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DEFINITIONS
This source file includes following definitions.
- byteReverse
- MD5Init
- MD5Update
- MD5Final
- MD5Transform
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 * To compute the message digest of a chunk of bytes, declare an
13 * MD5Context structure, pass it to MD5Init, call MD5Update as
14 * needed on buffers full of bytes, and then call MD5Final, which
15 * will fill a supplied 16-byte array with the digest.
16 */
17
18 #include <string.h> /* for memcpy() */
19 #include "md5.h"
20
21 #if !defined(WORDS_BIGENDIAN)
22 /* on little endian machines, we can skip this part */
23 #define byteReverse(buf, len)
24 #else
25 void byteReverse(unsigned char *buf, unsigned longs)
26 {
27 u_int32_t t;
28 do {
29 t = (u_int32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
30 ((unsigned) buf[1] << 8 | buf[0]);
31 *(u_int32_t *) buf = t;
32 buf += 4;
33 } while (--longs);
34 }
35 #endif
36
37 /*
38 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
39 * initialization constants.
40 */
41 void MD5Init(MD5_CTX *ctx)
42 {
43 ctx->buf[0] = 0x67452301;
44 ctx->buf[1] = 0xefcdab89;
45 ctx->buf[2] = 0x98badcfe;
46 ctx->buf[3] = 0x10325476;
47
48 ctx->bits[0] = 0;
49 ctx->bits[1] = 0;
50 }
51
52 /*
53 * Update context to reflect the concatenation of another buffer full
54 * of bytes.
55 */
56 void MD5Update(MD5_CTX *ctx, unsigned char const *buf, unsigned len)
57 {
58 u_int32_t t;
59
60 /* Update bitcount */
61
62 t = ctx->bits[0];
63 if ((ctx->bits[0] = t + ((u_int32_t) len << 3)) < t)
64 ctx->bits[1]++; /* Carry from low to high */
65 ctx->bits[1] += len >> 29;
66
67 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
68
69 /* Handle any leading odd-sized chunks */
70
71 if (t) {
72 unsigned char *p = (unsigned char *) ctx->in + t;
73
74 t = 64 - t;
75 if (len < t) {
76 memcpy(p, buf, len);
77 return;
78 }
79 memcpy(p, buf, t);
80 byteReverse(ctx->in, 16);
81 MD5Transform(ctx->buf, (u_int32_t *) ctx->in);
82 buf += t;
83 len -= t;
84 }
85 /* Process data in 64-byte chunks */
86
87 while (len >= 64) {
88 memcpy(ctx->in, buf, 64);
89 byteReverse(ctx->in, 16);
90 MD5Transform(ctx->buf, (u_int32_t *) ctx->in);
91 buf += 64;
92 len -= 64;
93 }
94
95 /* Handle any remaining bytes of data. */
96
97 memcpy(ctx->in, buf, len);
98 }
99
100 /*
101 * Final wrapup - pad to 64-byte boundary with the bit pattern
102 * 1 0* (64-bit count of bits processed, MSB-first)
103 */
104 void MD5Final(unsigned char digest[16], MD5_CTX *ctx)
105 {
106 unsigned count;
107 unsigned char *p;
108
109 /* Compute number of bytes mod 64 */
110 count = (ctx->bits[0] >> 3) & 0x3F;
111
112 /* Set the first char of padding to 0x80. This is safe since there is
113 always at least one byte free */
114 p = ctx->in + count;
115 *p++ = 0x80;
116
117 /* Bytes of padding needed to make 64 bytes */
118 count = 64 - 1 - count;
119
120 /* Pad out to 56 mod 64 */
121 if (count < 8) {
122 /* Two lots of padding: Pad the first block to 64 bytes */
123 memset(p, 0, count);
124 byteReverse(ctx->in, 16);
125 MD5Transform(ctx->buf, (u_int32_t *) ctx->in);
126
127 /* Now fill the next block with 56 bytes */
128 memset(ctx->in, 0, 56);
129 } else {
130 /* Pad block to 56 bytes */
131 memset(p, 0, count - 8);
132 }
133 byteReverse(ctx->in, 14);
134
135 /* Append length in bits and transform */
136 ((u_int32_t *) ctx->in)[14] = ctx->bits[0];
137 ((u_int32_t *) ctx->in)[15] = ctx->bits[1];
138
139 MD5Transform(ctx->buf, (u_int32_t *) ctx->in);
140 byteReverse((unsigned char *) ctx->buf, 4);
141 memcpy(digest, ctx->buf, 16);
142 memset((char *) ctx, 0, sizeof(ctx)); /* In case it's sensitive */
143 }
144
145 /* The four core functions - F1 is optimized somewhat */
146
147 /* #define F1(x, y, z) (x & y | ~x & z) */
148 #define F1(x, y, z) (z ^ (x & (y ^ z)))
149 #define F2(x, y, z) F1(z, x, y)
150 #define F3(x, y, z) (x ^ y ^ z)
151 #define F4(x, y, z) (y ^ (x | ~z))
152
153 /* This is the central step in the MD5 algorithm. */
154 #define MD5STEP(f, w, x, y, z, data, s) \
155 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
156
157 /*
158 * The core of the MD5 algorithm, this alters an existing MD5 hash to
159 * reflect the addition of 16 longwords of new data. MD5Update blocks
160 * the data and converts bytes into longwords for this routine.
161 */
162 void MD5Transform(u_int32_t buf[4], u_int32_t const in[16])
163 {
164 register u_int32_t a, b, c, d;
165
166 a = buf[0];
167 b = buf[1];
168 c = buf[2];
169 d = buf[3];
170
171 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
172 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
173 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
174 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
175 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
176 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
177 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
178 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
179 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
180 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
181 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
182 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
183 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
184 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
185 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
186 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
187
188 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
189 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
190 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
191 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
192 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
193 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
194 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
195 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
196 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
197 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
198 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
199 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
200 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
201 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
202 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
203 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
204
205 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
206 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
207 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
208 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
209 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
210 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
211 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
212 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
213 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
214 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
215 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
216 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
217 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
218 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
219 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
220 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
221
222 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
223 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
224 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
225 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
226 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
227 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
228 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
229 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
230 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
231 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
232 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
233 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
234 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
235 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
236 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
237 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
238
239 buf[0] += a;
240 buf[1] += b;
241 buf[2] += c;
242 buf[3] += d;
243 }