source: MondoRescue/branches/2.2.2/mindi-busybox/libbb/md5.c@ 1247

Last change on this file since 1247 was 821, checked in by Bruno Cornec, 18 years ago

Addition of busybox 1.2.1 as a mindi-busybox new package
This should avoid delivering binary files in mindi not built there (Fedora and Debian are quite serious about that)
File size: 12.4 KB
Line 
1/*
2 * md5.c - Compute MD5 checksum of strings according to the
3 * definition of MD5 in RFC 1321 from April 1992.
4 *
5 * Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.
6 *
7 * Copyright (C) 1995-1999 Free Software Foundation, Inc.
8 * Copyright (C) 2001 Manuel Novoa III
9 * Copyright (C) 2003 Glenn L. McGrath
10 * Copyright (C) 2003 Erik Andersen
11 *
12 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
13 */
14#include <fcntl.h>
15#include <limits.h>
16#include <stdio.h>
17#include <stdint.h>
18#include <stdlib.h>
19#include <string.h>
20#include <unistd.h>
21
22#include "libbb.h"
23
24# if CONFIG_MD5_SIZE_VS_SPEED < 0 || CONFIG_MD5_SIZE_VS_SPEED > 3
25# define MD5_SIZE_VS_SPEED 2
26# else
27# define MD5_SIZE_VS_SPEED CONFIG_MD5_SIZE_VS_SPEED
28# endif
29
30/* Initialize structure containing state of computation.
31 * (RFC 1321, 3.3: Step 3)
32 */
33void md5_begin(md5_ctx_t *ctx)
34{
35 ctx->A = 0x67452301;
36 ctx->B = 0xefcdab89;
37 ctx->C = 0x98badcfe;
38 ctx->D = 0x10325476;
39
40 ctx->total = 0;
41 ctx->buflen = 0;
42}
43
44/* These are the four functions used in the four steps of the MD5 algorithm
45 * and defined in the RFC 1321. The first function is a little bit optimized
46 * (as found in Colin Plumbs public domain implementation).
47 * #define FF(b, c, d) ((b & c) | (~b & d))
48 */
49# define FF(b, c, d) (d ^ (b & (c ^ d)))
50# define FG(b, c, d) FF (d, b, c)
51# define FH(b, c, d) (b ^ c ^ d)
52# define FI(b, c, d) (c ^ (b | ~d))
53
54/* Hash a single block, 64 bytes long and 4-byte aligned. */
55static void md5_hash_block(const void *buffer, md5_ctx_t *ctx)
56{
57 uint32_t correct_words[16];
58 const uint32_t *words = buffer;
59
60# if MD5_SIZE_VS_SPEED > 0
61 static const uint32_t C_array[] = {
62 /* round 1 */
63 0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
64 0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
65 0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
66 0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
67 /* round 2 */
68 0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
69 0xd62f105d, 0x2441453, 0xd8a1e681, 0xe7d3fbc8,
70 0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
71 0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
72 /* round 3 */
73 0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
74 0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
75 0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x4881d05,
76 0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
77 /* round 4 */
78 0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
79 0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
80 0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
81 0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391
82 };
83
84 static const char P_array[] = {
85# if MD5_SIZE_VS_SPEED > 1
86 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, /* 1 */
87# endif /* MD5_SIZE_VS_SPEED > 1 */
88 1, 6, 11, 0, 5, 10, 15, 4, 9, 14, 3, 8, 13, 2, 7, 12, /* 2 */
89 5, 8, 11, 14, 1, 4, 7, 10, 13, 0, 3, 6, 9, 12, 15, 2, /* 3 */
90 0, 7, 14, 5, 12, 3, 10, 1, 8, 15, 6, 13, 4, 11, 2, 9 /* 4 */
91 };
92
93# if MD5_SIZE_VS_SPEED > 1
94 static const char S_array[] = {
95 7, 12, 17, 22,
96 5, 9, 14, 20,
97 4, 11, 16, 23,
98 6, 10, 15, 21
99 };
100# endif /* MD5_SIZE_VS_SPEED > 1 */
101# endif
102
103 uint32_t A = ctx->A;
104 uint32_t B = ctx->B;
105 uint32_t C = ctx->C;
106 uint32_t D = ctx->D;
107
108 /* Process all bytes in the buffer with 64 bytes in each round of
109 the loop. */
110 uint32_t *cwp = correct_words;
111 uint32_t A_save = A;
112 uint32_t B_save = B;
113 uint32_t C_save = C;
114 uint32_t D_save = D;
115
116# if MD5_SIZE_VS_SPEED > 1
117# define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
118
119 const uint32_t *pc;
120 const char *pp;
121 const char *ps;
122 int i;
123 uint32_t temp;
124
125 for (i = 0; i < 16; i++) {
126 cwp[i] = SWAP_LE32(words[i]);
127 }
128 words += 16;
129
130# if MD5_SIZE_VS_SPEED > 2
131 pc = C_array;
132 pp = P_array;
133 ps = S_array - 4;
134
135 for (i = 0; i < 64; i++) {
136 if ((i & 0x0f) == 0)
137 ps += 4;
138 temp = A;
139 switch (i >> 4) {
140 case 0:
141 temp += FF(B, C, D);
142 break;
143 case 1:
144 temp += FG(B, C, D);
145 break;
146 case 2:
147 temp += FH(B, C, D);
148 break;
149 case 3:
150 temp += FI(B, C, D);
151 }
152 temp += cwp[(int) (*pp++)] + *pc++;
153 CYCLIC(temp, ps[i & 3]);
154 temp += B;
155 A = D;
156 D = C;
157 C = B;
158 B = temp;
159 }
160# else
161 pc = C_array;
162 pp = P_array;
163 ps = S_array;
164
165 for (i = 0; i < 16; i++) {
166 temp = A + FF(B, C, D) + cwp[(int) (*pp++)] + *pc++;
167 CYCLIC(temp, ps[i & 3]);
168 temp += B;
169 A = D;
170 D = C;
171 C = B;
172 B = temp;
173 }
174
175 ps += 4;
176 for (i = 0; i < 16; i++) {
177 temp = A + FG(B, C, D) + cwp[(int) (*pp++)] + *pc++;
178 CYCLIC(temp, ps[i & 3]);
179 temp += B;
180 A = D;
181 D = C;
182 C = B;
183 B = temp;
184 }
185 ps += 4;
186 for (i = 0; i < 16; i++) {
187 temp = A + FH(B, C, D) + cwp[(int) (*pp++)] + *pc++;
188 CYCLIC(temp, ps[i & 3]);
189 temp += B;
190 A = D;
191 D = C;
192 C = B;
193 B = temp;
194 }
195 ps += 4;
196 for (i = 0; i < 16; i++) {
197 temp = A + FI(B, C, D) + cwp[(int) (*pp++)] + *pc++;
198 CYCLIC(temp, ps[i & 3]);
199 temp += B;
200 A = D;
201 D = C;
202 C = B;
203 B = temp;
204 }
205
206# endif /* MD5_SIZE_VS_SPEED > 2 */
207# else
208 /* First round: using the given function, the context and a constant
209 the next context is computed. Because the algorithms processing
210 unit is a 32-bit word and it is determined to work on words in
211 little endian byte order we perhaps have to change the byte order
212 before the computation. To reduce the work for the next steps
213 we store the swapped words in the array CORRECT_WORDS. */
214
215# define OP(a, b, c, d, s, T) \
216 do \
217 { \
218 a += FF (b, c, d) + (*cwp++ = SWAP_LE32(*words)) + T; \
219 ++words; \
220 CYCLIC (a, s); \
221 a += b; \
222 } \
223 while (0)
224
225 /* It is unfortunate that C does not provide an operator for
226 cyclic rotation. Hope the C compiler is smart enough. */
227 /* gcc 2.95.4 seems to be --aaronl */
228# define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
229
230 /* Before we start, one word to the strange constants.
231 They are defined in RFC 1321 as
232
233 T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
234 */
235
236# if MD5_SIZE_VS_SPEED == 1
237 const uint32_t *pc;
238 const char *pp;
239 int i;
240# endif /* MD5_SIZE_VS_SPEED */
241
242 /* Round 1. */
243# if MD5_SIZE_VS_SPEED == 1
244 pc = C_array;
245 for (i = 0; i < 4; i++) {
246 OP(A, B, C, D, 7, *pc++);
247 OP(D, A, B, C, 12, *pc++);
248 OP(C, D, A, B, 17, *pc++);
249 OP(B, C, D, A, 22, *pc++);
250 }
251# else
252 OP(A, B, C, D, 7, 0xd76aa478);
253 OP(D, A, B, C, 12, 0xe8c7b756);
254 OP(C, D, A, B, 17, 0x242070db);
255 OP(B, C, D, A, 22, 0xc1bdceee);
256 OP(A, B, C, D, 7, 0xf57c0faf);
257 OP(D, A, B, C, 12, 0x4787c62a);
258 OP(C, D, A, B, 17, 0xa8304613);
259 OP(B, C, D, A, 22, 0xfd469501);
260 OP(A, B, C, D, 7, 0x698098d8);
261 OP(D, A, B, C, 12, 0x8b44f7af);
262 OP(C, D, A, B, 17, 0xffff5bb1);
263 OP(B, C, D, A, 22, 0x895cd7be);
264 OP(A, B, C, D, 7, 0x6b901122);
265 OP(D, A, B, C, 12, 0xfd987193);
266 OP(C, D, A, B, 17, 0xa679438e);
267 OP(B, C, D, A, 22, 0x49b40821);
268# endif /* MD5_SIZE_VS_SPEED == 1 */
269
270 /* For the second to fourth round we have the possibly swapped words
271 in CORRECT_WORDS. Redefine the macro to take an additional first
272 argument specifying the function to use. */
273# undef OP
274# define OP(f, a, b, c, d, k, s, T) \
275 do \
276 { \
277 a += f (b, c, d) + correct_words[k] + T; \
278 CYCLIC (a, s); \
279 a += b; \
280 } \
281 while (0)
282
283 /* Round 2. */
284# if MD5_SIZE_VS_SPEED == 1
285 pp = P_array;
286 for (i = 0; i < 4; i++) {
287 OP(FG, A, B, C, D, (int) (*pp++), 5, *pc++);
288 OP(FG, D, A, B, C, (int) (*pp++), 9, *pc++);
289 OP(FG, C, D, A, B, (int) (*pp++), 14, *pc++);
290 OP(FG, B, C, D, A, (int) (*pp++), 20, *pc++);
291 }
292# else
293 OP(FG, A, B, C, D, 1, 5, 0xf61e2562);
294 OP(FG, D, A, B, C, 6, 9, 0xc040b340);
295 OP(FG, C, D, A, B, 11, 14, 0x265e5a51);
296 OP(FG, B, C, D, A, 0, 20, 0xe9b6c7aa);
297 OP(FG, A, B, C, D, 5, 5, 0xd62f105d);
298 OP(FG, D, A, B, C, 10, 9, 0x02441453);
299 OP(FG, C, D, A, B, 15, 14, 0xd8a1e681);
300 OP(FG, B, C, D, A, 4, 20, 0xe7d3fbc8);
301 OP(FG, A, B, C, D, 9, 5, 0x21e1cde6);
302 OP(FG, D, A, B, C, 14, 9, 0xc33707d6);
303 OP(FG, C, D, A, B, 3, 14, 0xf4d50d87);
304 OP(FG, B, C, D, A, 8, 20, 0x455a14ed);
305 OP(FG, A, B, C, D, 13, 5, 0xa9e3e905);
306 OP(FG, D, A, B, C, 2, 9, 0xfcefa3f8);
307 OP(FG, C, D, A, B, 7, 14, 0x676f02d9);
308 OP(FG, B, C, D, A, 12, 20, 0x8d2a4c8a);
309# endif /* MD5_SIZE_VS_SPEED == 1 */
310
311 /* Round 3. */
312# if MD5_SIZE_VS_SPEED == 1
313 for (i = 0; i < 4; i++) {
314 OP(FH, A, B, C, D, (int) (*pp++), 4, *pc++);
315 OP(FH, D, A, B, C, (int) (*pp++), 11, *pc++);
316 OP(FH, C, D, A, B, (int) (*pp++), 16, *pc++);
317 OP(FH, B, C, D, A, (int) (*pp++), 23, *pc++);
318 }
319# else
320 OP(FH, A, B, C, D, 5, 4, 0xfffa3942);
321 OP(FH, D, A, B, C, 8, 11, 0x8771f681);
322 OP(FH, C, D, A, B, 11, 16, 0x6d9d6122);
323 OP(FH, B, C, D, A, 14, 23, 0xfde5380c);
324 OP(FH, A, B, C, D, 1, 4, 0xa4beea44);
325 OP(FH, D, A, B, C, 4, 11, 0x4bdecfa9);
326 OP(FH, C, D, A, B, 7, 16, 0xf6bb4b60);
327 OP(FH, B, C, D, A, 10, 23, 0xbebfbc70);
328 OP(FH, A, B, C, D, 13, 4, 0x289b7ec6);
329 OP(FH, D, A, B, C, 0, 11, 0xeaa127fa);
330 OP(FH, C, D, A, B, 3, 16, 0xd4ef3085);
331 OP(FH, B, C, D, A, 6, 23, 0x04881d05);
332 OP(FH, A, B, C, D, 9, 4, 0xd9d4d039);
333 OP(FH, D, A, B, C, 12, 11, 0xe6db99e5);
334 OP(FH, C, D, A, B, 15, 16, 0x1fa27cf8);
335 OP(FH, B, C, D, A, 2, 23, 0xc4ac5665);
336# endif /* MD5_SIZE_VS_SPEED == 1 */
337
338 /* Round 4. */
339# if MD5_SIZE_VS_SPEED == 1
340 for (i = 0; i < 4; i++) {
341 OP(FI, A, B, C, D, (int) (*pp++), 6, *pc++);
342 OP(FI, D, A, B, C, (int) (*pp++), 10, *pc++);
343 OP(FI, C, D, A, B, (int) (*pp++), 15, *pc++);
344 OP(FI, B, C, D, A, (int) (*pp++), 21, *pc++);
345 }
346# else
347 OP(FI, A, B, C, D, 0, 6, 0xf4292244);
348 OP(FI, D, A, B, C, 7, 10, 0x432aff97);
349 OP(FI, C, D, A, B, 14, 15, 0xab9423a7);
350 OP(FI, B, C, D, A, 5, 21, 0xfc93a039);
351 OP(FI, A, B, C, D, 12, 6, 0x655b59c3);
352 OP(FI, D, A, B, C, 3, 10, 0x8f0ccc92);
353 OP(FI, C, D, A, B, 10, 15, 0xffeff47d);
354 OP(FI, B, C, D, A, 1, 21, 0x85845dd1);
355 OP(FI, A, B, C, D, 8, 6, 0x6fa87e4f);
356 OP(FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
357 OP(FI, C, D, A, B, 6, 15, 0xa3014314);
358 OP(FI, B, C, D, A, 13, 21, 0x4e0811a1);
359 OP(FI, A, B, C, D, 4, 6, 0xf7537e82);
360 OP(FI, D, A, B, C, 11, 10, 0xbd3af235);
361 OP(FI, C, D, A, B, 2, 15, 0x2ad7d2bb);
362 OP(FI, B, C, D, A, 9, 21, 0xeb86d391);
363# endif /* MD5_SIZE_VS_SPEED == 1 */
364# endif /* MD5_SIZE_VS_SPEED > 1 */
365
366 /* Add the starting values of the context. */
367 A += A_save;
368 B += B_save;
369 C += C_save;
370 D += D_save;
371
372 /* Put checksum in context given as argument. */
373 ctx->A = A;
374 ctx->B = B;
375 ctx->C = C;
376 ctx->D = D;
377}
378
379/* Feed data through a temporary buffer to call md5_hash_aligned_block()
380 * with chunks of data that are 4-byte aligned and a multiple of 64 bytes.
381 * This function's internal buffer remembers previous data until it has 64
382 * bytes worth to pass on. Call md5_end() to flush this buffer. */
383
384void md5_hash(const void *buffer, size_t len, md5_ctx_t *ctx)
385{
386 char *buf=(char *)buffer;
387
388 /* RFC 1321 specifies the possible length of the file up to 2^64 bits,
389 * Here we only track the number of bytes. */
390
391 ctx->total += len;
392
393 // Process all input.
394
395 while (len) {
396 int i = 64 - ctx->buflen;
397
398 // Copy data into aligned buffer.
399
400 if (i > len) i = len;
401 memcpy(ctx->buffer + ctx->buflen, buf, i);
402 len -= i;
403 ctx->buflen += i;
404 buf += i;
405
406 // When buffer fills up, process it.
407
408 if (ctx->buflen == 64) {
409 md5_hash_block(ctx->buffer, ctx);
410 ctx->buflen = 0;
411 }
412 }
413}
414
415/* Process the remaining bytes in the buffer and put result from CTX
416 * in first 16 bytes following RESBUF. The result is always in little
417 * endian byte order, so that a byte-wise output yields to the wanted
418 * ASCII representation of the message digest.
419 *
420 * IMPORTANT: On some systems it is required that RESBUF is correctly
421 * aligned for a 32 bits value.
422 */
423void *md5_end(void *resbuf, md5_ctx_t *ctx)
424{
425 char *buf = ctx->buffer;
426 int i;
427
428 /* Pad data to block size. */
429
430 buf[ctx->buflen++] = 0x80;
431 memset(buf + ctx->buflen, 0, 128 - ctx->buflen);
432
433 /* Put the 64-bit file length in *bits* at the end of the buffer. */
434 ctx->total <<= 3;
435 if (ctx->buflen > 56) buf += 64;
436 for (i = 0; i < 8; i++) buf[56 + i] = ctx->total >> (i*8);
437
438 /* Process last bytes. */
439 if (buf != ctx->buffer) md5_hash_block(ctx->buffer, ctx);
440 md5_hash_block(buf, ctx);
441
442 /* Put result from CTX in first 16 bytes following RESBUF. The result is
443 * always in little endian byte order, so that a byte-wise output yields
444 * to the wanted ASCII representation of the message digest.
445 *
446 * IMPORTANT: On some systems it is required that RESBUF is correctly
447 * aligned for a 32 bits value.
448 */
449 ((uint32_t *) resbuf)[0] = SWAP_LE32(ctx->A);
450 ((uint32_t *) resbuf)[1] = SWAP_LE32(ctx->B);
451 ((uint32_t *) resbuf)[2] = SWAP_LE32(ctx->C);
452 ((uint32_t *) resbuf)[3] = SWAP_LE32(ctx->D);
453
454 return resbuf;
455}
456
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