0N/A/*
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2362N/A * published by the Free Software Foundation. Oracle designates this
0N/A * particular file as subject to the "Classpath" exception as provided
2362N/A * by Oracle in the LICENSE file that accompanied this code.
0N/A *
0N/A * This code is distributed in the hope that it will be useful, but WITHOUT
0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
0N/A * version 2 for more details (a copy is included in the LICENSE file that
0N/A * accompanied this code).
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0N/A * You should have received a copy of the GNU General Public License version
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0N/A *
2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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0N/A */
0N/A
0N/Apackage com.sun.crypto.provider;
0N/A
0N/Aimport java.security.SecureRandom;
0N/Aimport java.security.InvalidParameterException;
0N/Aimport java.security.InvalidAlgorithmParameterException;
0N/Aimport java.security.InvalidKeyException;
0N/Aimport java.security.spec.AlgorithmParameterSpec;
0N/Aimport javax.crypto.KeyGeneratorSpi;
0N/Aimport javax.crypto.SecretKey;
0N/Aimport javax.crypto.spec.DESKeySpec;
0N/A
0N/A/**
0N/A * This class generates a DES key.
0N/A *
0N/A * @author Jan Luehe
0N/A *
0N/A */
0N/A
0N/Apublic final class DESKeyGenerator extends KeyGeneratorSpi {
0N/A
0N/A private SecureRandom random = null;
0N/A
0N/A /**
1460N/A * Empty constructor
0N/A */
0N/A public DESKeyGenerator() {
0N/A }
0N/A
0N/A /**
0N/A * Initializes this key generator.
0N/A *
0N/A * @param random the source of randomness for this generator
0N/A */
0N/A protected void engineInit(SecureRandom random) {
0N/A this.random = random;
0N/A }
0N/A
0N/A /**
0N/A * Initializes this key generator with the specified parameter
0N/A * set and a user-provided source of randomness.
0N/A *
0N/A * @param params the key generation parameters
0N/A * @param random the source of randomness for this key generator
0N/A *
0N/A * @exception InvalidAlgorithmParameterException if <code>params</code> is
0N/A * inappropriate for this key generator
0N/A */
0N/A protected void engineInit(AlgorithmParameterSpec params,
0N/A SecureRandom random)
0N/A throws InvalidAlgorithmParameterException {
0N/A throw new InvalidAlgorithmParameterException
0N/A ("DES key generation does not take any parameters");
0N/A }
0N/A
0N/A /**
0N/A * Initializes this key generator for a certain keysize, using the given
0N/A * source of randomness.
0N/A *
0N/A * @param keysize the keysize. This is an algorithm-specific
0N/A * metric specified in number of bits.
0N/A * @param random the source of randomness for this key generator
0N/A */
0N/A protected void engineInit(int keysize, SecureRandom random) {
0N/A if (keysize != 56) {
0N/A throw new InvalidParameterException("Wrong keysize: must "
0N/A + "be equal to 56");
0N/A }
0N/A this.engineInit(random);
0N/A }
0N/A
0N/A /**
0N/A * Generates the DES key.
0N/A *
0N/A * @return the new DES key
0N/A */
0N/A protected SecretKey engineGenerateKey() {
0N/A DESKey desKey = null;
0N/A
0N/A if (this.random == null) {
0N/A this.random = SunJCE.RANDOM;
0N/A }
0N/A
0N/A try {
0N/A byte[] key = new byte[DESKeySpec.DES_KEY_LEN];
0N/A do {
0N/A this.random.nextBytes(key);
0N/A setParityBit(key, 0);
0N/A } while (DESKeySpec.isWeak(key, 0));
0N/A desKey = new DESKey(key);
0N/A } catch (InvalidKeyException e) {
0N/A // this is never thrown
0N/A }
0N/A
0N/A return desKey;
0N/A }
0N/A
0N/A /*
0N/A * Does parity adjustment, using bit in position 8 as the parity bit,
0N/A * for 8 key bytes, starting at <code>offset</code>.
0N/A *
0N/A * The 8 parity bits of a DES key are only used for sanity-checking
0N/A * of the key, to see if the key could actually be a key. If you check
0N/A * the parity of the quantity, and it winds up not having the correct
0N/A * parity, then you'll know something went wrong.
0N/A *
0N/A * A key that is not parity adjusted (e.g. e4e4e4e4e4e4e4e4) produces the
0N/A * same output as a key that is parity adjusted (e.g. e5e5e5e5e5e5e5e5),
0N/A * because it is the 56 bits of the DES key that are cryptographically
0N/A * significant/"effective" -- the other 8 bits are just used for parity
0N/A * checking.
0N/A */
0N/A static void setParityBit(byte[] key, int offset) {
0N/A if (key == null)
0N/A return;
0N/A
0N/A for (int i = 0; i < DESKeySpec.DES_KEY_LEN; i++) {
0N/A int b = key[offset] & 0xfe;
0N/A b |= (Integer.bitCount(b) & 1) ^ 1;
0N/A key[offset++] = (byte)b;
0N/A }
0N/A }
0N/A}