OpenWrt – Rev 4
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/*
* Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* This code was based on:
* PC1 Cipher Algorithm ( Pukall Cipher 1 )
* By Alexander PUKALL 1991
* free code no restriction to use
* please include the name of the Author in the final software
* the Key is 128 bits
* http://membres.lycos.fr/pc1/
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h> /* for unlink() */
#include <libgen.h>
#include <getopt.h> /* for getopt() */
#include <stdarg.h>
#include <errno.h>
#include <sys/stat.h>
struct pc1_ctx {
unsigned short ax;
unsigned short bx;
unsigned short cx;
unsigned short dx;
unsigned short si;
unsigned short tmp;
unsigned short x1a2;
unsigned short x1a0[8];
unsigned short res;
unsigned short i;
unsigned short inter;
unsigned short cfc;
unsigned short cfd;
unsigned short compte;
unsigned char cle[17];
short c;
};
static void pc1_finish(struct pc1_ctx *pc1)
{
/* erase all variables */
memset(pc1, 0, sizeof(struct pc1_ctx));
}
static void pc1_code(struct pc1_ctx *pc1)
{
pc1->dx = pc1->x1a2 + pc1->i;
pc1->ax = pc1->x1a0[pc1->i];
pc1->cx = 0x015a;
pc1->bx = 0x4e35;
pc1->tmp = pc1->ax;
pc1->ax = pc1->si;
pc1->si = pc1->tmp;
pc1->tmp = pc1->ax;
pc1->ax = pc1->dx;
pc1->dx = pc1->tmp;
if (pc1->ax != 0) {
pc1->ax = pc1->ax * pc1->bx;
}
pc1->tmp = pc1->ax;
pc1->ax = pc1->cx;
pc1->cx = pc1->tmp;
if (pc1->ax != 0) {
pc1->ax = pc1->ax * pc1->si;
pc1->cx = pc1->ax + pc1->cx;
}
pc1->tmp = pc1->ax;
pc1->ax = pc1->si;
pc1->si = pc1->tmp;
pc1->ax = pc1->ax * pc1->bx;
pc1->dx = pc1->cx + pc1->dx;
pc1->ax = pc1->ax + 1;
pc1->x1a2 = pc1->dx;
pc1->x1a0[pc1->i] = pc1->ax;
pc1->res = pc1->ax ^ pc1->dx;
pc1->i = pc1->i + 1;
}
static void pc1_assemble(struct pc1_ctx *pc1)
{
pc1->x1a0[0] = (pc1->cle[0] * 256) + pc1->cle[1];
pc1_code(pc1);
pc1->inter = pc1->res;
pc1->x1a0[1] = pc1->x1a0[0] ^ ((pc1->cle[2]*256) + pc1->cle[3]);
pc1_code(pc1);
pc1->inter = pc1->inter ^ pc1->res;
pc1->x1a0[2] = pc1->x1a0[1] ^ ((pc1->cle[4]*256) + pc1->cle[5]);
pc1_code(pc1);
pc1->inter = pc1->inter ^ pc1->res;
pc1->x1a0[3] = pc1->x1a0[2] ^ ((pc1->cle[6]*256) + pc1->cle[7]);
pc1_code(pc1);
pc1->inter = pc1->inter ^ pc1->res;
pc1->x1a0[4] = pc1->x1a0[3] ^ ((pc1->cle[8]*256) + pc1->cle[9]);
pc1_code(pc1);
pc1->inter = pc1->inter ^ pc1->res;
pc1->x1a0[5] = pc1->x1a0[4] ^ ((pc1->cle[10]*256) + pc1->cle[11]);
pc1_code(pc1);
pc1->inter = pc1->inter ^ pc1->res;
pc1->x1a0[6] = pc1->x1a0[5] ^ ((pc1->cle[12]*256) + pc1->cle[13]);
pc1_code(pc1);
pc1->inter = pc1->inter ^ pc1->res;
pc1->x1a0[7] = pc1->x1a0[6] ^ ((pc1->cle[14]*256) + pc1->cle[15]);
pc1_code(pc1);
pc1->inter = pc1->inter ^ pc1->res;
pc1->i = 0;
}
static unsigned char pc1_decrypt(struct pc1_ctx *pc1, short c)
{
pc1_assemble(pc1);
pc1->cfc = pc1->inter >> 8;
pc1->cfd = pc1->inter & 255; /* cfc^cfd = random byte */
c = c ^ (pc1->cfc ^ pc1->cfd);
for (pc1->compte = 0; pc1->compte <= 15; pc1->compte++) {
/* we mix the plaintext byte with the key */
pc1->cle[pc1->compte] = pc1->cle[pc1->compte] ^ c;
}
return c;
}
static unsigned char pc1_encrypt(struct pc1_ctx *pc1, short c)
{
pc1_assemble(pc1);
pc1->cfc = pc1->inter >> 8;
pc1->cfd = pc1->inter & 255; /* cfc^cfd = random byte */
for (pc1->compte = 0; pc1->compte <= 15; pc1->compte++) {
/* we mix the plaintext byte with the key */
pc1->cle[pc1->compte] = pc1->cle[pc1->compte] ^ c;
}
c = c ^ (pc1->cfc ^ pc1->cfd);
return c;
}
static void pc1_init(struct pc1_ctx *pc1)
{
memset(pc1, 0, sizeof(struct pc1_ctx));
/* ('Remsaalps!123456') is the key used, you can change it */
strcpy(pc1->cle, "Remsaalps!123456");
}
static void pc1_decrypt_buf(struct pc1_ctx *pc1, unsigned char *buf,
unsigned len)
{
unsigned i;
for (i = 0; i < len; i++)
buf[i] = pc1_decrypt(pc1, buf[i]);
}
static void pc1_encrypt_buf(struct pc1_ctx *pc1, unsigned char *buf,
unsigned len)
{
unsigned i;
for (i = 0; i < len; i++)
buf[i] = pc1_encrypt(pc1, buf[i]);
}
/*
* Globals
*/
static char *ifname;
static char *progname;
static char *ofname;
static int decrypt;
/*
* Message macros
*/
#define ERR(fmt, ...) do { \
fflush(0); \
fprintf(stderr, "[%s] *** error: " fmt "\n", \
progname, ## __VA_ARGS__ ); \
} while (0)
#define ERRS(fmt, ...) do { \
int save = errno; \
fflush(0); \
fprintf(stderr, "[%s] *** error: " fmt ": %s\n", \
progname, ## __VA_ARGS__, strerror(save)); \
} while (0)
void usage(int status)
{
FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
struct board_info *board;
fprintf(stream, "Usage: %s [OPTIONS...]\n", progname);
fprintf(stream,
"\n"
"Options:\n"
" -d decrypt instead of encrypt"
" -i <file> read input from the file <file>\n"
" -o <file> write output to the file <file>\n"
" -h show this screen\n"
);
exit(status);
}
#define BUFSIZE (64 * 1024)
int main(int argc, char *argv[])
{
struct pc1_ctx pc1;
int res = EXIT_FAILURE;
int err;
struct stat st;
char *buf;
unsigned total;
FILE *outfile, *infile;
progname = basename(argv[0]);
while ( 1 ) {
int c;
c = getopt(argc, argv, "di:o:h");
if (c == -1)
break;
switch (c) {
case 'd':
decrypt = 1;
break;
case 'i':
ifname = optarg;
break;
case 'o':
ofname = optarg;
break;
case 'h':
usage(EXIT_SUCCESS);
break;
default:
usage(EXIT_FAILURE);
break;
}
}
if (ifname == NULL) {
ERR("no input file specified");
goto err;
}
if (ofname == NULL) {
ERR("no output file specified");
goto err;
}
err = stat(ifname, &st);
if (err){
ERRS("stat failed on %s", ifname);
goto err;
}
total = st.st_size;
buf = malloc(BUFSIZE);
if (!buf) {
ERR("no memory for buffer\n");
goto err;
}
infile = fopen(ifname, "r");
if (infile == NULL) {
ERRS("could not open \"%s\" for reading", ifname);
goto err_free;
}
outfile = fopen(ofname, "w");
if (outfile == NULL) {
ERRS("could not open \"%s\" for writing", ofname);
goto err_close_in;
}
pc1_init(&pc1);
while (total > 0) {
unsigned datalen;
if (total > BUFSIZE)
datalen = BUFSIZE;
else
datalen = total;
errno = 0;
fread(buf, datalen, 1, infile);
if (errno != 0) {
ERRS("unable to read from file %s", ifname);
goto err_close_out;
}
if (decrypt)
pc1_decrypt_buf(&pc1, buf, datalen);
else
pc1_encrypt_buf(&pc1, buf, datalen);
errno = 0;
fwrite(buf, datalen, 1, outfile);
if (errno) {
ERRS("unable to write to file %s", ofname);
goto err_close_out;
}
total -= datalen;
}
pc1_finish(&pc1);
res = EXIT_SUCCESS;
out_flush:
fflush(outfile);
err_close_out:
fclose(outfile);
if (res != EXIT_SUCCESS) {
unlink(ofname);
}
err_close_in:
fclose(infile);
err_free:
free(buf);
err:
return res;
}