1 /*
2 * This code implements the MD5 message-digest algorithm.
3 * The algorithm is due to Ron Rivest. This code was
4 * written by Colin Plumb in 1993, no copyright is claimed.
5 * This code is in the public domain; do with it what you wish.
6 *
7 * Equivalent code is available from RSA Data Security, Inc.
8 * This code has been tested against that, and is equivalent,
9 * except that you don't need to include two pages of legalese
10 * with every copy.
11 *
12 * To compute the message digest of a chunk of bytes, declare an
13 * MD5Context structure, pass it to MD5Init, call MD5Update as
14 * needed on buffers full of bytes, and then call MD5Final, which
15 * will fill a supplied 16-byte array with the digest.
16 */
17
18 #include <stdlib.h>
19 #include <stdio.h>
20 #include <assert.h>
21 #include <string.h>
22 #include <sys/types.h>
23
24 #ifdef __FreeBSD__
25 #include <machine/endian.h>
26 #else
27 #include <endian.h>
28 #endif
29 #if __BYTE_ORDER == __BIG_ENDIAN
30 #define WORDS_BIGENDIAN
31 #endif
32
33 #include "md5.h"
34
35 #ifndef WORDS_BIGENDIAN
36 #define byteReverse(buf, len) /* Nothing */
37 #else
38 void byteReverse(unsigned char *buf, unsigned longs);
39
40 #ifndef ASM_MD5
41 /*
42 * Note: this code is harmless on little-endian machines.
43 */
44
byteReverse(unsigned char * buf,unsigned longs)45 void byteReverse(unsigned char *buf, unsigned longs)
46 {
47 u32 t;
48 do {
49 t = (u32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
50 ((unsigned) buf[1] << 8 | buf[0]);
51 *(u32 *) buf = t;
52 buf += 4;
53 } while (--longs);
54 }
55 #endif
56 #endif
57
58 /*
59 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
60 * initialization constants.
61 */
MD5Init(struct MD5Context * ctx)62 void MD5Init(struct MD5Context *ctx)
63 {
64 ctx->buf[0] = 0x67452301;
65 ctx->buf[1] = 0xefcdab89;
66 ctx->buf[2] = 0x98badcfe;
67 ctx->buf[3] = 0x10325476;
68
69 ctx->bits[0] = 0;
70 ctx->bits[1] = 0;
71 }
72
73 /*
74 * Update context to reflect the concatenation of another buffer full
75 * of bytes.
76 */
MD5Update(struct MD5Context * ctx,unsigned char const * buf,unsigned len)77 void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
78 {
79 u32 t;
80
81 /* Update bitcount */
82
83 t = ctx->bits[0];
84 if ((ctx->bits[0] = t + ((u32) len << 3)) < t)
85 ctx->bits[1]++; /* Carry from low to high */
86 ctx->bits[1] += len >> 29;
87
88 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
89
90 /* Handle any leading odd-sized chunks */
91
92 if (t) {
93 unsigned char *p = (unsigned char *) ctx->in + t;
94
95 t = 64 - t;
96 if (len < t) {
97 memcpy(p, buf, len);
98 return;
99 }
100 memcpy(p, buf, t);
101 byteReverse(ctx->in, 16);
102 MD5Transform(ctx->buf, (u32 *) ctx->in);
103 buf += t;
104 len -= t;
105 }
106 /* Process data in 64-byte chunks */
107
108 while (len >= 64) {
109 memcpy(ctx->in, buf, 64);
110 byteReverse(ctx->in, 16);
111 MD5Transform(ctx->buf, (u32 *) ctx->in);
112 buf += 64;
113 len -= 64;
114 }
115
116 /* Handle any remaining bytes of data. */
117
118 memcpy(ctx->in, buf, len);
119 }
120
121 /*
122 * Final wrapup - pad to 64-byte boundary with the bit pattern
123 * 1 0* (64-bit count of bits processed, MSB-first)
124 */
MD5Final(unsigned char digest[16],struct MD5Context * ctx)125 void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
126 {
127 unsigned count;
128 unsigned char *p;
129
130 /* Compute number of bytes mod 64 */
131 count = (ctx->bits[0] >> 3) & 0x3F;
132
133 /* Set the first char of padding to 0x80. This is safe since there is
134 always at least one byte free */
135 p = ctx->in + count;
136 *p++ = 0x80;
137
138 /* Bytes of padding needed to make 64 bytes */
139 count = 64 - 1 - count;
140
141 /* Pad out to 56 mod 64 */
142 if (count < 8) {
143 /* Two lots of padding: Pad the first block to 64 bytes */
144 memset(p, 0, count);
145 byteReverse(ctx->in, 16);
146 MD5Transform(ctx->buf, (u32 *) ctx->in);
147
148 /* Now fill the next block with 56 bytes */
149 memset(ctx->in, 0, 56);
150 } else {
151 /* Pad block to 56 bytes */
152 memset(p, 0, count - 8);
153 }
154 byteReverse(ctx->in, 14);
155
156 /* Append length in bits and transform */
157 ((u32 *) ctx->in)[14] = ctx->bits[0];
158 ((u32 *) ctx->in)[15] = ctx->bits[1];
159
160 MD5Transform(ctx->buf, (u32 *) ctx->in);
161 byteReverse((unsigned char *) ctx->buf, 4);
162 memcpy(digest, ctx->buf, 16);
163 memset(ctx, 0, sizeof(ctx)); /* In case it's sensitive */
164 }
165
166 #ifndef ASM_MD5
167
168 /* The four core functions - F1 is optimized somewhat */
169
170 /* #define F1(x, y, z) (x & y | ~x & z) */
171 #define F1(x, y, z) (z ^ (x & (y ^ z)))
172 #define F2(x, y, z) F1(z, x, y)
173 #define F3(x, y, z) (x ^ y ^ z)
174 #define F4(x, y, z) (y ^ (x | ~z))
175
176 /* This is the central step in the MD5 algorithm. */
177 #define MD5STEP(f, w, x, y, z, data, s) \
178 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
179
180 /*
181 * The core of the MD5 algorithm, this alters an existing MD5 hash to
182 * reflect the addition of 16 longwords of new data. MD5Update blocks
183 * the data and converts bytes into longwords for this routine.
184 */
MD5Transform(u32 buf[4],u32 const in[16])185 void MD5Transform(u32 buf[4], u32 const in[16])
186 {
187 register u32 a, b, c, d;
188
189 a = buf[0];
190 b = buf[1];
191 c = buf[2];
192 d = buf[3];
193
194 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
195 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
196 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
197 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
198 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
199 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
200 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
201 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
202 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
203 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
204 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
205 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
206 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
207 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
208 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
209 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
210
211 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
212 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
213 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
214 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
215 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
216 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
217 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
218 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
219 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
220 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
221 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
222 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
223 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
224 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
225 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
226 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
227
228 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
229 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
230 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
231 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
232 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
233 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
234 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
235 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
236 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
237 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
238 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
239 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
240 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
241 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
242 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
243 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
244
245 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
246 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
247 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
248 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
249 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
250 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
251 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
252 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
253 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
254 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
255 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
256 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
257 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
258 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
259 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
260 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
261
262 buf[0] += a;
263 buf[1] += b;
264 buf[2] += c;
265 buf[3] += d;
266 }
267
268 #endif
269