1 /* $Id: md5.c,v 1.6 2006/02/17 10:24:52 yjung Exp $
2 *
3 * This file is part of the ESO QFITS Library
4 * Copyright (C) 2001-2004 European Southern Observatory
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21 /*
22 * $Author: yjung $
23 * $Date: 2006/02/17 10:24:52 $
24 * $Revision: 1.6 $
25 * $Name: qfits-6_2_0 $
26 */
27
28 /*-----------------------------------------------------------------------------
29 Includes
30 -----------------------------------------------------------------------------*/
31
32 #include <string.h>
33
34 #include "md5.h"
35
36 /*-----------------------------------------------------------------------------
37 Function prototypes
38 -----------------------------------------------------------------------------*/
39
40 static void byteReverse(unsigned char *buf, unsigned longs);
41
42 /*----------------------------------------------------------------------------*/
43 /**
44 * @defgroup md5 MD5 message-digest algorithm
45 *
46 * The algorithm is due to Ron Rivest. This code was written by Colin Plumb
47 * in 1993, no copyright is claimed. This code is in the public domain; do
48 * with it what you wish.
49 * Equivalent code is available from RSA Data Security, Inc. This code has
50 * been tested against that, and is equivalent, except that you don't need to
51 * include two pages of legalese with every copy.
52 * To compute the message digest of a chunk of bytes, declare an MD5Context
53 * structure, pass it to MD5Init, call MD5Update as needed on buffers full of
54 * bytes, and then call MD5Final, which will fill a supplied 16-byte array with
55 * the digest.
56 */
57 /*----------------------------------------------------------------------------*/
58 /**@{*/
59
60 /*-----------------------------------------------------------------------------
61 Function codes
62 -----------------------------------------------------------------------------*/
63
64 /*
65 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
66 * initialization constants.
67 */
MD5Init(struct MD5Context * ctx)68 void MD5Init(struct MD5Context *ctx)
69 {
70 ctx->buf[0] = 0x67452301;
71 ctx->buf[1] = 0xefcdab89;
72 ctx->buf[2] = 0x98badcfe;
73 ctx->buf[3] = 0x10325476;
74
75 ctx->bits[0] = 0;
76 ctx->bits[1] = 0;
77 }
78
79 /*
80 * Update context to reflect the concatenation of another buffer full
81 * of bytes.
82 */
MD5Update(struct MD5Context * ctx,unsigned char const * buf,unsigned len)83 void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
84 {
85 register word32 t;
86
87 /* Update bitcount */
88
89 t = ctx->bits[0];
90 if ((ctx->bits[0] = t + ((word32) len << 3)) < t)
91 ctx->bits[1]++; /* Carry from low to high */
92 ctx->bits[1] += len >> 29;
93
94 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
95
96 /* Handle any leading odd-sized chunks */
97
98 if (t) {
99 unsigned char *p = (unsigned char *) ctx->in + t;
100
101 t = 64 - t;
102 if (len < t) {
103 memmove(p, buf, len);
104 return;
105 }
106 memmove(p, buf, t);
107 byteReverse(ctx->in, 16);
108 MD5Transform(ctx->buf, (word32 *) ctx->in);
109 buf += t;
110 len -= t;
111 }
112 /* Process data in 64-byte chunks */
113
114 while (len >= 64) {
115 memmove(ctx->in, buf, 64);
116 byteReverse(ctx->in, 16);
117 MD5Transform(ctx->buf, (word32 *) ctx->in);
118 buf += 64;
119 len -= 64;
120 }
121
122 /* Handle any remaining bytes of data. */
123
124 memmove(ctx->in, buf, len);
125 }
126
127 /*
128 * Final wrapup - pad to 64-byte boundary with the bit pattern
129 * 1 0* (64-bit count of bits processed, MSB-first)
130 */
MD5Final(unsigned char digest[16],struct MD5Context * ctx)131 void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
132 {
133 unsigned int count;
134 unsigned char *p;
135
136 /* Compute number of bytes mod 64 */
137 count = (ctx->bits[0] >> 3) & 0x3F;
138
139 /* Set the first char of padding to 0x80. This is safe since there is
140 always at least one byte free */
141 p = ctx->in + count;
142 *p++ = 0x80;
143
144 /* Bytes of padding needed to make 64 bytes */
145 count = 64 - 1 - count;
146
147 /* Pad out to 56 mod 64 */
148 if (count < 8) {
149 /* Two lots of padding: Pad the first block to 64 bytes */
150 memset(p, 0, count);
151 byteReverse(ctx->in, 16);
152 MD5Transform(ctx->buf, (word32 *) ctx->in);
153
154 /* Now fill the next block with 56 bytes */
155 memset(ctx->in, 0, 56);
156 } else {
157 /* Pad block to 56 bytes */
158 memset(p, 0, count - 8);
159 }
160 byteReverse(ctx->in, 14);
161
162 /* Append length in bits and transform */
163 ctx->in32[14] = ctx->bits[0];
164 ctx->in32[15] = ctx->bits[1];
165
166 MD5Transform(ctx->buf, (word32 *) ctx->in);
167 byteReverse((unsigned char *) ctx->buf, 4);
168 memmove(digest, ctx->buf, 16);
169 memset(ctx, 0, sizeof(struct MD5Context));
170 }
171
172 /* The four core functions - F1 is optimized somewhat */
173
174 /* #define F1(x, y, z) (x & y | ~x & z) */
175 #define F1(x, y, z) (z ^ (x & (y ^ z)))
176 #define F2(x, y, z) F1(z, x, y)
177 #define F3(x, y, z) (x ^ y ^ z)
178 #define F4(x, y, z) (y ^ (x | ~z))
179
180 /* This is the central step in the MD5 algorithm. */
181 #define MD5STEP(f, w, x, y, z, data, s) \
182 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
183
184 /*
185 * The core of the MD5 algorithm, this alters an existing MD5 hash to
186 * reflect the addition of 16 longwords of new data. MD5Update blocks
187 * the data and converts bytes into longwords for this routine.
188 */
MD5Transform(word32 buf[4],word32 const in[16])189 void MD5Transform(word32 buf[4], word32 const in[16])
190 {
191 register word32 a, b, c, d;
192
193 a = buf[0];
194 b = buf[1];
195 c = buf[2];
196 d = buf[3];
197
198 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
199 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
200 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
201 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
202 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
203 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
204 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
205 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
206 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
207 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
208 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
209 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
210 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
211 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
212 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
213 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
214
215 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
216 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
217 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
218 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
219 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
220 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
221 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
222 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
223 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
224 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
225 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
226 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
227 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
228 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
229 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
230 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
231
232 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
233 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
234 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
235 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
236 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
237 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
238 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
239 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
240 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
241 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
242 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
243 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
244 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
245 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
246 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
247 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
248
249 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
250 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
251 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
252 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
253 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
254 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
255 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
256 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
257 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
258 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
259 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
260 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
261 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
262 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
263 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
264 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
265
266 buf[0] += a;
267 buf[1] += b;
268 buf[2] += c;
269 buf[3] += d;
270 }
271
272 /**@}*/
273
274 /*
275 * Note: this code is harmless on little-endian machines.
276 */
byteReverse(unsigned char * buf,unsigned longs)277 static void byteReverse(unsigned char *buf, unsigned longs)
278 {
279 word32 t;
280 do {
281 t = (word32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
282 ((unsigned) buf[1] << 8 | buf[0]);
283 *(word32 *) buf = t;
284 buf += 4;
285 } while (--longs);
286 }
287