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1: /* IBlockCipher.java -- 2: Copyright (C) 2001, 2002, 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.cipher; 40: 41: import java.security.InvalidKeyException; 42: import java.util.Iterator; 43: import java.util.Map; 44: 45: /** 46: * The basic visible methods of any symmetric key block cipher. 47: * <p> 48: * A symmetric key block cipher is a function that maps n-bit plaintext blocks 49: * to n-bit ciphertext blocks; n being the cipher's <i>block size</i>. This 50: * encryption function is parameterised by a k-bit key, and is invertible. Its 51: * inverse is the decryption function. 52: * <p> 53: * Possible initialisation values for an instance of this type are: 54: * <ul> 55: * <li>The block size in which to operate this block cipher instance. This 56: * value is <b>optional</b>, if unspecified, the block cipher's default block 57: * size shall be used.</li> 58: * <li>The byte array containing the user supplied key material to use for 59: * generating the cipher's session key(s). This value is <b>mandatory</b> and 60: * should be included in the initialisation parameters. If it isn't, an 61: * {@link IllegalStateException} will be thrown if any method, other than 62: * <code>reset()</code> is invoked on the instance. Furthermore, the size of 63: * this key material shall be taken as an indication on the key size in which to 64: * operate this instance.</li> 65: * </ul> 66: * <p> 67: * <b>IMPLEMENTATION NOTE</b>: Although all the concrete classes in this 68: * package implement the {@link Cloneable} interface, it is important to note 69: * here that such an operation <b>DOES NOT</b> clone any session key material 70: * that may have been used in initialising the source cipher (the instance to be 71: * cloned). Instead a clone of an already initialised cipher is another instance 72: * that operates with the <b>same block size</b> but without any knowledge of 73: * neither key material nor key size. 74: */ 75: public interface IBlockCipher 76: extends Cloneable 77: { 78: /** 79: * Property name of the block size in which to operate a block cipher. The 80: * value associated with this property name is taken to be an {@link Integer}. 81: */ 82: String CIPHER_BLOCK_SIZE = "gnu.crypto.cipher.block.size"; 83: /** 84: * Property name of the user-supplied key material. The value associated to 85: * this property name is taken to be a byte array. 86: */ 87: String KEY_MATERIAL = "gnu.crypto.cipher.key.material"; 88: 89: /** 90: * Returns the canonical name of this instance. 91: * 92: * @return the canonical name of this instance. 93: */ 94: String name(); 95: 96: /** 97: * Returns the default value, in bytes, of the algorithm's block size. 98: * 99: * @return the default value, in bytes, of the algorithm's block size. 100: */ 101: int defaultBlockSize(); 102: 103: /** 104: * Returns the default value, in bytes, of the algorithm's key size. 105: * 106: * @return the default value, in bytes, of the algorithm's key size. 107: */ 108: int defaultKeySize(); 109: 110: /** 111: * Returns an {@link Iterator} over the supported block sizes. Each element 112: * returned by this object is an {@link Integer}. 113: * 114: * @return an {@link Iterator} over the supported block sizes. 115: */ 116: Iterator blockSizes(); 117: 118: /** 119: * Returns an {@link Iterator} over the supported key sizes. Each element 120: * returned by this object is an {@link Integer}. 121: * 122: * @return an {@link Iterator} over the supported key sizes. 123: */ 124: Iterator keySizes(); 125: 126: /** 127: * Returns a clone of this instance. 128: * 129: * @return a clone copy of this instance. 130: */ 131: Object clone(); 132: 133: /** 134: * Initialises the algorithm with designated attributes. Permissible names and 135: * values are described in the class documentation above. 136: * 137: * @param attributes a set of name-value pairs that describes the desired 138: * future behaviour of this instance. 139: * @exception InvalidKeyException if the key data is invalid. 140: * @exception IllegalStateException if the instance is already initialised. 141: * @see #KEY_MATERIAL 142: * @see #CIPHER_BLOCK_SIZE 143: */ 144: void init(Map attributes) throws InvalidKeyException, IllegalStateException; 145: 146: /** 147: * Returns the currently set block size for this instance. 148: * 149: * @return the current block size for this instance. 150: * @exception IllegalStateException if the instance is not initialised. 151: */ 152: int currentBlockSize() throws IllegalStateException; 153: 154: /** 155: * Resets the algorithm instance for re-initialisation and use with other 156: * characteristics. This method always succeeds. 157: */ 158: void reset(); 159: 160: /** 161: * Encrypts exactly one block of plaintext. 162: * 163: * @param in the plaintext. 164: * @param inOffset index of <code>in</code> from which to start considering 165: * data. 166: * @param out the ciphertext. 167: * @param outOffset index of <code>out</code> from which to store result. 168: * @exception IllegalStateException if the instance is not initialised. 169: */ 170: void encryptBlock(byte[] in, int inOffset, byte[] out, int outOffset) 171: throws IllegalStateException; 172: 173: /** 174: * Decrypts exactly one block of ciphertext. 175: * 176: * @param in the plaintext. 177: * @param inOffset index of <code>in</code> from which to start considering 178: * data. 179: * @param out the ciphertext. 180: * @param outOffset index of <code>out</code> from which to store result. 181: * @exception IllegalStateException if the instance is not initialised. 182: */ 183: void decryptBlock(byte[] in, int inOffset, byte[] out, int outOffset) 184: throws IllegalStateException; 185: 186: /** 187: * A <i>correctness</i> test that consists of basic symmetric encryption / 188: * decryption test(s) for all supported block and key sizes, as well as one 189: * (1) variable key Known Answer Test (KAT). 190: * 191: * @return <code>true</code> if the implementation passes simple 192: * <i>correctness</i> tests. Returns <code>false</code> otherwise. 193: */ 194: boolean selfTest(); 195: }