/*?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?
#include?
#include?
#include?
#include?
#include?
#include?

#include?

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(chǎn)‘）&&（c?<=?‘f‘））
		return?c?-?‘a(chǎn)‘?+?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?		p[i]?=?hex2bin_c（str[i*2]）?<	
	*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?		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?（memcmp（h4?ht?20）?!=?0）
		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?mod