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