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Java > Open Source Codes > net > jforum > util > MD5


1 /*
2  * Copyright (c) 2003, Rafael Steil
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms,
6  * with or without modification, are permitted provided
7  * that the following conditions are met:
8  *
9  * 1) Redistributions of source code must retain the above
10  * copyright notice, this list of conditions and the
11  * following disclaimer.
12  * 2) Redistributions in binary form must reproduce the
13  * above copyright notice, this list of conditions and
14  * the following disclaimer in the documentation and/or
15  * other materials provided with the distribution.
16  * 3) Neither the name of "Rafael Steil" nor
17  * the names of its contributors may be used to endorse
18  * or promote products derived from this software without
19  * specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT
22  * HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
23  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
24  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
27  * THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
29  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES
30  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
32  * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
33  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
34  * IN CONTRACT, STRICT LIABILITY, OR TORT
35  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
36  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
37  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE
38  *
39  * This file creation date: Mar 29, 2003 / 1:15:50 AM
40  * The JForum Project
41  * http://www.jforum.net
42  */
43 package net.jforum.util;
44
45 import java.security.MessageDigest JavaDoc;
46 import java.security.NoSuchAlgorithmException JavaDoc;
47
48 import net.jforum.exceptions.ForumException;
49
50 /**
51  * Encodes a string using MD5 hashing
52  *
53  * @author Rafael Steil
54  * @version $Id: MD5.java,v 1.6 2005/07/26 03:05:26 rafaelsteil Exp $
55  */
56 public class MD5
57 {
58     /**
59      * Encodes a string
60      *
61      * @param str String to encode
62      * @return Encoded String
63      * @throws NoSuchAlgorithmException
64      */
65     public static String JavaDoc crypt(String JavaDoc str)
66     {
67         if (str == null || str.length() == 0) {
68             throw new IllegalArgumentException JavaDoc("String to encript cannot be null or zero length");
69         }
70         
71         StringBuffer JavaDoc hexString = new StringBuffer JavaDoc();
72         
73         try {
74             MessageDigest JavaDoc md = MessageDigest.getInstance("MD5");
75             md.update(str.getBytes());
76             byte[] hash = md.digest();
77             
78             for (int i = 0; i < hash.length; i++) {
79                 if ((0xff & hash[i]) < 0x10) {
80                     hexString.append("0" + Integer.toHexString((0xFF & hash[i])));
81                 }
82                 else {
83                     hexString.append(Integer.toHexString(0xFF & hash[i]));
84                 }
85             }
86         }
87         catch (NoSuchAlgorithmException JavaDoc e) {
88             throw new ForumException("" + e);
89         }
90         
91         return hexString.toString();
92     }
93 }
94
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