428
+ − 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.
800
+ − 4 Copyright (C) 2001, 2002 Ben Wing.
428
+ − 5 NOTE: The canonical source of this file is maintained with the GNU C
+ − 6 Library. Bugs can be reported to bug-glibc@prep.ai.mit.edu.
+ − 7
+ − 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
+ − 11 later version.
+ − 12
+ − 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.
+ − 17
+ − 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. */
+ − 21
+ − 22 /* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */
+ − 23
+ − 24 /* XEmacs frontend written by Ben Wing, Jareth Hein and Hrvoje Niksic. */
+ − 25
+ − 26 #ifdef HAVE_CONFIG_H
+ − 27 # include <config.h>
+ − 28 #endif
+ − 29
+ − 30 #include <sys/types.h>
+ − 31 #include <string.h>
+ − 32 #include <stdio.h>
442
+ − 33 #include <limits.h>
428
+ − 34
+ − 35 /* The following contortions are an attempt to use the C preprocessor
+ − 36 to determine an unsigned integral type that is 32 bits wide. An
+ − 37 alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
+ − 38 doing that would require that the configure script compile and *run*
+ − 39 the resulting executable. Locally running cross-compiled executables
+ − 40 is usually not possible. */
+ − 41
+ − 42 #ifdef _LIBC
+ − 43 # include <sys/types.h>
+ − 44 typedef u_int32_t md5_uint32;
+ − 45 #else
+ − 46 # if defined __STDC__ && __STDC__
+ − 47 # define UINT_MAX_32_BITS 4294967295U
+ − 48 # else
+ − 49 # define UINT_MAX_32_BITS 0xFFFFFFFF
+ − 50 # endif
+ − 51
+ − 52 /* If UINT_MAX isn't defined, assume it's a 32-bit type.
+ − 53 This should be valid for all systems GNU cares about because
+ − 54 that doesn't include 16-bit systems, and only modern systems
+ − 55 (that certainly have <limits.h>) have 64+-bit integral types. */
+ − 56
+ − 57 # ifndef UINT_MAX
+ − 58 # define UINT_MAX UINT_MAX_32_BITS
+ − 59 # endif
+ − 60
+ − 61 # if UINT_MAX == UINT_MAX_32_BITS
+ − 62 typedef unsigned int md5_uint32;
+ − 63 # else
+ − 64 # if USHRT_MAX == UINT_MAX_32_BITS
+ − 65 typedef unsigned short md5_uint32;
+ − 66 # else
+ − 67 # if ULONG_MAX == UINT_MAX_32_BITS
+ − 68 typedef unsigned long md5_uint32;
+ − 69 # else
+ − 70 /* The following line is intended to evoke an error.
+ − 71 Using #error is not portable enough. */
+ − 72 "Cannot determine unsigned 32-bit data type."
+ − 73 # endif
+ − 74 # endif
+ − 75 # endif
+ − 76 #endif
+ − 77
+ − 78 #include "lisp.h"
+ − 79 #include "buffer.h"
+ − 80 #include "lstream.h"
+ − 81 # include "file-coding.h"
+ − 82
+ − 83 /* Structure to save state of computation between the single steps. */
+ − 84 struct md5_ctx
+ − 85 {
+ − 86 md5_uint32 A;
+ − 87 md5_uint32 B;
+ − 88 md5_uint32 C;
+ − 89 md5_uint32 D;
+ − 90
+ − 91 md5_uint32 total[2];
+ − 92 md5_uint32 buflen;
+ − 93 char buffer[128];
+ − 94 };
+ − 95
+ − 96 #ifdef WORDS_BIGENDIAN
+ − 97 # define SWAP(n) \
+ − 98 (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
+ − 99 #else
+ − 100 # define SWAP(n) (n)
+ − 101 #endif
+ − 102
+ − 103
+ − 104 /* This array contains the bytes used to pad the buffer to the next
+ − 105 64-byte boundary. (RFC 1321, 3.1: Step 1) */
+ − 106 static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
+ − 107
+ − 108
442
+ − 109 static void md5_process_block (const void *, size_t, struct md5_ctx *);
428
+ − 110
+ − 111
+ − 112 /* Initialize structure containing state of computation.
+ − 113 (RFC 1321, 3.3: Step 3) */
+ − 114 static void
+ − 115 md5_init_ctx (struct md5_ctx *ctx)
+ − 116 {
+ − 117 ctx->A = 0x67452301;
+ − 118 ctx->B = 0xefcdab89;
+ − 119 ctx->C = 0x98badcfe;
+ − 120 ctx->D = 0x10325476;
+ − 121
+ − 122 ctx->total[0] = ctx->total[1] = 0;
+ − 123 ctx->buflen = 0;
+ − 124 }
+ − 125
+ − 126 /* Put result from CTX in first 16 bytes following RESBUF. The result
+ − 127 must be in little endian byte order.
+ − 128
+ − 129 IMPORTANT: On some systems it is required that RESBUF is correctly
+ − 130 aligned for a 32 bits value. */
+ − 131 static void *
442
+ − 132 md5_read_ctx (const struct md5_ctx *ctx, void *resbuf)
428
+ − 133 {
+ − 134 ((md5_uint32 *) resbuf)[0] = SWAP (ctx->A);
+ − 135 ((md5_uint32 *) resbuf)[1] = SWAP (ctx->B);
+ − 136 ((md5_uint32 *) resbuf)[2] = SWAP (ctx->C);
+ − 137 ((md5_uint32 *) resbuf)[3] = SWAP (ctx->D);
+ − 138
+ − 139 return resbuf;
+ − 140 }
+ − 141
+ − 142 /* Process the remaining bytes in the internal buffer and the usual
+ − 143 prolog according to the standard and write the result to RESBUF.
+ − 144
+ − 145 IMPORTANT: On some systems it is required that RESBUF is correctly
+ − 146 aligned for a 32 bits value. */
+ − 147 static void *
+ − 148 md5_finish_ctx (struct md5_ctx *ctx, void *resbuf)
+ − 149 {
+ − 150 /* Take yet unprocessed bytes into account. */
+ − 151 md5_uint32 bytes = ctx->buflen;
+ − 152 size_t pad;
+ − 153
+ − 154 /* Now count remaining bytes. */
+ − 155 ctx->total[0] += bytes;
+ − 156 if (ctx->total[0] < bytes)
+ − 157 ++ctx->total[1];
+ − 158
+ − 159 pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
+ − 160 memcpy (&ctx->buffer[bytes], fillbuf, pad);
+ − 161
+ − 162 /* Put the 64-bit file length in *bits* at the end of the buffer. */
+ − 163 *(md5_uint32 *) &ctx->buffer[bytes + pad] = SWAP (ctx->total[0] << 3);
+ − 164 *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = SWAP ((ctx->total[1] << 3) |
+ − 165 (ctx->total[0] >> 29));
+ − 166
+ − 167 /* Process last bytes. */
+ − 168 md5_process_block (ctx->buffer, bytes + pad + 8, ctx);
+ − 169
+ − 170 return md5_read_ctx (ctx, resbuf);
+ − 171 }
+ − 172
+ − 173 #ifndef emacs /* unused in Emacs */
+ − 174 /* Compute MD5 message digest for bytes read from STREAM. The
+ − 175 resulting message digest number will be written into the 16 bytes
+ − 176 beginning at RESBLOCK. */
+ − 177 int
+ − 178 md5_stream (FILE *stream, void *resblock)
+ − 179 {
+ − 180 /* Important: BLOCKSIZE must be a multiple of 64. */
+ − 181 #define BLOCKSIZE 4096
+ − 182 struct md5_ctx ctx;
+ − 183 char buffer[BLOCKSIZE + 72];
+ − 184 size_t sum;
+ − 185
+ − 186 /* Initialize the computation context. */
+ − 187 md5_init_ctx (&ctx);
+ − 188
+ − 189 /* Iterate over full file contents. */
+ − 190 while (1)
+ − 191 {
+ − 192 /* We read the file in blocks of BLOCKSIZE bytes. One call of the
+ − 193 computation function processes the whole buffer so that with the
+ − 194 next round of the loop another block can be read. */
+ − 195 size_t n;
+ − 196 sum = 0;
+ − 197
+ − 198 /* Read block. Take care for partial reads. */
+ − 199 do
+ − 200 {
771
+ − 201 n = retry_fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
428
+ − 202
+ − 203 sum += n;
+ − 204 }
+ − 205 while (sum < BLOCKSIZE && n != 0);
+ − 206 if (n == 0 && ferror (stream))
+ − 207 return 1;
+ − 208
+ − 209 /* If end of file is reached, end the loop. */
+ − 210 if (n == 0)
+ − 211 break;
+ − 212
+ − 213 /* Process buffer with BLOCKSIZE bytes. Note that
+ − 214 BLOCKSIZE % 64 == 0
+ − 215 */
+ − 216 md5_process_block (buffer, BLOCKSIZE, &ctx);
+ − 217 }
+ − 218
+ − 219 /* Add the last bytes if necessary. */
+ − 220 if (sum > 0)
+ − 221 md5_process_bytes (buffer, sum, &ctx);
+ − 222
+ − 223 /* Construct result in desired memory. */
+ − 224 md5_finish_ctx (&ctx, resblock);
+ − 225 return 0;
+ − 226 }
+ − 227
+ − 228 /* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
+ − 229 result is always in little endian byte order, so that a byte-wise
+ − 230 output yields to the wanted ASCII representation of the message
+ − 231 digest. */
+ − 232 void *
+ − 233 md5_buffer (const char *buffer, size_t len, void *resblock)
+ − 234 {
+ − 235 struct md5_ctx ctx;
+ − 236
+ − 237 /* Initialize the computation context. */
+ − 238 md5_init_ctx (&ctx);
+ − 239
+ − 240 /* Process whole buffer but last len % 64 bytes. */
+ − 241 md5_process_bytes (buffer, len, &ctx);
+ − 242
+ − 243 /* Put result in desired memory area. */
+ − 244 return md5_finish_ctx (&ctx, resblock);
+ − 245 }
+ − 246 #endif /* not emacs */
+ − 247
+ − 248
+ − 249 static void
442
+ − 250 md5_process_bytes (const void *buffer, size_t len, struct md5_ctx *ctx)
428
+ − 251 {
+ − 252 /* When we already have some bits in our internal buffer concatenate
+ − 253 both inputs first. */
+ − 254 if (ctx->buflen != 0)
+ − 255 {
+ − 256 size_t left_over = ctx->buflen;
+ − 257 size_t add = 128 - left_over > len ? len : 128 - left_over;
+ − 258
+ − 259 memcpy (&ctx->buffer[left_over], buffer, add);
+ − 260 ctx->buflen += add;
+ − 261
+ − 262 if (left_over + add > 64)
+ − 263 {
+ − 264 md5_process_block (ctx->buffer, (left_over + add) & ~63, ctx);
+ − 265 /* The regions in the following copy operation cannot overlap. */
+ − 266 memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
+ − 267 (left_over + add) & 63);
+ − 268 ctx->buflen = (left_over + add) & 63;
+ − 269 }
+ − 270
+ − 271 buffer = (const char *) buffer + add;
+ − 272 len -= add;
+ − 273 }
+ − 274
+ − 275 /* Process available complete blocks. */
+ − 276 if (len > 64)
+ − 277 {
+ − 278 md5_process_block (buffer, len & ~63, ctx);
+ − 279 buffer = (const char *) buffer + (len & ~63);
+ − 280 len &= 63;
+ − 281 }
+ − 282
+ − 283 /* Move remaining bytes in internal buffer. */
+ − 284 if (len > 0)
+ − 285 {
+ − 286 memcpy (ctx->buffer, buffer, len);
+ − 287 ctx->buflen = len;
+ − 288 }
+ − 289 }
+ − 290
+ − 291
+ − 292 /* These are the four functions used in the four steps of the MD5 algorithm
+ − 293 and defined in the RFC 1321. The first function is a little bit optimized
+ − 294 (as found in Colin Plumbs public domain implementation). */
+ − 295 /* #define FF(b, c, d) ((b & c) | (~b & d)) */
+ − 296 #define FF(b, c, d) (d ^ (b & (c ^ d)))
+ − 297 #define FG(b, c, d) FF (d, b, c)
+ − 298 #define FH(b, c, d) (b ^ c ^ d)
+ − 299 #define FI(b, c, d) (c ^ (b | ~d))
+ − 300
+ − 301 /* Process LEN bytes of BUFFER, accumulating context into CTX.
+ − 302 It is assumed that LEN % 64 == 0. */
+ − 303
+ − 304 static void
442
+ − 305 md5_process_block (const void *buffer, size_t len, struct md5_ctx *ctx)
428
+ − 306 {
+ − 307 md5_uint32 correct_words[16];
+ − 308 const md5_uint32 *words = (const md5_uint32 *) buffer;
+ − 309 size_t nwords = len / sizeof (md5_uint32);
+ − 310 const md5_uint32 *endp = words + nwords;
+ − 311 md5_uint32 A = ctx->A;
+ − 312 md5_uint32 B = ctx->B;
+ − 313 md5_uint32 C = ctx->C;
+ − 314 md5_uint32 D = ctx->D;
+ − 315
+ − 316 /* First increment the byte count. RFC 1321 specifies the possible
+ − 317 length of the file up to 2^64 bits. Here we only compute the
+ − 318 number of bytes. Do a double word increment. */
+ − 319 ctx->total[0] += len;
+ − 320 if (ctx->total[0] < len)
+ − 321 ++ctx->total[1];
+ − 322
+ − 323 /* Process all bytes in the buffer with 64 bytes in each round of
+ − 324 the loop. */
+ − 325 while (words < endp)
+ − 326 {
+ − 327 md5_uint32 *cwp = correct_words;
+ − 328 md5_uint32 A_save = A;
+ − 329 md5_uint32 B_save = B;
+ − 330 md5_uint32 C_save = C;
+ − 331 md5_uint32 D_save = D;
+ − 332
+ − 333 /* First round: using the given function, the context and a constant
+ − 334 the next context is computed. Because the algorithms processing
+ − 335 unit is a 32-bit word and it is determined to work on words in
+ − 336 little endian byte order we perhaps have to change the byte order
+ − 337 before the computation. To reduce the work for the next steps
+ − 338 we store the swapped words in the array CORRECT_WORDS. */
+ − 339
+ − 340 #define OP(a, b, c, d, s, T) \
+ − 341 do \
+ − 342 { \
+ − 343 a += FF (b, c, d) + (*cwp++ = SWAP (*words)) + T; \
+ − 344 ++words; \
+ − 345 CYCLIC (a, s); \
+ − 346 a += b; \
+ − 347 } \
+ − 348 while (0)
+ − 349
+ − 350 /* It is unfortunate that C does not provide an operator for
+ − 351 cyclic rotation. Hope the C compiler is smart enough. */
+ − 352 #define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
+ − 353
+ − 354 /* Before we start, one word to the strange constants.
+ − 355 They are defined in RFC 1321 as
+ − 356
+ − 357 T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
+ − 358 */
+ − 359
+ − 360 /* Round 1. */
+ − 361 OP (A, B, C, D, 7, 0xd76aa478);
+ − 362 OP (D, A, B, C, 12, 0xe8c7b756);
+ − 363 OP (C, D, A, B, 17, 0x242070db);
+ − 364 OP (B, C, D, A, 22, 0xc1bdceee);
+ − 365 OP (A, B, C, D, 7, 0xf57c0faf);
+ − 366 OP (D, A, B, C, 12, 0x4787c62a);
+ − 367 OP (C, D, A, B, 17, 0xa8304613);
+ − 368 OP (B, C, D, A, 22, 0xfd469501);
+ − 369 OP (A, B, C, D, 7, 0x698098d8);
+ − 370 OP (D, A, B, C, 12, 0x8b44f7af);
+ − 371 OP (C, D, A, B, 17, 0xffff5bb1);
+ − 372 OP (B, C, D, A, 22, 0x895cd7be);
+ − 373 OP (A, B, C, D, 7, 0x6b901122);
+ − 374 OP (D, A, B, C, 12, 0xfd987193);
+ − 375 OP (C, D, A, B, 17, 0xa679438e);
+ − 376 OP (B, C, D, A, 22, 0x49b40821);
+ − 377
+ − 378 /* For the second to fourth round we have the possibly swapped words
+ − 379 in CORRECT_WORDS. Redefine the macro to take an additional first
+ − 380 argument specifying the function to use. */
+ − 381 #undef OP
+ − 382 #define OP(f, a, b, c, d, k, s, T) \
+ − 383 do \
+ − 384 { \
+ − 385 a += f (b, c, d) + correct_words[k] + T; \
+ − 386 CYCLIC (a, s); \
+ − 387 a += b; \
+ − 388 } \
+ − 389 while (0)
+ − 390
+ − 391 /* Round 2. */
+ − 392 OP (FG, A, B, C, D, 1, 5, 0xf61e2562);
+ − 393 OP (FG, D, A, B, C, 6, 9, 0xc040b340);
+ − 394 OP (FG, C, D, A, B, 11, 14, 0x265e5a51);
+ − 395 OP (FG, B, C, D, A, 0, 20, 0xe9b6c7aa);
+ − 396 OP (FG, A, B, C, D, 5, 5, 0xd62f105d);
+ − 397 OP (FG, D, A, B, C, 10, 9, 0x02441453);
+ − 398 OP (FG, C, D, A, B, 15, 14, 0xd8a1e681);
+ − 399 OP (FG, B, C, D, A, 4, 20, 0xe7d3fbc8);
+ − 400 OP (FG, A, B, C, D, 9, 5, 0x21e1cde6);
+ − 401 OP (FG, D, A, B, C, 14, 9, 0xc33707d6);
+ − 402 OP (FG, C, D, A, B, 3, 14, 0xf4d50d87);
+ − 403 OP (FG, B, C, D, A, 8, 20, 0x455a14ed);
+ − 404 OP (FG, A, B, C, D, 13, 5, 0xa9e3e905);
+ − 405 OP (FG, D, A, B, C, 2, 9, 0xfcefa3f8);
+ − 406 OP (FG, C, D, A, B, 7, 14, 0x676f02d9);
+ − 407 OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a);
+ − 408
+ − 409 /* Round 3. */
+ − 410 OP (FH, A, B, C, D, 5, 4, 0xfffa3942);
+ − 411 OP (FH, D, A, B, C, 8, 11, 0x8771f681);
+ − 412 OP (FH, C, D, A, B, 11, 16, 0x6d9d6122);
+ − 413 OP (FH, B, C, D, A, 14, 23, 0xfde5380c);
+ − 414 OP (FH, A, B, C, D, 1, 4, 0xa4beea44);
+ − 415 OP (FH, D, A, B, C, 4, 11, 0x4bdecfa9);
+ − 416 OP (FH, C, D, A, B, 7, 16, 0xf6bb4b60);
+ − 417 OP (FH, B, C, D, A, 10, 23, 0xbebfbc70);
+ − 418 OP (FH, A, B, C, D, 13, 4, 0x289b7ec6);
+ − 419 OP (FH, D, A, B, C, 0, 11, 0xeaa127fa);
+ − 420 OP (FH, C, D, A, B, 3, 16, 0xd4ef3085);
+ − 421 OP (FH, B, C, D, A, 6, 23, 0x04881d05);
+ − 422 OP (FH, A, B, C, D, 9, 4, 0xd9d4d039);
+ − 423 OP (FH, D, A, B, C, 12, 11, 0xe6db99e5);
+ − 424 OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8);
+ − 425 OP (FH, B, C, D, A, 2, 23, 0xc4ac5665);
+ − 426
+ − 427 /* Round 4. */
+ − 428 OP (FI, A, B, C, D, 0, 6, 0xf4292244);
+ − 429 OP (FI, D, A, B, C, 7, 10, 0x432aff97);
+ − 430 OP (FI, C, D, A, B, 14, 15, 0xab9423a7);
+ − 431 OP (FI, B, C, D, A, 5, 21, 0xfc93a039);
+ − 432 OP (FI, A, B, C, D, 12, 6, 0x655b59c3);
+ − 433 OP (FI, D, A, B, C, 3, 10, 0x8f0ccc92);
+ − 434 OP (FI, C, D, A, B, 10, 15, 0xffeff47d);
+ − 435 OP (FI, B, C, D, A, 1, 21, 0x85845dd1);
+ − 436 OP (FI, A, B, C, D, 8, 6, 0x6fa87e4f);
+ − 437 OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
+ − 438 OP (FI, C, D, A, B, 6, 15, 0xa3014314);
+ − 439 OP (FI, B, C, D, A, 13, 21, 0x4e0811a1);
+ − 440 OP (FI, A, B, C, D, 4, 6, 0xf7537e82);
+ − 441 OP (FI, D, A, B, C, 11, 10, 0xbd3af235);
+ − 442 OP (FI, C, D, A, B, 2, 15, 0x2ad7d2bb);
+ − 443 OP (FI, B, C, D, A, 9, 21, 0xeb86d391);
+ − 444
+ − 445 /* Add the starting values of the context. */
+ − 446 A += A_save;
+ − 447 B += B_save;
+ − 448 C += C_save;
+ − 449 D += D_save;
+ − 450 }
+ − 451
+ − 452 /* Put checksum in context given as argument. */
+ − 453 ctx->A = A;
+ − 454 ctx->B = B;
+ − 455 ctx->C = C;
+ − 456 ctx->D = D;
+ − 457 }
+ − 458
+ − 459
+ − 460 #ifdef emacs
+ − 461 /* Find out what format the buffer will be saved in, so we can make
+ − 462 the digest based on what it will look like on disk. */
+ − 463 static Lisp_Object
+ − 464 md5_coding_system (Lisp_Object object, Lisp_Object coding, Lisp_Object istream,
+ − 465 int error_me_not)
+ − 466 {
+ − 467 Lisp_Object coding_system;
+ − 468
+ − 469 if (NILP (coding))
+ − 470 {
+ − 471 if (BUFFERP (object))
771
+ − 472 /* Use the file coding for this buffer by default. */
+ − 473 coding = XBUFFER (object)->buffer_file_coding_system;
428
+ − 474 else
771
+ − 475 /* Attempt to autodetect the coding of the string. This is
+ − 476 VERY hit-and-miss. #### It shouldn't be. */
+ − 477 coding = detect_coding_stream (istream);
+ − 478 }
+ − 479
+ − 480 if (error_me_not)
+ − 481 {
+ − 482 coding_system = find_coding_system_for_text_file (coding, 0);
+ − 483 if (NILP (coding_system))
+ − 484 /* Default to binary. */
428
+ − 485 coding_system = Fget_coding_system (Qbinary);
+ − 486 }
+ − 487 else
771
+ − 488 coding_system = get_coding_system_for_text_file (coding, 0);
+ − 489
428
+ − 490 return coding_system;
+ − 491 }
+ − 492
+ − 493 DEFUN ("md5", Fmd5, 1, 5, 0, /*
+ − 494 Return the MD5 message digest of OBJECT, a buffer or string.
+ − 495
+ − 496 Optional arguments START and END denote positions for computing the
+ − 497 digest of a portion of OBJECT.
+ − 498
+ − 499 The optional CODING argument specifies the coding system the text is to be
+ − 500 represented in while computing the digest. If unspecified, it defaults
+ − 501 to the current format of the data, or is guessed.
+ − 502
+ − 503 If NOERROR is non-nil, silently assume binary coding if the guesswork
+ − 504 fails. Normally, an error is signaled in such case.
+ − 505
+ − 506 CODING and NOERROR arguments are meaningful only in XEmacsen with
+ − 507 file-coding or Mule support. Otherwise, they are ignored.
+ − 508 */
+ − 509 (object, start, end, coding, noerror))
+ − 510 {
+ − 511 /* This function can GC */
+ − 512 /* Can this really GC? How? */
+ − 513 struct md5_ctx ctx;
+ − 514 unsigned char digest[16];
+ − 515 unsigned char thehash[33];
+ − 516 int i;
+ − 517
800
+ − 518 Lisp_Object raw_instream = Qnil, instream = Qnil;
+ − 519 struct gcpro gcpro1, gcpro2;
428
+ − 520
800
+ − 521 GCPRO2 (raw_instream, instream);
428
+ − 522 /* Set up the input stream. */
+ − 523 if (BUFFERP (object))
+ − 524 {
+ − 525 struct buffer *b;
665
+ − 526 Charbpos begv, endv;
428
+ − 527 CHECK_LIVE_BUFFER (object);
+ − 528 b = XBUFFER (object);
+ − 529 /* Figure out where we need to get info from */
+ − 530 get_buffer_range_char (b, start, end, &begv, &endv, GB_ALLOW_NIL);
+ − 531
800
+ − 532 raw_instream = make_lisp_buffer_input_stream (b, begv, endv, 0);
428
+ − 533 }
+ − 534 else
+ − 535 {
+ − 536 Bytecount bstart, bend;
+ − 537 CHECK_STRING (object);
+ − 538 get_string_range_byte (object, start, end, &bstart, &bend,
+ − 539 GB_HISTORICAL_STRING_BEHAVIOR);
800
+ − 540 raw_instream = make_lisp_string_input_stream (object, bstart,
+ − 541 bend - bstart);
428
+ − 542 }
+ − 543
+ − 544 /* Determine the coding and set up the conversion stream. */
800
+ − 545 coding = md5_coding_system (object, coding, raw_instream, !NILP (noerror));
+ − 546 Lstream_rewind (XLSTREAM (raw_instream));
+ − 547 instream = make_coding_input_stream (XLSTREAM (raw_instream), coding,
+ − 548 CODING_ENCODE, 0);
428
+ − 549
+ − 550 /* Initialize MD5 context. */
+ − 551 md5_init_ctx (&ctx);
+ − 552
+ − 553 /* Get the data while doing the conversion. */
+ − 554 while (1)
+ − 555 {
867
+ − 556 Ibyte tempbuf[1024]; /* some random amount */
665
+ − 557 Bytecount size_in_bytes =
428
+ − 558 Lstream_read (XLSTREAM (instream), tempbuf, sizeof (tempbuf));
+ − 559 if (!size_in_bytes)
+ − 560 break;
+ − 561
+ − 562 /* Process the bytes. */
+ − 563 md5_process_bytes (tempbuf, size_in_bytes, &ctx);
+ − 564 }
+ − 565 Lstream_delete (XLSTREAM (instream));
+ − 566 Lstream_delete (XLSTREAM (raw_instream));
+ − 567 UNGCPRO;
+ − 568
+ − 569 md5_finish_ctx (&ctx, digest);
+ − 570 for (i = 0; i < 16; i++)
+ − 571 sprintf ((char *) (thehash + (i * 2)), "%02x", digest[i]);
+ − 572
+ − 573 return make_string (thehash, 32);
+ − 574 }
+ − 575
+ − 576 void
+ − 577 syms_of_md5 (void)
+ − 578 {
+ − 579 DEFSUBR (Fmd5);
+ − 580 }
+ − 581
+ − 582 void
+ − 583 vars_of_md5 (void)
+ − 584 {
+ − 585 Fprovide (intern ("md5"));
+ − 586 }
+ − 587 #endif /* emacs */
