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 #if STDC_HEADERS || defined _LIBC
28 # include <stdlib.h>
29 # include <string.h>
30 #else
31 #ifdef HAVE_STRING_H
32 #include <string.h>
33 #endif
34 # ifndef HAVE_MEMCPY
35 # define memcpy(d, s, n) bcopy ((s), (d), (n))
36 # endif
37 #endif
38
39 #include <ctype.h> /* for tolower */
40
41 #include "ne_md5.h"
42 #include "ne_string.h" /* for NE_ASC2HEX */
43
44 #ifdef _LIBC
45 # include <endian.h>
46 # if __BYTE_ORDER == __BIG_ENDIAN
47 # define WORDS_BIGENDIAN 1
48 # endif
49 #endif
50
51 #define md5_init_ctx ne_md5_init_ctx
52 #define md5_process_block ne_md5_process_block
53 #define md5_process_bytes ne_md5_process_bytes
54 #define md5_finish_ctx ne_md5_finish_ctx
55 #define md5_read_ctx ne_md5_read_ctx
56 #define md5_stream ne_md5_stream
57 #define md5_ctx ne_md5_ctx
58
59 #ifdef WORDS_BIGENDIAN
60 # define SWAP(n) \
61 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
62 #else
63 # define SWAP(n) (n)
64 #endif
65
66
67 /* This array contains the bytes used to pad the buffer to the next
68 64-byte boundary. (RFC 1321, 3.1: Step 1) */
69 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
70
71
72 /* Initialize structure containing state of computation.
73 (RFC 1321, 3.3: Step 3) */
74 void
md5_init_ctx(ctx)75 md5_init_ctx (ctx)
76 struct md5_ctx *ctx;
77 {
78 ctx->A = 0x67452301;
79 ctx->B = 0xefcdab89;
80 ctx->C = 0x98badcfe;
81 ctx->D = 0x10325476;
82
83 ctx->total[0] = ctx->total[1] = 0;
84 ctx->buflen = 0;
85 }
86
87 /* Put result from CTX in first 16 bytes following RESBUF. The result
88 must be in little endian byte order.
89
90 IMPORTANT: On some systems it is required that RESBUF is correctly
91 aligned for a 32 bits value. */
92 void *
md5_read_ctx(ctx,resbuf)93 md5_read_ctx (ctx, resbuf)
94 const struct md5_ctx *ctx;
95 void *resbuf;
96 {
97 ((md5_uint32 *) resbuf)[0] = SWAP (ctx->A);
98 ((md5_uint32 *) resbuf)[1] = SWAP (ctx->B);
99 ((md5_uint32 *) resbuf)[2] = SWAP (ctx->C);
100 ((md5_uint32 *) resbuf)[3] = SWAP (ctx->D);
101
102 return resbuf;
103 }
104
105 /* Process the remaining bytes in the internal buffer and the usual
106 prolog according to the standard and write the result to RESBUF.
107
108 IMPORTANT: On some systems it is required that RESBUF is correctly
109 aligned for a 32 bits value. */
110 void *
md5_finish_ctx(ctx,resbuf)111 md5_finish_ctx (ctx, resbuf)
112 struct md5_ctx *ctx;
113 void *resbuf;
114 {
115 /* Take yet unprocessed bytes into account. */
116 md5_uint32 bytes = ctx->buflen;
117 size_t pad;
118
119 /* Now count remaining bytes. */
120 ctx->total[0] += bytes;
121 if (ctx->total[0] < bytes)
122 ++ctx->total[1];
123
124 pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
125 memcpy (&ctx->buffer[bytes], fillbuf, pad);
126
127 /* Put the 64-bit file length in *bits* at the end of the buffer. */
128 *(md5_uint32 *) &ctx->buffer[bytes + pad] = SWAP (ctx->total[0] << 3);
129 *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = SWAP ((ctx->total[1] << 3) |
130 (ctx->total[0] >> 29));
131
132 /* Process last bytes. */
133 md5_process_block (ctx->buffer, bytes + pad + 8, ctx);
134
135 return md5_read_ctx (ctx, resbuf);
136 }
137
138 /* Compute MD5 message digest for bytes read from STREAM. The
139 resulting message digest number will be written into the 16 bytes
140 beginning at RESBLOCK. */
141 int
md5_stream(stream,resblock)142 md5_stream (stream, resblock)
143 FILE *stream;
144 void *resblock;
145 {
146 /* Important: BLOCKSIZE must be a multiple of 64. */
147 #define BLOCKSIZE 4096
148 struct md5_ctx ctx;
149 char buffer[BLOCKSIZE + 72];
150 size_t sum;
151
152 /* Initialize the computation context. */
153 md5_init_ctx (&ctx);
154
155 /* Iterate over full file contents. */
156 while (1)
157 {
158 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
159 computation function processes the whole buffer so that with the
160 next round of the loop another block can be read. */
161 size_t n;
162 sum = 0;
163
164 /* Read block. Take care for partial reads. */
165 do
166 {
167 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
168
169 sum += n;
170 }
171 while (sum < BLOCKSIZE && n != 0);
172 if (n == 0 && ferror (stream))
173 return 1;
174
175 /* If end of file is reached, end the loop. */
176 if (n == 0)
177 break;
178
179 /* Process buffer with BLOCKSIZE bytes. Note that
180 BLOCKSIZE % 64 == 0
181 */
182 md5_process_block (buffer, BLOCKSIZE, &ctx);
183 }
184
185 /* Add the last bytes if necessary. */
186 if (sum > 0)
187 md5_process_bytes (buffer, sum, &ctx);
188
189 /* Construct result in desired memory. */
190 md5_finish_ctx (&ctx, resblock);
191 return 0;
192 }
193
194 void
md5_process_bytes(buffer,len,ctx)195 md5_process_bytes (buffer, len, ctx)
196 const void *buffer;
197 size_t len;
198 struct md5_ctx *ctx;
199 {
200 /* When we already have some bits in our internal buffer concatenate
201 both inputs first. */
202 if (ctx->buflen != 0)
203 {
204 size_t left_over = ctx->buflen;
205 size_t add = 128 - left_over > len ? len : 128 - left_over;
206
207 memcpy (&ctx->buffer[left_over], buffer, add);
208 ctx->buflen += add;
209
210 if (left_over + add > 64)
211 {
212 md5_process_block (ctx->buffer, (left_over + add) & ~63, ctx);
213 /* The regions in the following copy operation cannot overlap. */
214 memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
215 (left_over + add) & 63);
216 ctx->buflen = (left_over + add) & 63;
217 }
218
219 buffer = (const char *) buffer + add;
220 len -= add;
221 }
222
223 /* Process available complete blocks. */
224 if (len > 64)
225 {
226 md5_process_block (buffer, len & ~63, ctx);
227 buffer = (const char *) buffer + (len & ~63);
228 len &= 63;
229 }
230
231 /* Move remaining bytes in internal buffer. */
232 if (len > 0)
233 {
234 memcpy (ctx->buffer, buffer, len);
235 ctx->buflen = len;
236 }
237 }
238
239
240 /* These are the four functions used in the four steps of the MD5 algorithm
241 and defined in the RFC 1321. The first function is a little bit optimized
242 (as found in Colin Plumbs public domain implementation). */
243 /* #define FF(b, c, d) ((b & c) | (~b & d)) */
244 #define FF(b, c, d) (d ^ (b & (c ^ d)))
245 #define FG(b, c, d) FF (d, b, c)
246 #define FH(b, c, d) (b ^ c ^ d)
247 #define FI(b, c, d) (c ^ (b | ~d))
248
249 /* Process LEN bytes of BUFFER, accumulating context into CTX.
250 It is assumed that LEN % 64 == 0. */
251
252 void
md5_process_block(buffer,len,ctx)253 md5_process_block (buffer, len, ctx)
254 const void *buffer;
255 size_t len;
256 struct md5_ctx *ctx;
257 {
258 md5_uint32 correct_words[16];
259 const unsigned char *words = buffer;
260 const unsigned char *endp = words + len;
261 md5_uint32 A = ctx->A;
262 md5_uint32 B = ctx->B;
263 md5_uint32 C = ctx->C;
264 md5_uint32 D = ctx->D;
265
266 /* First increment the byte count. RFC 1321 specifies the possible
267 length of the file up to 2^64 bits. Here we only compute the
268 number of bytes. Do a double word increment. */
269 ctx->total[0] += len;
270 if (ctx->total[0] < len)
271 ++ctx->total[1];
272
273 /* Process all bytes in the buffer with 64 bytes in each round of
274 the loop. */
275 while (words < endp)
276 {
277 md5_uint32 *cwp = correct_words;
278 md5_uint32 A_save = A;
279 md5_uint32 B_save = B;
280 md5_uint32 C_save = C;
281 md5_uint32 D_save = D;
282
283 /* First round: using the given function, the context and a constant
284 the next context is computed. Because the algorithms processing
285 unit is a 32-bit word and it is determined to work on words in
286 little endian byte order we perhaps have to change the byte order
287 before the computation. To reduce the work for the next steps
288 we store the swapped words in the array CORRECT_WORDS. */
289
290 #define OP(a, b, c, d, s, T) \
291 do \
292 { \
293 md5_uint32 WORD_ = (md5_uint32)words[0] | ((md5_uint32)words[1] << 8) \
294 | ((md5_uint32)words[2] << 16) | ((md5_uint32)words[3] << 24); \
295 a += FF (b, c, d) + (*cwp++ = WORD_) + T; \
296 words += 4; \
297 CYCLIC (a, s); \
298 a += b; \
299 } \
300 while (0)
301
302 /* It is unfortunate that C does not provide an operator for
303 cyclic rotation. Hope the C compiler is smart enough. */
304 #define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
305
306 /* Before we start, one word to the strange constants.
307 They are defined in RFC 1321 as
308
309 T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
310 */
311
312 /* Round 1. */
313 OP (A, B, C, D, 7, 0xd76aa478);
314 OP (D, A, B, C, 12, 0xe8c7b756);
315 OP (C, D, A, B, 17, 0x242070db);
316 OP (B, C, D, A, 22, 0xc1bdceee);
317 OP (A, B, C, D, 7, 0xf57c0faf);
318 OP (D, A, B, C, 12, 0x4787c62a);
319 OP (C, D, A, B, 17, 0xa8304613);
320 OP (B, C, D, A, 22, 0xfd469501);
321 OP (A, B, C, D, 7, 0x698098d8);
322 OP (D, A, B, C, 12, 0x8b44f7af);
323 OP (C, D, A, B, 17, 0xffff5bb1);
324 OP (B, C, D, A, 22, 0x895cd7be);
325 OP (A, B, C, D, 7, 0x6b901122);
326 OP (D, A, B, C, 12, 0xfd987193);
327 OP (C, D, A, B, 17, 0xa679438e);
328 OP (B, C, D, A, 22, 0x49b40821);
329
330 /* For the second to fourth round we have the possibly swapped words
331 in CORRECT_WORDS. Redefine the macro to take an additional first
332 argument specifying the function to use. */
333 #undef OP
334 #define OP(f, a, b, c, d, k, s, T) \
335 do \
336 { \
337 a += f (b, c, d) + correct_words[k] + T; \
338 CYCLIC (a, s); \
339 a += b; \
340 } \
341 while (0)
342
343 /* Round 2. */
344 OP (FG, A, B, C, D, 1, 5, 0xf61e2562);
345 OP (FG, D, A, B, C, 6, 9, 0xc040b340);
346 OP (FG, C, D, A, B, 11, 14, 0x265e5a51);
347 OP (FG, B, C, D, A, 0, 20, 0xe9b6c7aa);
348 OP (FG, A, B, C, D, 5, 5, 0xd62f105d);
349 OP (FG, D, A, B, C, 10, 9, 0x02441453);
350 OP (FG, C, D, A, B, 15, 14, 0xd8a1e681);
351 OP (FG, B, C, D, A, 4, 20, 0xe7d3fbc8);
352 OP (FG, A, B, C, D, 9, 5, 0x21e1cde6);
353 OP (FG, D, A, B, C, 14, 9, 0xc33707d6);
354 OP (FG, C, D, A, B, 3, 14, 0xf4d50d87);
355 OP (FG, B, C, D, A, 8, 20, 0x455a14ed);
356 OP (FG, A, B, C, D, 13, 5, 0xa9e3e905);
357 OP (FG, D, A, B, C, 2, 9, 0xfcefa3f8);
358 OP (FG, C, D, A, B, 7, 14, 0x676f02d9);
359 OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a);
360
361 /* Round 3. */
362 OP (FH, A, B, C, D, 5, 4, 0xfffa3942);
363 OP (FH, D, A, B, C, 8, 11, 0x8771f681);
364 OP (FH, C, D, A, B, 11, 16, 0x6d9d6122);
365 OP (FH, B, C, D, A, 14, 23, 0xfde5380c);
366 OP (FH, A, B, C, D, 1, 4, 0xa4beea44);
367 OP (FH, D, A, B, C, 4, 11, 0x4bdecfa9);
368 OP (FH, C, D, A, B, 7, 16, 0xf6bb4b60);
369 OP (FH, B, C, D, A, 10, 23, 0xbebfbc70);
370 OP (FH, A, B, C, D, 13, 4, 0x289b7ec6);
371 OP (FH, D, A, B, C, 0, 11, 0xeaa127fa);
372 OP (FH, C, D, A, B, 3, 16, 0xd4ef3085);
373 OP (FH, B, C, D, A, 6, 23, 0x04881d05);
374 OP (FH, A, B, C, D, 9, 4, 0xd9d4d039);
375 OP (FH, D, A, B, C, 12, 11, 0xe6db99e5);
376 OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8);
377 OP (FH, B, C, D, A, 2, 23, 0xc4ac5665);
378
379 /* Round 4. */
380 OP (FI, A, B, C, D, 0, 6, 0xf4292244);
381 OP (FI, D, A, B, C, 7, 10, 0x432aff97);
382 OP (FI, C, D, A, B, 14, 15, 0xab9423a7);
383 OP (FI, B, C, D, A, 5, 21, 0xfc93a039);
384 OP (FI, A, B, C, D, 12, 6, 0x655b59c3);
385 OP (FI, D, A, B, C, 3, 10, 0x8f0ccc92);
386 OP (FI, C, D, A, B, 10, 15, 0xffeff47d);
387 OP (FI, B, C, D, A, 1, 21, 0x85845dd1);
388 OP (FI, A, B, C, D, 8, 6, 0x6fa87e4f);
389 OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
390 OP (FI, C, D, A, B, 6, 15, 0xa3014314);
391 OP (FI, B, C, D, A, 13, 21, 0x4e0811a1);
392 OP (FI, A, B, C, D, 4, 6, 0xf7537e82);
393 OP (FI, D, A, B, C, 11, 10, 0xbd3af235);
394 OP (FI, C, D, A, B, 2, 15, 0x2ad7d2bb);
395 OP (FI, B, C, D, A, 9, 21, 0xeb86d391);
396
397 /* Add the starting values of the context. */
398 A += A_save;
399 B += B_save;
400 C += C_save;
401 D += D_save;
402 }
403
404 /* Put checksum in context given as argument. */
405 ctx->A = A;
406 ctx->B = B;
407 ctx->C = C;
408 ctx->D = D;
409 }
410
411 /* Writes the ASCII representation of the MD5 digest into the
412 * given buffer, which must be at least 33 characters long. */
ne_md5_to_ascii(const unsigned char md5_buf[16],char * buffer)413 void ne_md5_to_ascii(const unsigned char md5_buf[16], char *buffer)
414 {
415 int count;
416 for (count = 0; count<16; count++) {
417 buffer[count*2] = NE_HEX2ASC(md5_buf[count] >> 4);
418 buffer[count*2+1] = NE_HEX2ASC(md5_buf[count] & 0x0f);
419 }
420 buffer[32] = '\0';
421 }
422
423 /* Reads the ASCII representation of an MD5 digest. The buffer must
424 * be at least 32 characters long. */
ne_ascii_to_md5(const char * buffer,unsigned char md5_buf[16])425 void ne_ascii_to_md5(const char *buffer, unsigned char md5_buf[16])
426 {
427 int count;
428 for (count = 0; count<16; count++) {
429 md5_buf[count] = ((NE_ASC2HEX(buffer[count*2])) << 4) |
430 NE_ASC2HEX(buffer[count*2+1]);
431 }
432 }
433