001    package org.apache.fulcrum.crypto.provider;
002    
003    /*
004     * Licensed to the Apache Software Foundation (ASF) under one
005     * or more contributor license agreements.  See the NOTICE file
006     * distributed with this work for additional information
007     * regarding copyright ownership.  The ASF licenses this file
008     * to you under the Apache License, Version 2.0 (the
009     * "License"); you may not use this file except in compliance
010     * with the License.  You may obtain a copy of the License at
011     *
012     *   http://www.apache.org/licenses/LICENSE-2.0
013     *
014     * Unless required by applicable law or agreed to in writing,
015     * software distributed under the License is distributed on an
016     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017     * KIND, either express or implied.  See the License for the
018     * specific language governing permissions and limitations
019     * under the License.
020     */
021    
022    
023    import org.apache.fulcrum.crypto.CryptoAlgorithm;
024    
025    import java.util.Random;
026    
027    /**
028     * Implements Standard Unix crypt(3) for use with the Crypto Service.
029     *
030     * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
031     * @version $Id: UnixCrypt.java 581797 2007-10-04 08:26:18Z sgoeschl $
032     */
033    
034    public class UnixCrypt
035        implements CryptoAlgorithm
036    {
037    
038        /** The seed to use */
039        private String seed = null;
040    
041        /** standard Unix crypt chars (64) */
042        private static final char[] SALT_CHARS =
043            (("abcdefghijklmnopqrstuvwxyz" +
044             "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789./").toCharArray());
045    
046    
047        /**
048         * C'tor
049         *
050         */
051    
052        public UnixCrypt()
053        {
054        }
055    
056        /**
057         * This class never uses anything but
058         * UnixCrypt, so it is just a dummy
059         * (Fixme: Should we throw an exception if
060         * something is requested that we don't support?
061         *
062         * @param cipher    Cipher (ignored)
063         */
064    
065        public void setCipher(String cipher)
066        {
067            /* dummy */
068        }
069    
070        /**
071         * Setting the seed for the UnixCrypt
072         * algorithm. If a null value is supplied,
073         * or no seed is set, then a random seed is used.
074         *
075         * @param seed     The seed value to use.
076         */
077    
078        public void setSeed(String seed)
079        {
080            this.seed = seed;
081        }
082    
083        /**
084         * encrypt the supplied string with the requested cipher
085         *
086         * @param value       The value to be encrypted
087         * @return The encrypted value
088         * @throws Exception An Exception of the underlying implementation.
089         */
090        public String encrypt(String value)
091            throws Exception
092        {
093            if (seed == null)
094            {
095                Random randomGenerator = new java.util.Random();
096                int numSaltChars = SALT_CHARS.length;
097    
098                seed = (new StringBuffer())
099                    .append(SALT_CHARS[Math.abs(randomGenerator.nextInt())
100                                       % numSaltChars])
101                    .append(SALT_CHARS[Math.abs(randomGenerator.nextInt())
102                                       % numSaltChars])
103                    .toString();
104            }
105    
106            return org.apache.fulcrum.crypto.impl.UnixCrypt.crypt(seed, value);
107        }
108    }