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Java > Open Source Codes > com > jcorporate > expresso > core > security > StringHash


1 /* ====================================================================
2  * The Jcorporate Apache Style Software License, Version 1.2 05-07-2002
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61  * Portions of this software are based upon other open source
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64
65 package com.jcorporate.expresso.core.security;
66
67 import com.jcorporate.expresso.kernel.exception.ChainedException;
68 import org.apache.log4j.Logger;
69
70 import java.security.MessageDigest JavaDoc;
71 import java.security.NoSuchAlgorithmException JavaDoc;
72
73
74 /**
75  * Base class for hashing. Takes a string or byte array and returns a
76  * byte array that's the hash of the encryption.
77  *
78  * @author Michael Rimov
79  */
80 public final class StringHash {
81     private static final String JavaDoc thisClass = "com.jcorporate.expresso.core.security.strongencryption.StringHash";
82     private MessageDigest JavaDoc sha;
83     static Logger logCat = Logger.getLogger(StringHash.class);
84     private CryptoManager cryptoManager;
85
86     /**
87      * @throws ChainedException
88      */
89     public StringHash()
90             throws ChainedException {
91         try {
92             sha = MessageDigest.getInstance("SHA");
93             logCat.debug("StringHash initialized and SHA-1 algorithm loaded");
94         } catch (NoSuchAlgorithmException JavaDoc ex) {
95             logCat.error("Unable to load SHA-1 Hash Algorithm", ex);
96             throw new ChainedException(thisClass + ".StringHash()" +
97                     ":Error loading SHA-1 Algorithm." +
98                     " You may not have installed the" +
99                     " Cryptography Extensions Properly:",
100                     ex);
101         }
102     } /* StringHash() */
103
104     /**
105      * Produces a strong cryptographic hash.
106      *
107      * @param inputData The data to produce the Hash for
108      * @return A byte array representing the hashed input data.
109      */
110     public byte[] produceHash(byte[] inputData)
111             throws ChainedException {
112         final String JavaDoc myName = thisClass + ".produceHash(byte)";
113
114         if (inputData.length == 0) {
115             throw new IllegalArgumentException JavaDoc(myName +
116                     " inputData's length must not be zero");
117         }
118         if (logCat.isDebugEnabled()) {
119             logCat.debug("Producing a hash for the data: " +
120                     new String JavaDoc(inputData));
121         }
122
123         return sha.digest(inputData);
124     }
125
126     public void setCryptoManager(CryptoManager cryptoManager) {
127         this.cryptoManager = cryptoManager;
128     }
129
130     public CryptoManager getCryptoManager() {
131         return cryptoManager;
132     } /* produceHash(byte) */
133
134
135 } /* StringHash */
136
137 /* StringHash */
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