Line data Source code
1 : /*
2 : * written by Colin Plumb in 1993, no copyright is claimed.
3 : * This code is in the public domain; do with it what you wish.
4 : *
5 : * Equivalent code is available from RSA Data Security, Inc.
6 : * This code has been tested against that, and is equivalent,
7 : * except that you don't need to include two pages of legalese
8 : * with every copy.
9 : *
10 : * To compute the message digest of a chunk of bytes, declare an
11 : * MD5Context structure, pass it to MD5Init, call MD5Update as
12 : * needed on buffers full of bytes, and then call MD5Final, which
13 : * will fill a supplied 16-byte array with the digest.
14 : */
15 :
16 : #include <string.h>
17 :
18 : #include "common/md5.h"
19 :
20 : namespace google_breakpad {
21 :
22 : #ifndef WORDS_BIGENDIAN
23 : #define byteReverse(buf, len) /* Nothing */
24 : #else
25 : /*
26 : * Note: this code is harmless on little-endian machines.
27 : */
28 : static void byteReverse(unsigned char *buf, unsigned longs)
29 : {
30 : u32 t;
31 : do {
32 : t = (u32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
33 : ((unsigned) buf[1] << 8 | buf[0]);
34 : *(u32 *) buf = t;
35 : buf += 4;
36 : } while (--longs);
37 : }
38 : #endif
39 :
40 : static void MD5Transform(u32 buf[4], u32 const in[16]);
41 :
42 : /*
43 : * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
44 : * initialization constants.
45 : */
46 0 : void MD5Init(struct MD5Context *ctx)
47 : {
48 0 : ctx->buf[0] = 0x67452301;
49 0 : ctx->buf[1] = 0xefcdab89;
50 0 : ctx->buf[2] = 0x98badcfe;
51 0 : ctx->buf[3] = 0x10325476;
52 :
53 0 : ctx->bits[0] = 0;
54 0 : ctx->bits[1] = 0;
55 0 : }
56 :
57 : /*
58 : * Update context to reflect the concatenation of another buffer full
59 : * of bytes.
60 : */
61 0 : void MD5Update(struct MD5Context *ctx, unsigned char const *buf, size_t len)
62 : {
63 : u32 t;
64 :
65 : /* Update bitcount */
66 :
67 0 : t = ctx->bits[0];
68 0 : if ((ctx->bits[0] = t + ((u32) len << 3)) < t)
69 0 : ctx->bits[1]++; /* Carry from low to high */
70 0 : ctx->bits[1] += len >> 29;
71 :
72 0 : t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
73 :
74 : /* Handle any leading odd-sized chunks */
75 :
76 0 : if (t) {
77 0 : unsigned char *p = (unsigned char *) ctx->in + t;
78 :
79 0 : t = 64 - t;
80 0 : if (len < t) {
81 0 : memcpy(p, buf, len);
82 0 : return;
83 : }
84 0 : memcpy(p, buf, t);
85 : byteReverse(ctx->in, 16);
86 0 : MD5Transform(ctx->buf, (u32 *) ctx->in);
87 0 : buf += t;
88 0 : len -= t;
89 : }
90 : /* Process data in 64-byte chunks */
91 :
92 0 : while (len >= 64) {
93 0 : memcpy(ctx->in, buf, 64);
94 : byteReverse(ctx->in, 16);
95 0 : MD5Transform(ctx->buf, (u32 *) ctx->in);
96 0 : buf += 64;
97 0 : len -= 64;
98 : }
99 :
100 : /* Handle any remaining bytes of data. */
101 :
102 0 : memcpy(ctx->in, buf, len);
103 : }
104 :
105 : /*
106 : * Final wrapup - pad to 64-byte boundary with the bit pattern
107 : * 1 0* (64-bit count of bits processed, MSB-first)
108 : */
109 0 : void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
110 : {
111 : unsigned count;
112 : unsigned char *p;
113 :
114 : /* Compute number of bytes mod 64 */
115 0 : count = (ctx->bits[0] >> 3) & 0x3F;
116 :
117 : /* Set the first char of padding to 0x80. This is safe since there is
118 : always at least one byte free */
119 0 : p = ctx->in + count;
120 0 : *p++ = 0x80;
121 :
122 : /* Bytes of padding needed to make 64 bytes */
123 0 : count = 64 - 1 - count;
124 :
125 : /* Pad out to 56 mod 64 */
126 0 : if (count < 8) {
127 : /* Two lots of padding: Pad the first block to 64 bytes */
128 0 : memset(p, 0, count);
129 : byteReverse(ctx->in, 16);
130 0 : MD5Transform(ctx->buf, (u32 *) ctx->in);
131 :
132 : /* Now fill the next block with 56 bytes */
133 0 : memset(ctx->in, 0, 56);
134 : } else {
135 : /* Pad block to 56 bytes */
136 0 : memset(p, 0, count - 8);
137 : }
138 : byteReverse(ctx->in, 14);
139 :
140 : /* Append length in bits and transform */
141 0 : ((u32 *) ctx->in)[14] = ctx->bits[0];
142 0 : ((u32 *) ctx->in)[15] = ctx->bits[1];
143 :
144 0 : MD5Transform(ctx->buf, (u32 *) ctx->in);
145 : byteReverse((unsigned char *) ctx->buf, 4);
146 0 : memcpy(digest, ctx->buf, 16);
147 0 : memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
148 0 : }
149 :
150 : /* The four core functions - F1 is optimized somewhat */
151 :
152 : /* #define F1(x, y, z) (x & y | ~x & z) */
153 : #define F1(x, y, z) (z ^ (x & (y ^ z)))
154 : #define F2(x, y, z) F1(z, x, y)
155 : #define F3(x, y, z) (x ^ y ^ z)
156 : #define F4(x, y, z) (y ^ (x | ~z))
157 :
158 : /* This is the central step in the MD5 algorithm. */
159 : #define MD5STEP(f, w, x, y, z, data, s) \
160 : ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
161 :
162 : /*
163 : * The core of the MD5 algorithm, this alters an existing MD5 hash to
164 : * reflect the addition of 16 longwords of new data. MD5Update blocks
165 : * the data and converts bytes into longwords for this routine.
166 : */
167 0 : static void MD5Transform(u32 buf[4], u32 const in[16])
168 : {
169 : u32 a, b, c, d;
170 :
171 0 : a = buf[0];
172 0 : b = buf[1];
173 0 : c = buf[2];
174 0 : d = buf[3];
175 :
176 0 : MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
177 0 : MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
178 0 : MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
179 0 : MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
180 0 : MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
181 0 : MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
182 0 : MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
183 0 : MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
184 0 : MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
185 0 : MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
186 0 : MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
187 0 : MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
188 0 : MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
189 0 : MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
190 0 : MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
191 0 : MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
192 :
193 0 : MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
194 0 : MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
195 0 : MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
196 0 : MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
197 0 : MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
198 0 : MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
199 0 : MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
200 0 : MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
201 0 : MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
202 0 : MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
203 0 : MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
204 0 : MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
205 0 : MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
206 0 : MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
207 0 : MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
208 0 : MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
209 :
210 0 : MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
211 0 : MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
212 0 : MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
213 0 : MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
214 0 : MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
215 0 : MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
216 0 : MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
217 0 : MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
218 0 : MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
219 0 : MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
220 0 : MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
221 0 : MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
222 0 : MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
223 0 : MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
224 0 : MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
225 0 : MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
226 :
227 0 : MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
228 0 : MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
229 0 : MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
230 0 : MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
231 0 : MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
232 0 : MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
233 0 : MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
234 0 : MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
235 0 : MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
236 0 : MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
237 0 : MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
238 0 : MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
239 0 : MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
240 0 : MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
241 0 : MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
242 0 : MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
243 :
244 0 : buf[0] += a;
245 0 : buf[1] += b;
246 0 : buf[2] += c;
247 0 : buf[3] += d;
248 0 : }
249 :
250 : } // namespace google_breakpad
251 :
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