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/* IPsec VPN client compatible with Cisco equipment.
Copyright (C) 2004-2005 Maurice Massar
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
$Id: config.c 242 2007-09-09 07:55:21Z Joerg Mayer $
*/
#define _GNU_SOURCE
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <sys/utsname.h>
#include <gcrypt.h>
static int hex2bin_c(unsigned int c)
{
if ((c >= '0') && (c <= '9'))
return c - '0';
if ((c >= 'A') && (c <= 'F'))
return c - 'A' + 10;
if ((c >= 'a') && (c <= 'f'))
return c - 'a' + 10;
return -1;
}
int hex2bin(const char *str, char **bin, int *len)
{
char *p;
int i, l;
if (!bin)
return EINVAL;
for (i = 0; str[i] != '\0'; i++)
if (hex2bin_c(str[i]) == -1)
return EINVAL;
l = i;
if ((l & 1) != 0)
return EINVAL;
l /= 2;
p = malloc(l);
if (p == NULL)
return ENOMEM;
for (i = 0; i < l; i++)
p[i] = hex2bin_c(str[i * 2]) << 4 | hex2bin_c(str[i * 2 + 1]);
*bin = p;
if (len)
*len = l;
return 0;
}
int deobfuscate(char *ct, int len, const char **resp, char *reslenp)
{
const char *h1 = ct;
const char *h4 = ct + 20;
const char *enc = ct + 40;
char ht[20], h2[20], h3[20], key[24];
const char *iv = h1;
char *res;
gcry_cipher_hd_t ctx;
int reslen;
if (len < 48)
return -1;
len -= 40;
memcpy(ht, h1, 20);
ht[19]++;
gcry_md_hash_buffer(GCRY_MD_SHA1, h2, ht, 20);
ht[19] += 2;
gcry_md_hash_buffer(GCRY_MD_SHA1, h3, ht, 20);
memcpy(key, h2, 20);
memcpy(key + 20, h3, 4);
/* who cares about parity anyway? */
gcry_md_hash_buffer(GCRY_MD_SHA1, ht, enc, len);
if (!memeq(h4, ht, 20))
return -1;
res = malloc(len);
if (res == NULL)
return -1;
gcry_cipher_open(&ctx, GCRY_CIPHER_3DES, GCRY_CIPHER_MODE_CBC, 0);
gcry_cipher_setkey(ctx, key, 24);
gcry_cipher_setiv(ctx, iv, 8);
gcry_cipher_decrypt(ctx, (unsigned char *)res, len,
(unsigned char *)enc, len);
gcry_cipher_close(ctx);
reslen = len - res[len - 1];
res[reslen] = '\0';
if (resp)
*resp = res;
if (reslenp)
*reslenp = reslen;
return 0;
}
/* Decoder for password encoding of Cisco VPN client.
Copyright (C) 2005 Maurice Massar
Thanks to HAL-9000@evilscientists.de for decoding and posting the algorithm!
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 <gcrypt.h>
#include <errno.h>
int main(int argc, char *argv[])
{
int i, len, ret = 0;
char *bin, *pw = NULL;
gcry_check_version(NULL);
if (argc == 1 || *argv[1] == '-') {
fprintf(stderr,
"\nUsage: %s DEADBEEF...012345678 424242...7261\n"
" Print decoded result to stdout\n\n",
argv[0]);
exit(1);
}
/* Hack for use in pcf2vpnc */
if (*argv[1] == 'q')
exit(1);
for (i = 1; i < argc; i++) {
ret = hex2bin(argv[i], &bin, &len);
if (ret != 0) {
perror("decoding input");
continue;
}
ret = deobfuscate(bin, len, (const char **)&pw, NULL);
free(bin);
if (ret != 0) {
perror("decrypting input");
continue;
}
printf("%s\n", pw);
free(pw);
}
exit(ret != 0);
}
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