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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 
27 struct 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  */
byteReverse(unsigned char * buf,unsigned longs)36 static 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  */
MD5Transform(uint32 buf[4],const uint32 in[16])62 static 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  */
MD5Init(MD5Context * pCtx)148 void 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  */
MD5Update(MD5Context * pCtx,const void * inbuf,size_t len)162 void 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  */
MD5Final(MD5Digest * digest,MD5Context * pCtx)212 void 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 
MD5DigestToBase16(const MD5Digest & digest)253 std::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 
MD5Sum(const void * data,size_t length,MD5Digest * digest)268 void 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 
MD5String(const std::string & str)275 std::string MD5String(const std::string& str) {
276   MD5Digest digest;
277   MD5Sum(str.data(), str.length(), &digest);
278   return MD5DigestToBase16(digest);
279 }
280