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1/*
2 * This code implements the MD5 message-digest algorithm.
3 * The algorithm is due to Ron Rivest. This code was
4 * written by Colin Plumb in 1993, no copyright is claimed.
5 * This code is in the public domain; do with it what you wish.
6 *
7 * Equivalent code is available from RSA Data Security, Inc.
8 * This code has been tested against that, and is equivalent,
9 * except that you don't need to include two pages of legalese
10 * with every copy.
11 *
12 * LIC: GPL
13 *
14 * To compute the message digest of a chunk of bytes, declare an
15 * MD5Context structure, pass it to MD5Init, call MD5Update as
16 * needed on buffers full of bytes, and then call MD5Final, which
17 * will fill a supplied 16-byte array with the digest.
18 */
19#include <string.h> /* for memcpy() */
20#include "md5.h"
21
22static void byteReverse(unsigned char *buf, unsigned longs);
23
24/*
25 * Note: this code is harmless on little-endian machines.
26 */
27static void
28byteReverse(unsigned char *buf, unsigned longs)
29{
30 uint32 t;
31 do {
32 t = (uint32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
33 ((unsigned) buf[1] << 8 | buf[0]);
34 *(uint32 *) buf = t;
35 buf += 4;
36 } while (--longs);
37}
38
39/*
40 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
41 * initialization constants.
42 */
43void MD5Init(struct MD5Context *ctx)
44{
45 ctx->buf[0] = 0x67452301;
46 ctx->buf[1] = 0xefcdab89;
47 ctx->buf[2] = 0x98badcfe;
48 ctx->buf[3] = 0x10325476;
49
50 ctx->bits[0] = 0;
51 ctx->bits[1] = 0;
52}
53
54/*
55 * Update context to reflect the concatenation of another buffer full
56 * of bytes.
57 */
58void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
59{
60 uint32 t;
61
62 /* Update bitcount */
63
64 t = ctx->bits[0];
65 if ((ctx->bits[0] = t + ((uint32) len << 3)) < t)
66 ctx->bits[1]++; /* Carry from low to high */
67 ctx->bits[1] += len >> 29;
68
69 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
70
71 /* Handle any leading odd-sized chunks */
72
73 if (t) {
74 unsigned char *p = (unsigned char *) ctx->in + t;
75
76 t = 64 - t;
77 if (len < t) {
78 memcpy(p, buf, len);
79 return;
80 }
81 memcpy(p, buf, t);
82 byteReverse(ctx->in, 16);
83 MD5Transform(ctx->buf, (uint32 *) ctx->in);
84 buf += t;
85 len -= t;
86 }
87 /* Process data in 64-byte chunks */
88
89 while (len >= 64) {
90 memcpy(ctx->in, buf, 64);
91 byteReverse(ctx->in, 16);
92 MD5Transform(ctx->buf, (uint32 *) ctx->in);
93 buf += 64;
94 len -= 64;
95 }
96
97 /* Handle any remaining bytes of data. */
98
99 memcpy(ctx->in, buf, len);
100}
101
102/*
103 * Final wrapup - pad to 64-byte boundary with the bit pattern
104 * 1 0* (64-bit count of bits processed, MSB-first)
105 */
106void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
107{
108 unsigned count;
109 unsigned char *p;
110
111 /* Compute number of bytes mod 64 */
112 count = (ctx->bits[0] >> 3) & 0x3F;
113
114 /* Set the first char of padding to 0x80. This is safe since there is
115 always at least one byte free */
116 p = ctx->in + count;
117 *p++ = 0x80;
118
119 /* Bytes of padding needed to make 64 bytes */
120 count = 64 - 1 - count;
121
122 /* Pad out to 56 mod 64 */
123 if (count < 8) {
124 /* Two lots of padding: Pad the first block to 64 bytes */
125 memset(p, 0, count);
126 byteReverse(ctx->in, 16);
127 MD5Transform(ctx->buf, (uint32 *) ctx->in);
128
129 /* Now fill the next block with 56 bytes */
130 memset(ctx->in, 0, 56);
131 } else {
132 /* Pad block to 56 bytes */
133 memset(p, 0, count - 8);
134 }
135 byteReverse(ctx->in, 14);
136
137 /* Append length in bits and transform */
138 ((uint32 *) ctx->in)[14] = ctx->bits[0];
139 ((uint32 *) ctx->in)[15] = ctx->bits[1];
140
141 MD5Transform(ctx->buf, (uint32 *) ctx->in);
142 byteReverse((unsigned char *) ctx->buf, 4);
143 memcpy(digest, ctx->buf, 16);
144 memset(ctx, 0, sizeof(ctx)); /* In case it's sensitive */
145}
146
147#ifndef ASM_MD5
148
149/* The four core functions - F1 is optimized somewhat */
150
151/* #define F1(x, y, z) (x & y | ~x & z) */
152#define F1(x, y, z) (z ^ (x & (y ^ z)))
153#define F2(x, y, z) F1(z, x, y)
154#define F3(x, y, z) (x ^ y ^ z)
155#define F4(x, y, z) (y ^ (x | ~z))
156
157/* This is the central step in the MD5 algorithm. */
158#define MD5STEP(f, w, x, y, z, data, s) \
159 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
160
161/*
162 * The core of the MD5 algorithm, this alters an existing MD5 hash to
163 * reflect the addition of 16 longwords of new data. MD5Update blocks
164 * the data and converts bytes into longwords for this routine.
165 */
166void MD5Transform(uint32 buf[4], uint32 const in[16])
167{
168 register uint32 a, b, c, d;
169
170 a = buf[0];
171 b = buf[1];
172 c = buf[2];
173 d = buf[3];
174
175 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
176 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
177 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
178 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
179 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
180 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
181 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
182 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
183 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
184 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
185 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
186 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
187 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
188 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
189 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
190 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
191
192 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
193 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
194 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
195 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
196 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
197 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
198 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
199 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
200 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
201 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
202 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
203 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
204 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
205 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
206 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
207 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
208
209 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
210 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
211 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
212 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
213 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
214 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
215 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
216 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
217 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
218 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
219 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
220 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
221 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
222 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
223 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
224 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
225
226 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
227 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
228 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
229 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
230 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
231 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
232 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
233 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
234 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
235 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
236 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
237 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
238 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
239 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
240 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
241 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
242
243 buf[0] += a;
244 buf[1] += b;
245 buf[2] += c;
246 buf[3] += d;
247}
248
249#endif
250
generated by cgit at 2024-05-18 06:04:32 (GMT)