debuggers.hg

view tools/blktap2/drivers/md5.c @ 22848:6341fe0f4e5a

Added tag 4.1.0-rc2 for changeset 9dca60d88c63
author Keir Fraser <keir@xen.org>
date Tue Jan 25 14:06:55 2011 +0000 (2011-01-25)
parents ca2738f258f8
children
line source
1 /* start - public domain MD5 implementation */
2 /*
3 * This code implements the MD5 message-digest algorithm.
4 * The algorithm is due to Ron Rivest. This code was
5 * written by Colin Plumb in 1993, no copyright is claimed.
6 * This code is in the public domain; do with it what you wish.
7 *
8 * Equivalent code is available from RSA Data Security, Inc.
9 * This code has been tested against that, and is equivalent,
10 * except that you don't need to include two pages of legalese
11 * with every copy.
12 *
13 * To compute the message digest of a chunk of bytes, declare an
14 * MD5Context structure, pass it to MD5Init, call MD5Update as
15 * needed on buffers full of bytes, and then call MD5Final, which
16 * will fill a supplied 16-byte array with the digest.
17 */
19 #include <string.h>
20 #include <stdint.h>
22 struct MD5Context {
23 uint32_t buf[4];
24 uint32_t bits[2];
25 uint8_t in[64];
26 };
28 static void MD5Init(struct MD5Context *context);
29 static void MD5Update(struct MD5Context *context, unsigned char const *buf,
30 unsigned len);
31 static void MD5Final(unsigned char digest[16], struct MD5Context *context);
32 static void MD5Transform(uint32_t buf[4], uint32_t const in[16]);
35 typedef struct MD5Context MD5_CTX;
38 /**
39 * md5_sum - MD5 hash for a data block
40 * @addr: Pointers to the data area
41 * @len: Lengths of the data block
42 * @mac: Buffer for the hash
43 */
44 void md5_sum(const uint8_t *addr, const size_t len, uint8_t *mac)
45 {
46 MD5_CTX ctx;
48 MD5Init(&ctx);
49 MD5Update(&ctx, addr, len);
50 MD5Final(mac, &ctx);
51 }
54 #ifndef WORDS_BIGENDIAN
55 #define byteReverse(buf, len) /* Nothing */
56 #else
57 /*
58 * Note: this code is harmless on little-endian machines.
59 */
60 static void byteReverse(unsigned char *buf, unsigned longs)
61 {
62 uint32_t t;
63 do {
64 t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
65 ((unsigned) buf[1] << 8 | buf[0]);
66 *(uint32_t *) buf = t;
67 buf += 4;
68 } while (--longs);
69 }
70 #endif
72 /*
73 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
74 * initialization constants.
75 */
76 void MD5Init(struct MD5Context *ctx)
77 {
78 ctx->buf[0] = 0x67452301;
79 ctx->buf[1] = 0xefcdab89;
80 ctx->buf[2] = 0x98badcfe;
81 ctx->buf[3] = 0x10325476;
83 ctx->bits[0] = 0;
84 ctx->bits[1] = 0;
85 }
87 /*
88 * Update context to reflect the concatenation of another buffer full
89 * of bytes.
90 */
91 void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
92 {
93 uint32_t t;
95 /* Update bitcount */
97 t = ctx->bits[0];
98 if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t)
99 ctx->bits[1]++; /* Carry from low to high */
100 ctx->bits[1] += len >> 29;
102 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
104 /* Handle any leading odd-sized chunks */
106 if (t) {
107 unsigned char *p = (unsigned char *) ctx->in + t;
109 t = 64 - t;
110 if (len < t) {
111 memcpy(p, buf, len);
112 return;
113 }
114 memcpy(p, buf, t);
115 byteReverse(ctx->in, 16);
116 MD5Transform(ctx->buf, (uint32_t *) ctx->in);
117 buf += t;
118 len -= t;
119 }
120 /* Process data in 64-byte chunks */
122 while (len >= 64) {
123 memcpy(ctx->in, buf, 64);
124 byteReverse(ctx->in, 16);
125 MD5Transform(ctx->buf, (uint32_t *) ctx->in);
126 buf += 64;
127 len -= 64;
128 }
130 /* Handle any remaining bytes of data. */
132 memcpy(ctx->in, buf, len);
133 }
135 /*
136 * Final wrapup - pad to 64-byte boundary with the bit pattern
137 * 1 0* (64-bit count of bits processed, MSB-first)
138 */
139 void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
140 {
141 unsigned count;
142 unsigned char *p;
144 /* Compute number of bytes mod 64 */
145 count = (ctx->bits[0] >> 3) & 0x3F;
147 /* Set the first char of padding to 0x80. This is safe since there is
148 always at least one byte free */
149 p = ctx->in + count;
150 *p++ = 0x80;
152 /* Bytes of padding needed to make 64 bytes */
153 count = 64 - 1 - count;
155 /* Pad out to 56 mod 64 */
156 if (count < 8) {
157 /* Two lots of padding: Pad the first block to 64 bytes */
158 memset(p, 0, count);
159 byteReverse(ctx->in, 16);
160 MD5Transform(ctx->buf, (uint32_t *) ctx->in);
162 /* Now fill the next block with 56 bytes */
163 memset(ctx->in, 0, 56);
164 } else {
165 /* Pad block to 56 bytes */
166 memset(p, 0, count - 8);
167 }
168 byteReverse(ctx->in, 14);
170 /* Append length in bits and transform */
171 ((uint32_t *) ctx->in)[14] = ctx->bits[0];
172 ((uint32_t *) ctx->in)[15] = ctx->bits[1];
174 MD5Transform(ctx->buf, (uint32_t *) ctx->in);
175 byteReverse((unsigned char *) ctx->buf, 4);
176 memcpy(digest, ctx->buf, 16);
177 memset(ctx, 0, sizeof(ctx)); /* In case it's sensitive */
178 }
180 /* The four core functions - F1 is optimized somewhat */
182 /* #define F1(x, y, z) (x & y | ~x & z) */
183 #define F1(x, y, z) (z ^ (x & (y ^ z)))
184 #define F2(x, y, z) F1(z, x, y)
185 #define F3(x, y, z) (x ^ y ^ z)
186 #define F4(x, y, z) (y ^ (x | ~z))
188 /* This is the central step in the MD5 algorithm. */
189 #define MD5STEP(f, w, x, y, z, data, s) \
190 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
192 /*
193 * The core of the MD5 algorithm, this alters an existing MD5 hash to
194 * reflect the addition of 16 longwords of new data. MD5Update blocks
195 * the data and converts bytes into longwords for this routine.
196 */
197 static void MD5Transform(uint32_t buf[4], uint32_t const in[16])
198 {
199 register uint32_t a, b, c, d;
201 a = buf[0];
202 b = buf[1];
203 c = buf[2];
204 d = buf[3];
206 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
207 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
208 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
209 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
210 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
211 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
212 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
213 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
214 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
215 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
216 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
217 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
218 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
219 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
220 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
221 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
223 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
224 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
225 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
226 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
227 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
228 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
229 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
230 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
231 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
232 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
233 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
234 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
235 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
236 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
237 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
238 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
240 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
241 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
242 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
243 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
244 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
245 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
246 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
247 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
248 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
249 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
250 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
251 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
252 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
253 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
254 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
255 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
257 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
258 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
259 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
260 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
261 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
262 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
263 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
264 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
265 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
266 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
267 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
268 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
269 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
270 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
271 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
272 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
274 buf[0] += a;
275 buf[1] += b;
276 buf[2] += c;
277 buf[3] += d;
278 }