src/md5sum.c

   1 /* Compute checksums of files or strings.
   2    Copyright (C) 1995-2012 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>.  */
  18
  19 #include <config.h>
  20
  21 #include <getopt.h>
  22 #include <sys/types.h>
  23
  24 #include "system.h"
  25
  26 #if HASH_ALGO_MD5
  27 # include "md5.h"
  28 #endif
  29 #if HASH_ALGO_SHA1
  30 # include "sha1.h"
  31 #endif
  32 #if HASH_ALGO_SHA256 || HASH_ALGO_SHA224
  33 # include "sha256.h"
  34 #endif
  35 #if HASH_ALGO_SHA512 || HASH_ALGO_SHA384
  36 # include "sha512.h"
  37 #endif
  38 #include "error.h"
  39 #include "fadvise.h"
  40 #include "stdio--.h"
  41 #include "xfreopen.h"
  42
  43 /* The official name of this program (e.g., no 'g' prefix).  */
  44 #if HASH_ALGO_MD5
  45 # define PROGRAM_NAME "md5sum"
  46 # define DIGEST_TYPE_STRING "MD5"
  47 # define DIGEST_STREAM md5_stream
  48 # define DIGEST_BITS 128
  49 # define DIGEST_REFERENCE "RFC 1321"
  50 # define DIGEST_ALIGN 4
  51 #elif HASH_ALGO_SHA1
  52 # define PROGRAM_NAME "sha1sum"
  53 # define DIGEST_TYPE_STRING "SHA1"
  54 # define DIGEST_STREAM sha1_stream
  55 # define DIGEST_BITS 160
  56 # define DIGEST_REFERENCE "FIPS-180-1"
  57 # define DIGEST_ALIGN 4
  58 #elif HASH_ALGO_SHA256
  59 # define PROGRAM_NAME "sha256sum"
  60 # define DIGEST_TYPE_STRING "SHA256"
  61 # define DIGEST_STREAM sha256_stream
  62 # define DIGEST_BITS 256
  63 # define DIGEST_REFERENCE "FIPS-180-2"
  64 # define DIGEST_ALIGN 4
  65 #elif HASH_ALGO_SHA224
  66 # define PROGRAM_NAME "sha224sum"
  67 # define DIGEST_TYPE_STRING "SHA224"
  68 # define DIGEST_STREAM sha224_stream
  69 # define DIGEST_BITS 224
  70 # define DIGEST_REFERENCE "RFC 3874"
  71 # define DIGEST_ALIGN 4
  72 #elif HASH_ALGO_SHA512
  73 # define PROGRAM_NAME "sha512sum"
  74 # define DIGEST_TYPE_STRING "SHA512"
  75 # define DIGEST_STREAM sha512_stream
  76 # define DIGEST_BITS 512
  77 # define DIGEST_REFERENCE "FIPS-180-2"
  78 # define DIGEST_ALIGN 8
  79 #elif HASH_ALGO_SHA384
  80 # define PROGRAM_NAME "sha384sum"
  81 # define DIGEST_TYPE_STRING "SHA384"
  82 # define DIGEST_STREAM sha384_stream
  83 # define DIGEST_BITS 384
  84 # define DIGEST_REFERENCE "FIPS-180-2"
  85 # define DIGEST_ALIGN 8
  86 #else
  87 # error "Can't decide which hash algorithm to compile."
  88 #endif
  89
  90 #define DIGEST_HEX_BYTES (DIGEST_BITS / 4)
  91 #define DIGEST_BIN_BYTES (DIGEST_BITS / 8)
  92
  93 #define AUTHORS \
  94   proper_name ("Ulrich Drepper"), \
  95   proper_name ("Scott Miller"), \
  96   proper_name ("David Madore")
  97
  98 /* The minimum length of a valid digest line.  This length does
  99    not include any newline character at the end of a line.  */
 100 #define MIN_DIGEST_LINE_LENGTH \
 101   (DIGEST_HEX_BYTES /* length of hexadecimal message digest */ \
 102    + 1 /* blank */ \
 103    + 1 /* minimum filename length */ )
 104
 105 /* True if any of the files read were the standard input. */
 106 static bool have_read_stdin;
 107
 108 /* The minimum length of a valid checksum line for the selected algorithm.  */
 109 static size_t min_digest_line_length;
 110
 111 /* Set to the length of a digest hex string for the selected algorithm.  */
 112 static size_t digest_hex_bytes;
 113
 114 /* With --check, don't generate any output.
 115    The exit code indicates success or failure.  */
 116 static bool status_only = false;
 117
 118 /* With --check, print a message to standard error warning about each
 119    improperly formatted checksum line.  */
 120 static bool warn = false;
 121
 122 /* With --check, suppress the "OK" printed for each verified file.  */
 123 static bool quiet = false;
 124
 125 /* With --check, exit with a non-zero return code if any line is
 126    improperly formatted. */
 127 static bool strict = false;
 128
 129 /* Whether a BSD reversed format checksum is detected.  */
 130 static int bsd_reversed = -1;
 131
 132 /* For long options that have no equivalent short option, use a
 133    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
 134 enum
 135 {
 136   STATUS_OPTION = CHAR_MAX + 1,
 137   QUIET_OPTION,
 138   STRICT_OPTION
 139 };
 140
 141 static struct option const long_options[] =
 142 {
 143   { "binary", no_argument, NULL, 'b' },
 144   { "check", no_argument, NULL, 'c' },
 145   { "quiet", no_argument, NULL, QUIET_OPTION },
 146   { "status", no_argument, NULL, STATUS_OPTION },
 147   { "text", no_argument, NULL, 't' },
 148   { "warn", no_argument, NULL, 'w' },
 149   { "strict", no_argument, NULL, STRICT_OPTION },
 150   { GETOPT_HELP_OPTION_DECL },
 151   { GETOPT_VERSION_OPTION_DECL },
 152   { NULL, 0, NULL, 0 }
 153 };
 154
 155 void
 156 usage (int status)
 157 {
 158   if (status != EXIT_SUCCESS)
 159     emit_try_help ();
 160   else
 161     {
 162       printf (_("\
 163 Usage: %s [OPTION]... [FILE]...\n\
 164 Print or check %s (%d-bit) checksums.\n\
 165 With no FILE, or when FILE is -, read standard input.\n\
 166 \n\
 167 "),
 168               program_name,
 169               DIGEST_TYPE_STRING,
 170               DIGEST_BITS);
 171       if (O_BINARY)
 172         fputs (_("\
 173   -b, --binary         read in binary mode (default unless reading tty stdin)\n\
 174 "), stdout);
 175       else
 176         fputs (_("\
 177   -b, --binary         read in binary mode\n\
 178 "), stdout);
 179       printf (_("\
 180   -c, --check          read %s sums from the FILEs and check them\n"),
 181               DIGEST_TYPE_STRING);
 182       if (O_BINARY)
 183         fputs (_("\
 184   -t, --text           read in text mode (default if reading tty stdin)\n\
 185 "), stdout);
 186       else
 187         fputs (_("\
 188   -t, --text           read in text mode (default)\n\
 189 "), stdout);
 190       fputs (_("\
 191 \n\
 192 The following three options are useful only when verifying checksums:\n\
 193       --quiet          don't print OK for each successfully verified file\n\
 194       --status         don't output anything, status code shows success\n\
 195   -w, --warn           warn about improperly formatted checksum lines\n\
 196 \n\
 197 "), stdout);
 198       fputs (_("\
 199       --strict         with --check, exit non-zero for any invalid input\n\
 200 "), stdout);
 201       fputs (HELP_OPTION_DESCRIPTION, stdout);
 202       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 203       printf (_("\
 204 \n\
 205 The sums are computed as described in %s.  When checking, the input\n\
 206 should be a former output of this program.  The default mode is to print\n\
 207 a line with checksum, a character indicating input mode ('*' for binary,\n\
 208 space for text), and name for each FILE.\n"),
 209               DIGEST_REFERENCE);
 210       emit_ancillary_info ();
 211     }
 212
 213   exit (status);
 214 }
 215
 216 #define ISWHITE(c) ((c) == ' ' || (c) == '\t')
 217
 218 /* Split the checksum string S (of length S_LEN) from a BSD 'md5' or
 219    'sha1' command into two parts: a hexadecimal digest, and the file
 220    name.  S is modified.  Return true if successful.  */
 221
 222 static bool
 223 bsd_split_3 (char *s, size_t s_len, unsigned char **hex_digest,
 224              char **file_name)
 225 {
 226   size_t i;
 227
 228   if (s_len == 0)
 229     return false;
 230
 231   *file_name = s;
 232
 233   /* Find end of filename. The BSD 'md5' and 'sha1' commands do not escape
 234      filenames, so search backwards for the last ')'. */
 235   i = s_len - 1;
 236   while (i && s[i] != ')')
 237     i--;
 238
 239   if (s[i] != ')')
 240     return false;
 241
 242   s[i++] = '\0';
 243
 244   while (ISWHITE (s[i]))
 245     i++;
 246
 247   if (s[i] != '=')
 248     return false;
 249
 250   i++;
 251
 252   while (ISWHITE (s[i]))
 253     i++;
 254
 255   *hex_digest = (unsigned char *) &s[i];
 256   return true;
 257 }
 258
 259 /* Split the string S (of length S_LEN) into three parts:
 260    a hexadecimal digest, binary flag, and the file name.
 261    S is modified.  Return true if successful.  */
 262
 263 static bool
 264 split_3 (char *s, size_t s_len,
 265          unsigned char **hex_digest, int *binary, char **file_name)
 266 {
 267   bool escaped_filename = false;
 268   size_t algo_name_len;
 269
 270   size_t i = 0;
 271   while (ISWHITE (s[i]))
 272     ++i;
 273
 274   /* Check for BSD-style checksum line. */
 275   algo_name_len = strlen (DIGEST_TYPE_STRING);
 276   if (STREQ_LEN (s + i, DIGEST_TYPE_STRING, algo_name_len))
 277     {
 278       if (s[i + algo_name_len] == ' ')
 279         ++i;
 280       if (s[i + algo_name_len] == '(')
 281         {
 282           *binary = 0;
 283           return bsd_split_3 (s +      i + algo_name_len + 1,
 284                               s_len - (i + algo_name_len + 1),
 285                               hex_digest, file_name);
 286         }
 287     }
 288
 289   /* Ignore this line if it is too short.
 290      Each line must have at least 'min_digest_line_length - 1' (or one more, if
 291      the first is a backslash) more characters to contain correct message digest
 292      information.  */
 293   if (s_len - i < min_digest_line_length + (s[i] == '\\'))
 294     return false;
 295
 296   if (s[i] == '\\')
 297     {
 298       ++i;
 299       escaped_filename = true;
 300     }
 301   *hex_digest = (unsigned char *) &s[i];
 302
 303   /* The first field has to be the n-character hexadecimal
 304      representation of the message digest.  If it is not followed
 305      immediately by a white space it's an error.  */
 306   i += digest_hex_bytes;
 307   if (!ISWHITE (s[i]))
 308     return false;
 309
 310   s[i++] = '\0';
 311
 312   /* If "bsd reversed" format detected.  */
 313   if ((s_len - i == 1) || (s[i] != ' ' && s[i] != '*'))
 314     {
 315       /* Don't allow mixing bsd and standard formats,
 316          to minimize security issues with attackers
 317          renaming files with leading spaces.
 318          This assumes that with bsd format checksums
 319          that the first file name does not have
 320          a leading ' ' or '*'.  */
 321       if (bsd_reversed == 0)
 322         return false;
 323       bsd_reversed = 1;
 324     }
 325   else if (bsd_reversed != 1)
 326     {
 327       bsd_reversed = 0;
 328       *binary = (s[i++] == '*');
 329     }
 330
 331   /* All characters between the type indicator and end of line are
 332      significant -- that includes leading and trailing white space.  */
 333   *file_name = &s[i];
 334
 335   if (escaped_filename)
 336     {
 337       /* Translate each '\n' string in the file name to a NEWLINE,
 338          and each '\\' string to a backslash.  */
 339
 340       char *dst = &s[i];
 341
 342       while (i < s_len)
 343         {
 344           switch (s[i])
 345             {
 346             case '\\':
 347               if (i == s_len - 1)
 348                 {
 349                   /* A valid line does not end with a backslash.  */
 350                   return false;
 351                 }
 352               ++i;
 353               switch (s[i++])
 354                 {
 355                 case 'n':
 356                   *dst++ = '\n';
 357                   break;
 358                 case '\\':
 359                   *dst++ = '\\';
 360                   break;
 361                 default:
 362                   /* Only '\' or 'n' may follow a backslash.  */
 363                   return false;
 364                 }
 365               break;
 366
 367             case '\0':
 368               /* The file name may not contain a NUL.  */
 369               return false;
 370               break;
 371
 372             default:
 373               *dst++ = s[i++];
 374               break;
 375             }
 376         }
 377       *dst = '\0';
 378     }
 379   return true;
 380 }
 381
 382 /* Return true if S is a NUL-terminated string of DIGEST_HEX_BYTES hex digits.
 383    Otherwise, return false.  */
 384 static bool _GL_ATTRIBUTE_PURE
 385 hex_digits (unsigned char const *s)
 386 {
 387   unsigned int i;
 388   for (i = 0; i < digest_hex_bytes; i++)
 389     {
 390       if (!isxdigit (*s))
 391         return false;
 392       ++s;
 393     }
 394   return *s == '\0';
 395 }
 396
 397 /* An interface to the function, DIGEST_STREAM.
 398    Operate on FILENAME (it may be "-").
 399
 400    *BINARY indicates whether the file is binary.  BINARY < 0 means it
 401    depends on whether binary mode makes any difference and the file is
 402    a terminal; in that case, clear *BINARY if the file was treated as
 403    text because it was a terminal.
 404
 405    Put the checksum in *BIN_RESULT, which must be properly aligned.
 406    Return true if successful.  */
 407
 408 static bool
 409 digest_file (const char *filename, int *binary, unsigned char *bin_result)
 410 {
 411   FILE *fp;
 412   int err;
 413   bool is_stdin = STREQ (filename, "-");
 414
 415   if (is_stdin)
 416     {
 417       have_read_stdin = true;
 418       fp = stdin;
 419       if (O_BINARY && *binary)
 420         {
 421           if (*binary < 0)
 422             *binary = ! isatty (STDIN_FILENO);
 423           if (*binary)
 424             xfreopen (NULL, "rb", stdin);
 425         }
 426     }
 427   else
 428     {
 429       fp = fopen (filename, (O_BINARY && *binary ? "rb" : "r"));
 430       if (fp == NULL)
 431         {
 432           error (0, errno, "%s", filename);
 433           return false;
 434         }
 435     }
 436
 437   fadvise (fp, FADVISE_SEQUENTIAL);
 438
 439   err = DIGEST_STREAM (fp, bin_result);
 440   if (err)
 441     {
 442       error (0, errno, "%s", filename);
 443       if (fp != stdin)
 444         fclose (fp);
 445       return false;
 446     }
 447
 448   if (!is_stdin && fclose (fp) != 0)
 449     {
 450       error (0, errno, "%s", filename);
 451       return false;
 452     }
 453
 454   return true;
 455 }
 456
 457 static bool
 458 digest_check (const char *checkfile_name)
 459 {
 460   FILE *checkfile_stream;
 461   uintmax_t n_misformatted_lines = 0;
 462   uintmax_t n_properly_formatted_lines = 0;
 463   uintmax_t n_improperly_formatted_lines = 0;
 464   uintmax_t n_mismatched_checksums = 0;
 465   uintmax_t n_open_or_read_failures = 0;
 466   unsigned char bin_buffer_unaligned[DIGEST_BIN_BYTES + DIGEST_ALIGN];
 467   /* Make sure bin_buffer is properly aligned. */
 468   unsigned char *bin_buffer = ptr_align (bin_buffer_unaligned, DIGEST_ALIGN);
 469   uintmax_t line_number;
 470   char *line;
 471   size_t line_chars_allocated;
 472   bool is_stdin = STREQ (checkfile_name, "-");
 473
 474   if (is_stdin)
 475     {
 476       have_read_stdin = true;
 477       checkfile_name = _("standard input");
 478       checkfile_stream = stdin;
 479     }
 480   else
 481     {
 482       checkfile_stream = fopen (checkfile_name, "r");
 483       if (checkfile_stream == NULL)
 484         {
 485           error (0, errno, "%s", checkfile_name);
 486           return false;
 487         }
 488     }
 489
 490   line_number = 0;
 491   line = NULL;
 492   line_chars_allocated = 0;
 493   do
 494     {
 495       char *filename IF_LINT ( = NULL);
 496       int binary;
 497       unsigned char *hex_digest IF_LINT ( = NULL);
 498       ssize_t line_length;
 499
 500       ++line_number;
 501       if (line_number == 0)
 502         error (EXIT_FAILURE, 0, _("%s: too many checksum lines"),
 503                checkfile_name);
 504
 505       line_length = getline (&line, &line_chars_allocated, checkfile_stream);
 506       if (line_length <= 0)
 507         break;
 508
 509       /* Ignore comment lines, which begin with a '#' character.  */
 510       if (line[0] == '#')
 511         continue;
 512
 513       /* Remove any trailing newline.  */
 514       if (line[line_length - 1] == '\n')
 515         line[--line_length] = '\0';
 516
 517       if (! (split_3 (line, line_length, &hex_digest, &binary, &filename)
 518              && ! (is_stdin && STREQ (filename, "-"))
 519              && hex_digits (hex_digest)))
 520         {
 521           ++n_misformatted_lines;
 522
 523           if (warn)
 524             {
 525               error (0, 0,
 526                      _("%s: %" PRIuMAX
 527                        ": improperly formatted %s checksum line"),
 528                      checkfile_name, line_number,
 529                      DIGEST_TYPE_STRING);
 530             }
 531
 532           ++n_improperly_formatted_lines;
 533         }
 534       else
 535         {
 536           static const char bin2hex[] = { '0', '1', '2', '3',
 537                                           '4', '5', '6', '7',
 538                                           '8', '9', 'a', 'b',
 539                                           'c', 'd', 'e', 'f' };
 540           bool ok;
 541
 542           ++n_properly_formatted_lines;
 543
 544           ok = digest_file (filename, &binary, bin_buffer);
 545
 546           if (!ok)
 547             {
 548               ++n_open_or_read_failures;
 549               if (!status_only)
 550                 {
 551                   printf (_("%s: FAILED open or read\n"), filename);
 552                 }
 553             }
 554           else
 555             {
 556               size_t digest_bin_bytes = digest_hex_bytes / 2;
 557               size_t cnt;
 558               /* Compare generated binary number with text representation
 559                  in check file.  Ignore case of hex digits.  */
 560               for (cnt = 0; cnt < digest_bin_bytes; ++cnt)
 561                 {
 562                   if (tolower (hex_digest[2 * cnt])
 563                       != bin2hex[bin_buffer[cnt] >> 4]
 564                       || (tolower (hex_digest[2 * cnt + 1])
 565                           != (bin2hex[bin_buffer[cnt] & 0xf])))
 566                     break;
 567                 }
 568               if (cnt != digest_bin_bytes)
 569                 ++n_mismatched_checksums;
 570
 571               if (!status_only)
 572                 {
 573                   if (cnt != digest_bin_bytes)
 574                     printf ("%s: %s\n", filename, _("FAILED"));
 575                   else if (!quiet)
 576                     printf ("%s: %s\n", filename, _("OK"));
 577                 }
 578             }
 579         }
 580     }
 581   while (!feof (checkfile_stream) && !ferror (checkfile_stream));
 582
 583   free (line);
 584
 585   if (ferror (checkfile_stream))
 586     {
 587       error (0, 0, _("%s: read error"), checkfile_name);
 588       return false;
 589     }
 590
 591   if (!is_stdin && fclose (checkfile_stream) != 0)
 592     {
 593       error (0, errno, "%s", checkfile_name);
 594       return false;
 595     }
 596
 597   if (n_properly_formatted_lines == 0)
 598     {
 599       /* Warn if no tests are found.  */
 600       error (0, 0, _("%s: no properly formatted %s checksum lines found"),
 601              checkfile_name, DIGEST_TYPE_STRING);
 602     }
 603   else
 604     {
 605       if (!status_only)
 606         {
 607           if (n_misformatted_lines != 0)
 608             error (0, 0,
 609                    (ngettext
 610                     ("WARNING: %" PRIuMAX " line is improperly formatted",
 611                      "WARNING: %" PRIuMAX " lines are improperly formatted",
 612                      select_plural (n_misformatted_lines))),
 613                    n_misformatted_lines);
 614
 615           if (n_open_or_read_failures != 0)
 616             error (0, 0,
 617                    (ngettext
 618                     ("WARNING: %" PRIuMAX " listed file could not be read",
 619                      "WARNING: %" PRIuMAX " listed files could not be read",
 620                      select_plural (n_open_or_read_failures))),
 621                    n_open_or_read_failures);
 622
 623           if (n_mismatched_checksums != 0)
 624             error (0, 0,
 625                    (ngettext
 626                     ("WARNING: %" PRIuMAX " computed checksum did NOT match",
 627                      "WARNING: %" PRIuMAX " computed checksums did NOT match",
 628                      select_plural (n_mismatched_checksums))),
 629                    n_mismatched_checksums);
 630         }
 631     }
 632
 633   return (n_properly_formatted_lines != 0
 634           && n_mismatched_checksums == 0
 635           && n_open_or_read_failures == 0
 636           && (!strict || n_improperly_formatted_lines == 0));
 637 }
 638
 639 int
 640 main (int argc, char **argv)
 641 {
 642   unsigned char bin_buffer_unaligned[DIGEST_BIN_BYTES + DIGEST_ALIGN];
 643   /* Make sure bin_buffer is properly aligned. */
 644   unsigned char *bin_buffer = ptr_align (bin_buffer_unaligned, DIGEST_ALIGN);
 645   bool do_check = false;
 646   int opt;
 647   bool ok = true;
 648   int binary = -1;
 649
 650   /* Setting values of global variables.  */
 651   initialize_main (&argc, &argv);
 652   set_program_name (argv[0]);
 653   setlocale (LC_ALL, "");
 654   bindtextdomain (PACKAGE, LOCALEDIR);
 655   textdomain (PACKAGE);
 656
 657   atexit (close_stdout);
 658
 659   /* Line buffer stdout to ensure lines are written atomically and immediately
 660      so that processes running in parallel do not intersperse their output.  */
 661   setvbuf (stdout, NULL, _IOLBF, 0);
 662
 663   while ((opt = getopt_long (argc, argv, "bctw", long_options, NULL)) != -1)
 664     switch (opt)
 665       {
 666       case 'b':
 667         binary = 1;
 668         break;
 669       case 'c':
 670         do_check = true;
 671         break;
 672       case STATUS_OPTION:
 673         status_only = true;
 674         warn = false;
 675         quiet = false;
 676         break;
 677       case 't':
 678         binary = 0;
 679         break;
 680       case 'w':
 681         status_only = false;
 682         warn = true;
 683         quiet = false;
 684         break;
 685       case QUIET_OPTION:
 686         status_only = false;
 687         warn = false;
 688         quiet = true;
 689         break;
 690       case STRICT_OPTION:
 691         strict = true;
 692         break;
 693       case_GETOPT_HELP_CHAR;
 694       case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 695       default:
 696         usage (EXIT_FAILURE);
 697       }
 698
 699   min_digest_line_length = MIN_DIGEST_LINE_LENGTH;
 700   digest_hex_bytes = DIGEST_HEX_BYTES;
 701
 702   if (0 <= binary && do_check)
 703     {
 704       error (0, 0, _("the --binary and --text options are meaningless when "
 705                      "verifying checksums"));
 706       usage (EXIT_FAILURE);
 707     }
 708
 709   if (status_only && !do_check)
 710     {
 711       error (0, 0,
 712        _("the --status option is meaningful only when verifying checksums"));
 713       usage (EXIT_FAILURE);
 714     }
 715
 716   if (warn && !do_check)
 717     {
 718       error (0, 0,
 719        _("the --warn option is meaningful only when verifying checksums"));
 720       usage (EXIT_FAILURE);
 721     }
 722
 723   if (quiet && !do_check)
 724     {
 725       error (0, 0,
 726        _("the --quiet option is meaningful only when verifying checksums"));
 727       usage (EXIT_FAILURE);
 728     }
 729
 730   if (strict & !do_check)
 731    {
 732      error (0, 0,
 733         _("the --strict option is meaningful only when verifying checksums"));
 734      usage (EXIT_FAILURE);
 735    }
 736
 737   if (!O_BINARY && binary < 0)
 738     binary = 0;
 739
 740   if (optind == argc)
 741     argv[argc++] = bad_cast ("-");
 742
 743   for (; optind < argc; ++optind)
 744     {
 745       char *file = argv[optind];
 746
 747       if (do_check)
 748         ok &= digest_check (file);
 749       else
 750         {
 751           int file_is_binary = binary;
 752
 753           if (! digest_file (file, &file_is_binary, bin_buffer))
 754             ok = false;
 755           else
 756             {
 757               size_t i;
 758
 759               /* Output a leading backslash if the file name contains
 760                  a newline or backslash.  */
 761               if (strchr (file, '\n') || strchr (file, '\\'))
 762                 putchar ('\\');
 763
 764               for (i = 0; i < (digest_hex_bytes / 2); ++i)
 765                 printf ("%02x", bin_buffer[i]);
 766
 767               putchar (' ');
 768               if (file_is_binary)
 769                 putchar ('*');
 770               else
 771                 putchar (' ');
 772
 773               /* Translate each NEWLINE byte to the string, "\\n",
 774                  and each backslash to "\\\\".  */
 775               for (i = 0; i < strlen (file); ++i)
 776                 {
 777                   switch (file[i])
 778                     {
 779                     case '\n':
 780                       fputs ("\\n", stdout);
 781                       break;
 782
 783                     case '\\':
 784                       fputs ("\\\\", stdout);
 785                       break;
 786
 787                     default:
 788                       putchar (file[i]);
 789                       break;
 790                     }
 791                 }
 792               putchar ('\n');
 793             }
 794         }
 795     }
 796
 797   if (have_read_stdin && fclose (stdin) == EOF)
 798     error (EXIT_FAILURE, errno, _("standard input"));
 799
 800   exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 801 }