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Diffstat (limited to 'libjava/classpath/gnu/javax/crypto/cipher/BaseCipher.java')
| -rw-r--r-- | libjava/classpath/gnu/javax/crypto/cipher/BaseCipher.java | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/libjava/classpath/gnu/javax/crypto/cipher/BaseCipher.java b/libjava/classpath/gnu/javax/crypto/cipher/BaseCipher.java new file mode 100644 index 00000000000..9d62311ed58 --- /dev/null +++ b/libjava/classpath/gnu/javax/crypto/cipher/BaseCipher.java @@ -0,0 +1,304 @@ +/* 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.util.Util; + +import java.security.InvalidKeyException; +import java.util.Arrays; +import java.util.Iterator; +import java.util.Map; + +/** + * <p>A basic abstract class to facilitate implementing symmetric key block + * ciphers.</p> + */ +public abstract class BaseCipher implements IBlockCipher, IBlockCipherSpi +{ + + // Constants and variables + // ------------------------------------------------------------------------- + + /** 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(); + + // Constructor(s) + // ------------------------------------------------------------------------- + + /** + * <p>Trivial constructor for use by concrete subclasses.</p> + * + * @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; + } + + // Class methods + // ------------------------------------------------------------------------- + + // Instance methods + // ------------------------------------------------------------------------- + + // IBlockCipher interface implementation ----------------------------------- + + 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) + { + // currentBlockSize = 0; + 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; + } + + // own methods ------------------------------------------------------------- + + 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) + { + x.printStackTrace(System.err); + 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) + { + x.printStackTrace(System.err); + return false; + } + } +}
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