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 
18 static int
read_one_file(FILE * ip,const char * name)19 read_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 
main(int argc,char ** argv)64 int 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 }
103