You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
136 lines
2.8 KiB
136 lines
2.8 KiB
![]()
14 years ago
|
/*
|
||
|
* xorimage.c - partially based on OpenWrt's addpattern.c
|
||
|
*
|
||
|
* This program is free software; you can redistribute it and/or modify
|
||
|
* it under the terms of the GNU General Public License as published by
|
||
|
* the Free Software Foundation; either version 2 of the License, or
|
||
|
* (at your option) any later version.
|
||
|
*
|
||
|
* This program is distributed in the hope that it will be useful,
|
||
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||
|
* General Public License for more details.
|
||
|
*
|
||
|
* You should have received a copy of the GNU General Public License
|
||
|
* along with this program; if not, write to the Free Software
|
||
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
||
|
*/
|
||
|
|
||
|
|
||
|
#include <stdio.h>
|
||
|
#include <stdlib.h>
|
||
|
#include <string.h>
|
||
|
#include <stdint.h>
|
||
|
#include <time.h>
|
||
|
#include <unistd.h>
|
||
|
#include <sys/stat.h>
|
||
|
|
||
|
static char default_pattern[] = "12345678";
|
||
|
|
||
|
|
||
|
int xor_data(uint8_t *data, size_t len, const uint8_t *pattern, int p_len, int p_off)
|
||
|
{
|
||
|
int offset = p_off;
|
||
|
while (len--) {
|
||
|
*data ^= pattern[offset];
|
||
|
data++;
|
||
|
offset = (offset + 1) % p_len;
|
||
|
}
|
||
|
return offset;
|
||
|
}
|
||
|
|
||
|
|
||
|
void usage(void) __attribute__ (( __noreturn__ ));
|
||
|
|
||
|
void usage(void)
|
||
|
{
|
||
|
fprintf(stderr, "Usage: xorimage [-i infile] [-o outfile] [-p <pattern>]\n");
|
||
|
exit(EXIT_FAILURE);
|
||
|
}
|
||
|
|
||
|
|
||
|
int main(int argc, char **argv)
|
||
|
{
|
||
|
char buf[1024]; /* keep this at 1k or adjust garbage calc below */
|
||
|
FILE *in = stdin;
|
||
|
FILE *out = stdout;
|
||
|
char *ifn = NULL;
|
||
|
char *ofn = NULL;
|
||
|
const char *pattern = default_pattern;
|
||
|
int c;
|
||
|
int v0, v1, v2;
|
||
|
size_t n;
|
||
|
int p_len, p_off = 0;
|
||
|
|
||
|
while ((c = getopt(argc, argv, "i:o:p:h")) != -1) {
|
||
|
switch (c) {
|
||
|
case 'i':
|
||
|
ifn = optarg;
|
||
|
break;
|
||
|
case 'o':
|
||
|
ofn = optarg;
|
||
|
break;
|
||
|
case 'p':
|
||
|
pattern = optarg;
|
||
|
break;
|
||
|
case 'h':
|
||
|
default:
|
||
|
usage();
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (optind != argc || optind == 1) {
|
||
|
fprintf(stderr, "illegal arg \"%s\"\n", argv[optind]);
|
||
|
usage();
|
||
|
}
|
||
|
|
||
|
if (ifn && !(in = fopen(ifn, "r"))) {
|
||
|
fprintf(stderr, "can not open \"%s\" for reading\n", ifn);
|
||
|
usage();
|
||
|
}
|
||
|
|
||
|
if (ofn && !(out = fopen(ofn, "w"))) {
|
||
|
fprintf(stderr, "can not open \"%s\" for writing\n", ofn);
|
||
|
usage();
|
||
|
}
|
||
|
|
||
|
p_len = strlen(pattern);
|
||
|
|
||
|
if (p_len == 0) {
|
||
|
fprintf(stderr, "pattern cannot be empty\n");
|
||
|
usage();
|
||
|
}
|
||
|
|
||
|
|
||
|
while ((n = fread(buf, 1, sizeof(buf), in)) > 0) {
|
||
|
if (n < sizeof(buf)) {
|
||
|
if (ferror(in)) {
|
||
|
FREAD_ERROR:
|
||
|
fprintf(stderr, "fread error\n");
|
||
|
return EXIT_FAILURE;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
p_off = xor_data(buf, n, pattern, p_len, p_off);
|
||
|
|
||
|
if (!fwrite(buf, n, 1, out)) {
|
||
|
FWRITE_ERROR:
|
||
|
fprintf(stderr, "fwrite error\n");
|
||
|
return EXIT_FAILURE;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (ferror(in)) {
|
||
|
goto FREAD_ERROR;
|
||
|
}
|
||
|
|
||
|
if (fflush(out)) {
|
||
|
goto FWRITE_ERROR;
|
||
|
}
|
||
|
|
||
|
fclose(in);
|
||
|
fclose(out);
|
||
|
|
||
|
return EXIT_SUCCESS;
|
||
|
}
|