteristics. 128: * 129: * @param attributes a set of name-value pairs that describes the desired 130: * future behaviour of this instance. 131: * @throws IllegalStateException if the instance is already initialised. 132: * @throws InvalidKeyException if the key data is invalid. 133: */ 134: public void init(Map attributes) throws InvalidKeyException 135: { 136: if (wired != null) 137: throw new IllegalStateException(); 138: Direction flow = (Direction) attributes.get(DIRECTION); 139: if (flow == null) 140: { 141: flow = Direction.FORWARD; 142: attributes.put(DIRECTION, flow); 143: } 144: initDelegate(attributes); 145: wired = flow; 146: } 147: 148: /** 149: * Returns the currently set block size for the stage. 150: * 151: * @return the current block size for this stage. 152: * @throws IllegalStateException if the instance is not initialised. 153: */ 154: public abstract int currentBlockSize() throws IllegalStateException; 155: 156: /** 157: * Resets the stage for re-initialisation and use with other characteristics. 158: * This method always succeeds. 159: */ 160: public void reset() 161: { 162: resetDelegate(); 163: wired = null; 164: } 165: 166: /** 167: * Processes exactly one block of <i>plaintext</i> (if initialised in the 168: * {@link Direction#FORWARD} state) or <i>ciphertext</i> (if initialised in 169: * the {@link Direction#REVERSED} state). 170: * 171: * @param in the plaintext. 172: * @param inOffset index of <code>in</code> from which to start considering 173: * data. 174: * @param out the ciphertext. 175: * @param outOffset index of <code>out</code> from which to store result. 176: * @throws IllegalStateException if the instance is not initialised. 177: */ 178: public void update(byte[] in, int inOffset, byte[] out, int outOffset) 179: { 180: if (wired == null) 181: throw new IllegalStateException(); 182: updateDelegate(in, inOffset, out, outOffset); 183: } 184: 185: /** 186: * Conducts a simple <i>correctness</i> test that consists of basic symmetric 187: * encryption / decryption test(s) for all supported block and key sizes of 188: * underlying block cipher(s) wrapped by Mode leafs. The test also includes 189: * one (1) variable key Known Answer Test (KAT) for each block cipher. 190: * 191: * @return <code>true</code> if the implementation passes simple 192: * <i>correctness</i> tests. Returns <code>false</code> otherwise. 193: */ 194: public abstract boolean selfTest(); 195: 196: abstract void initDelegate(Map attributes) throws InvalidKeyException; 197: 198: abstract void resetDelegate(); 199: 200: abstract void updateDelegate(byte[] in, int inOffset, byte[] out, 201: int outOffset); 202: }