OpenWrt – Rev 4
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/*
* Copyright (C) 2009-2011 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.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <libgen.h>
#include <getopt.h> /* for getopt() */
#include <stdarg.h>
#include "buffalo-lib.h"
#define ERR(fmt, args...) do { \
fflush(0); \
fprintf(stderr, "[%s] *** error: " fmt "\n", \
progname, ## args ); \
} while (0)
static char *progname;
static char *ifname;
static char *ofname;
static char *crypt_key = "Buffalo";
static char *magic = "start";
static int longstate;
static unsigned char seed = 'O';
static char *product;
static char *version;
static int do_decrypt;
static int offset;
static int size;
void usage(int status)
{
FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
fprintf(stream, "Usage: %s [OPTIONS...]\n", progname);
fprintf(stream,
"\n"
"Options:\n"
" -d decrypt instead of encrypt\n"
" -i <file> read input from the file <file>\n"
" -o <file> write output to the file <file>\n"
" -l use longstate {en,de}cryption method\n"
" -k <key> use <key> for encryption (default: Buffalo)\n"
" -m <magic> set magic to <magic>\n"
" -p <product> set product name to <product>\n"
" -v <version> set version to <version>\n"
" -h show this screen\n"
" -O Offset of encrypted data in file (decryption)\n"
" -S Size of unencrypted data in file (encryption)\n"
);
exit(status);
}
static int decrypt_file(void)
{
struct enc_param ep;
ssize_t src_len;
unsigned char *buf = NULL;
int err;
int ret = -1;
src_len = get_file_size(ifname);
if (src_len < 0) {
ERR("unable to get size of '%s'", ifname);
goto out;
}
buf = malloc(src_len);
if (buf == NULL) {
ERR("no memory for the buffer");
goto out;
}
err = read_file_to_buf(ifname, buf, src_len);
if (err) {
ERR("unable to read from file '%s'", ifname);
goto out;
}
memset(&ep, '\0', sizeof(ep));
ep.key = (unsigned char *) crypt_key;
ep.longstate = longstate;
err = decrypt_buf(&ep, buf + offset, src_len - offset);
if (err) {
ERR("unable to decrypt '%s'", ifname);
goto out;
}
printf("Magic\t\t: '%s'\n", ep.magic);
printf("Seed\t\t: 0x%02x\n", ep.seed);
printf("Product\t\t: '%s'\n", ep.product);
printf("Version\t\t: '%s'\n", ep.version);
printf("Data len\t: %u\n", ep.datalen);
printf("Checksum\t: 0x%08x\n", ep.csum);
err = write_buf_to_file(ofname, buf + offset, ep.datalen);
if (err) {
ERR("unable to write to file '%s'", ofname);
goto out;
}
ret = 0;
out:
free(buf);
return ret;
}
static int encrypt_file(void)
{
struct enc_param ep;
ssize_t src_len, tail_dst, tail_len, tail_src;
unsigned char *buf;
uint32_t hdrlen;
ssize_t totlen = 0;
int err;
int ret = -1;
src_len = get_file_size(ifname);
if (src_len < 0) {
ERR("unable to get size of '%s'", ifname);
goto out;
}
if (size) {
tail_dst = enc_compute_buf_len(product, version, size);
tail_len = src_len - size;
totlen = tail_dst + tail_len;
} else
totlen = enc_compute_buf_len(product, version, src_len);
buf = malloc(totlen);
if (buf == NULL) {
ERR("no memory for the buffer");
goto out;
}
hdrlen = enc_compute_header_len(product, version);
err = read_file_to_buf(ifname, &buf[hdrlen], src_len);
if (err) {
ERR("unable to read from file '%s'", ofname);
goto free_buf;
}
if (size) {
tail_src = hdrlen + size;
memmove(&buf[tail_dst], &buf[tail_src], tail_len);
memset(&buf[tail_src], 0, tail_dst - tail_src);
src_len = size;
}
memset(&ep, '\0', sizeof(ep));
ep.key = (unsigned char *) crypt_key;
ep.seed = seed;
ep.longstate = longstate;
ep.csum = buffalo_csum(src_len, &buf[hdrlen], src_len);
ep.datalen = src_len;
strcpy((char *) ep.magic, magic);
strcpy((char *) ep.product, product);
strcpy((char *) ep.version, version);
err = encrypt_buf(&ep, buf, &buf[hdrlen]);
if (err) {
ERR("invalid input file");
goto free_buf;
}
err = write_buf_to_file(ofname, buf, totlen);
if (err) {
ERR("unable to write to file '%s'", ofname);
goto free_buf;
}
ret = 0;
free_buf:
free(buf);
out:
return ret;
}
static int check_params(void)
{
int ret = -1;
if (ifname == NULL) {
ERR("no input file specified");
goto out;
}
if (ofname == NULL) {
ERR("no output file specified");
goto out;
}
if (crypt_key == NULL) {
ERR("no key specified");
goto out;
} else if (strlen(crypt_key) > BCRYPT_MAX_KEYLEN) {
ERR("key '%s' is too long", crypt_key);
goto out;
}
if (strlen(magic) != (ENC_MAGIC_LEN - 1)) {
ERR("length of magic must be %d", ENC_MAGIC_LEN - 1);
goto out;
}
if (!do_decrypt) {
if (product == NULL) {
ERR("no product specified");
goto out;
}
if (version == NULL) {
ERR("no version specified");
goto out;
}
if (strlen(product) > (ENC_PRODUCT_LEN - 1)) {
ERR("product name '%s' is too long", product);
goto out;
}
if (strlen(version) > (ENC_VERSION_LEN - 1)) {
ERR("version '%s' is too long", version);
goto out;
}
}
ret = 0;
out:
return ret;
}
int main(int argc, char *argv[])
{
int res = EXIT_FAILURE;
int err;
progname = basename(argv[0]);
while ( 1 ) {
int c;
c = getopt(argc, argv, "adi:m:o:hlp:v:k:O:r:s:S:");
if (c == -1)
break;
switch (c) {
case 'd':
do_decrypt = 1;
break;
case 'i':
ifname = optarg;
break;
case 'l':
longstate = 1;
break;
case 'm':
magic = optarg;
break;
case 'o':
ofname = optarg;
break;
case 'p':
product = optarg;
break;
case 'v':
version = optarg;
break;
case 'k':
crypt_key = optarg;
break;
case 's':
seed = strtoul(optarg, NULL, 16);
break;
case 'O':
offset = strtoul(optarg, NULL, 0);
break;
case 'S':
size = strtoul(optarg, NULL, 0);
break;
case 'h':
usage(EXIT_SUCCESS);
break;
default:
usage(EXIT_FAILURE);
break;
}
}
err = check_params();
if (err)
goto out;
if (do_decrypt)
err = decrypt_file();
else
err = encrypt_file();
if (err)
goto out;
res = EXIT_SUCCESS;
out:
return res;
}