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.
5 NOTE: This source is derived from an old version taken from the GNU C
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
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.
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,
20 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
22 /* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */
28 #include <sys/types.h>
30 #if STDC_HEADERS || defined _LIBC
35 # define memcpy(d, s, n) bcopy ((s), (d), (n))
44 # if __BYTE_ORDER == __BIG_ENDIAN
45 # define WORDS_BIGENDIAN 1
49 #ifdef WORDS_BIGENDIAN
51 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
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, ... */ };
62 /* Initialize structure containing state of computation.
63 (RFC 1321, 3.3: Step 3) */
68 ctx
->A
= (md5_uint32
) 0x67452301;
69 ctx
->B
= (md5_uint32
) 0xefcdab89;
70 ctx
->C
= (md5_uint32
) 0x98badcfe;
71 ctx
->D
= (md5_uint32
) 0x10325476;
73 ctx
->total
[0] = ctx
->total
[1] = 0;
77 /* Put result from CTX in first 16 bytes following RESBUF. The result
78 must be in little endian byte order.
80 IMPORTANT: On some systems it is required that RESBUF is correctly
81 aligned for a 32 bits value. */
83 md5_read_ctx (ctx
, resbuf
)
84 const struct md5_ctx
*ctx
;
87 ((md5_uint32
*) resbuf
)[0] = SWAP (ctx
->A
);
88 ((md5_uint32
*) resbuf
)[1] = SWAP (ctx
->B
);
89 ((md5_uint32
*) resbuf
)[2] = SWAP (ctx
->C
);
90 ((md5_uint32
*) resbuf
)[3] = SWAP (ctx
->D
);
95 /* Process the remaining bytes in the internal buffer and the usual
96 prolog according to the standard and write the result to RESBUF.
98 IMPORTANT: On some systems it is required that RESBUF is correctly
99 aligned for a 32 bits value. */
101 md5_finish_ctx (ctx
, resbuf
)
105 /* Take yet unprocessed bytes into account. */
106 md5_uint32 bytes
= ctx
->buflen
;
109 /* Now count remaining bytes. */
110 ctx
->total
[0] += bytes
;
111 if (ctx
->total
[0] < bytes
)
114 pad
= bytes
>= 56 ? 64 + 56 - bytes
: 56 - bytes
;
115 memcpy (&ctx
->buffer
[bytes
], fillbuf
, pad
);
117 /* Put the 64-bit file length in *bits* at the end of the buffer. */
118 *(md5_uint32
*) &ctx
->buffer
[bytes
+ pad
] = SWAP (ctx
->total
[0] << 3);
119 *(md5_uint32
*) &ctx
->buffer
[bytes
+ pad
+ 4] = SWAP ((ctx
->total
[1] << 3) |
120 (ctx
->total
[0] >> 29));
122 /* Process last bytes. */
123 md5_process_block (ctx
->buffer
, bytes
+ pad
+ 8, ctx
);
125 return md5_read_ctx (ctx
, resbuf
);
128 /* Compute MD5 message digest for bytes read from STREAM. The
129 resulting message digest number will be written into the 16 bytes
130 beginning at RESBLOCK. */
132 md5_stream (stream
, resblock
)
136 /* Important: BLOCKSIZE must be a multiple of 64. */
137 #define BLOCKSIZE 4096
139 char buffer
[BLOCKSIZE
+ 72];
142 /* Initialize the computation context. */
145 /* Iterate over full file contents. */
148 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
149 computation function processes the whole buffer so that with the
150 next round of the loop another block can be read. */
154 /* Read block. Take care for partial reads. */
157 n
= fread (buffer
+ sum
, 1, BLOCKSIZE
- sum
, stream
);
161 while (sum
< BLOCKSIZE
&& n
!= 0);
162 if (n
== 0 && ferror (stream
))
165 /* If end of file is reached, end the loop. */
169 /* Process buffer with BLOCKSIZE bytes. Note that
172 md5_process_block (buffer
, BLOCKSIZE
, &ctx
);
175 /* Add the last bytes if necessary. */
177 md5_process_bytes (buffer
, sum
, &ctx
);
179 /* Construct result in desired memory. */
180 md5_finish_ctx (&ctx
, resblock
);
184 /* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
185 result is always in little endian byte order, so that a byte-wise
186 output yields to the wanted ASCII representation of the message
189 md5_buffer (buffer
, len
, resblock
)
196 /* Initialize the computation context. */
199 /* Process whole buffer but last len % 64 bytes. */
200 md5_process_bytes (buffer
, len
, &ctx
);
202 /* Put result in desired memory area. */
203 return md5_finish_ctx (&ctx
, resblock
);
208 md5_process_bytes (buffer
, len
, ctx
)
213 /* When we already have some bits in our internal buffer concatenate
214 both inputs first. */
215 if (ctx
->buflen
!= 0)
217 size_t left_over
= ctx
->buflen
;
218 size_t add
= 128 - left_over
> len
? len
: 128 - left_over
;
220 memcpy (&ctx
->buffer
[left_over
], buffer
, add
);
223 if (left_over
+ add
> 64)
225 md5_process_block (ctx
->buffer
, (left_over
+ add
) & ~63, ctx
);
226 /* The regions in the following copy operation cannot overlap. */
227 memcpy (ctx
->buffer
, &ctx
->buffer
[(left_over
+ add
) & ~63],
228 (left_over
+ add
) & 63);
229 ctx
->buflen
= (left_over
+ add
) & 63;
232 buffer
= (const void *) ((const char *) buffer
+ add
);
236 /* Process available complete blocks. */
239 md5_process_block (buffer
, len
& ~63, ctx
);
240 buffer
= (const void *) ((const char *) buffer
+ (len
& ~63));
244 /* Move remaining bytes in internal buffer. */
247 memcpy (ctx
->buffer
, buffer
, len
);
253 /* These are the four functions used in the four steps of the MD5 algorithm
254 and defined in the RFC 1321. The first function is a little bit optimized
255 (as found in Colin Plumbs public domain implementation). */
256 /* #define FF(b, c, d) ((b & c) | (~b & d)) */
257 #define FF(b, c, d) (d ^ (b & (c ^ d)))
258 #define FG(b, c, d) FF (d, b, c)
259 #define FH(b, c, d) (b ^ c ^ d)
260 #define FI(b, c, d) (c ^ (b | ~d))
262 /* Process LEN bytes of BUFFER, accumulating context into CTX.
263 It is assumed that LEN % 64 == 0. */
266 md5_process_block (buffer
, len
, ctx
)
271 md5_uint32 correct_words
[16];
272 const md5_uint32
*words
= (const md5_uint32
*) buffer
;
273 size_t nwords
= len
/ sizeof (md5_uint32
);
274 const md5_uint32
*endp
= words
+ nwords
;
275 md5_uint32 A
= ctx
->A
;
276 md5_uint32 B
= ctx
->B
;
277 md5_uint32 C
= ctx
->C
;
278 md5_uint32 D
= ctx
->D
;
280 /* First increment the byte count. RFC 1321 specifies the possible
281 length of the file up to 2^64 bits. Here we only compute the
282 number of bytes. Do a double word increment. */
283 ctx
->total
[0] += len
;
284 if (ctx
->total
[0] < len
)
287 /* Process all bytes in the buffer with 64 bytes in each round of
291 md5_uint32
*cwp
= correct_words
;
292 md5_uint32 A_save
= A
;
293 md5_uint32 B_save
= B
;
294 md5_uint32 C_save
= C
;
295 md5_uint32 D_save
= D
;
297 /* First round: using the given function, the context and a constant
298 the next context is computed. Because the algorithms processing
299 unit is a 32-bit word and it is determined to work on words in
300 little endian byte order we perhaps have to change the byte order
301 before the computation. To reduce the work for the next steps
302 we store the swapped words in the array CORRECT_WORDS. */
304 #define OP(a, b, c, d, s, T) \
307 a += FF (b, c, d) + (*cwp++ = SWAP (*words)) + T; \
314 /* It is unfortunate that C does not provide an operator for
315 cyclic rotation. Hope the C compiler is smart enough. */
316 #define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
318 /* Before we start, one word to the strange constants.
319 They are defined in RFC 1321 as
321 T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
325 OP (A
, B
, C
, D
, 7, (md5_uint32
) 0xd76aa478);
326 OP (D
, A
, B
, C
, 12, (md5_uint32
) 0xe8c7b756);
327 OP (C
, D
, A
, B
, 17, (md5_uint32
) 0x242070db);
328 OP (B
, C
, D
, A
, 22, (md5_uint32
) 0xc1bdceee);
329 OP (A
, B
, C
, D
, 7, (md5_uint32
) 0xf57c0faf);
330 OP (D
, A
, B
, C
, 12, (md5_uint32
) 0x4787c62a);
331 OP (C
, D
, A
, B
, 17, (md5_uint32
) 0xa8304613);
332 OP (B
, C
, D
, A
, 22, (md5_uint32
) 0xfd469501);
333 OP (A
, B
, C
, D
, 7, (md5_uint32
) 0x698098d8);
334 OP (D
, A
, B
, C
, 12, (md5_uint32
) 0x8b44f7af);
335 OP (C
, D
, A
, B
, 17, (md5_uint32
) 0xffff5bb1);
336 OP (B
, C
, D
, A
, 22, (md5_uint32
) 0x895cd7be);
337 OP (A
, B
, C
, D
, 7, (md5_uint32
) 0x6b901122);
338 OP (D
, A
, B
, C
, 12, (md5_uint32
) 0xfd987193);
339 OP (C
, D
, A
, B
, 17, (md5_uint32
) 0xa679438e);
340 OP (B
, C
, D
, A
, 22, (md5_uint32
) 0x49b40821);
342 /* For the second to fourth round we have the possibly swapped words
343 in CORRECT_WORDS. Redefine the macro to take an additional first
344 argument specifying the function to use. */
346 #define OP(a, b, c, d, k, s, T) \
349 a += FX (b, c, d) + correct_words[k] + T; \
355 #define FX(b, c, d) FG (b, c, d)
358 OP (A
, B
, C
, D
, 1, 5, (md5_uint32
) 0xf61e2562);
359 OP (D
, A
, B
, C
, 6, 9, (md5_uint32
) 0xc040b340);
360 OP (C
, D
, A
, B
, 11, 14, (md5_uint32
) 0x265e5a51);
361 OP (B
, C
, D
, A
, 0, 20, (md5_uint32
) 0xe9b6c7aa);
362 OP (A
, B
, C
, D
, 5, 5, (md5_uint32
) 0xd62f105d);
363 OP (D
, A
, B
, C
, 10, 9, (md5_uint32
) 0x02441453);
364 OP (C
, D
, A
, B
, 15, 14, (md5_uint32
) 0xd8a1e681);
365 OP (B
, C
, D
, A
, 4, 20, (md5_uint32
) 0xe7d3fbc8);
366 OP (A
, B
, C
, D
, 9, 5, (md5_uint32
) 0x21e1cde6);
367 OP (D
, A
, B
, C
, 14, 9, (md5_uint32
) 0xc33707d6);
368 OP (C
, D
, A
, B
, 3, 14, (md5_uint32
) 0xf4d50d87);
369 OP (B
, C
, D
, A
, 8, 20, (md5_uint32
) 0x455a14ed);
370 OP (A
, B
, C
, D
, 13, 5, (md5_uint32
) 0xa9e3e905);
371 OP (D
, A
, B
, C
, 2, 9, (md5_uint32
) 0xfcefa3f8);
372 OP (C
, D
, A
, B
, 7, 14, (md5_uint32
) 0x676f02d9);
373 OP (B
, C
, D
, A
, 12, 20, (md5_uint32
) 0x8d2a4c8a);
376 #define FX(b, c, d) FH (b, c, d)
379 OP (A
, B
, C
, D
, 5, 4, (md5_uint32
) 0xfffa3942);
380 OP (D
, A
, B
, C
, 8, 11, (md5_uint32
) 0x8771f681);
381 OP (C
, D
, A
, B
, 11, 16, (md5_uint32
) 0x6d9d6122);
382 OP (B
, C
, D
, A
, 14, 23, (md5_uint32
) 0xfde5380c);
383 OP (A
, B
, C
, D
, 1, 4, (md5_uint32
) 0xa4beea44);
384 OP (D
, A
, B
, C
, 4, 11, (md5_uint32
) 0x4bdecfa9);
385 OP (C
, D
, A
, B
, 7, 16, (md5_uint32
) 0xf6bb4b60);
386 OP (B
, C
, D
, A
, 10, 23, (md5_uint32
) 0xbebfbc70);
387 OP (A
, B
, C
, D
, 13, 4, (md5_uint32
) 0x289b7ec6);
388 OP (D
, A
, B
, C
, 0, 11, (md5_uint32
) 0xeaa127fa);
389 OP (C
, D
, A
, B
, 3, 16, (md5_uint32
) 0xd4ef3085);
390 OP (B
, C
, D
, A
, 6, 23, (md5_uint32
) 0x04881d05);
391 OP (A
, B
, C
, D
, 9, 4, (md5_uint32
) 0xd9d4d039);
392 OP (D
, A
, B
, C
, 12, 11, (md5_uint32
) 0xe6db99e5);
393 OP (C
, D
, A
, B
, 15, 16, (md5_uint32
) 0x1fa27cf8);
394 OP (B
, C
, D
, A
, 2, 23, (md5_uint32
) 0xc4ac5665);
397 #define FX(b, c, d) FI (b, c, d)
400 OP (A
, B
, C
, D
, 0, 6, (md5_uint32
) 0xf4292244);
401 OP (D
, A
, B
, C
, 7, 10, (md5_uint32
) 0x432aff97);
402 OP (C
, D
, A
, B
, 14, 15, (md5_uint32
) 0xab9423a7);
403 OP (B
, C
, D
, A
, 5, 21, (md5_uint32
) 0xfc93a039);
404 OP (A
, B
, C
, D
, 12, 6, (md5_uint32
) 0x655b59c3);
405 OP (D
, A
, B
, C
, 3, 10, (md5_uint32
) 0x8f0ccc92);
406 OP (C
, D
, A
, B
, 10, 15, (md5_uint32
) 0xffeff47d);
407 OP (B
, C
, D
, A
, 1, 21, (md5_uint32
) 0x85845dd1);
408 OP (A
, B
, C
, D
, 8, 6, (md5_uint32
) 0x6fa87e4f);
409 OP (D
, A
, B
, C
, 15, 10, (md5_uint32
) 0xfe2ce6e0);
410 OP (C
, D
, A
, B
, 6, 15, (md5_uint32
) 0xa3014314);
411 OP (B
, C
, D
, A
, 13, 21, (md5_uint32
) 0x4e0811a1);
412 OP (A
, B
, C
, D
, 4, 6, (md5_uint32
) 0xf7537e82);
413 OP (D
, A
, B
, C
, 11, 10, (md5_uint32
) 0xbd3af235);
414 OP (C
, D
, A
, B
, 2, 15, (md5_uint32
) 0x2ad7d2bb);
415 OP (B
, C
, D
, A
, 9, 21, (md5_uint32
) 0xeb86d391);
417 /* Add the starting values of the context. */
424 /* Put checksum in context given as argument. */
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