]>
Commit | Line | Data |
---|---|---|
718e3744 | 1 | /* md5.c - Functions to compute MD5 message digest of files or memory blocks |
2 | according to the definition of MD5 in RFC 1321 from April 1992. | |
3 | Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc. | |
4 | This file is part of the GNU C Library. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Library General Public License as | |
8 | published by the Free Software Foundation; either version 2 of the | |
9 | License, or (at your option) any later version. | |
10 | ||
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Library General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Library General Public | |
17 | License along with the GNU C Library; see the file COPYING.LIB. If not, | |
18 | write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | /* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */ | |
22 | ||
23 | #ifdef HAVE_CONFIG_H | |
24 | # include <config.h> | |
25 | #endif | |
26 | ||
27 | #include <sys/types.h> | |
28 | ||
29 | #if STDC_HEADERS || defined _LIBC | |
30 | # include <stdlib.h> | |
31 | # include <string.h> | |
32 | #else | |
33 | # ifndef HAVE_MEMCPY | |
34 | # define memcpy(d, s, n) bcopy ((s), (d), (n)) | |
35 | # endif | |
36 | #endif | |
37 | ||
38 | #include "md5-gnu.h" | |
39 | ||
40 | #ifdef _LIBC | |
41 | # include <endian.h> | |
42 | # if __BYTE_ORDER == __BIG_ENDIAN | |
43 | # define WORDS_BIGENDIAN 1 | |
44 | # endif | |
45 | /* We need to keep the namespace clean so define the MD5 function | |
46 | protected using leading __ and use weak aliases. */ | |
47 | # define md5_init_ctx __md5_init_ctx | |
48 | # define md5_process_block __md5_process_block | |
49 | # define md5_process_bytes __md5_process_bytes | |
50 | # define md5_finish_ctx __md5_finish_ctx | |
51 | # define md5_read_ctx __md5_read_ctx | |
52 | # define md5_stream __md5_stream | |
53 | # define md5_buffer __md5_buffer | |
54 | #endif | |
55 | ||
56 | #ifdef WORDS_BIGENDIAN | |
57 | # define SWAP(n) \ | |
58 | (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24)) | |
59 | #else | |
60 | # define SWAP(n) (n) | |
61 | #endif | |
62 | ||
63 | ||
64 | /* This array contains the bytes used to pad the buffer to the next | |
65 | 64-byte boundary. (RFC 1321, 3.1: Step 1) */ | |
66 | static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ }; | |
67 | ||
68 | ||
69 | /* Initialize structure containing state of computation. | |
70 | (RFC 1321, 3.3: Step 3) */ | |
71 | void | |
72 | md5_init_ctx (ctx) | |
73 | struct md5_ctx *ctx; | |
74 | { | |
75 | ctx->A = 0x67452301; | |
76 | ctx->B = 0xefcdab89; | |
77 | ctx->C = 0x98badcfe; | |
78 | ctx->D = 0x10325476; | |
79 | ||
80 | ctx->total[0] = ctx->total[1] = 0; | |
81 | ctx->buflen = 0; | |
82 | } | |
83 | ||
84 | /* Put result from CTX in first 16 bytes following RESBUF. The result | |
85 | must be in little endian byte order. | |
86 | ||
87 | IMPORTANT: On some systems it is required that RESBUF is correctly | |
88 | aligned for a 32 bits value. */ | |
89 | void * | |
90 | md5_read_ctx (ctx, resbuf) | |
91 | const struct md5_ctx *ctx; | |
92 | void *resbuf; | |
93 | { | |
94 | ((md5_uint32 *) resbuf)[0] = SWAP (ctx->A); | |
95 | ((md5_uint32 *) resbuf)[1] = SWAP (ctx->B); | |
96 | ((md5_uint32 *) resbuf)[2] = SWAP (ctx->C); | |
97 | ((md5_uint32 *) resbuf)[3] = SWAP (ctx->D); | |
98 | ||
99 | return resbuf; | |
100 | } | |
101 | ||
102 | /* Process the remaining bytes in the internal buffer and the usual | |
103 | prolog according to the standard and write the result to RESBUF. | |
104 | ||
105 | IMPORTANT: On some systems it is required that RESBUF is correctly | |
106 | aligned for a 32 bits value. */ | |
107 | void * | |
108 | md5_finish_ctx (ctx, resbuf) | |
109 | struct md5_ctx *ctx; | |
110 | void *resbuf; | |
111 | { | |
112 | /* Take yet unprocessed bytes into account. */ | |
113 | md5_uint32 bytes = ctx->buflen; | |
114 | size_t pad; | |
115 | ||
116 | /* Now count remaining bytes. */ | |
117 | ctx->total[0] += bytes; | |
118 | if (ctx->total[0] < bytes) | |
119 | ++ctx->total[1]; | |
120 | ||
121 | pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes; | |
122 | memcpy (&ctx->buffer[bytes], fillbuf, pad); | |
123 | ||
124 | /* Put the 64-bit file length in *bits* at the end of the buffer. */ | |
125 | *(md5_uint32 *) &ctx->buffer[bytes + pad] = SWAP (ctx->total[0] << 3); | |
126 | *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = SWAP ((ctx->total[1] << 3) | | |
127 | (ctx->total[0] >> 29)); | |
128 | ||
129 | /* Process last bytes. */ | |
130 | md5_process_block (ctx->buffer, bytes + pad + 8, ctx); | |
131 | ||
132 | return md5_read_ctx (ctx, resbuf); | |
133 | } | |
134 | ||
135 | /* Compute MD5 message digest for bytes read from STREAM. The | |
136 | resulting message digest number will be written into the 16 bytes | |
137 | beginning at RESBLOCK. */ | |
138 | int | |
139 | md5_stream (stream, resblock) | |
140 | FILE *stream; | |
141 | void *resblock; | |
142 | { | |
143 | /* Important: BLOCKSIZE must be a multiple of 64. */ | |
144 | #define BLOCKSIZE 4096 | |
145 | struct md5_ctx ctx; | |
146 | char buffer[BLOCKSIZE + 72]; | |
147 | size_t sum; | |
148 | ||
149 | /* Initialize the computation context. */ | |
150 | md5_init_ctx (&ctx); | |
151 | ||
152 | /* Iterate over full file contents. */ | |
153 | while (1) | |
154 | { | |
155 | /* We read the file in blocks of BLOCKSIZE bytes. One call of the | |
156 | computation function processes the whole buffer so that with the | |
157 | next round of the loop another block can be read. */ | |
158 | size_t n; | |
159 | sum = 0; | |
160 | ||
161 | /* Read block. Take care for partial reads. */ | |
162 | do | |
163 | { | |
164 | n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream); | |
165 | ||
166 | sum += n; | |
167 | } | |
168 | while (sum < BLOCKSIZE && n != 0); | |
169 | if (n == 0 && ferror (stream)) | |
170 | return 1; | |
171 | ||
172 | /* If end of file is reached, end the loop. */ | |
173 | if (n == 0) | |
174 | break; | |
175 | ||
176 | /* Process buffer with BLOCKSIZE bytes. Note that | |
177 | BLOCKSIZE % 64 == 0 | |
178 | */ | |
179 | md5_process_block (buffer, BLOCKSIZE, &ctx); | |
180 | } | |
181 | ||
182 | /* Add the last bytes if necessary. */ | |
183 | if (sum > 0) | |
184 | md5_process_bytes (buffer, sum, &ctx); | |
185 | ||
186 | /* Construct result in desired memory. */ | |
187 | md5_finish_ctx (&ctx, resblock); | |
188 | return 0; | |
189 | } | |
190 | ||
191 | /* Compute MD5 message digest for LEN bytes beginning at BUFFER. The | |
192 | result is always in little endian byte order, so that a byte-wise | |
193 | output yields to the wanted ASCII representation of the message | |
194 | digest. */ | |
195 | void * | |
196 | md5_buffer (buffer, len, resblock) | |
197 | const char *buffer; | |
198 | size_t len; | |
199 | void *resblock; | |
200 | { | |
201 | struct md5_ctx ctx; | |
202 | ||
203 | /* Initialize the computation context. */ | |
204 | md5_init_ctx (&ctx); | |
205 | ||
206 | /* Process whole buffer but last len % 64 bytes. */ | |
207 | md5_process_bytes (buffer, len, &ctx); | |
208 | ||
209 | /* Put result in desired memory area. */ | |
210 | return md5_finish_ctx (&ctx, resblock); | |
211 | } | |
212 | ||
213 | ||
214 | void | |
215 | md5_process_bytes (buffer, len, ctx) | |
216 | const void *buffer; | |
217 | size_t len; | |
218 | struct md5_ctx *ctx; | |
219 | { | |
220 | /* When we already have some bits in our internal buffer concatenate | |
221 | both inputs first. */ | |
222 | if (ctx->buflen != 0) | |
223 | { | |
224 | size_t left_over = ctx->buflen; | |
225 | size_t add = 128 - left_over > len ? len : 128 - left_over; | |
226 | ||
227 | memcpy (&ctx->buffer[left_over], buffer, add); | |
228 | ctx->buflen += add; | |
229 | ||
230 | if (left_over + add > 64) | |
231 | { | |
232 | md5_process_block (ctx->buffer, (left_over + add) & ~63, ctx); | |
233 | /* The regions in the following copy operation cannot overlap. */ | |
234 | memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63], | |
235 | (left_over + add) & 63); | |
236 | ctx->buflen = (left_over + add) & 63; | |
237 | } | |
238 | ||
239 | buffer = (const char *) buffer + add; | |
240 | len -= add; | |
241 | } | |
242 | ||
243 | /* Process available complete blocks. */ | |
244 | if (len > 64) | |
245 | { | |
246 | md5_process_block (buffer, len & ~63, ctx); | |
247 | buffer = (const char *) buffer + (len & ~63); | |
248 | len &= 63; | |
249 | } | |
250 | ||
251 | /* Move remaining bytes in internal buffer. */ | |
252 | if (len > 0) | |
253 | { | |
254 | memcpy (ctx->buffer, buffer, len); | |
255 | ctx->buflen = len; | |
256 | } | |
257 | } | |
258 | ||
259 | ||
260 | /* These are the four functions used in the four steps of the MD5 algorithm | |
261 | and defined in the RFC 1321. The first function is a little bit optimized | |
262 | (as found in Colin Plumbs public domain implementation). */ | |
263 | /* #define FF(b, c, d) ((b & c) | (~b & d)) */ | |
264 | #define FF(b, c, d) (d ^ (b & (c ^ d))) | |
265 | #define FG(b, c, d) FF (d, b, c) | |
266 | #define FH(b, c, d) (b ^ c ^ d) | |
267 | #define FI(b, c, d) (c ^ (b | ~d)) | |
268 | ||
269 | /* Process LEN bytes of BUFFER, accumulating context into CTX. | |
270 | It is assumed that LEN % 64 == 0. */ | |
271 | ||
272 | void | |
273 | md5_process_block (buffer, len, ctx) | |
274 | const void *buffer; | |
275 | size_t len; | |
276 | struct md5_ctx *ctx; | |
277 | { | |
278 | md5_uint32 correct_words[16]; | |
279 | const md5_uint32 *words = buffer; | |
280 | size_t nwords = len / sizeof (md5_uint32); | |
281 | const md5_uint32 *endp = words + nwords; | |
282 | md5_uint32 A = ctx->A; | |
283 | md5_uint32 B = ctx->B; | |
284 | md5_uint32 C = ctx->C; | |
285 | md5_uint32 D = ctx->D; | |
286 | ||
287 | /* First increment the byte count. RFC 1321 specifies the possible | |
288 | length of the file up to 2^64 bits. Here we only compute the | |
289 | number of bytes. Do a double word increment. */ | |
290 | ctx->total[0] += len; | |
291 | if (ctx->total[0] < len) | |
292 | ++ctx->total[1]; | |
293 | ||
294 | /* Process all bytes in the buffer with 64 bytes in each round of | |
295 | the loop. */ | |
296 | while (words < endp) | |
297 | { | |
298 | md5_uint32 *cwp = correct_words; | |
299 | md5_uint32 A_save = A; | |
300 | md5_uint32 B_save = B; | |
301 | md5_uint32 C_save = C; | |
302 | md5_uint32 D_save = D; | |
303 | ||
304 | /* First round: using the given function, the context and a constant | |
305 | the next context is computed. Because the algorithms processing | |
306 | unit is a 32-bit word and it is determined to work on words in | |
307 | little endian byte order we perhaps have to change the byte order | |
308 | before the computation. To reduce the work for the next steps | |
309 | we store the swapped words in the array CORRECT_WORDS. */ | |
310 | ||
311 | #define OP(a, b, c, d, s, T) \ | |
312 | do \ | |
313 | { \ | |
314 | a += FF (b, c, d) + (*cwp++ = SWAP (*words)) + T; \ | |
315 | ++words; \ | |
316 | CYCLIC (a, s); \ | |
317 | a += b; \ | |
318 | } \ | |
319 | while (0) | |
320 | ||
321 | /* It is unfortunate that C does not provide an operator for | |
322 | cyclic rotation. Hope the C compiler is smart enough. */ | |
323 | #define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s))) | |
324 | ||
325 | /* Before we start, one word to the strange constants. | |
326 | They are defined in RFC 1321 as | |
327 | ||
328 | T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64 | |
329 | */ | |
330 | ||
331 | /* Round 1. */ | |
332 | OP (A, B, C, D, 7, 0xd76aa478); | |
333 | OP (D, A, B, C, 12, 0xe8c7b756); | |
334 | OP (C, D, A, B, 17, 0x242070db); | |
335 | OP (B, C, D, A, 22, 0xc1bdceee); | |
336 | OP (A, B, C, D, 7, 0xf57c0faf); | |
337 | OP (D, A, B, C, 12, 0x4787c62a); | |
338 | OP (C, D, A, B, 17, 0xa8304613); | |
339 | OP (B, C, D, A, 22, 0xfd469501); | |
340 | OP (A, B, C, D, 7, 0x698098d8); | |
341 | OP (D, A, B, C, 12, 0x8b44f7af); | |
342 | OP (C, D, A, B, 17, 0xffff5bb1); | |
343 | OP (B, C, D, A, 22, 0x895cd7be); | |
344 | OP (A, B, C, D, 7, 0x6b901122); | |
345 | OP (D, A, B, C, 12, 0xfd987193); | |
346 | OP (C, D, A, B, 17, 0xa679438e); | |
347 | OP (B, C, D, A, 22, 0x49b40821); | |
348 | ||
349 | /* For the second to fourth round we have the possibly swapped words | |
350 | in CORRECT_WORDS. Redefine the macro to take an additional first | |
351 | argument specifying the function to use. */ | |
352 | #undef OP | |
353 | #define OP(f, a, b, c, d, k, s, T) \ | |
354 | do \ | |
355 | { \ | |
356 | a += f (b, c, d) + correct_words[k] + T; \ | |
357 | CYCLIC (a, s); \ | |
358 | a += b; \ | |
359 | } \ | |
360 | while (0) | |
361 | ||
362 | /* Round 2. */ | |
363 | OP (FG, A, B, C, D, 1, 5, 0xf61e2562); | |
364 | OP (FG, D, A, B, C, 6, 9, 0xc040b340); | |
365 | OP (FG, C, D, A, B, 11, 14, 0x265e5a51); | |
366 | OP (FG, B, C, D, A, 0, 20, 0xe9b6c7aa); | |
367 | OP (FG, A, B, C, D, 5, 5, 0xd62f105d); | |
368 | OP (FG, D, A, B, C, 10, 9, 0x02441453); | |
369 | OP (FG, C, D, A, B, 15, 14, 0xd8a1e681); | |
370 | OP (FG, B, C, D, A, 4, 20, 0xe7d3fbc8); | |
371 | OP (FG, A, B, C, D, 9, 5, 0x21e1cde6); | |
372 | OP (FG, D, A, B, C, 14, 9, 0xc33707d6); | |
373 | OP (FG, C, D, A, B, 3, 14, 0xf4d50d87); | |
374 | OP (FG, B, C, D, A, 8, 20, 0x455a14ed); | |
375 | OP (FG, A, B, C, D, 13, 5, 0xa9e3e905); | |
376 | OP (FG, D, A, B, C, 2, 9, 0xfcefa3f8); | |
377 | OP (FG, C, D, A, B, 7, 14, 0x676f02d9); | |
378 | OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a); | |
379 | ||
380 | /* Round 3. */ | |
381 | OP (FH, A, B, C, D, 5, 4, 0xfffa3942); | |
382 | OP (FH, D, A, B, C, 8, 11, 0x8771f681); | |
383 | OP (FH, C, D, A, B, 11, 16, 0x6d9d6122); | |
384 | OP (FH, B, C, D, A, 14, 23, 0xfde5380c); | |
385 | OP (FH, A, B, C, D, 1, 4, 0xa4beea44); | |
386 | OP (FH, D, A, B, C, 4, 11, 0x4bdecfa9); | |
387 | OP (FH, C, D, A, B, 7, 16, 0xf6bb4b60); | |
388 | OP (FH, B, C, D, A, 10, 23, 0xbebfbc70); | |
389 | OP (FH, A, B, C, D, 13, 4, 0x289b7ec6); | |
390 | OP (FH, D, A, B, C, 0, 11, 0xeaa127fa); | |
391 | OP (FH, C, D, A, B, 3, 16, 0xd4ef3085); | |
392 | OP (FH, B, C, D, A, 6, 23, 0x04881d05); | |
393 | OP (FH, A, B, C, D, 9, 4, 0xd9d4d039); | |
394 | OP (FH, D, A, B, C, 12, 11, 0xe6db99e5); | |
395 | OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8); | |
396 | OP (FH, B, C, D, A, 2, 23, 0xc4ac5665); | |
397 | ||
398 | /* Round 4. */ | |
399 | OP (FI, A, B, C, D, 0, 6, 0xf4292244); | |
400 | OP (FI, D, A, B, C, 7, 10, 0x432aff97); | |
401 | OP (FI, C, D, A, B, 14, 15, 0xab9423a7); | |
402 | OP (FI, B, C, D, A, 5, 21, 0xfc93a039); | |
403 | OP (FI, A, B, C, D, 12, 6, 0x655b59c3); | |
404 | OP (FI, D, A, B, C, 3, 10, 0x8f0ccc92); | |
405 | OP (FI, C, D, A, B, 10, 15, 0xffeff47d); | |
406 | OP (FI, B, C, D, A, 1, 21, 0x85845dd1); | |
407 | OP (FI, A, B, C, D, 8, 6, 0x6fa87e4f); | |
408 | OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0); | |
409 | OP (FI, C, D, A, B, 6, 15, 0xa3014314); | |
410 | OP (FI, B, C, D, A, 13, 21, 0x4e0811a1); | |
411 | OP (FI, A, B, C, D, 4, 6, 0xf7537e82); | |
412 | OP (FI, D, A, B, C, 11, 10, 0xbd3af235); | |
413 | OP (FI, C, D, A, B, 2, 15, 0x2ad7d2bb); | |
414 | OP (FI, B, C, D, A, 9, 21, 0xeb86d391); | |
415 | ||
416 | /* Add the starting values of the context. */ | |
417 | A += A_save; | |
418 | B += B_save; | |
419 | C += C_save; | |
420 | D += D_save; | |
421 | } | |
422 | ||
423 | /* Put checksum in context given as argument. */ | |
424 | ctx->A = A; | |
425 | ctx->B = B; | |
426 | ctx->C = C; | |
427 | ctx->D = D; | |
428 | } | |
429 | ||
430 | ||
431 | #ifdef _LIBC | |
432 | /* Define weak aliases. */ | |
433 | # undef md5_init_ctx | |
434 | weak_alias (__md5_init_ctx, md5_init_ctx) | |
435 | # undef md5_process_block | |
436 | weak_alias (__md5_process_block, md5_process_block) | |
437 | # undef md5_process_bytes | |
438 | weak_alias (__md5_process_bytes, md5_process_bytes) | |
439 | # undef md5_finish_ctx | |
440 | weak_alias (__md5_finish_ctx, md5_finish_ctx) | |
441 | # undef md5_read_ctx | |
442 | weak_alias (__md5_read_ctx, md5_read_ctx) | |
443 | # undef md5_stream | |
444 | weak_alias (__md5_stream, md5_stream) | |
445 | # undef md5_buffer | |
446 | weak_alias (__md5_buffer, md5_buffer) | |
447 | #endif |