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050823ca JM |
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 Free Software Foundation, Inc. | |
f6528837 DD |
4 | |
5 | NOTE: This source is derived from an old version taken from the GNU C | |
6 | Library (glibc). | |
050823ca JM |
7 | |
8 | This program is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU General Public License as published by the | |
10 | Free Software Foundation; either version 2, or (at your option) any | |
11 | later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software Foundation, | |
979c05d3 | 20 | Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ |
050823ca JM |
21 | |
22 | /* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */ | |
23 | ||
24 | #ifdef HAVE_CONFIG_H | |
25 | # include <config.h> | |
26 | #endif | |
27 | ||
28 | #include <sys/types.h> | |
29 | ||
30 | #if STDC_HEADERS || defined _LIBC | |
31 | # include <stdlib.h> | |
32 | # include <string.h> | |
33 | #else | |
34 | # ifndef HAVE_MEMCPY | |
35 | # define memcpy(d, s, n) bcopy ((s), (d), (n)) | |
36 | # endif | |
37 | #endif | |
38 | ||
87263c36 | 39 | #include "ansidecl.h" |
050823ca JM |
40 | #include "md5.h" |
41 | ||
42 | #ifdef _LIBC | |
43 | # include <endian.h> | |
44 | # if __BYTE_ORDER == __BIG_ENDIAN | |
45 | # define WORDS_BIGENDIAN 1 | |
46 | # endif | |
47 | #endif | |
48 | ||
49 | #ifdef WORDS_BIGENDIAN | |
50 | # define SWAP(n) \ | |
51 | (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24)) | |
52 | #else | |
53 | # define SWAP(n) (n) | |
54 | #endif | |
55 | ||
56 | ||
57 | /* This array contains the bytes used to pad the buffer to the next | |
58 | 64-byte boundary. (RFC 1321, 3.1: Step 1) */ | |
59 | static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ }; | |
60 | ||
61 | ||
62 | /* Initialize structure containing state of computation. | |
63 | (RFC 1321, 3.3: Step 3) */ | |
64 | void | |
49b1fae4 | 65 | md5_init_ctx (struct md5_ctx *ctx) |
050823ca | 66 | { |
b50c4073 DD |
67 | ctx->A = (md5_uint32) 0x67452301; |
68 | ctx->B = (md5_uint32) 0xefcdab89; | |
69 | ctx->C = (md5_uint32) 0x98badcfe; | |
70 | ctx->D = (md5_uint32) 0x10325476; | |
050823ca JM |
71 | |
72 | ctx->total[0] = ctx->total[1] = 0; | |
73 | ctx->buflen = 0; | |
74 | } | |
75 | ||
76 | /* Put result from CTX in first 16 bytes following RESBUF. The result | |
77 | must be in little endian byte order. | |
78 | ||
091c2a96 DD |
79 | IMPORTANT: RESBUF may not be aligned as strongly as MD5_UNIT32 so we |
80 | put things in a local (aligned) buffer first, then memcpy into RESBUF. */ | |
050823ca | 81 | void * |
49b1fae4 | 82 | md5_read_ctx (const struct md5_ctx *ctx, void *resbuf) |
050823ca | 83 | { |
091c2a96 DD |
84 | md5_uint32 buffer[4]; |
85 | ||
86 | buffer[0] = SWAP (ctx->A); | |
87 | buffer[1] = SWAP (ctx->B); | |
88 | buffer[2] = SWAP (ctx->C); | |
89 | buffer[3] = SWAP (ctx->D); | |
90 | ||
91 | memcpy (resbuf, buffer, 16); | |
050823ca JM |
92 | |
93 | return resbuf; | |
94 | } | |
95 | ||
96 | /* Process the remaining bytes in the internal buffer and the usual | |
97 | prolog according to the standard and write the result to RESBUF. | |
98 | ||
99 | IMPORTANT: On some systems it is required that RESBUF is correctly | |
100 | aligned for a 32 bits value. */ | |
101 | void * | |
49b1fae4 | 102 | md5_finish_ctx (struct md5_ctx *ctx, void *resbuf) |
050823ca JM |
103 | { |
104 | /* Take yet unprocessed bytes into account. */ | |
105 | md5_uint32 bytes = ctx->buflen; | |
106 | size_t pad; | |
107 | ||
108 | /* Now count remaining bytes. */ | |
109 | ctx->total[0] += bytes; | |
110 | if (ctx->total[0] < bytes) | |
111 | ++ctx->total[1]; | |
112 | ||
113 | pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes; | |
114 | memcpy (&ctx->buffer[bytes], fillbuf, pad); | |
115 | ||
116 | /* Put the 64-bit file length in *bits* at the end of the buffer. */ | |
117 | *(md5_uint32 *) &ctx->buffer[bytes + pad] = SWAP (ctx->total[0] << 3); | |
118 | *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = SWAP ((ctx->total[1] << 3) | | |
119 | (ctx->total[0] >> 29)); | |
120 | ||
121 | /* Process last bytes. */ | |
122 | md5_process_block (ctx->buffer, bytes + pad + 8, ctx); | |
123 | ||
124 | return md5_read_ctx (ctx, resbuf); | |
125 | } | |
126 | ||
127 | /* Compute MD5 message digest for bytes read from STREAM. The | |
128 | resulting message digest number will be written into the 16 bytes | |
129 | beginning at RESBLOCK. */ | |
130 | int | |
49b1fae4 | 131 | md5_stream (FILE *stream, void *resblock) |
050823ca JM |
132 | { |
133 | /* Important: BLOCKSIZE must be a multiple of 64. */ | |
134 | #define BLOCKSIZE 4096 | |
135 | struct md5_ctx ctx; | |
136 | char buffer[BLOCKSIZE + 72]; | |
137 | size_t sum; | |
138 | ||
139 | /* Initialize the computation context. */ | |
140 | md5_init_ctx (&ctx); | |
141 | ||
142 | /* Iterate over full file contents. */ | |
143 | while (1) | |
144 | { | |
145 | /* We read the file in blocks of BLOCKSIZE bytes. One call of the | |
146 | computation function processes the whole buffer so that with the | |
147 | next round of the loop another block can be read. */ | |
148 | size_t n; | |
149 | sum = 0; | |
150 | ||
151 | /* Read block. Take care for partial reads. */ | |
152 | do | |
153 | { | |
154 | n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream); | |
155 | ||
156 | sum += n; | |
157 | } | |
158 | while (sum < BLOCKSIZE && n != 0); | |
159 | if (n == 0 && ferror (stream)) | |
160 | return 1; | |
161 | ||
162 | /* If end of file is reached, end the loop. */ | |
163 | if (n == 0) | |
164 | break; | |
165 | ||
166 | /* Process buffer with BLOCKSIZE bytes. Note that | |
167 | BLOCKSIZE % 64 == 0 | |
168 | */ | |
169 | md5_process_block (buffer, BLOCKSIZE, &ctx); | |
170 | } | |
171 | ||
172 | /* Add the last bytes if necessary. */ | |
173 | if (sum > 0) | |
174 | md5_process_bytes (buffer, sum, &ctx); | |
175 | ||
176 | /* Construct result in desired memory. */ | |
177 | md5_finish_ctx (&ctx, resblock); | |
178 | return 0; | |
179 | } | |
180 | ||
181 | /* Compute MD5 message digest for LEN bytes beginning at BUFFER. The | |
182 | result is always in little endian byte order, so that a byte-wise | |
183 | output yields to the wanted ASCII representation of the message | |
184 | digest. */ | |
185 | void * | |
49b1fae4 | 186 | md5_buffer (const char *buffer, size_t len, void *resblock) |
050823ca JM |
187 | { |
188 | struct md5_ctx ctx; | |
189 | ||
190 | /* Initialize the computation context. */ | |
191 | md5_init_ctx (&ctx); | |
192 | ||
193 | /* Process whole buffer but last len % 64 bytes. */ | |
194 | md5_process_bytes (buffer, len, &ctx); | |
195 | ||
196 | /* Put result in desired memory area. */ | |
197 | return md5_finish_ctx (&ctx, resblock); | |
198 | } | |
199 | ||
200 | ||
201 | void | |
49b1fae4 | 202 | md5_process_bytes (const void *buffer, size_t len, struct md5_ctx *ctx) |
050823ca JM |
203 | { |
204 | /* When we already have some bits in our internal buffer concatenate | |
205 | both inputs first. */ | |
206 | if (ctx->buflen != 0) | |
207 | { | |
208 | size_t left_over = ctx->buflen; | |
209 | size_t add = 128 - left_over > len ? len : 128 - left_over; | |
210 | ||
211 | memcpy (&ctx->buffer[left_over], buffer, add); | |
212 | ctx->buflen += add; | |
213 | ||
214 | if (left_over + add > 64) | |
215 | { | |
216 | md5_process_block (ctx->buffer, (left_over + add) & ~63, ctx); | |
217 | /* The regions in the following copy operation cannot overlap. */ | |
218 | memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63], | |
219 | (left_over + add) & 63); | |
220 | ctx->buflen = (left_over + add) & 63; | |
221 | } | |
222 | ||
585cc78f | 223 | buffer = (const void *) ((const char *) buffer + add); |
050823ca JM |
224 | len -= add; |
225 | } | |
226 | ||
227 | /* Process available complete blocks. */ | |
228 | if (len > 64) | |
229 | { | |
6ba85b8c DD |
230 | #if !_STRING_ARCH_unaligned |
231 | /* To check alignment gcc has an appropriate operator. Other | |
232 | compilers don't. */ | |
233 | # if __GNUC__ >= 2 | |
234 | # define UNALIGNED_P(p) (((md5_uintptr) p) % __alignof__ (md5_uint32) != 0) | |
235 | # else | |
236 | # define UNALIGNED_P(p) (((md5_uintptr) p) % sizeof (md5_uint32) != 0) | |
237 | # endif | |
238 | if (UNALIGNED_P (buffer)) | |
239 | while (len > 64) | |
240 | { | |
3f69c6bf DD |
241 | memcpy (ctx->buffer, buffer, 64); |
242 | md5_process_block (ctx->buffer, 64, ctx); | |
6ba85b8c DD |
243 | buffer = (const char *) buffer + 64; |
244 | len -= 64; | |
245 | } | |
246 | else | |
247 | #endif | |
050823ca | 248 | md5_process_block (buffer, len & ~63, ctx); |
585cc78f | 249 | buffer = (const void *) ((const char *) buffer + (len & ~63)); |
050823ca JM |
250 | len &= 63; |
251 | } | |
252 | ||
253 | /* Move remaining bytes in internal buffer. */ | |
254 | if (len > 0) | |
255 | { | |
256 | memcpy (ctx->buffer, buffer, len); | |
257 | ctx->buflen = len; | |
258 | } | |
259 | } | |
260 | ||
261 | ||
262 | /* These are the four functions used in the four steps of the MD5 algorithm | |
263 | and defined in the RFC 1321. The first function is a little bit optimized | |
264 | (as found in Colin Plumbs public domain implementation). */ | |
265 | /* #define FF(b, c, d) ((b & c) | (~b & d)) */ | |
266 | #define FF(b, c, d) (d ^ (b & (c ^ d))) | |
267 | #define FG(b, c, d) FF (d, b, c) | |
268 | #define FH(b, c, d) (b ^ c ^ d) | |
269 | #define FI(b, c, d) (c ^ (b | ~d)) | |
270 | ||
271 | /* Process LEN bytes of BUFFER, accumulating context into CTX. | |
272 | It is assumed that LEN % 64 == 0. */ | |
273 | ||
274 | void | |
49b1fae4 | 275 | md5_process_block (const void *buffer, size_t len, struct md5_ctx *ctx) |
050823ca JM |
276 | { |
277 | md5_uint32 correct_words[16]; | |
585cc78f | 278 | const md5_uint32 *words = (const md5_uint32 *) buffer; |
050823ca JM |
279 | size_t nwords = len / sizeof (md5_uint32); |
280 | const md5_uint32 *endp = words + nwords; | |
281 | md5_uint32 A = ctx->A; | |
282 | md5_uint32 B = ctx->B; | |
283 | md5_uint32 C = ctx->C; | |
284 | md5_uint32 D = ctx->D; | |
285 | ||
286 | /* First increment the byte count. RFC 1321 specifies the possible | |
287 | length of the file up to 2^64 bits. Here we only compute the | |
288 | number of bytes. Do a double word increment. */ | |
289 | ctx->total[0] += len; | |
290 | if (ctx->total[0] < len) | |
291 | ++ctx->total[1]; | |
292 | ||
293 | /* Process all bytes in the buffer with 64 bytes in each round of | |
294 | the loop. */ | |
295 | while (words < endp) | |
296 | { | |
297 | md5_uint32 *cwp = correct_words; | |
298 | md5_uint32 A_save = A; | |
299 | md5_uint32 B_save = B; | |
300 | md5_uint32 C_save = C; | |
301 | md5_uint32 D_save = D; | |
302 | ||
303 | /* First round: using the given function, the context and a constant | |
304 | the next context is computed. Because the algorithms processing | |
305 | unit is a 32-bit word and it is determined to work on words in | |
306 | little endian byte order we perhaps have to change the byte order | |
307 | before the computation. To reduce the work for the next steps | |
308 | we store the swapped words in the array CORRECT_WORDS. */ | |
309 | ||
310 | #define OP(a, b, c, d, s, T) \ | |
311 | do \ | |
312 | { \ | |
313 | a += FF (b, c, d) + (*cwp++ = SWAP (*words)) + T; \ | |
314 | ++words; \ | |
315 | CYCLIC (a, s); \ | |
316 | a += b; \ | |
317 | } \ | |
318 | while (0) | |
319 | ||
320 | /* It is unfortunate that C does not provide an operator for | |
321 | cyclic rotation. Hope the C compiler is smart enough. */ | |
322 | #define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s))) | |
323 | ||
324 | /* Before we start, one word to the strange constants. | |
325 | They are defined in RFC 1321 as | |
326 | ||
327 | T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64 | |
328 | */ | |
329 | ||
330 | /* Round 1. */ | |
b50c4073 DD |
331 | OP (A, B, C, D, 7, (md5_uint32) 0xd76aa478); |
332 | OP (D, A, B, C, 12, (md5_uint32) 0xe8c7b756); | |
333 | OP (C, D, A, B, 17, (md5_uint32) 0x242070db); | |
334 | OP (B, C, D, A, 22, (md5_uint32) 0xc1bdceee); | |
335 | OP (A, B, C, D, 7, (md5_uint32) 0xf57c0faf); | |
336 | OP (D, A, B, C, 12, (md5_uint32) 0x4787c62a); | |
337 | OP (C, D, A, B, 17, (md5_uint32) 0xa8304613); | |
338 | OP (B, C, D, A, 22, (md5_uint32) 0xfd469501); | |
339 | OP (A, B, C, D, 7, (md5_uint32) 0x698098d8); | |
340 | OP (D, A, B, C, 12, (md5_uint32) 0x8b44f7af); | |
341 | OP (C, D, A, B, 17, (md5_uint32) 0xffff5bb1); | |
342 | OP (B, C, D, A, 22, (md5_uint32) 0x895cd7be); | |
343 | OP (A, B, C, D, 7, (md5_uint32) 0x6b901122); | |
344 | OP (D, A, B, C, 12, (md5_uint32) 0xfd987193); | |
345 | OP (C, D, A, B, 17, (md5_uint32) 0xa679438e); | |
346 | OP (B, C, D, A, 22, (md5_uint32) 0x49b40821); | |
050823ca JM |
347 | |
348 | /* For the second to fourth round we have the possibly swapped words | |
349 | in CORRECT_WORDS. Redefine the macro to take an additional first | |
350 | argument specifying the function to use. */ | |
351 | #undef OP | |
768b20d8 | 352 | #define OP(a, b, c, d, k, s, T) \ |
050823ca JM |
353 | do \ |
354 | { \ | |
768b20d8 | 355 | a += FX (b, c, d) + correct_words[k] + T; \ |
050823ca JM |
356 | CYCLIC (a, s); \ |
357 | a += b; \ | |
358 | } \ | |
359 | while (0) | |
360 | ||
768b20d8 JJ |
361 | #define FX(b, c, d) FG (b, c, d) |
362 | ||
050823ca | 363 | /* Round 2. */ |
768b20d8 JJ |
364 | OP (A, B, C, D, 1, 5, (md5_uint32) 0xf61e2562); |
365 | OP (D, A, B, C, 6, 9, (md5_uint32) 0xc040b340); | |
366 | OP (C, D, A, B, 11, 14, (md5_uint32) 0x265e5a51); | |
367 | OP (B, C, D, A, 0, 20, (md5_uint32) 0xe9b6c7aa); | |
368 | OP (A, B, C, D, 5, 5, (md5_uint32) 0xd62f105d); | |
369 | OP (D, A, B, C, 10, 9, (md5_uint32) 0x02441453); | |
370 | OP (C, D, A, B, 15, 14, (md5_uint32) 0xd8a1e681); | |
371 | OP (B, C, D, A, 4, 20, (md5_uint32) 0xe7d3fbc8); | |
372 | OP (A, B, C, D, 9, 5, (md5_uint32) 0x21e1cde6); | |
373 | OP (D, A, B, C, 14, 9, (md5_uint32) 0xc33707d6); | |
374 | OP (C, D, A, B, 3, 14, (md5_uint32) 0xf4d50d87); | |
375 | OP (B, C, D, A, 8, 20, (md5_uint32) 0x455a14ed); | |
376 | OP (A, B, C, D, 13, 5, (md5_uint32) 0xa9e3e905); | |
377 | OP (D, A, B, C, 2, 9, (md5_uint32) 0xfcefa3f8); | |
378 | OP (C, D, A, B, 7, 14, (md5_uint32) 0x676f02d9); | |
379 | OP (B, C, D, A, 12, 20, (md5_uint32) 0x8d2a4c8a); | |
380 | ||
381 | #undef FX | |
382 | #define FX(b, c, d) FH (b, c, d) | |
050823ca JM |
383 | |
384 | /* Round 3. */ | |
768b20d8 JJ |
385 | OP (A, B, C, D, 5, 4, (md5_uint32) 0xfffa3942); |
386 | OP (D, A, B, C, 8, 11, (md5_uint32) 0x8771f681); | |
387 | OP (C, D, A, B, 11, 16, (md5_uint32) 0x6d9d6122); | |
388 | OP (B, C, D, A, 14, 23, (md5_uint32) 0xfde5380c); | |
389 | OP (A, B, C, D, 1, 4, (md5_uint32) 0xa4beea44); | |
390 | OP (D, A, B, C, 4, 11, (md5_uint32) 0x4bdecfa9); | |
391 | OP (C, D, A, B, 7, 16, (md5_uint32) 0xf6bb4b60); | |
392 | OP (B, C, D, A, 10, 23, (md5_uint32) 0xbebfbc70); | |
393 | OP (A, B, C, D, 13, 4, (md5_uint32) 0x289b7ec6); | |
394 | OP (D, A, B, C, 0, 11, (md5_uint32) 0xeaa127fa); | |
395 | OP (C, D, A, B, 3, 16, (md5_uint32) 0xd4ef3085); | |
396 | OP (B, C, D, A, 6, 23, (md5_uint32) 0x04881d05); | |
397 | OP (A, B, C, D, 9, 4, (md5_uint32) 0xd9d4d039); | |
398 | OP (D, A, B, C, 12, 11, (md5_uint32) 0xe6db99e5); | |
399 | OP (C, D, A, B, 15, 16, (md5_uint32) 0x1fa27cf8); | |
400 | OP (B, C, D, A, 2, 23, (md5_uint32) 0xc4ac5665); | |
401 | ||
402 | #undef FX | |
403 | #define FX(b, c, d) FI (b, c, d) | |
050823ca JM |
404 | |
405 | /* Round 4. */ | |
768b20d8 JJ |
406 | OP (A, B, C, D, 0, 6, (md5_uint32) 0xf4292244); |
407 | OP (D, A, B, C, 7, 10, (md5_uint32) 0x432aff97); | |
408 | OP (C, D, A, B, 14, 15, (md5_uint32) 0xab9423a7); | |
409 | OP (B, C, D, A, 5, 21, (md5_uint32) 0xfc93a039); | |
410 | OP (A, B, C, D, 12, 6, (md5_uint32) 0x655b59c3); | |
411 | OP (D, A, B, C, 3, 10, (md5_uint32) 0x8f0ccc92); | |
412 | OP (C, D, A, B, 10, 15, (md5_uint32) 0xffeff47d); | |
413 | OP (B, C, D, A, 1, 21, (md5_uint32) 0x85845dd1); | |
414 | OP (A, B, C, D, 8, 6, (md5_uint32) 0x6fa87e4f); | |
415 | OP (D, A, B, C, 15, 10, (md5_uint32) 0xfe2ce6e0); | |
416 | OP (C, D, A, B, 6, 15, (md5_uint32) 0xa3014314); | |
417 | OP (B, C, D, A, 13, 21, (md5_uint32) 0x4e0811a1); | |
418 | OP (A, B, C, D, 4, 6, (md5_uint32) 0xf7537e82); | |
419 | OP (D, A, B, C, 11, 10, (md5_uint32) 0xbd3af235); | |
420 | OP (C, D, A, B, 2, 15, (md5_uint32) 0x2ad7d2bb); | |
421 | OP (B, C, D, A, 9, 21, (md5_uint32) 0xeb86d391); | |
050823ca JM |
422 | |
423 | /* Add the starting values of the context. */ | |
424 | A += A_save; | |
425 | B += B_save; | |
426 | C += C_save; | |
427 | D += D_save; | |
428 | } | |
429 | ||
430 | /* Put checksum in context given as argument. */ | |
431 | ctx->A = A; | |
432 | ctx->B = B; | |
433 | ctx->C = C; | |
434 | ctx->D = D; | |
435 | } |