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) 1995-2019 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., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, 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) */
65 md5_init_ctx (struct md5_ctx
*ctx
)
67 ctx
->A
= (md5_uint32
) 0x67452301;
68 ctx
->B
= (md5_uint32
) 0xefcdab89;
69 ctx
->C
= (md5_uint32
) 0x98badcfe;
70 ctx
->D
= (md5_uint32
) 0x10325476;
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: 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. */
82 md5_read_ctx (const struct md5_ctx
*ctx
, void *resbuf
)
86 buffer
[0] = SWAP (ctx
->A
);
87 buffer
[1] = SWAP (ctx
->B
);
88 buffer
[2] = SWAP (ctx
->C
);
89 buffer
[3] = SWAP (ctx
->D
);
91 memcpy (resbuf
, buffer
, 16);
96 /* Process the remaining bytes in the internal buffer and the usual
97 prolog according to the standard and write the result to RESBUF.
99 IMPORTANT: On some systems it is required that RESBUF is correctly
100 aligned for a 32 bits value. */
102 md5_finish_ctx (struct md5_ctx
*ctx
, void *resbuf
)
104 /* Take yet unprocessed bytes into account. */
105 md5_uint32 bytes
= ctx
->buflen
;
106 md5_uint32 swap_bytes
;
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 Use memcpy to avoid aliasing problems. On most systems, this
119 will be optimized away to the same code. */
120 swap_bytes
= SWAP (ctx
->total
[0] << 3);
121 memcpy (&ctx
->buffer
[bytes
+ pad
], &swap_bytes
, sizeof (swap_bytes
));
122 swap_bytes
= SWAP ((ctx
->total
[1] << 3) | (ctx
->total
[0] >> 29));
123 memcpy (&ctx
->buffer
[bytes
+ pad
+ 4], &swap_bytes
, sizeof (swap_bytes
));
125 /* Process last bytes. */
126 md5_process_block (ctx
->buffer
, bytes
+ pad
+ 8, ctx
);
128 return md5_read_ctx (ctx
, resbuf
);
131 /* Compute MD5 message digest for bytes read from STREAM. The
132 resulting message digest number will be written into the 16 bytes
133 beginning at RESBLOCK. */
135 md5_stream (FILE *stream
, void *resblock
)
137 /* Important: BLOCKSIZE must be a multiple of 64. */
138 #define BLOCKSIZE 4096
140 char buffer
[BLOCKSIZE
+ 72];
143 /* Initialize the computation context. */
146 /* Iterate over full file contents. */
149 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
150 computation function processes the whole buffer so that with the
151 next round of the loop another block can be read. */
155 /* Read block. Take care for partial reads. */
158 n
= fread (buffer
+ sum
, 1, BLOCKSIZE
- sum
, stream
);
162 while (sum
< BLOCKSIZE
&& n
!= 0);
163 if (n
== 0 && ferror (stream
))
166 /* If end of file is reached, end the loop. */
170 /* Process buffer with BLOCKSIZE bytes. Note that
173 md5_process_block (buffer
, BLOCKSIZE
, &ctx
);
176 /* Add the last bytes if necessary. */
178 md5_process_bytes (buffer
, sum
, &ctx
);
180 /* Construct result in desired memory. */
181 md5_finish_ctx (&ctx
, resblock
);
185 /* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
186 result is always in little endian byte order, so that a byte-wise
187 output yields to the wanted ASCII representation of the message
190 md5_buffer (const char *buffer
, size_t len
, void *resblock
)
194 /* Initialize the computation context. */
197 /* Process whole buffer but last len % 64 bytes. */
198 md5_process_bytes (buffer
, len
, &ctx
);
200 /* Put result in desired memory area. */
201 return md5_finish_ctx (&ctx
, resblock
);
206 md5_process_bytes (const void *buffer
, size_t len
, struct md5_ctx
*ctx
)
208 /* When we already have some bits in our internal buffer concatenate
209 both inputs first. */
210 if (ctx
->buflen
!= 0)
212 size_t left_over
= ctx
->buflen
;
213 size_t add
= 128 - left_over
> len
? len
: 128 - left_over
;
215 memcpy (&ctx
->buffer
[left_over
], buffer
, add
);
218 if (left_over
+ add
> 64)
220 md5_process_block (ctx
->buffer
, (left_over
+ add
) & ~63, ctx
);
221 /* The regions in the following copy operation cannot overlap. */
222 memcpy (ctx
->buffer
, &ctx
->buffer
[(left_over
+ add
) & ~63],
223 (left_over
+ add
) & 63);
224 ctx
->buflen
= (left_over
+ add
) & 63;
227 buffer
= (const void *) ((const char *) buffer
+ add
);
231 /* Process available complete blocks. */
234 #if !_STRING_ARCH_unaligned || defined UBSAN_BOOTSTRAP
235 /* To check alignment gcc has an appropriate operator. Other
238 # define UNALIGNED_P(p) (((md5_uintptr) p) % __alignof__ (md5_uint32) != 0)
240 # define UNALIGNED_P(p) (((md5_uintptr) p) % sizeof (md5_uint32) != 0)
242 if (UNALIGNED_P (buffer
))
245 memcpy (ctx
->buffer
, buffer
, 64);
246 md5_process_block (ctx
->buffer
, 64, ctx
);
247 buffer
= (const char *) buffer
+ 64;
253 md5_process_block (buffer
, len
& ~63, ctx
);
254 buffer
= (const void *) ((const char *) buffer
+ (len
& ~63));
259 /* Move remaining bytes in internal buffer. */
262 memcpy (ctx
->buffer
, buffer
, len
);
268 /* These are the four functions used in the four steps of the MD5 algorithm
269 and defined in the RFC 1321. The first function is a little bit optimized
270 (as found in Colin Plumbs public domain implementation). */
271 /* #define FF(b, c, d) ((b & c) | (~b & d)) */
272 #define FF(b, c, d) (d ^ (b & (c ^ d)))
273 #define FG(b, c, d) FF (d, b, c)
274 #define FH(b, c, d) (b ^ c ^ d)
275 #define FI(b, c, d) (c ^ (b | ~d))
277 /* Process LEN bytes of BUFFER, accumulating context into CTX.
278 It is assumed that LEN % 64 == 0. */
281 md5_process_block (const void *buffer
, size_t len
, struct md5_ctx
*ctx
)
283 md5_uint32 correct_words
[16];
284 const md5_uint32
*words
= (const md5_uint32
*) buffer
;
285 size_t nwords
= len
/ sizeof (md5_uint32
);
286 const md5_uint32
*endp
= words
+ nwords
;
287 md5_uint32 A
= ctx
->A
;
288 md5_uint32 B
= ctx
->B
;
289 md5_uint32 C
= ctx
->C
;
290 md5_uint32 D
= ctx
->D
;
292 /* First increment the byte count. RFC 1321 specifies the possible
293 length of the file up to 2^64 bits. Here we only compute the
294 number of bytes. Do a double word increment. */
295 ctx
->total
[0] += len
;
296 ctx
->total
[1] += ((len
>> 31) >> 1) + (ctx
->total
[0] < len
);
298 /* Process all bytes in the buffer with 64 bytes in each round of
302 md5_uint32
*cwp
= correct_words
;
303 md5_uint32 A_save
= A
;
304 md5_uint32 B_save
= B
;
305 md5_uint32 C_save
= C
;
306 md5_uint32 D_save
= D
;
308 /* First round: using the given function, the context and a constant
309 the next context is computed. Because the algorithms processing
310 unit is a 32-bit word and it is determined to work on words in
311 little endian byte order we perhaps have to change the byte order
312 before the computation. To reduce the work for the next steps
313 we store the swapped words in the array CORRECT_WORDS. */
315 #define OP(a, b, c, d, s, T) \
318 a += FF (b, c, d) + (*cwp++ = SWAP (*words)) + T; \
325 /* It is unfortunate that C does not provide an operator for
326 cyclic rotation. Hope the C compiler is smart enough. */
327 #define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
329 /* Before we start, one word to the strange constants.
330 They are defined in RFC 1321 as
332 T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
336 OP (A
, B
, C
, D
, 7, (md5_uint32
) 0xd76aa478);
337 OP (D
, A
, B
, C
, 12, (md5_uint32
) 0xe8c7b756);
338 OP (C
, D
, A
, B
, 17, (md5_uint32
) 0x242070db);
339 OP (B
, C
, D
, A
, 22, (md5_uint32
) 0xc1bdceee);
340 OP (A
, B
, C
, D
, 7, (md5_uint32
) 0xf57c0faf);
341 OP (D
, A
, B
, C
, 12, (md5_uint32
) 0x4787c62a);
342 OP (C
, D
, A
, B
, 17, (md5_uint32
) 0xa8304613);
343 OP (B
, C
, D
, A
, 22, (md5_uint32
) 0xfd469501);
344 OP (A
, B
, C
, D
, 7, (md5_uint32
) 0x698098d8);
345 OP (D
, A
, B
, C
, 12, (md5_uint32
) 0x8b44f7af);
346 OP (C
, D
, A
, B
, 17, (md5_uint32
) 0xffff5bb1);
347 OP (B
, C
, D
, A
, 22, (md5_uint32
) 0x895cd7be);
348 OP (A
, B
, C
, D
, 7, (md5_uint32
) 0x6b901122);
349 OP (D
, A
, B
, C
, 12, (md5_uint32
) 0xfd987193);
350 OP (C
, D
, A
, B
, 17, (md5_uint32
) 0xa679438e);
351 OP (B
, C
, D
, A
, 22, (md5_uint32
) 0x49b40821);
353 /* For the second to fourth round we have the possibly swapped words
354 in CORRECT_WORDS. Redefine the macro to take an additional first
355 argument specifying the function to use. */
357 #define OP(a, b, c, d, k, s, T) \
360 a += FX (b, c, d) + correct_words[k] + T; \
366 #define FX(b, c, d) FG (b, c, d)
369 OP (A
, B
, C
, D
, 1, 5, (md5_uint32
) 0xf61e2562);
370 OP (D
, A
, B
, C
, 6, 9, (md5_uint32
) 0xc040b340);
371 OP (C
, D
, A
, B
, 11, 14, (md5_uint32
) 0x265e5a51);
372 OP (B
, C
, D
, A
, 0, 20, (md5_uint32
) 0xe9b6c7aa);
373 OP (A
, B
, C
, D
, 5, 5, (md5_uint32
) 0xd62f105d);
374 OP (D
, A
, B
, C
, 10, 9, (md5_uint32
) 0x02441453);
375 OP (C
, D
, A
, B
, 15, 14, (md5_uint32
) 0xd8a1e681);
376 OP (B
, C
, D
, A
, 4, 20, (md5_uint32
) 0xe7d3fbc8);
377 OP (A
, B
, C
, D
, 9, 5, (md5_uint32
) 0x21e1cde6);
378 OP (D
, A
, B
, C
, 14, 9, (md5_uint32
) 0xc33707d6);
379 OP (C
, D
, A
, B
, 3, 14, (md5_uint32
) 0xf4d50d87);
380 OP (B
, C
, D
, A
, 8, 20, (md5_uint32
) 0x455a14ed);
381 OP (A
, B
, C
, D
, 13, 5, (md5_uint32
) 0xa9e3e905);
382 OP (D
, A
, B
, C
, 2, 9, (md5_uint32
) 0xfcefa3f8);
383 OP (C
, D
, A
, B
, 7, 14, (md5_uint32
) 0x676f02d9);
384 OP (B
, C
, D
, A
, 12, 20, (md5_uint32
) 0x8d2a4c8a);
387 #define FX(b, c, d) FH (b, c, d)
390 OP (A
, B
, C
, D
, 5, 4, (md5_uint32
) 0xfffa3942);
391 OP (D
, A
, B
, C
, 8, 11, (md5_uint32
) 0x8771f681);
392 OP (C
, D
, A
, B
, 11, 16, (md5_uint32
) 0x6d9d6122);
393 OP (B
, C
, D
, A
, 14, 23, (md5_uint32
) 0xfde5380c);
394 OP (A
, B
, C
, D
, 1, 4, (md5_uint32
) 0xa4beea44);
395 OP (D
, A
, B
, C
, 4, 11, (md5_uint32
) 0x4bdecfa9);
396 OP (C
, D
, A
, B
, 7, 16, (md5_uint32
) 0xf6bb4b60);
397 OP (B
, C
, D
, A
, 10, 23, (md5_uint32
) 0xbebfbc70);
398 OP (A
, B
, C
, D
, 13, 4, (md5_uint32
) 0x289b7ec6);
399 OP (D
, A
, B
, C
, 0, 11, (md5_uint32
) 0xeaa127fa);
400 OP (C
, D
, A
, B
, 3, 16, (md5_uint32
) 0xd4ef3085);
401 OP (B
, C
, D
, A
, 6, 23, (md5_uint32
) 0x04881d05);
402 OP (A
, B
, C
, D
, 9, 4, (md5_uint32
) 0xd9d4d039);
403 OP (D
, A
, B
, C
, 12, 11, (md5_uint32
) 0xe6db99e5);
404 OP (C
, D
, A
, B
, 15, 16, (md5_uint32
) 0x1fa27cf8);
405 OP (B
, C
, D
, A
, 2, 23, (md5_uint32
) 0xc4ac5665);
408 #define FX(b, c, d) FI (b, c, d)
411 OP (A
, B
, C
, D
, 0, 6, (md5_uint32
) 0xf4292244);
412 OP (D
, A
, B
, C
, 7, 10, (md5_uint32
) 0x432aff97);
413 OP (C
, D
, A
, B
, 14, 15, (md5_uint32
) 0xab9423a7);
414 OP (B
, C
, D
, A
, 5, 21, (md5_uint32
) 0xfc93a039);
415 OP (A
, B
, C
, D
, 12, 6, (md5_uint32
) 0x655b59c3);
416 OP (D
, A
, B
, C
, 3, 10, (md5_uint32
) 0x8f0ccc92);
417 OP (C
, D
, A
, B
, 10, 15, (md5_uint32
) 0xffeff47d);
418 OP (B
, C
, D
, A
, 1, 21, (md5_uint32
) 0x85845dd1);
419 OP (A
, B
, C
, D
, 8, 6, (md5_uint32
) 0x6fa87e4f);
420 OP (D
, A
, B
, C
, 15, 10, (md5_uint32
) 0xfe2ce6e0);
421 OP (C
, D
, A
, B
, 6, 15, (md5_uint32
) 0xa3014314);
422 OP (B
, C
, D
, A
, 13, 21, (md5_uint32
) 0x4e0811a1);
423 OP (A
, B
, C
, D
, 4, 6, (md5_uint32
) 0xf7537e82);
424 OP (D
, A
, B
, C
, 11, 10, (md5_uint32
) 0xbd3af235);
425 OP (C
, D
, A
, B
, 2, 15, (md5_uint32
) 0x2ad7d2bb);
426 OP (B
, C
, D
, A
, 9, 21, (md5_uint32
) 0xeb86d391);
428 /* Add the starting values of the context. */
435 /* Put checksum in context given as argument. */