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/*
* Copyright (c) 2000,2001,2002 Guido Draheim <guidod@gmx.de>
* Use freely under the restrictions of the ZLIB License
*
* show a simple program to add xor-obfuscation.
* look at the resulting file with zzxordir an zzxorcat
* Remember that xor'ing data twice will result in the original data.
* This file has no dependency with zziplib - it's freestanding.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <zzip/_config.h> /* for ZZIP_VERSION */
#ifndef O_BINARY
#define O_BINARY 0
#endif
#if __STDC_VERSION__+0 < 199901
#define _ssize_t int
#define _size_t unsigned
#else
#define _ssize_t ssize_t
#define _size_t size_t
#endif
static const char usage[] =
{
" zzxopy [-#] <input-file> <output-file> \n"
" copies data from input-file to output-file adding simple \n"
" obfuscation by xor-ing each byte with the numeric value given. \n"
" the default xor-value is 0x55. Remember that copying data twice \n"
" with the same xor-value will result in the original file data. \n"
};
static int xor_value;
static _ssize_t xor_read (FILE* f, void* p, _size_t l)
{
_ssize_t r = fread(p, 1, l, f);
_ssize_t x; char* q; for (x=0, q=p; x < r; x++) q[x] ^= xor_value;
return r;
}
int
main (int argc, char ** argv)
{
int argn;
xor_value = 0x55;
if (argc <= 1 || ! strcmp (argv[1], "--help"))
{
printf (usage);
return 0;
}
if (! strcmp (argv[1], "--version"))
{
printf (__FILE__" version "ZZIP_PACKAGE" "ZZIP_VERSION"\n");
return 0;
}
for (argn=1; argn < argc; argn++)
{
FILE* iF = 0;
FILE* oF = 0;
if (argv[argn][0] == '-')
{
if (isdigit(argv[argn][1])) xor_value = atoi (argv[argn]+1);
continue;
}
if (argn + 1 >= argc)
{
printf (usage);
exit (1);
}
iF = fopen (argv[argn], "rb");
if (! iF) { perror (argv[argn]); exit (2); }
argn++;
oF = fopen (argv[argn], "wb");
if (! oF) { perror (argv[argn]); fclose(iF); exit (3); }
{
char buf[17];
_ssize_t n;
/* read chunks of 16 bytes into buf and print them to stdout */
while (0 < (n = xor_read(iF, buf, 16)))
{
buf[n] = '\0';
n = fwrite (buf, 1, n, oF);
if (n < 0) break;
}
if (n < 0 && ferror (iF))
perror (argv[argn]);
}
}
return 0;
}
/*
* Local variables:
* c-file-style: "stroustrup"
* End:
*/
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