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. */
23 /* XEmacs frontend written by Ben Wing, Jareth Hein and Hrvoje Niksic. */
29 #include <sys/types.h>
34 /* The following contortions are an attempt to use the C preprocessor
35 to determine an unsigned integral type that is 32 bits wide. An
36 alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
37 doing that would require that the configure script compile and *run*
38 the resulting executable. Locally running cross-compiled executables
39 is usually not possible. */
42 # include <sys/types.h>
43 typedef u_int32_t md5_uint32;
45 # if defined __STDC__ && __STDC__
46 # define UINT_MAX_32_BITS 4294967295U
48 # define UINT_MAX_32_BITS 0xFFFFFFFF
51 /* If UINT_MAX isn't defined, assume it's a 32-bit type.
52 This should be valid for all systems GNU cares about because
53 that doesn't include 16-bit systems, and only modern systems
54 (that certainly have <limits.h>) have 64+-bit integral types. */
57 # define UINT_MAX UINT_MAX_32_BITS
60 # if UINT_MAX == UINT_MAX_32_BITS
61 typedef unsigned int md5_uint32;
63 # if USHRT_MAX == UINT_MAX_32_BITS
64 typedef unsigned short md5_uint32;
66 # if ULONG_MAX == UINT_MAX_32_BITS
67 typedef unsigned long md5_uint32;
69 /* The following line is intended to evoke an error.
70 Using #error is not portable enough. */
71 "Cannot determine unsigned 32-bit data type."
81 # include "file-coding.h"
84 /* Structure to save state of computation between the single steps. */
97 #ifdef WORDS_BIGENDIAN
99 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
105 /* This array contains the bytes used to pad the buffer to the next
106 64-byte boundary. (RFC 1321, 3.1: Step 1) */
107 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
110 static void md5_process_block (const void *, size_t, struct md5_ctx *);
113 /* Initialize structure containing state of computation.
114 (RFC 1321, 3.3: Step 3) */
116 md5_init_ctx (struct md5_ctx *ctx)
123 ctx->total[0] = ctx->total[1] = 0;
127 /* Put result from CTX in first 16 bytes following RESBUF. The result
128 must be in little endian byte order.
130 IMPORTANT: On some systems it is required that RESBUF is correctly
131 aligned for a 32 bits value. */
133 md5_read_ctx (const struct md5_ctx *ctx, void *resbuf)
135 ((md5_uint32 *) resbuf)[0] = SWAP (ctx->A);
136 ((md5_uint32 *) resbuf)[1] = SWAP (ctx->B);
137 ((md5_uint32 *) resbuf)[2] = SWAP (ctx->C);
138 ((md5_uint32 *) resbuf)[3] = SWAP (ctx->D);
143 /* Process the remaining bytes in the internal buffer and the usual
144 prolog according to the standard and write the result to RESBUF.
146 IMPORTANT: On some systems it is required that RESBUF is correctly
147 aligned for a 32 bits value. */
149 md5_finish_ctx (struct md5_ctx *ctx, void *resbuf)
151 /* Take yet unprocessed bytes into account. */
152 md5_uint32 bytes = ctx->buflen;
155 /* Now count remaining bytes. */
156 ctx->total[0] += bytes;
157 if (ctx->total[0] < bytes)
160 pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
161 memcpy (&ctx->buffer[bytes], fillbuf, pad);
163 /* Put the 64-bit file length in *bits* at the end of the buffer. */
164 *(md5_uint32 *) &ctx->buffer[bytes + pad] = SWAP (ctx->total[0] << 3);
165 *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = SWAP ((ctx->total[1] << 3) |
166 (ctx->total[0] >> 29));
168 /* Process last bytes. */
169 md5_process_block (ctx->buffer, bytes + pad + 8, ctx);
171 return md5_read_ctx (ctx, resbuf);
174 #ifndef emacs /* unused in Emacs */
175 /* Compute MD5 message digest for bytes read from STREAM. The
176 resulting message digest number will be written into the 16 bytes
177 beginning at RESBLOCK. */
179 md5_stream (FILE *stream, void *resblock)
181 /* Important: BLOCKSIZE must be a multiple of 64. */
182 #define BLOCKSIZE 4096
184 char buffer[BLOCKSIZE + 72];
187 /* Initialize the computation context. */
190 /* Iterate over full file contents. */
193 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
194 computation function processes the whole buffer so that with the
195 next round of the loop another block can be read. */
199 /* Read block. Take care for partial reads. */
202 n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
206 while (sum < BLOCKSIZE && n != 0);
207 if (n == 0 && ferror (stream))
210 /* If end of file is reached, end the loop. */
214 /* Process buffer with BLOCKSIZE bytes. Note that
217 md5_process_block (buffer, BLOCKSIZE, &ctx);
220 /* Add the last bytes if necessary. */
222 md5_process_bytes (buffer, sum, &ctx);
224 /* Construct result in desired memory. */
225 md5_finish_ctx (&ctx, resblock);
229 /* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
230 result is always in little endian byte order, so that a byte-wise
231 output yields to the wanted ASCII representation of the message
234 md5_buffer (const char *buffer, size_t len, void *resblock)
238 /* Initialize the computation context. */
241 /* Process whole buffer but last len % 64 bytes. */
242 md5_process_bytes (buffer, len, &ctx);
244 /* Put result in desired memory area. */
245 return md5_finish_ctx (&ctx, resblock);
247 #endif /* not emacs */
251 md5_process_bytes (const void *buffer, size_t len, struct md5_ctx *ctx)
253 /* When we already have some bits in our internal buffer concatenate
254 both inputs first. */
255 if (ctx->buflen != 0)
257 size_t left_over = ctx->buflen;
258 size_t add = 128 - left_over > len ? len : 128 - left_over;
260 memcpy (&ctx->buffer[left_over], buffer, add);
263 if (left_over + add > 64)
265 md5_process_block (ctx->buffer, (left_over + add) & ~63, ctx);
266 /* The regions in the following copy operation cannot overlap. */
267 memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
268 (left_over + add) & 63);
269 ctx->buflen = (left_over + add) & 63;
272 buffer = (const char *) buffer + add;
276 /* Process available complete blocks. */
279 md5_process_block (buffer, len & ~63, ctx);
280 buffer = (const char *) buffer + (len & ~63);
284 /* Move remaining bytes in internal buffer. */
287 memcpy (ctx->buffer, buffer, len);
293 /* These are the four functions used in the four steps of the MD5 algorithm
294 and defined in the RFC 1321. The first function is a little bit optimized
295 (as found in Colin Plumbs public domain implementation). */
296 /* #define FF(b, c, d) ((b & c) | (~b & d)) */
297 #define FF(b, c, d) (d ^ (b & (c ^ d)))
298 #define FG(b, c, d) FF (d, b, c)
299 #define FH(b, c, d) (b ^ c ^ d)
300 #define FI(b, c, d) (c ^ (b | ~d))
302 /* Process LEN bytes of BUFFER, accumulating context into CTX.
303 It is assumed that LEN % 64 == 0. */
306 md5_process_block (const void *buffer, size_t len, struct md5_ctx *ctx)
308 md5_uint32 correct_words[16];
309 const md5_uint32 *words = (const md5_uint32 *) buffer;
310 size_t nwords = len / sizeof (md5_uint32);
311 const md5_uint32 *endp = words + nwords;
312 md5_uint32 A = ctx->A;
313 md5_uint32 B = ctx->B;
314 md5_uint32 C = ctx->C;
315 md5_uint32 D = ctx->D;
317 /* First increment the byte count. RFC 1321 specifies the possible
318 length of the file up to 2^64 bits. Here we only compute the
319 number of bytes. Do a double word increment. */
320 ctx->total[0] += len;
321 if (ctx->total[0] < len)
324 /* Process all bytes in the buffer with 64 bytes in each round of
328 md5_uint32 *cwp = correct_words;
329 md5_uint32 A_save = A;
330 md5_uint32 B_save = B;
331 md5_uint32 C_save = C;
332 md5_uint32 D_save = D;
334 /* First round: using the given function, the context and a constant
335 the next context is computed. Because the algorithms processing
336 unit is a 32-bit word and it is determined to work on words in
337 little endian byte order we perhaps have to change the byte order
338 before the computation. To reduce the work for the next steps
339 we store the swapped words in the array CORRECT_WORDS. */
341 #define OP(a, b, c, d, s, T) \
344 a += FF (b, c, d) + (*cwp++ = SWAP (*words)) + T; \
351 /* It is unfortunate that C does not provide an operator for
352 cyclic rotation. Hope the C compiler is smart enough. */
353 #define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
355 /* Before we start, one word to the strange constants.
356 They are defined in RFC 1321 as
358 T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
362 OP (A, B, C, D, 7, 0xd76aa478);
363 OP (D, A, B, C, 12, 0xe8c7b756);
364 OP (C, D, A, B, 17, 0x242070db);
365 OP (B, C, D, A, 22, 0xc1bdceee);
366 OP (A, B, C, D, 7, 0xf57c0faf);
367 OP (D, A, B, C, 12, 0x4787c62a);
368 OP (C, D, A, B, 17, 0xa8304613);
369 OP (B, C, D, A, 22, 0xfd469501);
370 OP (A, B, C, D, 7, 0x698098d8);
371 OP (D, A, B, C, 12, 0x8b44f7af);
372 OP (C, D, A, B, 17, 0xffff5bb1);
373 OP (B, C, D, A, 22, 0x895cd7be);
374 OP (A, B, C, D, 7, 0x6b901122);
375 OP (D, A, B, C, 12, 0xfd987193);
376 OP (C, D, A, B, 17, 0xa679438e);
377 OP (B, C, D, A, 22, 0x49b40821);
379 /* For the second to fourth round we have the possibly swapped words
380 in CORRECT_WORDS. Redefine the macro to take an additional first
381 argument specifying the function to use. */
383 #define OP(f, a, b, c, d, k, s, T) \
386 a += f (b, c, d) + correct_words[k] + T; \
393 OP (FG, A, B, C, D, 1, 5, 0xf61e2562);
394 OP (FG, D, A, B, C, 6, 9, 0xc040b340);
395 OP (FG, C, D, A, B, 11, 14, 0x265e5a51);
396 OP (FG, B, C, D, A, 0, 20, 0xe9b6c7aa);
397 OP (FG, A, B, C, D, 5, 5, 0xd62f105d);
398 OP (FG, D, A, B, C, 10, 9, 0x02441453);
399 OP (FG, C, D, A, B, 15, 14, 0xd8a1e681);
400 OP (FG, B, C, D, A, 4, 20, 0xe7d3fbc8);
401 OP (FG, A, B, C, D, 9, 5, 0x21e1cde6);
402 OP (FG, D, A, B, C, 14, 9, 0xc33707d6);
403 OP (FG, C, D, A, B, 3, 14, 0xf4d50d87);
404 OP (FG, B, C, D, A, 8, 20, 0x455a14ed);
405 OP (FG, A, B, C, D, 13, 5, 0xa9e3e905);
406 OP (FG, D, A, B, C, 2, 9, 0xfcefa3f8);
407 OP (FG, C, D, A, B, 7, 14, 0x676f02d9);
408 OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a);
411 OP (FH, A, B, C, D, 5, 4, 0xfffa3942);
412 OP (FH, D, A, B, C, 8, 11, 0x8771f681);
413 OP (FH, C, D, A, B, 11, 16, 0x6d9d6122);
414 OP (FH, B, C, D, A, 14, 23, 0xfde5380c);
415 OP (FH, A, B, C, D, 1, 4, 0xa4beea44);
416 OP (FH, D, A, B, C, 4, 11, 0x4bdecfa9);
417 OP (FH, C, D, A, B, 7, 16, 0xf6bb4b60);
418 OP (FH, B, C, D, A, 10, 23, 0xbebfbc70);
419 OP (FH, A, B, C, D, 13, 4, 0x289b7ec6);
420 OP (FH, D, A, B, C, 0, 11, 0xeaa127fa);
421 OP (FH, C, D, A, B, 3, 16, 0xd4ef3085);
422 OP (FH, B, C, D, A, 6, 23, 0x04881d05);
423 OP (FH, A, B, C, D, 9, 4, 0xd9d4d039);
424 OP (FH, D, A, B, C, 12, 11, 0xe6db99e5);
425 OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8);
426 OP (FH, B, C, D, A, 2, 23, 0xc4ac5665);
429 OP (FI, A, B, C, D, 0, 6, 0xf4292244);
430 OP (FI, D, A, B, C, 7, 10, 0x432aff97);
431 OP (FI, C, D, A, B, 14, 15, 0xab9423a7);
432 OP (FI, B, C, D, A, 5, 21, 0xfc93a039);
433 OP (FI, A, B, C, D, 12, 6, 0x655b59c3);
434 OP (FI, D, A, B, C, 3, 10, 0x8f0ccc92);
435 OP (FI, C, D, A, B, 10, 15, 0xffeff47d);
436 OP (FI, B, C, D, A, 1, 21, 0x85845dd1);
437 OP (FI, A, B, C, D, 8, 6, 0x6fa87e4f);
438 OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
439 OP (FI, C, D, A, B, 6, 15, 0xa3014314);
440 OP (FI, B, C, D, A, 13, 21, 0x4e0811a1);
441 OP (FI, A, B, C, D, 4, 6, 0xf7537e82);
442 OP (FI, D, A, B, C, 11, 10, 0xbd3af235);
443 OP (FI, C, D, A, B, 2, 15, 0x2ad7d2bb);
444 OP (FI, B, C, D, A, 9, 21, 0xeb86d391);
446 /* Add the starting values of the context. */
453 /* Put checksum in context given as argument. */
463 /* Find out what format the buffer will be saved in, so we can make
464 the digest based on what it will look like on disk. */
466 md5_coding_system (Lisp_Object object, Lisp_Object coding, Lisp_Object istream,
469 Lisp_Object coding_system;
473 if (BUFFERP (object))
475 /* Use the file coding for this buffer by default. */
476 coding_system = XBUFFER (object)->buffer_file_coding_system;
480 /* Attempt to autodetect the coding of the string. This is
481 VERY hit-and-miss. */
482 eol_type_t eol = EOL_AUTODETECT;
483 coding_system = Fget_coding_system (Qundecided);
484 determine_real_coding_system (XLSTREAM (istream),
485 &coding_system, &eol);
487 if (NILP (coding_system))
488 coding_system = Fget_coding_system (Qbinary);
491 coding_system = Ffind_coding_system (coding_system);
492 if (NILP (coding_system))
493 coding_system = Fget_coding_system (Qbinary);
498 coding_system = Ffind_coding_system (coding);
499 if (NILP (coding_system))
502 /* Default to binary. */
503 coding_system = Fget_coding_system (Qbinary);
505 signal_simple_error ("No such coding system", coding);
508 return coding_system;
510 #endif /* FILE_CODING */
513 DEFUN ("md5", Fmd5, 1, 5, 0, /*
514 Return the MD5 message digest of OBJECT, a buffer or string.
516 Optional arguments START and END denote positions for computing the
517 digest of a portion of OBJECT.
519 The optional CODING argument specifies the coding system the text is to be
520 represented in while computing the digest. If unspecified, it defaults
521 to the current format of the data, or is guessed.
523 If NOERROR is non-nil, silently assume binary coding if the guesswork
524 fails. Normally, an error is signaled in such case.
526 CODING and NOERROR arguments are meaningful only in XEmacsen with
527 file-coding or Mule support. Otherwise, they are ignored.
529 (object, start, end, coding, noerror))
531 /* This function can GC */
532 /* Can this really GC? How? */
534 unsigned char digest[16];
535 unsigned char thehash[33];
538 Lisp_Object instream;
541 Lisp_Object raw_instream;
542 struct gcpro ngcpro1;
545 /* Set up the input stream. */
546 if (BUFFERP (object))
550 CHECK_LIVE_BUFFER (object);
551 b = XBUFFER (object);
552 /* Figure out where we need to get info from */
553 get_buffer_range_char (b, start, end, &begv, &endv, GB_ALLOW_NIL);
555 instream = make_lisp_buffer_input_stream (b, begv, endv, 0);
559 Bytecount bstart, bend;
560 CHECK_STRING (object);
561 get_string_range_byte (object, start, end, &bstart, &bend,
562 GB_HISTORICAL_STRING_BEHAVIOR);
563 instream = make_lisp_string_input_stream (object, bstart, bend - bstart);
568 /* Determine the coding and set up the conversion stream. */
569 coding = md5_coding_system (object, coding, instream, !NILP (noerror));
570 raw_instream = instream;
571 instream = make_encoding_input_stream (XLSTREAM (instream), coding);
572 NGCPRO1 (raw_instream);
575 /* Initialize MD5 context. */
578 /* Get the data while doing the conversion. */
581 Bufbyte tempbuf[1024]; /* some random amount */
582 Lstream_data_count size_in_bytes =
583 Lstream_read (XLSTREAM (instream), tempbuf, sizeof (tempbuf));
587 /* Process the bytes. */
588 md5_process_bytes (tempbuf, size_in_bytes, &ctx);
590 Lstream_delete (XLSTREAM (instream));
592 Lstream_delete (XLSTREAM (raw_instream));
597 md5_finish_ctx (&ctx, digest);
598 for (i = 0; i < 16; i++)
599 sprintf ((char *) (thehash + (i * 2)), "%02x", digest[i]);
601 return make_string (thehash, 32);
613 Fprovide (intern ("md5"));