1 /**************************************************************************/
2 /* */
3 /* OCaml */
4 /* */
5 /* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
6 /* */
7 /* Copyright 1996 Institut National de Recherche en Informatique et */
8 /* en Automatique. */
9 /* */
10 /* All rights reserved. This file is distributed under the terms of */
11 /* the GNU Lesser General Public License version 2.1, with the */
12 /* special exception on linking described in the file LICENSE. */
13 /* */
14 /**************************************************************************/
15
16 #define CAML_INTERNALS
17
18 #include <string.h>
19 #include "caml/alloc.h"
20 #include "caml/fail.h"
21 #include "caml/md5.h"
22 #include "caml/memory.h"
23 #include "caml/mlvalues.h"
24 #include "caml/io.h"
25 #include "caml/reverse.h"
26
27 /* MD5 message digest */
28
29 CAMLprim value caml_md5_string(value str, value ofs, value len)
30 {
31 struct MD5Context ctx;
32 value res;
33 caml_MD5Init(&ctx);
34 caml_MD5Update(&ctx, &Byte_u(str, Long_val(ofs)), Long_val(len));
35 res = caml_alloc_string(16);
36 caml_MD5Final(&Byte_u(res, 0), &ctx);
37 return res;
38 }
39
40 CAMLexport value caml_md5_channel(struct channel *chan, intnat toread)
41 {
42 CAMLparam0();
43 struct MD5Context ctx;
44 value res;
45 intnat read;
46 char buffer[4096];
47
48 Lock(chan);
49 caml_MD5Init(&ctx);
50 if (toread < 0){
51 while (1){
52 read = caml_getblock (chan, buffer, sizeof(buffer));
53 if (read == 0) break;
54 caml_MD5Update (&ctx, (unsigned char *) buffer, read);
55 }
56 }else{
57 while (toread > 0) {
58 read = caml_getblock(chan, buffer,
59 toread > sizeof(buffer) ? sizeof(buffer) : toread);
60 if (read == 0) caml_raise_end_of_file();
61 caml_MD5Update(&ctx, (unsigned char *) buffer, read);
62 toread -= read;
63 }
64 }
65 res = caml_alloc_string(16);
66 caml_MD5Final(&Byte_u(res, 0), &ctx);
67 Unlock(chan);
68 CAMLreturn (res);
69 }
70
71 CAMLprim value caml_md5_chan(value vchan, value len)
72 {
73 CAMLparam2 (vchan, len);
74 CAMLreturn (caml_md5_channel(Channel(vchan), Long_val(len)));
75 }
76
77 CAMLexport void caml_md5_block(unsigned char digest[16],
78 void * data, uintnat len)
79 {
80 struct MD5Context ctx;
81 caml_MD5Init(&ctx);
82 caml_MD5Update(&ctx, data, len);
83 caml_MD5Final(digest, &ctx);
84 }
85
86 /*
87 * This code implements the MD5 message-digest algorithm.
88 * The algorithm is due to Ron Rivest. This code was
89 * written by Colin Plumb in 1993, no copyright is claimed.
90 * This code is in the public domain; do with it what you wish.
91 *
92 * Equivalent code is available from RSA Data Security, Inc.
93 * This code has been tested against that, and is equivalent,
94 * except that you don't need to include two pages of legalese
95 * with every copy.
96 *
97 * To compute the message digest of a chunk of bytes, declare an
98 * MD5Context structure, pass it to caml_MD5Init, call caml_MD5Update as
99 * needed on buffers full of bytes, and then call caml_MD5Final, which
100 * will fill a supplied 16-byte array with the digest.
101 */
102
103 #ifndef ARCH_BIG_ENDIAN
104 #define byteReverse(buf, len) /* Nothing */
105 #else
106 static void byteReverse(unsigned char * buf, unsigned longs)
107 {
108 uint32_t t;
109 do {
110 t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
111 ((unsigned) buf[1] << 8 | buf[0]);
112 *(uint32_t *) buf = t;
113 buf += 4;
114 } while (--longs);
115 }
116 #endif
117
118 /*
119 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
120 * initialization constants.
121 */
122 CAMLexport void caml_MD5Init(struct MD5Context *ctx)
123 {
124 ctx->buf[0] = 0x67452301;
125 ctx->buf[1] = 0xefcdab89;
126 ctx->buf[2] = 0x98badcfe;
127 ctx->buf[3] = 0x10325476;
128
129 ctx->bits[0] = 0;
130 ctx->bits[1] = 0;
131 }
132
133 /*
134 * Update context to reflect the concatenation of another buffer full
135 * of bytes.
136 */
137 CAMLexport void caml_MD5Update(struct MD5Context *ctx, unsigned char *buf,
138 uintnat len)
139 {
140 uint32_t t;
141
142 /* Update bitcount */
143
144 t = ctx->bits[0];
145 if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t)
146 ctx->bits[1]++; /* Carry from low to high */
147 ctx->bits[1] += len >> 29;
148
149 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
150
151 /* Handle any leading odd-sized chunks */
152
153 if (t) {
154 unsigned char *p = (unsigned char *) ctx->in + t;
155
156 t = 64 - t;
157 if (len < t) {
158 memcpy(p, buf, len);
159 return;
160 }
161 memcpy(p, buf, t);
162 byteReverse(ctx->in, 16);
163 caml_MD5Transform(ctx->buf, (uint32_t *) ctx->in);
164 buf += t;
165 len -= t;
166 }
167 /* Process data in 64-byte chunks */
168
169 while (len >= 64) {
170 memcpy(ctx->in, buf, 64);
171 byteReverse(ctx->in, 16);
172 caml_MD5Transform(ctx->buf, (uint32_t *) ctx->in);
173 buf += 64;
174 len -= 64;
175 }
176
177 /* Handle any remaining bytes of data. */
178
179 memcpy(ctx->in, buf, len);
180 }
181
182 /*
183 * Final wrapup - pad to 64-byte boundary with the bit pattern
184 * 1 0* (64-bit count of bits processed, MSB-first)
185 */
186 CAMLexport void caml_MD5Final(unsigned char *digest, struct MD5Context *ctx)
187 {
188 unsigned count;
189 unsigned char *p;
190
191 /* Compute number of bytes mod 64 */
192 count = (ctx->bits[0] >> 3) & 0x3F;
193
194 /* Set the first char of padding to 0x80. This is safe since there is
195 always at least one byte free */
196 p = ctx->in + count;
197 *p++ = 0x80;
198
199 /* Bytes of padding needed to make 64 bytes */
200 count = 64 - 1 - count;
201
202 /* Pad out to 56 mod 64 */
203 if (count < 8) {
204 /* Two lots of padding: Pad the first block to 64 bytes */
205 memset(p, 0, count);
206 byteReverse(ctx->in, 16);
207 caml_MD5Transform(ctx->buf, (uint32_t *) ctx->in);
208
209 /* Now fill the next block with 56 bytes */
210 memset(ctx->in, 0, 56);
211 } else {
212 /* Pad block to 56 bytes */
213 memset(p, 0, count - 8);
214 }
215 byteReverse(ctx->in, 14);
216
217 /* Append length in bits and transform */
218 ((uint32_t *) ctx->in)[14] = ctx->bits[0];
219 ((uint32_t *) ctx->in)[15] = ctx->bits[1];
220
221 caml_MD5Transform(ctx->buf, (uint32_t *) ctx->in);
222 byteReverse((unsigned char *) ctx->buf, 4);
223 memcpy(digest, ctx->buf, 16);
224 memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
225 }
226
227 /* The four core functions - F1 is optimized somewhat */
228
229 /* #define F1(x, y, z) (x & y | ~x & z) */
230 #define F1(x, y, z) (z ^ (x & (y ^ z)))
231 #define F2(x, y, z) F1(z, x, y)
232 #define F3(x, y, z) (x ^ y ^ z)
233 #define F4(x, y, z) (y ^ (x | ~z))
234
235 /* This is the central step in the MD5 algorithm. */
236 #define MD5STEP(f, w, x, y, z, data, s) \
237 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
238
239 /*
240 * The core of the MD5 algorithm, this alters an existing MD5 hash to
241 * reflect the addition of 16 longwords of new data. caml_MD5Update blocks
242 * the data and converts bytes into longwords for this routine.
243 */
244 CAMLexport void caml_MD5Transform(uint32_t *buf, uint32_t *in)
245 {
246 register uint32_t a, b, c, d;
247
248 a = buf[0];
249 b = buf[1];
250 c = buf[2];
251 d = buf[3];
252
253 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
254 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
255 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
256 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
257 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
258 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
259 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
260 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
261 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
262 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
263 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
264 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
265 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
266 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
267 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
268 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
269
270 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
271 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
272 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
273 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
274 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
275 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
276 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
277 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
278 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
279 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
280 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
281 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
282 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
283 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
284 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
285 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
286
287 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
288 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
289 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
290 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
291 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
292 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
293 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
294 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
295 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
296 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
297 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
298 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
299 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
300 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
301 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
302 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
303
304 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
305 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
306 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
307 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
308 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
309 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
310 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
311 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
312 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
313 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
314 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
315 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
316 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
317 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
318 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
319 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
320
321 buf[0] += a;
322 buf[1] += b;
323 buf[2] += c;
324 buf[3] += d;
325 }
326