md5.cc revision c7f5f8508d98d5952d42ed7648c2a8f30a4da156 
1// The original file was copied from sqlite, and was in the public domain.
2// Modifications Copyright 2006 Google Inc. All Rights Reserved
3
4/*
5 * This code implements the MD5 message-digest algorithm.
6 * The algorithm is due to Ron Rivest.  This code was
7 * written by Colin Plumb in 1993, no copyright is claimed.
8 * This code is in the public domain; do with it what you wish.
9 *
10 * Equivalent code is available from RSA Data Security, Inc.
11 * This code has been tested against that, and is equivalent,
12 * except that you don't need to include two pages of legalese
13 * with every copy.
14 *
15 * To compute the message digest of a chunk of bytes, declare an
16 * MD5Context structure, pass it to MD5Init, call MD5Update as
17 * needed on buffers full of bytes, and then call MD5Final, which
18 * will fill a supplied 16-byte array with the digest.
19 */
20
21#include <string>
22
23#include "base/md5.h"
24
25#include "base/basictypes.h"
26
27struct Context {
28  uint32 buf[4];
29  uint32 bits[2];
30  unsigned char in[64];
31};
32
33/*
34 * Note: this code is harmless on little-endian machines.
35 */
36static void byteReverse(unsigned char *buf, unsigned longs){
37        uint32 t;
38        do {
39                t = (uint32)((unsigned)buf[3]<<8 | buf[2]) << 16 |
40                            ((unsigned)buf[1]<<8 | buf[0]);
41                *(uint32 *)buf = t;
42                buf += 4;
43        } while (--longs);
44}
45/* The four core functions - F1 is optimized somewhat */
46
47/* #define F1(x, y, z) (x & y | ~x & z) */
48#define F1(x, y, z) (z ^ (x & (y ^ z)))
49#define F2(x, y, z) F1(z, x, y)
50#define F3(x, y, z) (x ^ y ^ z)
51#define F4(x, y, z) (y ^ (x | ~z))
52
53/* This is the central step in the MD5 algorithm. */
54#define MD5STEP(f, w, x, y, z, data, s) \
55        ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
56
57/*
58 * The core of the MD5 algorithm, this alters an existing MD5 hash to
59 * reflect the addition of 16 longwords of new data.  MD5Update blocks
60 * the data and converts bytes into longwords for this routine.
61 */
62static void MD5Transform(uint32 buf[4], const uint32 in[16]){
63        register uint32 a, b, c, d;
64
65        a = buf[0];
66        b = buf[1];
67        c = buf[2];
68        d = buf[3];
69
70        MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478,  7);
71        MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12);
72        MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17);
73        MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22);
74        MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf,  7);
75        MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12);
76        MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17);
77        MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22);
78        MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8,  7);
79        MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12);
80        MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17);
81        MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22);
82        MD5STEP(F1, a, b, c, d, in[12]+0x6b901122,  7);
83        MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12);
84        MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17);
85        MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22);
86
87        MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562,  5);
88        MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340,  9);
89        MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14);
90        MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20);
91        MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d,  5);
92        MD5STEP(F2, d, a, b, c, in[10]+0x02441453,  9);
93        MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14);
94        MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20);
95        MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6,  5);
96        MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6,  9);
97        MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14);
98        MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20);
99        MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905,  5);
100        MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8,  9);
101        MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14);
102        MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20);
103
104        MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942,  4);
105        MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11);
106        MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16);
107        MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23);
108        MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44,  4);
109        MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11);
110        MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16);
111        MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23);
112        MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6,  4);
113        MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11);
114        MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16);
115        MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23);
116        MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039,  4);
117        MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11);
118        MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16);
119        MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23);
120
121        MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244,  6);
122        MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10);
123        MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15);
124        MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21);
125        MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3,  6);
126        MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10);
127        MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15);
128        MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21);
129        MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f,  6);
130        MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10);
131        MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15);
132        MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21);
133        MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82,  6);
134        MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10);
135        MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15);
136        MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21);
137
138        buf[0] += a;
139        buf[1] += b;
140        buf[2] += c;
141        buf[3] += d;
142}
143
144/*
145 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
146 * initialization constants.
147 */
148void MD5Init(MD5Context *pCtx){
149        struct Context *ctx = (struct Context *)pCtx;
150        ctx->buf[0] = 0x67452301;
151        ctx->buf[1] = 0xefcdab89;
152        ctx->buf[2] = 0x98badcfe;
153        ctx->buf[3] = 0x10325476;
154        ctx->bits[0] = 0;
155        ctx->bits[1] = 0;
156}
157
158/*
159 * Update context to reflect the concatenation of another buffer full
160 * of bytes.
161 */
162void MD5Update(MD5Context *pCtx, const void *inbuf, size_t len){
163        struct Context *ctx = (struct Context *)pCtx;
164        const unsigned char* buf = (const unsigned char*)inbuf;
165        uint32 t;
166
167        /* Update bitcount */
168
169        t = ctx->bits[0];
170        if ((ctx->bits[0] = t + ((uint32)len << 3)) < t)
171                ctx->bits[1]++; /* Carry from low to high */
172        ctx->bits[1] += static_cast<uint32>(len >> 29);
173
174        t = (t >> 3) & 0x3f;    /* Bytes already in shsInfo->data */
175
176        /* Handle any leading odd-sized chunks */
177
178        if (t) {
179                unsigned char *p = (unsigned char *)ctx->in + t;
180
181                t = 64-t;
182                if (len < t) {
183                        memcpy(p, buf, len);
184                        return;
185                }
186                memcpy(p, buf, t);
187                byteReverse(ctx->in, 16);
188                MD5Transform(ctx->buf, (uint32 *)ctx->in);
189                buf += t;
190                len -= t;
191        }
192
193        /* Process data in 64-byte chunks */
194
195        while (len >= 64) {
196                memcpy(ctx->in, buf, 64);
197                byteReverse(ctx->in, 16);
198                MD5Transform(ctx->buf, (uint32 *)ctx->in);
199                buf += 64;
200                len -= 64;
201        }
202
203        /* Handle any remaining bytes of data. */
204
205        memcpy(ctx->in, buf, len);
206}
207
208/*
209 * Final wrapup - pad to 64-byte boundary with the bit pattern
210 * 1 0* (64-bit count of bits processed, MSB-first)
211 */
212void MD5Final(MD5Digest* digest, MD5Context *pCtx){
213        struct Context *ctx = (struct Context *)pCtx;
214        unsigned count;
215        unsigned char *p;
216
217        /* Compute number of bytes mod 64 */
218        count = (ctx->bits[0] >> 3) & 0x3F;
219
220        /* Set the first char of padding to 0x80.  This is safe since there is
221           always at least one byte free */
222        p = ctx->in + count;
223        *p++ = 0x80;
224
225        /* Bytes of padding needed to make 64 bytes */
226        count = 64 - 1 - count;
227
228        /* Pad out to 56 mod 64 */
229        if (count < 8) {
230                /* Two lots of padding:  Pad the first block to 64 bytes */
231                memset(p, 0, count);
232                byteReverse(ctx->in, 16);
233                MD5Transform(ctx->buf, (uint32 *)ctx->in);
234
235                /* Now fill the next block with 56 bytes */
236                memset(ctx->in, 0, 56);
237        } else {
238                /* Pad block to 56 bytes */
239                memset(p, 0, count-8);
240        }
241        byteReverse(ctx->in, 14);
242
243        /* Append length in bits and transform */
244        ((uint32 *)ctx->in)[ 14 ] = ctx->bits[0];
245        ((uint32 *)ctx->in)[ 15 ] = ctx->bits[1];
246
247        MD5Transform(ctx->buf, (uint32 *)ctx->in);
248        byteReverse((unsigned char *)ctx->buf, 4);
249        memcpy(digest->a, ctx->buf, 16);
250        memset(ctx, 0, sizeof(ctx));    /* In case it's sensitive */
251}
252
253std::string MD5DigestToBase16(const MD5Digest& digest){
254  static char const zEncode[] = "0123456789abcdef";
255
256  std::string ret;
257  ret.resize(32);
258
259  int j = 0;
260  for (int i = 0; i < 16; i ++) {
261    int a = digest.a[i];
262    ret[j++] = zEncode[(a>>4)&0xf];
263    ret[j++] = zEncode[a & 0xf];
264  }
265  return ret;
266}
267
268void MD5Sum(const void* data, size_t length, MD5Digest* digest) {
269  MD5Context ctx;
270  MD5Init(&ctx);
271  MD5Update(&ctx, static_cast<const unsigned char*>(data), length);
272  MD5Final(digest, &ctx);
273}
274
275std::string MD5String(const std::string& str) {
276  MD5Digest digest;
277  MD5Sum(str.data(), str.length(), &digest);
278  return MD5DigestToBase16(digest);
279}
280