| /* BaseCipher.java -- |
| Copyright (C) 2001, 2002, 2003, 2006 Free Software Foundation, Inc. |
| |
| This file is a part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or (at |
| your option) any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 |
| USA |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.javax.crypto.cipher; |
| |
| import gnu.java.security.Configuration; |
| |
| import java.security.InvalidKeyException; |
| import java.util.Arrays; |
| import java.util.Iterator; |
| import java.util.Map; |
| import java.util.logging.Level; |
| import java.util.logging.Logger; |
| |
| /** |
| * A basic abstract class to facilitate implementing symmetric key block |
| * ciphers. |
| */ |
| public abstract class BaseCipher |
| implements IBlockCipher, IBlockCipherSpi |
| { |
| private static final Logger log = Logger.getLogger(BaseCipher.class.getName()); |
| /** The canonical name prefix of the cipher. */ |
| protected String name; |
| /** The default block size, in bytes. */ |
| protected int defaultBlockSize; |
| /** The default key size, in bytes. */ |
| protected int defaultKeySize; |
| /** The current block size, in bytes. */ |
| protected int currentBlockSize; |
| /** The session key for this instance. */ |
| protected transient Object currentKey; |
| /** The instance lock. */ |
| protected Object lock = new Object(); |
| |
| /** |
| * Trivial constructor for use by concrete subclasses. |
| * |
| * @param name the canonical name prefix of this instance. |
| * @param defaultBlockSize the default block size in bytes. |
| * @param defaultKeySize the default key size in bytes. |
| */ |
| protected BaseCipher(String name, int defaultBlockSize, int defaultKeySize) |
| { |
| super(); |
| |
| this.name = name; |
| this.defaultBlockSize = defaultBlockSize; |
| this.defaultKeySize = defaultKeySize; |
| } |
| |
| public abstract Object clone(); |
| |
| public String name() |
| { |
| StringBuffer sb = new StringBuffer(name).append('-'); |
| if (currentKey == null) |
| sb.append(String.valueOf(8 * defaultBlockSize)); |
| else |
| sb.append(String.valueOf(8 * currentBlockSize)); |
| return sb.toString(); |
| } |
| |
| public int defaultBlockSize() |
| { |
| return defaultBlockSize; |
| } |
| |
| public int defaultKeySize() |
| { |
| return defaultKeySize; |
| } |
| |
| public void init(Map attributes) throws InvalidKeyException |
| { |
| synchronized (lock) |
| { |
| if (currentKey != null) |
| throw new IllegalStateException(); |
| Integer bs = (Integer) attributes.get(CIPHER_BLOCK_SIZE); |
| if (bs == null) // no block size was specified |
| { |
| if (currentBlockSize == 0) // happy birthday |
| currentBlockSize = defaultBlockSize; |
| // else it's a clone. use as is |
| } |
| else |
| { |
| currentBlockSize = bs.intValue(); |
| // ensure that value is valid |
| Iterator it; |
| boolean ok = false; |
| for (it = blockSizes(); it.hasNext();) |
| { |
| ok = (currentBlockSize == ((Integer) it.next()).intValue()); |
| if (ok) |
| break; |
| } |
| if (! ok) |
| throw new IllegalArgumentException(IBlockCipher.CIPHER_BLOCK_SIZE); |
| } |
| byte[] k = (byte[]) attributes.get(KEY_MATERIAL); |
| currentKey = makeKey(k, currentBlockSize); |
| } |
| } |
| |
| public int currentBlockSize() |
| { |
| if (currentKey == null) |
| throw new IllegalStateException(); |
| return currentBlockSize; |
| } |
| |
| public void reset() |
| { |
| synchronized (lock) |
| { |
| currentKey = null; |
| } |
| } |
| |
| public void encryptBlock(byte[] in, int inOffset, byte[] out, int outOffset) |
| throws IllegalStateException |
| { |
| synchronized (lock) |
| { |
| if (currentKey == null) |
| throw new IllegalStateException(); |
| encrypt(in, inOffset, out, outOffset, currentKey, currentBlockSize); |
| } |
| } |
| |
| public void decryptBlock(byte[] in, int inOffset, byte[] out, int outOffset) |
| throws IllegalStateException |
| { |
| synchronized (lock) |
| { |
| if (currentKey == null) |
| throw new IllegalStateException(); |
| decrypt(in, inOffset, out, outOffset, currentKey, currentBlockSize); |
| } |
| } |
| |
| public boolean selfTest() |
| { |
| int ks; |
| Iterator bit; |
| // do symmetry tests for all block-size/key-size combos |
| for (Iterator kit = keySizes(); kit.hasNext();) |
| { |
| ks = ((Integer) kit.next()).intValue(); |
| for (bit = blockSizes(); bit.hasNext();) |
| if (! testSymmetry(ks, ((Integer) bit.next()).intValue())) |
| return false; |
| } |
| return true; |
| } |
| |
| private boolean testSymmetry(int ks, int bs) |
| { |
| try |
| { |
| byte[] kb = new byte[ks]; |
| byte[] pt = new byte[bs]; |
| byte[] ct = new byte[bs]; |
| byte[] cpt = new byte[bs]; |
| int i; |
| for (i = 0; i < ks; i++) |
| kb[i] = (byte) i; |
| for (i = 0; i < bs; i++) |
| pt[i] = (byte) i; |
| Object k = makeKey(kb, bs); |
| encrypt(pt, 0, ct, 0, k, bs); |
| decrypt(ct, 0, cpt, 0, k, bs); |
| return Arrays.equals(pt, cpt); |
| } |
| catch (Exception x) |
| { |
| if (Configuration.DEBUG) |
| log.log(Level.FINE, "Exception in testSymmetry() for " + name(), x); |
| return false; |
| } |
| } |
| |
| protected boolean testKat(byte[] kb, byte[] ct) |
| { |
| return testKat(kb, ct, new byte[ct.length]); // all-zero plaintext |
| } |
| |
| protected boolean testKat(byte[] kb, byte[] ct, byte[] pt) |
| { |
| try |
| { |
| int bs = pt.length; |
| byte[] t = new byte[bs]; |
| Object k = makeKey(kb, bs); |
| // test encryption |
| encrypt(pt, 0, t, 0, k, bs); |
| if (! Arrays.equals(t, ct)) |
| return false; |
| // test decryption |
| decrypt(t, 0, t, 0, k, bs); |
| return Arrays.equals(t, pt); |
| } |
| catch (Exception x) |
| { |
| if (Configuration.DEBUG) |
| log.log(Level.FINE, "Exception in testKat() for " + name(), x); |
| return false; |
| } |
| } |
| } |