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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 | * 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 | /* This code was modified in 1997 by Jim Kingdon of Cyclic Software to | |
19 | not require an integer type which is exactly 32 bits. This work | |
20 | draws on the changes for the same purpose by Tatu Ylonen | |
21 | <ylo@cs.hut.fi> as part of SSH, but since I didn't actually use | |
22 | that code, there is no copyright issue. I hereby disclaim | |
23 | copyright in any changes I have made; this code remains in the | |
24 | public domain. */ | |
25 | ||
26 | #include <string.h> /* for memcpy() and memset() */ | |
27 | ||
28 | /* Add prototype support. */ | |
29 | #ifndef PROTO | |
30 | #if defined (USE_PROTOTYPES) ? USE_PROTOTYPES : defined (__STDC__) | |
31 | #define PROTO(ARGS) ARGS | |
32 | #else | |
33 | #define PROTO(ARGS) () | |
34 | #endif | |
35 | #endif | |
36 | ||
37 | #include "md5.h" | |
38 | ||
39 | /* Little-endian byte-swapping routines. Note that these do not | |
40 | depend on the size of datatypes such as cvs_uint32, nor do they require | |
41 | us to detect the endianness of the machine we are running on. It | |
42 | is possible they should be macros for speed, but I would be | |
43 | surprised if they were a performance bottleneck for MD5. */ | |
44 | ||
45 | static uint32 | |
46 | getu32 (addr) | |
47 | const unsigned char *addr; | |
48 | { | |
49 | return (((((unsigned long)addr[3] << 8) | addr[2]) << 8) | |
50 | | addr[1]) << 8 | addr[0]; | |
51 | } | |
52 | ||
53 | static void | |
54 | putu32 (data, addr) | |
55 | uint32 data; | |
56 | unsigned char *addr; | |
57 | { | |
58 | addr[0] = (unsigned char)data; | |
59 | addr[1] = (unsigned char)(data >> 8); | |
60 | addr[2] = (unsigned char)(data >> 16); | |
61 | addr[3] = (unsigned char)(data >> 24); | |
62 | } | |
63 | ||
64 | /* | |
65 | * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious | |
66 | * initialization constants. | |
67 | */ | |
68 | void | |
69 | MD5Init (ctx) | |
70 | struct MD5Context *ctx; | |
71 | { | |
72 | ctx->buf[0] = 0x67452301; | |
73 | ctx->buf[1] = 0xefcdab89; | |
74 | ctx->buf[2] = 0x98badcfe; | |
75 | ctx->buf[3] = 0x10325476; | |
76 | ||
77 | ctx->bits[0] = 0; | |
78 | ctx->bits[1] = 0; | |
79 | } | |
80 | ||
81 | /* | |
82 | * Update context to reflect the concatenation of another buffer full | |
83 | * of bytes. | |
84 | */ | |
85 | void | |
86 | MD5Update (ctx, buf, len) | |
87 | struct MD5Context *ctx; | |
88 | unsigned char const *buf; | |
89 | unsigned len; | |
90 | { | |
91 | uint32 t; | |
92 | ||
93 | /* Update bitcount */ | |
94 | ||
95 | t = ctx->bits[0]; | |
96 | if ((ctx->bits[0] = (t + ((uint32)len << 3)) & 0xffffffff) < t) | |
97 | ctx->bits[1]++; /* Carry from low to high */ | |
98 | ctx->bits[1] += len >> 29; | |
99 | ||
100 | t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */ | |
101 | ||
102 | /* Handle any leading odd-sized chunks */ | |
103 | ||
104 | if ( t ) { | |
105 | unsigned char *p = ctx->in + t; | |
106 | ||
107 | t = 64-t; | |
108 | if (len < t) { | |
109 | memcpy(p, buf, len); | |
110 | return; | |
111 | } | |
112 | memcpy(p, buf, t); | |
113 | MD5Transform (ctx->buf, ctx->in); | |
114 | buf += t; | |
115 | len -= t; | |
116 | } | |
117 | ||
118 | /* Process data in 64-byte chunks */ | |
119 | ||
120 | while (len >= 64) { | |
121 | memcpy(ctx->in, buf, 64); | |
122 | MD5Transform (ctx->buf, ctx->in); | |
123 | buf += 64; | |
124 | len -= 64; | |
125 | } | |
126 | ||
127 | /* Handle any remaining bytes of data. */ | |
128 | ||
129 | memcpy(ctx->in, buf, len); | |
130 | } | |
131 | ||
132 | /* | |
133 | * Final wrapup - pad to 64-byte boundary with the bit pattern | |
134 | * 1 0* (64-bit count of bits processed, MSB-first) | |
135 | */ | |
136 | void | |
137 | MD5Final (digest, ctx) | |
138 | unsigned char digest[16]; | |
139 | struct MD5Context *ctx; | |
140 | { | |
141 | unsigned count; | |
142 | unsigned char *p; | |
143 | ||
144 | /* Compute number of bytes mod 64 */ | |
145 | count = (ctx->bits[0] >> 3) & 0x3F; | |
146 | ||
147 | /* Set the first char of padding to 0x80. This is safe since there is | |
148 | always at least one byte free */ | |
149 | p = ctx->in + count; | |
150 | *p++ = 0x80; | |
151 | ||
152 | /* Bytes of padding needed to make 64 bytes */ | |
153 | count = 64 - 1 - count; | |
154 | ||
155 | /* Pad out to 56 mod 64 */ | |
156 | if (count < 8) { | |
157 | /* Two lots of padding: Pad the first block to 64 bytes */ | |
158 | memset(p, 0, count); | |
159 | MD5Transform (ctx->buf, ctx->in); | |
160 | ||
161 | /* Now fill the next block with 56 bytes */ | |
162 | memset(ctx->in, 0, 56); | |
163 | } else { | |
164 | /* Pad block to 56 bytes */ | |
165 | memset(p, 0, count-8); | |
166 | } | |
167 | ||
168 | /* Append length in bits and transform */ | |
169 | putu32(ctx->bits[0], ctx->in + 56); | |
170 | putu32(ctx->bits[1], ctx->in + 60); | |
171 | ||
172 | MD5Transform (ctx->buf, ctx->in); | |
173 | putu32(ctx->buf[0], digest); | |
174 | putu32(ctx->buf[1], digest + 4); | |
175 | putu32(ctx->buf[2], digest + 8); | |
176 | putu32(ctx->buf[3], digest + 12); | |
177 | memset(ctx, 0, sizeof(MD5Context)); /* In case it's sensitive */ | |
178 | } | |
179 | ||
180 | /* The four core functions - F1 is optimized somewhat */ | |
181 | ||
182 | /* #define F1(x, y, z) (x & y | ~x & z) */ | |
183 | #define F1(x, y, z) (z ^ (x & (y ^ z))) | |
184 | #define F2(x, y, z) F1(z, x, y) | |
185 | #define F3(x, y, z) (x ^ y ^ z) | |
186 | #define F4(x, y, z) (y ^ (x | ~z)) | |
187 | ||
188 | /* This is the central step in the MD5 algorithm. */ | |
189 | #define MD5STEP(f, w, x, y, z, data, s) \ | |
190 | ( w += f(x, y, z) + data, w &= 0xffffffff, w = w<<s | w>>(32-s), w += x ) | |
191 | ||
192 | /* | |
193 | * The core of the MD5 algorithm, this alters an existing MD5 hash to | |
194 | * reflect the addition of 16 longwords of new data. MD5Update blocks | |
195 | * the data and converts bytes into longwords for this routine. | |
196 | */ | |
197 | void | |
198 | MD5Transform (buf, inraw) | |
199 | uint32 buf[4]; | |
200 | const unsigned char inraw[64]; | |
201 | { | |
202 | register uint32 a, b, c, d; | |
203 | uint32 in[16]; | |
204 | int i; | |
205 | ||
206 | for (i = 0; i < 16; ++i) | |
207 | in[i] = getu32 (inraw + 4 * i); | |
208 | ||
209 | a = buf[0]; | |
210 | b = buf[1]; | |
211 | c = buf[2]; | |
212 | d = buf[3]; | |
213 | ||
214 | MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478, 7); | |
215 | MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12); | |
216 | MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17); | |
217 | MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22); | |
218 | MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf, 7); | |
219 | MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12); | |
220 | MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17); | |
221 | MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22); | |
222 | MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8, 7); | |
223 | MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12); | |
224 | MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17); | |
225 | MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22); | |
226 | MD5STEP(F1, a, b, c, d, in[12]+0x6b901122, 7); | |
227 | MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12); | |
228 | MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17); | |
229 | MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22); | |
230 | ||
231 | MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562, 5); | |
232 | MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340, 9); | |
233 | MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14); | |
234 | MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20); | |
235 | MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d, 5); | |
236 | MD5STEP(F2, d, a, b, c, in[10]+0x02441453, 9); | |
237 | MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14); | |
238 | MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20); | |
239 | MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6, 5); | |
240 | MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6, 9); | |
241 | MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14); | |
242 | MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20); | |
243 | MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905, 5); | |
244 | MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8, 9); | |
245 | MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14); | |
246 | MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20); | |
247 | ||
248 | MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942, 4); | |
249 | MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11); | |
250 | MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16); | |
251 | MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23); | |
252 | MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44, 4); | |
253 | MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11); | |
254 | MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16); | |
255 | MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23); | |
256 | MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6, 4); | |
257 | MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11); | |
258 | MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16); | |
259 | MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23); | |
260 | MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039, 4); | |
261 | MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11); | |
262 | MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16); | |
263 | MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23); | |
264 | ||
265 | MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244, 6); | |
266 | MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10); | |
267 | MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15); | |
268 | MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21); | |
269 | MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3, 6); | |
270 | MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10); | |
271 | MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15); | |
272 | MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21); | |
273 | MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f, 6); | |
274 | MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10); | |
275 | MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15); | |
276 | MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21); | |
277 | MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82, 6); | |
278 | MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10); | |
279 | MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15); | |
280 | MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21); | |
281 | ||
282 | buf[0] += a; | |
283 | buf[1] += b; | |
284 | buf[2] += c; | |
285 | buf[3] += d; | |
286 | } |