1/* checksum-icc.c
  2 *
  3 * Copyright (c) 2013 John Cunningham Bowler
  4 *
  5 * Last changed in libpng 1.6.0 [February 14, 2013]
  6 *
  7 * This code is released under the libpng license.
  8 * For conditions of distribution and use, see the disclaimer
  9 * and license in png.h
 10 *
 11 * Generate crc32 and adler32 checksums of the given input files, used to
 12 * generate check-codes for use when matching ICC profiles within libpng.
 13 */
 14#include <stdio.h>
 15
 16#include <zlib.h>
 17
 18static int
 19read_one_file(FILE *ip, const char *name)
 20{
 21   uLong length = 0;
 22   uLong a32 = adler32(0, NULL, 0);
 23   uLong c32 = crc32(0, NULL, 0);
 24   Byte header[132];
 25
 26   for (;;)
 27   {
 28      int ch = getc(ip);
 29      Byte b;
 30
 31      if (ch == EOF) break;
 32
 33      b = (Byte)ch;
 34
 35      if (length < sizeof header)
 36         header[length] = b;
 37
 38      ++length;
 39      a32 = adler32(a32, &b, 1);
 40      c32 = crc32(c32, &b, 1);
 41   }
 42
 43   if (ferror(ip))
 44      return 0;
 45
 46   /* Success */
 47   printf("PNG_ICC_CHECKSUM(0x%8.8lx, 0x%8.8lx,\n   PNG_MD5("
 48      "0x%2.2x%2.2x%2.2x%2.2x, 0x%2.2x%2.2x%2.2x%2.2x, 0x%2.2x%2.2x%2.2x%2.2x,"
 49      " 0x%2.2x%2.2x%2.2x%2.2x), %d,\n"
 50      "   \"%4.4d/%2.2d/%2.2d %2.2d:%2.2d:%2.2d\", %lu, \"%s\")\n",
 51      (unsigned long)a32, (unsigned long)c32,
 52      header[84], header[85], header[86], header[87],
 53      header[88], header[89], header[90], header[91],
 54      header[92], header[93], header[94], header[95],
 55      header[96], header[97], header[98], header[99],
 56#     define u16(x) (header[x] * 256 + header[x+1])
 57#     define u32(x) (u16(x) * 65536 + u16(x+2))
 58      u32(64), u16(24), u16(26), u16(28), u16(30), u16(32), u16(34),
 59      (unsigned long)length, name);
 60
 61   return 1;
 62}
 63
 64int main(int argc, char **argv)
 65{
 66   int err = 0;
 67
 68   printf("/* adler32, crc32, MD5[16], intent, date, length, file-name */\n");
 69
 70   if (argc > 1)
 71   {
 72      int i;
 73
 74      for (i=1; i<argc; ++i)
 75      {
 76         FILE *ip = fopen(argv[i], "rb");
 77
 78         if (ip == NULL || !read_one_file(ip, argv[i]))
 79         {
 80            err = 1;
 81            perror(argv[i]);
 82            fprintf(stderr, "%s: read error\n", argv[i]);
 83            printf("/* ERROR: %s */\n", argv[i]);
 84         }
 85
 86         (void)fclose(ip);
 87      }
 88   }
 89
 90   else
 91   {
 92      if (!read_one_file(stdin, "-"))
 93      {
 94         err = 1;
 95         perror("stdin");
 96         fprintf(stderr, "stdin: read error\n");
 97         printf("/* ERROR: stdin */\n");
 98      }
 99   }
100
101   return err;
102}