source/libs/zziplib/zziplib-0.13.62/bins/zzobfuscated.c

   1 /*
   2  *      Copyright (c) 2002 Mike Nordell
   3  *  portions  Copyright (c) 2000,2001,2002 Guido Draheim <guidod@gmx.de>
   4  *      Use freely under the restrictions of the ZLIB License
   5  *
   6  * A small example that displays how the plugin I/O functions can be used
   7  * to read "encrypted" zip archives.
   8  */
   9
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <sys/stat.h>
  14 #include <zzip/zzip.h>
  15 #include <zzip/plugin.h>
  16
  17 #ifndef O_BINARY
  18 #define O_BINARY 0
  19 #endif
  20
  21 #if defined ZZIP_HAVE_UNISTD_H
  22 #include <unistd.h> /* read */
  23 #elif defined ZZIP_HAVE_IO_H
  24 #include <io.h>     /* win32 */
  25 #else
  26 #endif
  27
  28 #ifdef _MSC_VER
  29 #define _MSC_VER_NULL NULL
  30 #else
  31 #define _MSC_VER_NULL
  32 #endif
  33
  34 /*
  35  * Only override our the read handler. Let the system take care
  36  * the rest.
  37  */
  38
  39 static zzip_ssize_t our_read(int fd, void* buf, zzip_size_t len)
  40 {
  41     const zzip_ssize_t bytes = read(fd, buf, len);
  42     zzip_ssize_t i;
  43     char* pch = (char*)buf;
  44     for (i=0; i<bytes; ++i) {
  45         pch[i] ^= 0x55;
  46     }
  47     return bytes;
  48 }
  49
  50 static zzip_plugin_io_handlers our_handlers = { _MSC_VER_NULL };
  51 static const char* const our_fileext [] = { ".dat", ".sav", 0 };
  52
  53
  54 static const char usage[] =
  55 {
  56     " zzobfuscated <file> [in-zip filename]\n"
  57     "  - Demonstrates the use of installable file I/O handlers.\n"
  58     " Copies <file> to \"obfuscated[.dat]\" while \"encrypting\" it by xor'ing\n"
  59     " every byte with 0x55, installs file I/O handlers, and then uses the\n"
  60     " zzip_open_ext_io function to read and print the file to stdout.\n"
  61     " The file can be a normal file or an inflated part of a zip-archive,\n"
  62     " to get 'README' from test.zip you may write \n"
  63     "    zzobfuscated test.zip README \n"
  64 };
  65
  66 int
  67 main (int argc, char* argv[])
  68 {
  69     if (argc <= 1 || argc > 3 || ! strcmp (argv[1], "--help"))
  70     {
  71         printf (usage);
  72         return 0;
  73     }
  74     if (! strcmp (argv[1], "--version"))
  75     {
  76         printf (__FILE__" version "ZZIP_PACKAGE" "ZZIP_VERSION"\n");
  77         return 0;
  78     }
  79
  80     if (strlen(argv[1]) > 128) {
  81         fprintf(stderr, "Please provide a filename shorter than 128 chars.\n");
  82         exit(1);
  83     }
  84
  85     /* obfuscate the file */
  86     {
  87         int ch;
  88         FILE* fin;
  89         FILE* fout;
  90         fin  = fopen(argv[1], "rb");
  91         if (!fin) {
  92             fprintf(stderr, "Can't open input file \"%s\"\n", argv[1]);
  93             exit(1);
  94         }
  95         fout = fopen((argc == 2) ? "obfuscated" : "obfuscated.dat", "wb");
  96         if (!fout) {
  97             fprintf(stderr, "Can't open output file \"obfuscated\"\n");
  98             exit(1);
  99         }
 100         while ((ch = fgetc(fin)) != EOF) {
 101             ch ^= 0x55;
 102             fputc(ch, fout);
 103         }
 104         fclose(fout);
 105         fclose(fin);
 106     }
 107
 108     /* install our I/O hander */
 109     zzip_init_io(&our_handlers, 0);
 110     our_handlers.fd.read = &our_read;
 111
 112     {
 113 #       define argn 2
 114         ZZIP_FILE* fp;
 115         char name[256];
 116         if (argc == 3) {
 117             sprintf(name, "obfuscated/%s", argv[argn]);
 118         } else {
 119             sprintf(name, "obfuscated");
 120         }
 121         fp = zzip_open_ext_io (name, O_RDONLY|O_BINARY, ZZIP_PREFERZIP,
 122                                our_fileext, &our_handlers);
 123
 124         if (! fp)
 125         {
 126             perror (name);
 127             exit(1);
 128         }else{
 129             char buf[17];
 130             int n;
 131
 132         /* read chunks of 16 bytes into buf and print them to stdout */
 133             while (0 < (n = zzip_read(fp, buf, 16)))
 134             {
 135                 buf[n] = '\0';
 136 #             ifdef STDOUT_FILENO
 137                 write (STDOUT_FILENO, buf, n);
 138 #             else
 139                 fwrite (buf, 1, n, stdout);
 140 #             endif
 141             }
 142
 143             if (n == -1)
 144                 perror (argv[argn]);
 145         }
 146     }
 147
 148     return 0;
 149 }
 150
 151 /*
 152  * Local variables:
 153  * c-file-style: "stroustrup"
 154  * End:
 155  */