1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 // The original file was copied from sqlite, and was in the public domain.
6
7 /*
8 * This code implements the MD5 message-digest algorithm.
9 * The algorithm is due to Ron Rivest. This code was
10 * written by Colin Plumb in 1993, no copyright is claimed.
11 * This code is in the public domain; do with it what you wish.
12 *
13 * Equivalent code is available from RSA Data Security, Inc.
14 * This code has been tested against that, and is equivalent,
15 * except that you don't need to include two pages of legalese
16 * with every copy.
17 *
18 * To compute the message digest of a chunk of bytes, declare an
19 * MD5Context structure, pass it to MD5Init, call MD5Update as
20 * needed on buffers full of bytes, and then call MD5Final, which
21 * will fill a supplied 16-byte array with the digest.
22 */
23
24 #include "base/md5.h"
25
26 #include "base/basictypes.h"
27
28 namespace {
29
30 struct Context {
31 uint32 buf[4];
32 uint32 bits[2];
33 unsigned char in[64];
34 };
35
36 /*
37 * Note: this code is harmless on little-endian machines.
38 */
byteReverse(unsigned char * buf,unsigned longs)39 void byteReverse(unsigned char *buf, unsigned longs) {
40 uint32 t;
41 do {
42 t = (uint32)((unsigned)buf[3]<<8 | buf[2]) << 16 |
43 ((unsigned)buf[1]<<8 | buf[0]);
44 *(uint32 *)buf = t;
45 buf += 4;
46 } while (--longs);
47 }
48
49 /* The four core functions - F1 is optimized somewhat */
50
51 /* #define F1(x, y, z) (x & y | ~x & z) */
52 #define F1(x, y, z) (z ^ (x & (y ^ z)))
53 #define F2(x, y, z) F1(z, x, y)
54 #define F3(x, y, z) (x ^ y ^ z)
55 #define F4(x, y, z) (y ^ (x | ~z))
56
57 /* This is the central step in the MD5 algorithm. */
58 #define MD5STEP(f, w, x, y, z, data, s) \
59 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
60
61 /*
62 * The core of the MD5 algorithm, this alters an existing MD5 hash to
63 * reflect the addition of 16 longwords of new data. MD5Update blocks
64 * the data and converts bytes into longwords for this routine.
65 */
MD5Transform(uint32 buf[4],const uint32 in[16])66 void MD5Transform(uint32 buf[4], const uint32 in[16]) {
67 register uint32 a, b, c, d;
68
69 a = buf[0];
70 b = buf[1];
71 c = buf[2];
72 d = buf[3];
73
74 MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478, 7);
75 MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12);
76 MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17);
77 MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22);
78 MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf, 7);
79 MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12);
80 MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17);
81 MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22);
82 MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8, 7);
83 MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12);
84 MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17);
85 MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22);
86 MD5STEP(F1, a, b, c, d, in[12]+0x6b901122, 7);
87 MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12);
88 MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17);
89 MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22);
90
91 MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562, 5);
92 MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340, 9);
93 MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14);
94 MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20);
95 MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d, 5);
96 MD5STEP(F2, d, a, b, c, in[10]+0x02441453, 9);
97 MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14);
98 MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20);
99 MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6, 5);
100 MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6, 9);
101 MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14);
102 MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20);
103 MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905, 5);
104 MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8, 9);
105 MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14);
106 MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20);
107
108 MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942, 4);
109 MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11);
110 MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16);
111 MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23);
112 MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44, 4);
113 MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11);
114 MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16);
115 MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23);
116 MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6, 4);
117 MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11);
118 MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16);
119 MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23);
120 MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039, 4);
121 MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11);
122 MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16);
123 MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23);
124
125 MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244, 6);
126 MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10);
127 MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15);
128 MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21);
129 MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3, 6);
130 MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10);
131 MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15);
132 MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21);
133 MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f, 6);
134 MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10);
135 MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15);
136 MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21);
137 MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82, 6);
138 MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10);
139 MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15);
140 MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21);
141
142 buf[0] += a;
143 buf[1] += b;
144 buf[2] += c;
145 buf[3] += d;
146 }
147
148 } // namespace
149
150 namespace base {
151
152 /*
153 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
154 * initialization constants.
155 */
MD5Init(MD5Context * context)156 void MD5Init(MD5Context* context) {
157 struct Context *ctx = (struct Context *)context;
158 ctx->buf[0] = 0x67452301;
159 ctx->buf[1] = 0xefcdab89;
160 ctx->buf[2] = 0x98badcfe;
161 ctx->buf[3] = 0x10325476;
162 ctx->bits[0] = 0;
163 ctx->bits[1] = 0;
164 }
165
166 /*
167 * Update context to reflect the concatenation of another buffer full
168 * of bytes.
169 */
MD5Update(MD5Context * context,const StringPiece & data)170 void MD5Update(MD5Context* context, const StringPiece& data) {
171 const unsigned char* inbuf = (const unsigned char*)data.data();
172 size_t len = data.size();
173 struct Context *ctx = (struct Context *)context;
174 const unsigned char* buf = (const unsigned char*)inbuf;
175 uint32 t;
176
177 /* Update bitcount */
178
179 t = ctx->bits[0];
180 if ((ctx->bits[0] = t + ((uint32)len << 3)) < t)
181 ctx->bits[1]++; /* Carry from low to high */
182 ctx->bits[1] += static_cast<uint32>(len >> 29);
183
184 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
185
186 /* Handle any leading odd-sized chunks */
187
188 if (t) {
189 unsigned char *p = (unsigned char *)ctx->in + t;
190
191 t = 64-t;
192 if (len < t) {
193 memcpy(p, buf, len);
194 return;
195 }
196 memcpy(p, buf, t);
197 byteReverse(ctx->in, 16);
198 MD5Transform(ctx->buf, (uint32 *)ctx->in);
199 buf += t;
200 len -= t;
201 }
202
203 /* Process data in 64-byte chunks */
204
205 while (len >= 64) {
206 memcpy(ctx->in, buf, 64);
207 byteReverse(ctx->in, 16);
208 MD5Transform(ctx->buf, (uint32 *)ctx->in);
209 buf += 64;
210 len -= 64;
211 }
212
213 /* Handle any remaining bytes of data. */
214
215 memcpy(ctx->in, buf, len);
216 }
217
218 /*
219 * Final wrapup - pad to 64-byte boundary with the bit pattern
220 * 1 0* (64-bit count of bits processed, MSB-first)
221 */
MD5Final(MD5Digest * digest,MD5Context * context)222 void MD5Final(MD5Digest* digest, MD5Context* context) {
223 struct Context *ctx = (struct Context *)context;
224 unsigned count;
225 unsigned char *p;
226
227 /* Compute number of bytes mod 64 */
228 count = (ctx->bits[0] >> 3) & 0x3F;
229
230 /* Set the first char of padding to 0x80. This is safe since there is
231 always at least one byte free */
232 p = ctx->in + count;
233 *p++ = 0x80;
234
235 /* Bytes of padding needed to make 64 bytes */
236 count = 64 - 1 - count;
237
238 /* Pad out to 56 mod 64 */
239 if (count < 8) {
240 /* Two lots of padding: Pad the first block to 64 bytes */
241 memset(p, 0, count);
242 byteReverse(ctx->in, 16);
243 MD5Transform(ctx->buf, (uint32 *)ctx->in);
244
245 /* Now fill the next block with 56 bytes */
246 memset(ctx->in, 0, 56);
247 } else {
248 /* Pad block to 56 bytes */
249 memset(p, 0, count-8);
250 }
251 byteReverse(ctx->in, 14);
252
253 /* Append length in bits and transform */
254 memcpy(&ctx->in[14 * sizeof(ctx->bits[0])],
255 &ctx->bits[0],
256 sizeof(ctx->bits[0]));
257 memcpy(&ctx->in[15 * sizeof(ctx->bits[1])],
258 &ctx->bits[1],
259 sizeof(ctx->bits[1]));
260
261 MD5Transform(ctx->buf, (uint32 *)ctx->in);
262 byteReverse((unsigned char *)ctx->buf, 4);
263 memcpy(digest->a, ctx->buf, 16);
264 memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
265 }
266
MD5IntermediateFinal(MD5Digest * digest,const MD5Context * context)267 void MD5IntermediateFinal(MD5Digest* digest, const MD5Context* context) {
268 /* MD5Final mutates the MD5Context*. Make a copy for generating the
269 intermediate value. */
270 MD5Context context_copy;
271 memcpy(&context_copy, context, sizeof(context_copy));
272 MD5Final(digest, &context_copy);
273 }
274
MD5DigestToBase16(const MD5Digest & digest)275 std::string MD5DigestToBase16(const MD5Digest& digest) {
276 static char const zEncode[] = "0123456789abcdef";
277
278 std::string ret;
279 ret.resize(32);
280
281 int j = 0;
282 for (int i = 0; i < 16; i ++) {
283 int a = digest.a[i];
284 ret[j++] = zEncode[(a>>4)&0xf];
285 ret[j++] = zEncode[a & 0xf];
286 }
287 return ret;
288 }
289
MD5Sum(const void * data,size_t length,MD5Digest * digest)290 void MD5Sum(const void* data, size_t length, MD5Digest* digest) {
291 MD5Context ctx;
292 MD5Init(&ctx);
293 MD5Update(&ctx,
294 StringPiece(reinterpret_cast<const char*>(data), length));
295 MD5Final(digest, &ctx);
296 }
297
MD5String(const StringPiece & str)298 std::string MD5String(const StringPiece& str) {
299 MD5Digest digest;
300 MD5Sum(str.data(), str.length(), &digest);
301 return MD5DigestToBase16(digest);
302 }
303
304 } // namespace base
305