1/*
2** This code taken from the SQLite test library. Originally found on
3** the internet. The original header comment follows this comment.
4** The code is largerly unchanged, but there have been some modifications.
5*/
6/*
7 * This code implements the MD5 message-digest algorithm.
8 * The algorithm is due to Ron Rivest. This code was
9 * written by Colin Plumb in 1993, no copyright is claimed.
10 * This code is in the public domain; do with it what you wish.
11 *
12 * Equivalent code is available from RSA Data Security, Inc.
13 * This code has been tested against that, and is equivalent,
14 * except that you don't need to include two pages of legalese
15 * with every copy.
16 *
17 * To compute the message digest of a chunk of bytes, declare an
18 * MD5Context structure, pass it to MD5Init, call MD5Update as
19 * needed on buffers full of bytes, and then call MD5Final, which
20 * will fill a supplied 16-byte array with the digest.
21 */
22#include <string.h>
23
24/*
25 * If compiled on a machine that doesn't have a 32-bit integer,
26 * you just set "uint32" to the appropriate datatype for an
27 * unsigned 32-bit integer. For example:
28 *
29 * cc -Duint32='unsigned long' md5.c
30 *
31 */
32#ifndef uint32
33#define uint32 unsigned int
34#endif
35
36struct Context {
37 int isInit;
38 uint32 buf[4];
39 uint32 bits[2];
40 unsigned char in[64];
41};
42typedef struct Context MD5Context;
43
44/*
45 * Note: this code is harmless on little-endian machines.
46 */
47static void byteReverse(unsigned char *buf, unsigned longs) {
48 uint32 t;
49 do {
50 t = (uint32)((unsigned)buf[3] << 8 | buf[2]) << 16 | ((unsigned)buf[1] << 8 | buf[0]);
51 *(uint32 *)buf = t;
52 buf += 4;
53 } while (--longs);
54}
55/* The four core functions - F1 is optimized somewhat */
56
57/* #define F1(x, y, z) (x & y | ~x & z) */
58#define F1(x, y, z) (z ^ (x & (y ^ z)))
59#define F2(x, y, z) F1(z, x, y)
60#define F3(x, y, z) (x ^ y ^ z)
61#define F4(x, y, z) (y ^ (x | ~z))
62
63/* This is the central step in the MD5 algorithm. */
64#define MD5STEP(f, w, x, y, z, data, s) (w += f(x, y, z) + data, w = w << s | w >> (32 - s), w += x)
65
66/*
67 * The core of the MD5 algorithm, this alters an existing MD5 hash to
68 * reflect the addition of 16 longwords of new data. MD5Update blocks
69 * the data and converts bytes into longwords for this routine.
70 */
71static void MD5Transform(uint32 buf[4], const uint32 in[16]) {
72 uint32 a, b, c, d;
73
74 a = buf[0];
75 b = buf[1];
76 c = buf[2];
77 d = buf[3];
78
79 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
80 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
81 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
82 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
83 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
84 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
85 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
86 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
87 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
88 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
89 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
90 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
91 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
92 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
93 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
94 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
95
96 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
97 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
98 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
99 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
100 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
101 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
102 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
103 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
104 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
105 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
106 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
107 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
108 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
109 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
110 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
111 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
112
113 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
114 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
115 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
116 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
117 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
118 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
119 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
120 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
121 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
122 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
123 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
124 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
125 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
126 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
127 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
128 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
129
130 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
131 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
132 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
133 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
134 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
135 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
136 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
137 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
138 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
139 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
140 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
141 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
142 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
143 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
144 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
145 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
146
147 buf[0] += a;
148 buf[1] += b;
149 buf[2] += c;
150 buf[3] += d;
151}
152
153/*
154 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
155 * initialization constants.
156 */
157static void MD5Init(MD5Context *ctx) {
158 ctx->isInit = 1;
159 ctx->buf[0] = 0x67452301;
160 ctx->buf[1] = 0xefcdab89;
161 ctx->buf[2] = 0x98badcfe;
162 ctx->buf[3] = 0x10325476;
163 ctx->bits[0] = 0;
164 ctx->bits[1] = 0;
165}
166
167/*
168 * Update context to reflect the concatenation of another buffer full
169 * of bytes.
170 */
171static void MD5Update(MD5Context *pCtx, const unsigned char *buf, unsigned int len) {
172 struct Context *ctx = (struct Context *)pCtx;
173 uint32 t;
174
175 /* Update bitcount */
176
177 t = ctx->bits[0];
178 if ((ctx->bits[0] = t + ((uint32)len << 3)) < t)
179 ctx->bits[1]++; /* Carry from low to high */
180 ctx->bits[1] += len >> 29;
181
182 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
183
184 /* Handle any leading odd-sized chunks */
185
186 if (t) {
187 unsigned char *p = (unsigned char *)ctx->in + t;
188
189 t = 64 - t;
190 if (len < t) {
191 memcpy(p, buf, len);
192 return;
193 }
194 memcpy(p, buf, t);
195 byteReverse(ctx->in, 16);
196 MD5Transform(ctx->buf, (uint32 *)ctx->in);
197 buf += t;
198 len -= t;
199 }
200
201 /* Process data in 64-byte chunks */
202
203 while (len >= 64) {
204 memcpy(ctx->in, buf, 64);
205 byteReverse(ctx->in, 16);
206 MD5Transform(ctx->buf, (uint32 *)ctx->in);
207 buf += 64;
208 len -= 64;
209 }
210
211 /* Handle any remaining bytes of data. */
212
213 memcpy(ctx->in, buf, len);
214}
215
216/*
217 * Final wrapup - pad to 64-byte boundary with the bit pattern
218 * 1 0* (64-bit count of bits processed, MSB-first)
219 */
220static void MD5Final(unsigned char digest[16], MD5Context *pCtx) {
221 struct Context *ctx = (struct Context *)pCtx;
222 unsigned count;
223 unsigned char *p;
224
225 /* Compute number of bytes mod 64 */
226 count = (ctx->bits[0] >> 3) & 0x3F;
227
228 /* Set the first char of padding to 0x80. This is safe since there is
229 always at least one byte free */
230 p = ctx->in + count;
231 *p++ = 0x80;
232
233 /* Bytes of padding needed to make 64 bytes */
234 count = 64 - 1 - count;
235
236 /* Pad out to 56 mod 64 */
237 if (count < 8) {
238 /* Two lots of padding: Pad the first block to 64 bytes */
239 memset(p, 0, count);
240 byteReverse(ctx->in, 16);
241 MD5Transform(ctx->buf, (uint32 *)ctx->in);
242
243 /* Now fill the next block with 56 bytes */
244 memset(ctx->in, 0, 56);
245 } else {
246 /* Pad block to 56 bytes */
247 memset(p, 0, count - 8);
248 }
249 byteReverse(ctx->in, 14);
250
251 /* Append length in bits and transform */
252 ((uint32 *)ctx->in)[14] = ctx->bits[0];
253 ((uint32 *)ctx->in)[15] = ctx->bits[1];
254
255 MD5Transform(ctx->buf, (uint32 *)ctx->in);
256 byteReverse((unsigned char *)ctx->buf, 4);
257 memcpy(digest, ctx->buf, 16);
258 memset(&ctx, 0, sizeof(ctx)); /* In case it is sensitive */
259}
260
261/*
262** Convert a digest into base-16. digest should be declared as
263** "unsigned char digest[16]" in the calling function. The MD5
264** digest is stored in the first 16 bytes. zBuf should
265** be "char zBuf[33]".
266*/
267static void DigestToBase16(unsigned char *digest, char *zBuf) {
268 static char const zEncode[] = "0123456789abcdef";
269 int i, j;
270
271 for (j = i = 0; i < 16; i++) {
272 int a = digest[i];
273 zBuf[j++] = zEncode[(a >> 4) & 0xf];
274 zBuf[j++] = zEncode[a & 0xf];
275 }
276 zBuf[j] = 0;
277}
278
279/*
280** Status of an MD5 hash.
281*/
282static MD5Context ctx;
283static int isInit = 0;
284static char zResult[34] = "";
285
286/*
287** Add additional text to the current MD5 hash.
288*/
289void md5_add(const char *z);
290
291void md5_add(const char *z) {
292 if (!isInit) {
293 MD5Init(&ctx);
294 isInit = 1;
295 }
296 MD5Update(&ctx, (unsigned char *)z, (unsigned)strlen(z));
297}
298
299/*
300** Compute the final signature. Reset the hash generator in preparation
301** for the next round.
302*/
303const char *md5_finish(void);
304
305const char *md5_finish(void) {
306 if (isInit) {
307 unsigned char digest[16];
308 MD5Final(digest, &ctx);
309 isInit = 0;
310 DigestToBase16(digest, zResult);
311 }
312 return zResult;
313}
314