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Hello Gensokyo!
author Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
date Tue, 21 May 2013 10:29:21 +0200
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-1:000000000000 0:c55ea9478c80
1 /*! \file
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 <stdint.h>
18 #include <string.h>
19
20 typedef struct {
21 uint32_t buf[4];
22 uint32_t bytes[2];
23 uint32_t in[16];
24 } MD5_CTX;
25 #define ROTATE(a,n) ({ register unsigned int ret; \
26 __asm__ volatile("roll %%cl,%0" \
27 : "=r"(ret) \
28 : "c"(n), "0"((unsigned int)(a)) \
29 : "cc"); ret; })
30
31 /*!
32 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
33 * initialization constants.
34 */
35 void
36 MD5Init(MD5_CTX *ctx) {
37 ctx->buf[0] = 0x67452301;
38 ctx->buf[1] = 0xefcdab89;
39 ctx->buf[2] = 0x98badcfe;
40 ctx->buf[3] = 0x10325476;
41
42 ctx->bytes[0] = 0;
43 ctx->bytes[1] = 0;
44 }
45
46 /*@{*/
47 /*! The four core functions - F1 is optimized somewhat */
48
49 /* #define F1(x, y, z) (x & y | ~x & z) */
50 #define F1(x, y, z) (z ^ (x & (y ^ z)))
51 #define F2(x, y, z) F1(z, x, y)
52 #define F3(x, y, z) (x ^ y ^ z)
53 #define F4(x, y, z) (y ^ (x | ~z))
54 /*@}*/
55
56 /*! This is the central step in the MD5 algorithm. */
57 #define MD5STEP(f,w,x,y,z,in,s) \
58 (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
59
60 /*!
61 * The core of the MD5 algorithm, this alters an existing MD5 hash to
62 * reflect the addition of 16 longwords of new data. MD5Update blocks
63 * the data and converts bytes into longwords for this routine.
64 */
65 static void
66 transform(uint32_t buf[4], uint32_t const in[16]) {
67 register uint32_t a, b, c, d;
68
69 a = buf[0];
70 b = buf[1];
71 c = buf[2];
72 d = buf[3];
73
74 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
75 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
76 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
77 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
78 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
79 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
80 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
81 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
82 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
83 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
84 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
85 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
86 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
87 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
88 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
89 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
90
91 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
92 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
93 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
94 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
95 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
96 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
97 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
98 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
99 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
100 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
101 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
102 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
103 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
104 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
105 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
106 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
107
108 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
109 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
110 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
111 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
112 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
113 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
114 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
115 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
116 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
117 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
118 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
119 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
120 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
121 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
122 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
123 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
124
125 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
126 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
127 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
128 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
129 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
130 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
131 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
132 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
133 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
134 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
135 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
136 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
137 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
138 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
139 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
140 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
141
142 buf[0] += a;
143 buf[1] += b;
144 buf[2] += c;
145 buf[3] += d;
146 }
147
148 /*!
149 * Update context to reflect the concatenation of another buffer full
150 * of bytes.
151 */
152 void
153 MD5Update(MD5_CTX *ctx, const unsigned char *buf, unsigned int len) {
154 uint32_t t;
155
156 /* Update byte count */
157
158 t = ctx->bytes[0];
159 if ((ctx->bytes[0] = t + len) < t)
160 ctx->bytes[1]++; /* Carry from low to high */
161
162 t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */
163 if (t > len) {
164 memcpy((unsigned char *)ctx->in + 64 - t, buf, len);
165 return;
166 }
167 /* First chunk is an odd size */
168 memcpy((unsigned char *)ctx->in + 64 - t, buf, t);
169 transform(ctx->buf, ctx->in);
170 buf += t;
171 len -= t;
172
173 /* Process data in 64-byte chunks */
174 while (len >= 64) {
175 memcpy(ctx->in, buf, 64);
176 transform(ctx->buf, ctx->in);
177 buf += 64;
178 len -= 64;
179 }
180
181 /* Handle any remaining bytes of data. */
182 memcpy(ctx->in, buf, len);
183 }
184
185 static inline void small_memset(void *addr, int c, size_t size) {
186 __asm__ volatile("xor %%al, %%al \t\n"
187 "rep; stosb \t\n"
188 :"+D"(addr) :"c"(size) :"%al");
189 }
190
191 /*!
192 * Final wrapup - pad to 64-byte boundary with the bit pattern
193 * 1 0* (64-bit count of bits processed, MSB-first)
194 */
195 void
196 MD5Final(MD5_CTX *ctx, unsigned char *digest) {
197 int count = ctx->bytes[0] & 0x3f; /* Number of bytes in ctx->in */
198 unsigned char *p = (unsigned char *)ctx->in + count;
199
200 /* Set the first char of padding to 0x80. There is always room. */
201 *p++ = 0x80;
202
203 /* Bytes of padding needed to make 56 bytes (-8..55) */
204 count = 56 - 1 - count;
205
206 if (count < 0) { /* Padding forces an extra block */
207 small_memset(p, 0, count + 8);
208 transform(ctx->buf, ctx->in);
209 p = (unsigned char *)ctx->in;
210 count = 56;
211 }
212 small_memset(p, 0, count);
213
214 /* Append length in bits and transform */
215 ctx->in[14] = ctx->bytes[0] << 3;
216 ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
217 transform(ctx->buf, ctx->in);
218 memcpy(digest, ctx->buf, 16);
219 }
220
221 typedef struct {
222 unsigned int state[64];
223 unsigned int index;
224 } AVLFG;
225 static AVLFG c;
226
227 void lfg_srand(unsigned int seed){
228 uint32_t i, tmp[4]={0};
229 MD5_CTX ctx;
230
231 for(i=0; i<64; i+=4){
232 tmp[0]=seed; tmp[3]=i;
233 MD5Init(&ctx);
234 MD5Update(&ctx, (uint8_t*)tmp, 16);
235 MD5Final(&ctx, (uint8_t*)tmp);
236 c.state[i ]= tmp[0];
237 c.state[i+1]= tmp[1];
238 c.state[i+2]= tmp[2];
239 c.state[i+3]= tmp[3];
240 }
241 c.index=0;
242 }
243
244 /**
245 * Get the next random unsigned 32-bit number using an ALFG.
246 */
247 unsigned int lfg_rand(void){
248 c.state[c.index & 63] = c.state[(c.index-24) & 63] + c.state[(c.index-55) & 63];
249 return c.state[c.index++ & 63];
250 }
251
252 #ifdef TEST
253 #include <stdio.h>
254 void av_md5_sum(uint8_t *dst, const uint8_t *src, const int len)
255 {
256 MD5_CTX ctx;
257
258 MD5Init(&ctx);
259 MD5Update(&ctx, src, len);
260 MD5Final(&ctx, dst);
261 }
262
263 static void print_md5(uint8_t *md5)
264 {
265 int i;
266 for (i = 0; i < 16; i++)
267 printf("%02x", md5[i]);
268 printf("\n");
269 }
270
271 int main(void){
272 uint8_t md5val[16];
273 int i;
274 uint8_t in[1000];
275
276 for (i = 0; i < 1000; i++)
277 in[i] = i * i;
278 av_md5_sum(md5val, in, 1000); print_md5(md5val);
279 av_md5_sum(md5val, in, 63); print_md5(md5val);
280 av_md5_sum(md5val, in, 64); print_md5(md5val);
281 av_md5_sum(md5val, in, 65); print_md5(md5val);
282 for (i = 0; i < 1000; i++)
283 in[i] = i % 127;
284 av_md5_sum(md5val, in, 999); print_md5(md5val);
285
286 return 0;
287 }
288 #endif
289