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 #include "config.h"
24
25 #include <sys/types.h>
26
27 #include <stdlib.h>
28 #include <string.h>
29 #ifdef HAVE_LIMITS_H
30 # include <limits.h>
31 #endif
32
33 #include "ne_md5.h"
34 #include "ne_string.h" /* for NE_ASC2HEX */
35
36 #define md5_process_block ne_md5_process_block
37 #define md5_process_bytes ne_md5_process_bytes
38 #define md5_finish_ctx ne_md5_finish_ctx
39 #define md5_read_ctx ne_md5_read_ctx
40 #define md5_stream ne_md5_stream
41 #define md5_ctx ne_md5_ctx
42
43 #ifdef WORDS_BIGENDIAN
44 # define SWAP(n) \
45 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
46 #else
47 # define SWAP(n) (n)
48 #endif
49
50 #if SIZEOF_INT == 4
51 typedef unsigned int md5_uint32;
52 #elif SIZEOF_LONG == 4
53 typedef unsigned long md5_uint32;
54 #else
55 # error "Cannot determine unsigned 32-bit data type."
56 #endif
57
58 /* Structure to save state of computation between the single steps. */
59 struct md5_ctx
60 {
61 md5_uint32 A;
62 md5_uint32 B;
63 md5_uint32 C;
64 md5_uint32 D;
65
66 md5_uint32 total[2];
67 md5_uint32 buflen;
68 char buffer[128];
69 };
70
71 /* This array contains the bytes used to pad the buffer to the next
72 64-byte boundary. (RFC 1321, 3.1: Step 1) */
73 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
74
75
76 /* Initialize structure containing state of computation.
77 (RFC 1321, 3.3: Step 3) */
78 static void
md5_init_ctx(struct md5_ctx * ctx)79 md5_init_ctx (struct md5_ctx *ctx)
80 {
81 ctx->A = 0x67452301;
82 ctx->B = 0xefcdab89;
83 ctx->C = 0x98badcfe;
84 ctx->D = 0x10325476;
85
86 ctx->total[0] = ctx->total[1] = 0;
87 ctx->buflen = 0;
88 }
89
90 struct ne_md5_ctx *
ne_md5_create_ctx(void)91 ne_md5_create_ctx(void)
92 {
93 struct md5_ctx *ctx = ne_malloc(sizeof *ctx);
94 md5_init_ctx(ctx);
95 return ctx;
96 }
97
98 extern void
ne_md5_reset_ctx(struct ne_md5_ctx * ctx)99 ne_md5_reset_ctx(struct ne_md5_ctx *ctx)
100 {
101 md5_init_ctx(ctx);
102 }
103
104 struct ne_md5_ctx *
ne_md5_dup_ctx(struct ne_md5_ctx * ctx)105 ne_md5_dup_ctx(struct ne_md5_ctx *ctx)
106 {
107 return memcpy(ne_malloc(sizeof *ctx), ctx, sizeof *ctx);
108 }
109
110 void
ne_md5_destroy_ctx(struct ne_md5_ctx * ctx)111 ne_md5_destroy_ctx(struct ne_md5_ctx *ctx)
112 {
113 ne_free(ctx);
114 }
115
116 /* Put result from CTX in first 16 bytes following RESBUF. The result
117 must be in little endian byte order.
118
119 IMPORTANT: On some systems it is required that RESBUF is correctly
120 aligned for a 32 bits value. */
121 void *
md5_read_ctx(const struct md5_ctx * ctx,void * resbuf)122 md5_read_ctx (const struct md5_ctx *ctx, void *resbuf)
123 {
124 ((md5_uint32 *) resbuf)[0] = SWAP (ctx->A);
125 ((md5_uint32 *) resbuf)[1] = SWAP (ctx->B);
126 ((md5_uint32 *) resbuf)[2] = SWAP (ctx->C);
127 ((md5_uint32 *) resbuf)[3] = SWAP (ctx->D);
128
129 return resbuf;
130 }
131
132 /* Process the remaining bytes in the internal buffer and the usual
133 prolog according to the standard and write the result to RESBUF.
134
135 IMPORTANT: On some systems it is required that RESBUF is correctly
136 aligned for a 32 bits value. */
137 void *
md5_finish_ctx(struct md5_ctx * ctx,void * resbuf)138 md5_finish_ctx (struct md5_ctx *ctx, void *resbuf)
139 {
140 /* Take yet unprocessed bytes into account. */
141 md5_uint32 bytes = ctx->buflen;
142 size_t pad;
143
144 /* Now count remaining bytes. */
145 ctx->total[0] += bytes;
146 if (ctx->total[0] < bytes)
147 ++ctx->total[1];
148
149 pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
150 memcpy (&ctx->buffer[bytes], fillbuf, pad);
151
152 /* Put the 64-bit file length in *bits* at the end of the buffer. */
153 *(md5_uint32 *) &ctx->buffer[bytes + pad] = SWAP (ctx->total[0] << 3);
154 *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = SWAP ((ctx->total[1] << 3) |
155 (ctx->total[0] >> 29));
156
157 /* Process last bytes. */
158 md5_process_block (ctx->buffer, bytes + pad + 8, ctx);
159
160 return md5_read_ctx (ctx, resbuf);
161 }
162
163 /* Compute MD5 message digest for bytes read from STREAM. The
164 resulting message digest number will be written into the 16 bytes
165 beginning at RESBLOCK. */
166 int
md5_stream(FILE * stream,void * resblock)167 md5_stream (FILE *stream, void *resblock)
168 {
169 /* Important: BLOCKSIZE must be a multiple of 64. */
170 #define BLOCKSIZE 4096
171 struct md5_ctx ctx;
172 char buffer[BLOCKSIZE + 72];
173 size_t sum;
174
175 /* Initialize the computation context. */
176 md5_init_ctx (&ctx);
177
178 /* Iterate over full file contents. */
179 while (1)
180 {
181 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
182 computation function processes the whole buffer so that with the
183 next round of the loop another block can be read. */
184 size_t n;
185 sum = 0;
186
187 /* Read block. Take care for partial reads. */
188 do
189 {
190 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
191
192 sum += n;
193 }
194 while (sum < BLOCKSIZE && n != 0);
195 if (n == 0 && ferror (stream))
196 return 1;
197
198 /* If end of file is reached, end the loop. */
199 if (n == 0)
200 break;
201
202 /* Process buffer with BLOCKSIZE bytes. Note that
203 BLOCKSIZE % 64 == 0
204 */
205 md5_process_block (buffer, BLOCKSIZE, &ctx);
206 }
207
208 /* Add the last bytes if necessary. */
209 if (sum > 0)
210 md5_process_bytes (buffer, sum, &ctx);
211
212 /* Construct result in desired memory. */
213 md5_finish_ctx (&ctx, resblock);
214 return 0;
215 }
216
217 void
md5_process_bytes(const void * buffer,size_t len,struct md5_ctx * ctx)218 md5_process_bytes (const void *buffer, size_t len, 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
md5_process_block(const void * buffer,size_t len,struct md5_ctx * ctx)273 md5_process_block (const void *buffer, size_t len, struct md5_ctx *ctx)
274 {
275 md5_uint32 correct_words[16];
276 const unsigned char *words = buffer;
277 const unsigned char *endp = words + len;
278 md5_uint32 A = ctx->A;
279 md5_uint32 B = ctx->B;
280 md5_uint32 C = ctx->C;
281 md5_uint32 D = ctx->D;
282
283 /* First increment the byte count. RFC 1321 specifies the possible
284 length of the file up to 2^64 bits. Here we only compute the
285 number of bytes. Do a double word increment. */
286 ctx->total[0] += len;
287 if (ctx->total[0] < len)
288 ++ctx->total[1];
289
290 /* Process all bytes in the buffer with 64 bytes in each round of
291 the loop. */
292 while (words < endp)
293 {
294 md5_uint32 *cwp = correct_words;
295 md5_uint32 A_save = A;
296 md5_uint32 B_save = B;
297 md5_uint32 C_save = C;
298 md5_uint32 D_save = D;
299
300 /* First round: using the given function, the context and a constant
301 the next context is computed. Because the algorithms processing
302 unit is a 32-bit word and it is determined to work on words in
303 little endian byte order we perhaps have to change the byte order
304 before the computation. To reduce the work for the next steps
305 we store the swapped words in the array CORRECT_WORDS. */
306
307 #define OP(a, b, c, d, s, T) \
308 do \
309 { \
310 md5_uint32 WORD_ = (md5_uint32)words[0] | ((md5_uint32)words[1] << 8) \
311 | ((md5_uint32)words[2] << 16) | ((md5_uint32)words[3] << 24); \
312 a += FF (b, c, d) + (*cwp++ = WORD_) + T; \
313 words += 4; \
314 CYCLIC (a, s); \
315 a += b; \
316 } \
317 while (0)
318
319 /* It is unfortunate that C does not provide an operator for
320 cyclic rotation. Hope the C compiler is smart enough. */
321 #define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
322
323 /* Before we start, one word to the strange constants.
324 They are defined in RFC 1321 as
325
326 T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
327 */
328
329 /* Round 1. */
330 OP (A, B, C, D, 7, 0xd76aa478);
331 OP (D, A, B, C, 12, 0xe8c7b756);
332 OP (C, D, A, B, 17, 0x242070db);
333 OP (B, C, D, A, 22, 0xc1bdceee);
334 OP (A, B, C, D, 7, 0xf57c0faf);
335 OP (D, A, B, C, 12, 0x4787c62a);
336 OP (C, D, A, B, 17, 0xa8304613);
337 OP (B, C, D, A, 22, 0xfd469501);
338 OP (A, B, C, D, 7, 0x698098d8);
339 OP (D, A, B, C, 12, 0x8b44f7af);
340 OP (C, D, A, B, 17, 0xffff5bb1);
341 OP (B, C, D, A, 22, 0x895cd7be);
342 OP (A, B, C, D, 7, 0x6b901122);
343 OP (D, A, B, C, 12, 0xfd987193);
344 OP (C, D, A, B, 17, 0xa679438e);
345 OP (B, C, D, A, 22, 0x49b40821);
346
347 /* For the second to fourth round we have the possibly swapped words
348 in CORRECT_WORDS. Redefine the macro to take an additional first
349 argument specifying the function to use. */
350 #undef OP
351 #define OP(f, a, b, c, d, k, s, T) \
352 do \
353 { \
354 a += f (b, c, d) + correct_words[k] + T; \
355 CYCLIC (a, s); \
356 a += b; \
357 } \
358 while (0)
359
360 /* Round 2. */
361 OP (FG, A, B, C, D, 1, 5, 0xf61e2562);
362 OP (FG, D, A, B, C, 6, 9, 0xc040b340);
363 OP (FG, C, D, A, B, 11, 14, 0x265e5a51);
364 OP (FG, B, C, D, A, 0, 20, 0xe9b6c7aa);
365 OP (FG, A, B, C, D, 5, 5, 0xd62f105d);
366 OP (FG, D, A, B, C, 10, 9, 0x02441453);
367 OP (FG, C, D, A, B, 15, 14, 0xd8a1e681);
368 OP (FG, B, C, D, A, 4, 20, 0xe7d3fbc8);
369 OP (FG, A, B, C, D, 9, 5, 0x21e1cde6);
370 OP (FG, D, A, B, C, 14, 9, 0xc33707d6);
371 OP (FG, C, D, A, B, 3, 14, 0xf4d50d87);
372 OP (FG, B, C, D, A, 8, 20, 0x455a14ed);
373 OP (FG, A, B, C, D, 13, 5, 0xa9e3e905);
374 OP (FG, D, A, B, C, 2, 9, 0xfcefa3f8);
375 OP (FG, C, D, A, B, 7, 14, 0x676f02d9);
376 OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a);
377
378 /* Round 3. */
379 OP (FH, A, B, C, D, 5, 4, 0xfffa3942);
380 OP (FH, D, A, B, C, 8, 11, 0x8771f681);
381 OP (FH, C, D, A, B, 11, 16, 0x6d9d6122);
382 OP (FH, B, C, D, A, 14, 23, 0xfde5380c);
383 OP (FH, A, B, C, D, 1, 4, 0xa4beea44);
384 OP (FH, D, A, B, C, 4, 11, 0x4bdecfa9);
385 OP (FH, C, D, A, B, 7, 16, 0xf6bb4b60);
386 OP (FH, B, C, D, A, 10, 23, 0xbebfbc70);
387 OP (FH, A, B, C, D, 13, 4, 0x289b7ec6);
388 OP (FH, D, A, B, C, 0, 11, 0xeaa127fa);
389 OP (FH, C, D, A, B, 3, 16, 0xd4ef3085);
390 OP (FH, B, C, D, A, 6, 23, 0x04881d05);
391 OP (FH, A, B, C, D, 9, 4, 0xd9d4d039);
392 OP (FH, D, A, B, C, 12, 11, 0xe6db99e5);
393 OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8);
394 OP (FH, B, C, D, A, 2, 23, 0xc4ac5665);
395
396 /* Round 4. */
397 OP (FI, A, B, C, D, 0, 6, 0xf4292244);
398 OP (FI, D, A, B, C, 7, 10, 0x432aff97);
399 OP (FI, C, D, A, B, 14, 15, 0xab9423a7);
400 OP (FI, B, C, D, A, 5, 21, 0xfc93a039);
401 OP (FI, A, B, C, D, 12, 6, 0x655b59c3);
402 OP (FI, D, A, B, C, 3, 10, 0x8f0ccc92);
403 OP (FI, C, D, A, B, 10, 15, 0xffeff47d);
404 OP (FI, B, C, D, A, 1, 21, 0x85845dd1);
405 OP (FI, A, B, C, D, 8, 6, 0x6fa87e4f);
406 OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
407 OP (FI, C, D, A, B, 6, 15, 0xa3014314);
408 OP (FI, B, C, D, A, 13, 21, 0x4e0811a1);
409 OP (FI, A, B, C, D, 4, 6, 0xf7537e82);
410 OP (FI, D, A, B, C, 11, 10, 0xbd3af235);
411 OP (FI, C, D, A, B, 2, 15, 0x2ad7d2bb);
412 OP (FI, B, C, D, A, 9, 21, 0xeb86d391);
413
414 /* Add the starting values of the context. */
415 A += A_save;
416 B += B_save;
417 C += C_save;
418 D += D_save;
419 }
420
421 /* Put checksum in context given as argument. */
422 ctx->A = A;
423 ctx->B = B;
424 ctx->C = C;
425 ctx->D = D;
426 }
427
428 /* Writes the ASCII representation of the MD5 digest into the
429 * given buffer, which must be at least 33 characters long. */
ne_md5_to_ascii(const unsigned char md5_buf[16],char * buffer)430 void ne_md5_to_ascii(const unsigned char md5_buf[16], char *buffer)
431 {
432 int count;
433 for (count = 0; count<16; count++) {
434 buffer[count*2] = NE_HEX2ASC(md5_buf[count] >> 4);
435 buffer[count*2+1] = NE_HEX2ASC(md5_buf[count] & 0x0f);
436 }
437 buffer[32] = '\0';
438 }
439
440 /* Reads the ASCII representation of an MD5 digest. The buffer must
441 * be at least 32 characters long. */
ne_ascii_to_md5(const char * buffer,unsigned char md5_buf[16])442 void ne_ascii_to_md5(const char *buffer, unsigned char md5_buf[16])
443 {
444 int count;
445 for (count = 0; count<16; count++) {
446 md5_buf[count] = ((NE_ASC2HEX(buffer[count*2])) << 4) |
447 NE_ASC2HEX(buffer[count*2+1]);
448 }
449 }
450
ne_md5_finish_ascii(struct ne_md5_ctx * ctx,char buffer[33])451 char *ne_md5_finish_ascii(struct ne_md5_ctx *ctx, char buffer[33])
452 {
453 md5_uint32 result[4];
454
455 ne_md5_finish_ctx(ctx, (void *)result);
456 ne_md5_to_ascii((void *)result, buffer);
457
458 return buffer;
459 }
460
461