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 #include <string.h> /* for memcpy() */
18
19 #include "md5.h"
20
21 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
22 # define byteReverse(buf, len) /* Nothing */
23 #else
24 static void byteReverse(unsigned char *buf, unsigned longs);
25
26 #ifndef ASM_MD5
27 /*
28 * Note: this code is harmless on little-endian machines.
29 */
30 static void byteReverse(unsigned char *buf, unsigned longs)
31 {
32 uint32_t t;
33 do {
34 t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
35 ((unsigned) buf[1] << 8 | buf[0]);
36 *(uint32_t *) buf = t;
37 buf += 4;
38 } while (--longs);
39 }
40 #endif /* !ASM_MD5 */
41 #endif /* __ORDER_LITTLE_ENDIAN__ */
42
43 /*
44 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
45 * initialization constants.
46 */
47 void ul_MD5Init(struct UL_MD5Context *ctx)
48 {
49 ctx->buf[0] = 0x67452301;
50 ctx->buf[1] = 0xefcdab89;
51 ctx->buf[2] = 0x98badcfe;
52 ctx->buf[3] = 0x10325476;
53
54 ctx->bits[0] = 0;
55 ctx->bits[1] = 0;
56 }
57
58 /*
59 * Update context to reflect the concatenation of another buffer full
60 * of bytes.
61 */
62 void ul_MD5Update(struct UL_MD5Context *ctx, unsigned char const *buf, unsigned len)
63 {
64 uint32_t t;
65
66 /* Update bitcount */
67
68 t = ctx->bits[0];
69 if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t)
70 ctx->bits[1]++; /* Carry from low to high */
71 ctx->bits[1] += len >> 29;
72
73 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
74
75 /* Handle any leading odd-sized chunks */
76
77 if (t) {
78 unsigned char *p = (unsigned char *) ctx->in + t;
79
80 t = 64 - t;
81 if (len < t) {
82 memcpy(p, buf, len);
83 return;
84 }
85 memcpy(p, buf, t);
86 byteReverse(ctx->in, 16);
87 ul_MD5Transform(ctx->buf, (uint32_t *) ctx->in);
88 buf += t;
89 len -= t;
90 }
91 /* Process data in 64-byte chunks */
92
93 while (len >= 64) {
94 memcpy(ctx->in, buf, 64);
95 byteReverse(ctx->in, 16);
96 ul_MD5Transform(ctx->buf, (uint32_t *) ctx->in);
97 buf += 64;
98 len -= 64;
99 }
100
101 /* Handle any remaining bytes of data. */
102
103 memcpy(ctx->in, buf, len);
104 }
105
106 /*
107 * Final wrapup - pad to 64-byte boundary with the bit pattern
108 * 1 0* (64-bit count of bits processed, MSB-first)
109 */
110 void ul_MD5Final(unsigned char digest[UL_MD5LENGTH], struct UL_MD5Context *ctx)
111 {
112 unsigned count;
113 unsigned char *p;
114
115 /* Compute number of bytes mod 64 */
116 count = (ctx->bits[0] >> 3) & 0x3F;
117
118 /* Set the first char of padding to 0x80. This is safe since there is
119 always at least one byte free */
120 p = ctx->in + count;
121 *p++ = 0x80;
122
123 /* Bytes of padding needed to make 64 bytes */
124 count = 64 - 1 - count;
125
126 /* Pad out to 56 mod 64 */
127 if (count < 8) {
128 /* Two lots of padding: Pad the first block to 64 bytes */
129 memset(p, 0, count);
130 byteReverse(ctx->in, 16);
131 ul_MD5Transform(ctx->buf, (uint32_t *) ctx->in);
132
133 /* Now fill the next block with 56 bytes */
134 memset(ctx->in, 0, 56);
135 } else {
136 /* Pad block to 56 bytes */
137 memset(p, 0, count - 8);
138 }
139 byteReverse(ctx->in, 14);
140
141 /* Append length in bits and transform.
142 * Use memcpy to avoid aliasing problems. On most systems,
143 * this will be optimized away to the same code.
144 */
145 memcpy(&ctx->in[14 * sizeof(uint32_t)], &ctx->bits[0], 4);
146 memcpy(&ctx->in[15 * sizeof(uint32_t)], &ctx->bits[1], 4);
147
148 ul_MD5Transform(ctx->buf, (uint32_t *) ctx->in);
149 byteReverse((unsigned char *) ctx->buf, 4);
150 memcpy(digest, ctx->buf, UL_MD5LENGTH);
151 memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
152 }
153
154 #ifndef ASM_MD5
155
156 /* The four core functions - F1 is optimized somewhat */
157
158 /* #define F1(x, y, z) (x & y | ~x & z) */
159 #define F1(x, y, z) (z ^ (x & (y ^ z)))
160 #define F2(x, y, z) F1(z, x, y)
161 #define F3(x, y, z) (x ^ y ^ z)
162 #define F4(x, y, z) (y ^ (x | ~z))
163
164 /* This is the central step in the MD5 algorithm. */
165 #define MD5STEP(f, w, x, y, z, data, s) \
166 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
167
168 /*
169 * The core of the MD5 algorithm, this alters an existing MD5 hash to
170 * reflect the addition of 16 longwords of new data. MD5Update blocks
171 * the data and converts bytes into longwords for this routine.
172 */
173 void ul_MD5Transform(uint32_t buf[4], uint32_t const in[16])
174 {
175 register uint32_t a, b, c, d;
176
177 a = buf[0];
178 b = buf[1];
179 c = buf[2];
180 d = buf[3];
181
182 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
183 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
184 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
185 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
186 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
187 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
188 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
189 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
190 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
191 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
192 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
193 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
194 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
195 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
196 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
197 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
198
199 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
200 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
201 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
202 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
203 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
204 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
205 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
206 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
207 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
208 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
209 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
210 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
211 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
212 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
213 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
214 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
215
216 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
217 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
218 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
219 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
220 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
221 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
222 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
223 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
224 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
225 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
226 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
227 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
228 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
229 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
230 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
231 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
232
233 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
234 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
235 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
236 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
237 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
238 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
239 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
240 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
241 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
242 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
243 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
244 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
245 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
246 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
247 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
248 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
249
250 buf[0] += a;
251 buf[1] += b;
252 buf[2] += c;
253 buf[3] += d;
254 }
255
256 #endif
257