firmware-utils/buffalo-enc: add support for decrypting data with an offset

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 47185
This commit is contained in:
Felix Fietkau 2015-10-12 13:11:03 +00:00
parent d57bba8560
commit 772e2c0a77

View File

@ -34,6 +34,7 @@ static unsigned char seed = 'O';
static char *product;
static char *version;
static int do_decrypt;
static int offset;
void usage(int status)
{
@ -52,6 +53,7 @@ void usage(int status)
" -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"
);
exit(status);
@ -87,7 +89,7 @@ static int decrypt_file(void)
ep.key = (unsigned char *) crypt_key;
ep.longstate = longstate;
err = decrypt_buf(&ep, buf, src_len);
err = decrypt_buf(&ep, buf + offset, src_len - offset);
if (err) {
ERR("unable to decrypt '%s'", ifname);
goto out;
@ -100,7 +102,7 @@ static int decrypt_file(void)
printf("Data len\t: %u\n", ep.datalen);
printf("Checksum\t: 0x%08x\n", ep.csum);
err = write_buf_to_file(ofname, buf, ep.datalen);
err = write_buf_to_file(ofname, buf + offset, ep.datalen);
if (err) {
ERR("unable to write to file '%s'", ofname);
goto out;
@ -239,7 +241,7 @@ int main(int argc, char *argv[])
while ( 1 ) {
int c;
c = getopt(argc, argv, "adi:m:o:hlp:v:k:r:s:");
c = getopt(argc, argv, "adi:m:o:hlp:v:k:O:r:s:");
if (c == -1)
break;
@ -271,6 +273,9 @@ int main(int argc, char *argv[])
case 's':
seed = strtoul(optarg, NULL, 16);
break;
case 'O':
offset = strtoul(optarg, NULL, 0);
break;
case 'h':
usage(EXIT_SUCCESS);
break;