/*
   Unix SMB/Netbios implementation.
   Version 1.9.
   SMB parameters and setup
   Copyright (C) Andrew Tridgell 1992-2000
   Copyright (C) Luke Kenneth Casson Leighton 1996-2000
   Modified by Jeremy Allison 1995.
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2002-2003
   Modified by Steve French (sfrench@us.ibm.com) 2002-2003

   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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/random.h>
#include "cifs_unicode.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "md5.h"
#include "cifs_debug.h"
#include "cifsencrypt.h"

#ifndef false
#define false 0
#endif
#ifndef true
#define true 1
#endif

/* following came from the other byteorder.h to avoid include conflicts */
#define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
#define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8)
#define SSVAL(buf,pos,val) SSVALX((buf),(pos),((__u16)(val)))

/*The following definitions come from  libsmb/smbencrypt.c  */

void SMBencrypt(unsigned char *passwd, const unsigned char *c8,
		unsigned char *p24);
void E_md4hash(const unsigned char *passwd, unsigned char *p16);
static void SMBOWFencrypt(unsigned char passwd[16], const unsigned char *c8,
		   unsigned char p24[24]);
void SMBNTencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24);

/*
   This implements the X/Open SMB password encryption
   It takes a password, a 8 byte "crypt key" and puts 24 bytes of
   encrypted password into p24 */
/* Note that password must be uppercased and null terminated */
void
SMBencrypt(unsigned char *passwd, const unsigned char *c8, unsigned char *p24)
{
	unsigned char p14[15], p21[21];

	memset(p21, '\0', 21);
	memset(p14, '\0', 14);
	strncpy((char *) p14, (char *) passwd, 14);

/*	strupper((char *)p14); *//* BB at least uppercase the easy range */
	E_P16(p14, p21);

	SMBOWFencrypt(p21, c8, p24);

	memset(p14, 0, 15);
	memset(p21, 0, 21);
}

/* Routines for Windows NT MD4 Hash functions. */
static int
_my_wcslen(__u16 *str)
{
	int len = 0;
	while (*str++ != 0)
		len++;
	return len;
}

/*
 * Convert a string into an NT UNICODE string.
 * Note that regardless of processor type
 * this must be in intel (little-endian)
 * format.
 */

static int
_my_mbstowcs(__u16 *dst, const unsigned char *src, int len)
{	/* BB not a very good conversion routine - change/fix */
	int i;
	__u16 val;

	for (i = 0; i < len; i++) {
		val = *src;
		SSVAL(dst, 0, val);
		dst++;
		src++;
		if (val == 0)
			break;
	}
	return i;
}

/*
 * Creates the MD4 Hash of the users password in NT UNICODE.
 */

void
E_md4hash(const unsigned char *passwd, unsigned char *p16)
{
	int len;
	__u16 wpwd[129];

	/* Password cannot be longer than 128 characters */
	if (passwd) {
		len = strlen((char *) passwd);
		if (len > 128)
			len = 128;

		/* Password must be converted to NT unicode */
		_my_mbstowcs(wpwd, passwd, len);
	} else
		len = 0;

	wpwd[len] = 0;	/* Ensure string is null terminated */
	/* Calculate length in bytes */
	len = _my_wcslen(wpwd) * sizeof(__u16);

	mdfour(p16, (unsigned char *) wpwd, len);
	memset(wpwd, 0, 129 * 2);
}


/* Does the NTLMv2 owfs of a user's password */

/* Does the des encryption from the NT or LM MD4 hash. */
static void
SMBOWFencrypt(unsigned char passwd[16], const unsigned char *c8,
	      unsigned char p24[24])
{
	unsigned char p21[21];

	memset(p21, '\0', 21);

	memcpy(p21, passwd, 16);
	E_P24(p21, c8, p24);
}

/* Does the des encryption from the FIRST 8 BYTES of the NT or LM MD4 hash. */

/* Does the NT MD4 hash then des encryption. */

void
SMBNTencrypt(unsigned char *passwd, unsigned char *c8, unsigned char *p24)
{
	unsigned char p21[21];

	memset(p21, '\0', 21);

	E_md4hash(passwd, p21);
	SMBOWFencrypt(p21, c8, p24);
}


/* Does the md5 encryption from the NT hash for NTLMv2. */
/* These routines will be needed later */