0c0507dfeb153f46cf666d19156f10ec4037a146
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.
4 NOTE: The canonical source of this file is maintained with the GNU C
5 Library. Bugs can be reported to bug-glibc@prep.ai.mit.edu.
7 This program is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 2, or (at your option) any
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software Foundation,
19 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21 /* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */
27 #include <sys/types.h>
29 #if STDC_HEADERS || defined _LIBC
34 # define memcpy(d, s, n) bcopy ((s), (d), (n))
43 # if __BYTE_ORDER == __BIG_ENDIAN
44 # define WORDS_BIGENDIAN 1
48 #ifdef WORDS_BIGENDIAN
50 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
56 /* This array contains the bytes used to pad the buffer to the next
57 64-byte boundary. (RFC 1321, 3.1: Step 1) */
58 static const unsigned char fillbuf
[64] = { 0x80, 0 /* , 0, 0, ... */ };
61 /* Initialize structure containing state of computation.
62 (RFC 1321, 3.3: Step 3) */
72 ctx
->total
[0] = ctx
->total
[1] = 0;
76 /* Put result from CTX in first 16 bytes following RESBUF. The result
77 must be in little endian byte order.
79 IMPORTANT: On some systems it is required that RESBUF is correctly
80 aligned for a 32 bits value. */
82 md5_read_ctx (ctx
, resbuf
)
83 const struct md5_ctx
*ctx
;
86 ((md5_uint32
*) resbuf
)[0] = SWAP (ctx
->A
);
87 ((md5_uint32
*) resbuf
)[1] = SWAP (ctx
->B
);
88 ((md5_uint32
*) resbuf
)[2] = SWAP (ctx
->C
);
89 ((md5_uint32
*) resbuf
)[3] = SWAP (ctx
->D
);
94 /* Process the remaining bytes in the internal buffer and the usual
95 prolog according to the standard and write the result to RESBUF.
97 IMPORTANT: On some systems it is required that RESBUF is correctly
98 aligned for a 32 bits value. */
100 md5_finish_ctx (ctx
, resbuf
)
104 /* Take yet unprocessed bytes into account. */
105 md5_uint32 bytes
= ctx
->buflen
;
108 /* Now count remaining bytes. */
109 ctx
->total
[0] += bytes
;
110 if (ctx
->total
[0] < bytes
)
113 pad
= bytes
>= 56 ? 64 + 56 - bytes
: 56 - bytes
;
114 memcpy (&ctx
->buffer
[bytes
], fillbuf
, pad
);
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));
121 /* Process last bytes. */
122 md5_process_block (ctx
->buffer
, bytes
+ pad
+ 8, ctx
);
124 return md5_read_ctx (ctx
, resbuf
);
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. */
131 md5_stream (stream
, resblock
)
135 /* Important: BLOCKSIZE must be a multiple of 64. */
136 #define BLOCKSIZE 4096
138 char buffer
[BLOCKSIZE
+ 72];
141 /* Initialize the computation context. */
144 /* Iterate over full file contents. */
147 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
148 computation function processes the whole buffer so that with the
149 next round of the loop another block can be read. */
153 /* Read block. Take care for partial reads. */
156 n
= fread (buffer
+ sum
, 1, BLOCKSIZE
- sum
, stream
);
160 while (sum
< BLOCKSIZE
&& n
!= 0);
161 if (n
== 0 && ferror (stream
))
164 /* If end of file is reached, end the loop. */
168 /* Process buffer with BLOCKSIZE bytes. Note that
171 md5_process_block (buffer
, BLOCKSIZE
, &ctx
);
174 /* Add the last bytes if necessary. */
176 md5_process_bytes (buffer
, sum
, &ctx
);
178 /* Construct result in desired memory. */
179 md5_finish_ctx (&ctx
, resblock
);
183 /* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
184 result is always in little endian byte order, so that a byte-wise
185 output yields to the wanted ASCII representation of the message
188 md5_buffer (buffer
, len
, resblock
)
195 /* Initialize the computation context. */
198 /* Process whole buffer but last len % 64 bytes. */
199 md5_process_bytes (buffer
, len
, &ctx
);
201 /* Put result in desired memory area. */
202 return md5_finish_ctx (&ctx
, resblock
);
207 md5_process_bytes (buffer
, len
, ctx
)
212 /* When we already have some bits in our internal buffer concatenate
213 both inputs first. */
214 if (ctx
->buflen
!= 0)
216 size_t left_over
= ctx
->buflen
;
217 size_t add
= 128 - left_over
> len
? len
: 128 - left_over
;
219 memcpy (&ctx
->buffer
[left_over
], buffer
, add
);
222 if (left_over
+ add
> 64)
224 md5_process_block (ctx
->buffer
, (left_over
+ add
) & ~63, ctx
);
225 /* The regions in the following copy operation cannot overlap. */
226 memcpy (ctx
->buffer
, &ctx
->buffer
[(left_over
+ add
) & ~63],
227 (left_over
+ add
) & 63);
228 ctx
->buflen
= (left_over
+ add
) & 63;
231 buffer
= (const char *) buffer
+ add
;
235 /* Process available complete blocks. */
238 md5_process_block (buffer
, len
& ~63, ctx
);
239 buffer
= (const char *) buffer
+ (len
& ~63);
243 /* Move remaining bytes in internal buffer. */
246 memcpy (ctx
->buffer
, buffer
, len
);
252 /* These are the four functions used in the four steps of the MD5 algorithm
253 and defined in the RFC 1321. The first function is a little bit optimized
254 (as found in Colin Plumbs public domain implementation). */
255 /* #define FF(b, c, d) ((b & c) | (~b & d)) */
256 #define FF(b, c, d) (d ^ (b & (c ^ d)))
257 #define FG(b, c, d) FF (d, b, c)
258 #define FH(b, c, d) (b ^ c ^ d)
259 #define FI(b, c, d) (c ^ (b | ~d))
261 /* Process LEN bytes of BUFFER, accumulating context into CTX.
262 It is assumed that LEN % 64 == 0. */
265 md5_process_block (buffer
, len
, ctx
)
270 md5_uint32 correct_words
[16];
271 const md5_uint32
*words
= buffer
;
272 size_t nwords
= len
/ sizeof (md5_uint32
);
273 const md5_uint32
*endp
= words
+ nwords
;
274 md5_uint32 A
= ctx
->A
;
275 md5_uint32 B
= ctx
->B
;
276 md5_uint32 C
= ctx
->C
;
277 md5_uint32 D
= ctx
->D
;
279 /* First increment the byte count. RFC 1321 specifies the possible
280 length of the file up to 2^64 bits. Here we only compute the
281 number of bytes. Do a double word increment. */
282 ctx
->total
[0] += len
;
283 if (ctx
->total
[0] < len
)
286 /* Process all bytes in the buffer with 64 bytes in each round of
290 md5_uint32
*cwp
= correct_words
;
291 md5_uint32 A_save
= A
;
292 md5_uint32 B_save
= B
;
293 md5_uint32 C_save
= C
;
294 md5_uint32 D_save
= D
;
296 /* First round: using the given function, the context and a constant
297 the next context is computed. Because the algorithms processing
298 unit is a 32-bit word and it is determined to work on words in
299 little endian byte order we perhaps have to change the byte order
300 before the computation. To reduce the work for the next steps
301 we store the swapped words in the array CORRECT_WORDS. */
303 #define OP(a, b, c, d, s, T) \
306 a += FF (b, c, d) + (*cwp++ = SWAP (*words)) + T; \
313 /* It is unfortunate that C does not provide an operator for
314 cyclic rotation. Hope the C compiler is smart enough. */
315 #define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
317 /* Before we start, one word to the strange constants.
318 They are defined in RFC 1321 as
320 T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
324 OP (A
, B
, C
, D
, 7, 0xd76aa478);
325 OP (D
, A
, B
, C
, 12, 0xe8c7b756);
326 OP (C
, D
, A
, B
, 17, 0x242070db);
327 OP (B
, C
, D
, A
, 22, 0xc1bdceee);
328 OP (A
, B
, C
, D
, 7, 0xf57c0faf);
329 OP (D
, A
, B
, C
, 12, 0x4787c62a);
330 OP (C
, D
, A
, B
, 17, 0xa8304613);
331 OP (B
, C
, D
, A
, 22, 0xfd469501);
332 OP (A
, B
, C
, D
, 7, 0x698098d8);
333 OP (D
, A
, B
, C
, 12, 0x8b44f7af);
334 OP (C
, D
, A
, B
, 17, 0xffff5bb1);
335 OP (B
, C
, D
, A
, 22, 0x895cd7be);
336 OP (A
, B
, C
, D
, 7, 0x6b901122);
337 OP (D
, A
, B
, C
, 12, 0xfd987193);
338 OP (C
, D
, A
, B
, 17, 0xa679438e);
339 OP (B
, C
, D
, A
, 22, 0x49b40821);
341 /* For the second to fourth round we have the possibly swapped words
342 in CORRECT_WORDS. Redefine the macro to take an additional first
343 argument specifying the function to use. */
345 #define OP(f, a, b, c, d, k, s, T) \
348 a += f (b, c, d) + correct_words[k] + T; \
355 OP (FG
, A
, B
, C
, D
, 1, 5, 0xf61e2562);
356 OP (FG
, D
, A
, B
, C
, 6, 9, 0xc040b340);
357 OP (FG
, C
, D
, A
, B
, 11, 14, 0x265e5a51);
358 OP (FG
, B
, C
, D
, A
, 0, 20, 0xe9b6c7aa);
359 OP (FG
, A
, B
, C
, D
, 5, 5, 0xd62f105d);
360 OP (FG
, D
, A
, B
, C
, 10, 9, 0x02441453);
361 OP (FG
, C
, D
, A
, B
, 15, 14, 0xd8a1e681);
362 OP (FG
, B
, C
, D
, A
, 4, 20, 0xe7d3fbc8);
363 OP (FG
, A
, B
, C
, D
, 9, 5, 0x21e1cde6);
364 OP (FG
, D
, A
, B
, C
, 14, 9, 0xc33707d6);
365 OP (FG
, C
, D
, A
, B
, 3, 14, 0xf4d50d87);
366 OP (FG
, B
, C
, D
, A
, 8, 20, 0x455a14ed);
367 OP (FG
, A
, B
, C
, D
, 13, 5, 0xa9e3e905);
368 OP (FG
, D
, A
, B
, C
, 2, 9, 0xfcefa3f8);
369 OP (FG
, C
, D
, A
, B
, 7, 14, 0x676f02d9);
370 OP (FG
, B
, C
, D
, A
, 12, 20, 0x8d2a4c8a);
373 OP (FH
, A
, B
, C
, D
, 5, 4, 0xfffa3942);
374 OP (FH
, D
, A
, B
, C
, 8, 11, 0x8771f681);
375 OP (FH
, C
, D
, A
, B
, 11, 16, 0x6d9d6122);
376 OP (FH
, B
, C
, D
, A
, 14, 23, 0xfde5380c);
377 OP (FH
, A
, B
, C
, D
, 1, 4, 0xa4beea44);
378 OP (FH
, D
, A
, B
, C
, 4, 11, 0x4bdecfa9);
379 OP (FH
, C
, D
, A
, B
, 7, 16, 0xf6bb4b60);
380 OP (FH
, B
, C
, D
, A
, 10, 23, 0xbebfbc70);
381 OP (FH
, A
, B
, C
, D
, 13, 4, 0x289b7ec6);
382 OP (FH
, D
, A
, B
, C
, 0, 11, 0xeaa127fa);
383 OP (FH
, C
, D
, A
, B
, 3, 16, 0xd4ef3085);
384 OP (FH
, B
, C
, D
, A
, 6, 23, 0x04881d05);
385 OP (FH
, A
, B
, C
, D
, 9, 4, 0xd9d4d039);
386 OP (FH
, D
, A
, B
, C
, 12, 11, 0xe6db99e5);
387 OP (FH
, C
, D
, A
, B
, 15, 16, 0x1fa27cf8);
388 OP (FH
, B
, C
, D
, A
, 2, 23, 0xc4ac5665);
391 OP (FI
, A
, B
, C
, D
, 0, 6, 0xf4292244);
392 OP (FI
, D
, A
, B
, C
, 7, 10, 0x432aff97);
393 OP (FI
, C
, D
, A
, B
, 14, 15, 0xab9423a7);
394 OP (FI
, B
, C
, D
, A
, 5, 21, 0xfc93a039);
395 OP (FI
, A
, B
, C
, D
, 12, 6, 0x655b59c3);
396 OP (FI
, D
, A
, B
, C
, 3, 10, 0x8f0ccc92);
397 OP (FI
, C
, D
, A
, B
, 10, 15, 0xffeff47d);
398 OP (FI
, B
, C
, D
, A
, 1, 21, 0x85845dd1);
399 OP (FI
, A
, B
, C
, D
, 8, 6, 0x6fa87e4f);
400 OP (FI
, D
, A
, B
, C
, 15, 10, 0xfe2ce6e0);
401 OP (FI
, C
, D
, A
, B
, 6, 15, 0xa3014314);
402 OP (FI
, B
, C
, D
, A
, 13, 21, 0x4e0811a1);
403 OP (FI
, A
, B
, C
, D
, 4, 6, 0xf7537e82);
404 OP (FI
, D
, A
, B
, C
, 11, 10, 0xbd3af235);
405 OP (FI
, C
, D
, A
, B
, 2, 15, 0x2ad7d2bb);
406 OP (FI
, B
, C
, D
, A
, 9, 21, 0xeb86d391);
408 /* Add the starting values of the context. */
415 /* Put checksum in context given as argument. */