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Source code: com/ssttr/crypto/MD5.java


1   /*
2    * @(#)MD5.java  1.9 95/08/07
3    *
4    * Copyright (c) 1994 Sun Microsystems, Inc. All Rights Reserved.
5    *
6    * Permission to use, copy, modify, and distribute this software
7    * and its documentation for NON-COMMERCIAL purposes and without
8    * fee is hereby granted provided that this copyright notice
9    * appears in all copies. Please refer to the file "copyright.html"
10   * for further important copyright and licensing information.
11   *
12   * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
13   * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
14   * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
15   * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
16   * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
17   * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
18   *
19   * Updated to the JDK 1.0.2 release by Chuck McManis
20   * 
21   * This file was obtained from: http://www.mcmanis.com/~cmcmanis/java/src/util/crypt/MD5.java
22   * More information can be found here: http://www.mcmanis.com/~cmcmanis/java/
23   */
24  
25  package com.ssttr.crypto;
26  
27  /**
28   * The MD5 class is used to compute an MD5 message digest over a given
29   * buffer of bytes. It is an implementation of the RSA Data Security Inc
30   * MD5 algorithim as described in internet RFC 1321.
31   * @version   06 Oct 1996, 1.9.1
32   * @author   Chuck McManis
33   */
34  public final class MD5
35  extends MessageDigest
36  {
37      /** containss the computed message digest */
38  
39      private int state[];
40      private long count;
41      private byte buffer[];
42      private static int transformBuffer[];
43  
44      private static final int S11 = 7;
45      private static final int S12 = 12;
46      private static final int S13 = 17;
47      private static final int S14 = 22;
48      private static final int S21 = 5;
49      private static final int S22 = 9;
50      private static final int S23 = 14;
51      private static final int S24 = 20;
52      private static final int S31 = 4;
53      private static final int S32 = 11;
54      private static final int S33 = 16;
55      private static final int S34 = 23;
56      private static final int S41 = 6;
57      private static final int S42 = 10;
58      private static final int S43 = 15;
59      private static final int S44 = 21;
60  
61      /**
62       * Standard constructor, creates a new MD5 instance, allocates its
63       * buffers from the heap.
64       */
65      public MD5() {
66          state = new int[4];
67          count = 0;
68          if (transformBuffer == null)
69              transformBuffer = new int[16];
70          buffer = new byte[64];
71          digestBits = new byte[16];
72          digestValid = false;
73      }
74  
75      /**
76       * Alternate constructor, allows you to pass in the buffer where you
77       * want the resulting digest stored.
78       */
79      public MD5(byte mydigest[]) {
80          state = new int[4];
81          count = 0;
82          if (transformBuffer == null)
83              transformBuffer = new int[16];
84          buffer = new byte[64];
85          digestBits = mydigest;
86          digestValid = false;
87      }
88  
89      /* **********************************************************
90       * The MD5 Functions. These are copied verbatim from
91       * the RFC to insure accuracy. The results of this
92       * implementation were checked against the RSADSI version.
93       * **********************************************************
94       */
95  
96      private int F(int x, int y, int z) {
97          return ((x & y) | ((~x) & z));
98      }
99  
100     private int G(int x, int y, int z) {
101         return ((x & z) | (y & (~z)));
102     }
103 
104     private int H(int x, int y, int z) {
105         return ((x ^ y) ^ z);
106     }
107 
108     private int I(int x, int y, int z) {
109         return (y ^ (x | (~z)));
110     }
111 
112     private int rotateLeft(int a, int n) {
113         return ((a << n) | (a >>> (32 - n)));
114     }
115 
116     private int FF(int a, int b, int c, int d, int x, int s, int ac) {
117         a += F(b, c, d) + x + ac;
118         a = rotateLeft(a, s);
119         a += b;
120         return a;
121     }
122 
123     private int GG(int a, int b, int c, int d, int x, int s, int ac) {
124         a += G(b, c, d) + x + ac;
125         a = rotateLeft(a, s);
126         a += b;
127         return a;
128     }
129 
130     private int HH(int a, int b, int c, int d, int x, int s, int ac) {
131         a += H(b, c, d) + x + ac;
132         a = rotateLeft(a, s);
133         a += b;
134         return a;
135     }
136 
137     private int II(int a, int b, int c, int d, int x, int s, int ac) {
138         a += I(b, c, d) + x + ac;
139         a = rotateLeft(a, s);
140         a += b;
141         return a;
142     }
143 
144     /**
145      * This is where the functions come together as the generic MD5
146      * transformation operation, it is called by update() which is
147      * synchronized (to protect transformBuffer)
148      */
149     void transform(byte buf[], int offset) {
150         int a, b, c, d;
151         int x[] = transformBuffer;
152 
153         a = state[0];
154         b = state[1];
155         c = state[2];
156         d = state[3];
157 
158         for (int i = 0; i < 16; i++) {
159             x[i] = (int)buf[i*4+offset] & 0xff;
160             for (int j = 1; j < 4; j++) {
161           x[i] += ((int)buf[i*4+j+offset] & 0xff) << (j * 8);
162             }
163         }
164 
165         /* Round 1 */
166         a = FF ( a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
167         d = FF ( d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
168         c = FF ( c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
169         b = FF ( b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
170         a = FF ( a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
171         d = FF ( d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
172         c = FF ( c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
173         b = FF ( b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
174         a = FF ( a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
175         d = FF ( d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
176         c = FF ( c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
177         b = FF ( b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
178         a = FF ( a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
179         d = FF ( d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
180         c = FF ( c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
181         b = FF ( b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
182 
183         /* Round 2 */
184         a = GG ( a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
185         d = GG ( d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
186         c = GG ( c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
187         b = GG ( b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
188         a = GG ( a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
189         d = GG ( d, a, b, c, x[10], S22,  0x2441453); /* 22 */
190         c = GG ( c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
191         b = GG ( b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
192         a = GG ( a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
193         d = GG ( d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
194         c = GG ( c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
195         b = GG ( b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
196         a = GG ( a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
197         d = GG ( d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
198         c = GG ( c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
199         b = GG ( b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
200 
201         /* Round 3 */
202         a = HH ( a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
203         d = HH ( d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
204         c = HH ( c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
205         b = HH ( b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
206         a = HH ( a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
207         d = HH ( d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
208         c = HH ( c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
209         b = HH ( b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
210         a = HH ( a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
211         d = HH ( d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
212         c = HH ( c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
213         b = HH ( b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
214         a = HH ( a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
215         d = HH ( d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
216         c = HH ( c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
217         b = HH ( b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
218 
219         /* Round 4 */
220         a = II ( a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
221         d = II ( d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
222         c = II ( c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
223         b = II ( b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
224         a = II ( a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
225         d = II ( d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
226         c = II ( c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
227         b = II ( b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
228         a = II ( a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
229         d = II ( d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
230         c = II ( c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
231         b = II ( b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
232         a = II ( a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
233         d = II ( d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
234         c = II ( c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
235         b = II ( b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
236 
237         state[0] += a;
238         state[1] += b;
239         state[2] += c;
240         state[3] += d;
241     }
242 
243     /**
244      * Initialize the MD5 state information and reset the bit count
245      * to 0. Given this implementation you are constrained to counting
246      * 2^64 bits.
247      */
248     public void init() {
249         count = 0;
250         // Load magic initialization constants.
251         state[0] = 0x67452301;
252         state[1] = 0xefcdab89;
253         state[2] = 0x98badcfe;
254         state[3] = 0x10325476;
255         digestValid = false;
256         for (int i = 0; i < digestBits.length; i++)
257             digestBits[i] = 0;
258     }
259 
260     /**
261      * update adds the passed type to the input buffer
262      */
263     public synchronized void update(byte b) {
264         int  index;
265 
266         index = (int) ((count >>> 3) & 0x3f);
267         count += 8;
268         buffer[index] = b;
269         if (index  >= 63) {
270             transform(buffer, 0);
271         }
272     }
273 
274     /**
275      * Perform the final computations, any buffered bytes are added
276      * to the digest, the count is added to the digest, and the resulting
277      * digest is stored. After calling final you will need to call
278      * init() again to do another digest.
279      */
280     public void finish() {
281         byte  bits[] = new byte[8];
282         byte  padding[];
283         int  i, index, padLen;
284 
285         for (i = 0; i < 8; i++) {
286             bits[i] = (byte)((count >>> (i * 8)) & 0xff);
287         }
288 
289         index = (int)(count >> 3) & 0x3f;
290         padLen = (index < 56) ? (56 - index) : (120 - index);
291         padding = new byte[padLen];
292         padding[0] = (byte) 0x80;
293         update(padding);
294         update(bits);
295 
296         for (i = 0; i < 4; i++) {
297             for (int j = 0; j < 4; j++) {
298           digestBits[i*4+j] = (byte)((state[i] >>> (j * 8)) & 0xff);
299             }
300         }
301         digestValid = true;
302     }
303 
304     public String getAlg() {
305   return ("MD5");
306     }
307 }