egroupware/phpgwapi/inc/class.smbhash.inc.php

<?php
	/*
	$Id$

	This code is part of LDAP Account Manager (http://www.sourceforge.net/projects/lam)
	Copyright (C) 2004 Roland Gruber

	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

	*/

	/**
	* This class provides functions to calculate Samba NT and LM hashes.
	*
	* The code is a conversion from createntlm.pl (Benjamin Kuit) and smbdes.c/md4.c (Andrew Tridgell).
	*
	* @author Roland Gruber
	*
	* @package modules
	*/

	/**
	* Calculates NT and LM hashes.
	*
	* The important functions are lmhash($password) and nthash($password).
	*
	* @package modules
	*/
	class smbHash
	{
		# Contants used in lanlam hash calculations
		# Ported from SAMBA/source/libsmb/smbdes.c:perm1[56]

		var $perm1 = array(
			57, 49, 41, 33, 25, 17, 9,
			1, 58, 50, 42, 34, 26, 18,
			10, 2, 59, 51, 43, 35, 27,
			19, 11, 3, 60, 52, 44, 36,
			63, 55, 47, 39, 31, 23, 15,
			7, 62, 54, 46, 38, 30, 22,
			14, 6, 61, 53, 45, 37, 29,
			21, 13, 5, 28, 20, 12, 4
		);
		# Ported from SAMBA/source/libsmb/smbdes.c:perm2[48]

		var $perm2 = array(
			14, 17, 11, 24, 1, 5,
			3, 28, 15, 6, 21, 10,
			23, 19, 12, 4, 26, 8,
			16, 7, 27, 20, 13, 2,
			41, 52, 31, 37, 47, 55,
			30, 40, 51, 45, 33, 48,
			44, 49, 39, 56, 34, 53,
			46, 42, 50, 36, 29, 32
		);
		# Ported from SAMBA/source/libsmb/smbdes.c:perm3[64]

		var $perm3 = array(
			58, 50, 42, 34, 26, 18, 10, 2,
			60, 52, 44, 36, 28, 20, 12, 4,
			62, 54, 46, 38, 30, 22, 14, 6,
			64, 56, 48, 40, 32, 24, 16, 8,
			57, 49, 41, 33, 25, 17, 9, 1,
			59, 51, 43, 35, 27, 19, 11, 3,
			61, 53, 45, 37, 29, 21, 13, 5,
			63, 55, 47, 39, 31, 23, 15, 7
		);
		# Ported from SAMBA/source/libsmb/smbdes.c:perm4[48]

		var $perm4 = array(
			32, 1, 2, 3, 4, 5,
			4, 5, 6, 7, 8, 9,
			8, 9, 10, 11, 12, 13,
			12, 13, 14, 15, 16, 17,
			16, 17, 18, 19, 20, 21,
			20, 21, 22, 23, 24, 25,
			24, 25, 26, 27, 28, 29,
			28, 29, 30, 31, 32, 1
		);
		# Ported from SAMBA/source/libsmb/smbdes.c:perm5[32]

		var $perm5 = array(
			16, 7, 20, 21,
			29, 12, 28, 17,
			1, 15, 23, 26,
			5, 18, 31, 10,
			2, 8, 24, 14,
			32, 27, 3, 9,
			19, 13, 30, 6,
			22, 11, 4, 25
		);
		# Ported from SAMBA/source/libsmb/smbdes.c:perm6[64]

		var $perm6 = array(
			40, 8, 48, 16, 56, 24, 64, 32,
			39, 7, 47, 15, 55, 23, 63, 31,
			38, 6, 46, 14, 54, 22, 62, 30,
			37, 5, 45, 13, 53, 21, 61, 29,
			36, 4, 44, 12, 52, 20, 60, 28,
			35, 3, 43, 11, 51, 19, 59, 27,
			34, 2, 42, 10, 50, 18, 58, 26,
			33, 1, 41, 9, 49, 17, 57, 25
		);
		# Ported from SAMBA/source/libsmb/smbdes.c:sc[16]

		var $sc = array(1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1);
		# Ported from SAMBA/source/libsmb/smbdes.c:sbox[8][4][16]
		# Side note, I used cut and paste for all these numbers, I did NOT
		# type them all in =)

		var $sbox = array(
			array(
				array(14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7),
				array( 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8),
				array( 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0),
				array(15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13)
			),
			array(
				array(15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10),
				array( 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5),
				array( 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15),
				array(13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9)
			),
			array(
				array(10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8),
				array(13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1),
				array(13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7),
				array( 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12)
			),
			array(
				array( 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15),
				array(13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9),
				array(10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4),
				array( 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14)
			),
			array(
				array( 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9),
				array(14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6),
				array( 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14),
				array(11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3)
			),
			array(
				array(12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11),
				array(10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8),
				array( 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6),
				array( 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13)
			),
			array(
				array( 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1),
				array(13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6),
				array( 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2),
				array( 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12)
			),
			array(
				array(13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7),
				array( 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2),
				array( 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8),
				array( 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11)
			)
		);

		/**
		* @param integer count
		* @param array $data
		* @return array
		*/
		function lshift($count, $data)
		{
			$ret = array();
			for($i = 0; $i < sizeof($data); $i++)
			{
				$ret[$i] = $data[($i + $count)%sizeof($data)];
			}
			return $ret;
		}

		/**
		* @param array in input data
		* @param array p permutation
		* @return array
		*/
		function permute($in, $p, $n)
		{
			$ret = array();
			for($i = 0; $i < $n; $i++)
			{
				$ret[$i] = $in[$p[$i] - 1]?1:0;
			}
			return $ret;
		}

		/**
		* @param array $in1
		* @param array $in2
		* @return array
		*/
		function mxor($in1, $in2)
		{
			$ret = array();
			for($i = 0; $i < sizeof($in1); $i++)
			{
				$ret[$i] = $in1[$i] ^ $in2[$i];
			}
			return $ret;
		}

		/**
		* @param array $in
		* @param array $key
		* @param boolean $forw
		* @return array
		*/
		function doHash($in, $key, $forw)
		{
			$ki = array();

			$pk1 = $this->permute($key, $this->perm1, 56);

			$c = array();
			$d = array();
			for($i = 0; $i < 28; $i++)
			{
				$c[$i] = $pk1[$i];
				$d[$i] = $pk1[28 + $i];
			}

			for($i = 0; $i < 16; $i++)
			{
				$c = $this->lshift($this->sc[$i], $c);
				$d = $this->lshift($this->sc[$i], $d);

				$cd = $c;
				for($k = 0; $k < sizeof($d); $k++)
				{
					$cd[] = $d[$k];
				}
				$ki[$i] = $this->permute($cd, $this->perm2, 48);
			}

			$pd1 = $this->permute($in, $this->perm3, 64);

			$l = array();
			$r = array();
			for($i = 0; $i < 32; $i++)
			{
				$l[$i] = $pd1[$i];
				$r[$i] = $pd1[32 + $i];
			}

			for($i = 0; $i < 16; $i++)
			{
				$er = $this->permute($r, $this->perm4, 48);
				if($forw)
				{
					$erk = $this->mxor($er, $ki[$i]);
				}
				else
				{
					$erk = $this->mxor($er, $ki[15 - $i]);
				}

				for($j = 0; $j < 8; $j++)
				{
					for($k = 0; $k < 6; $k++)
					{
						$b[$j][$k] = $erk[($j * 6) + $k];
					}
				}
				for($j = 0; $j < 8; $j++)
				{
					$m = array();
					$n = array();
					$m = ($b[$j][0] << 1) | $b[$j][5];
					$n = ($b[$j][1] << 3) | ($b[$j][2] << 2) | ($b[$j][3] << 1) | $b[$j][4];

					for($k = 0; $k < 4; $k++)
					{
						$b[$j][$k]=($this->sbox[$j][$m][$n] & (1 << (3-$k)))?1:0;
					}
				}

				for($j = 0; $j < 8; $j++)
				{
					for($k = 0; $k < 4; $k++)
					{
						$cb[($j * 4) + $k] = $b[$j][$k];
					}
				}
				$pcb = $this->permute($cb, $this->perm5, 32);
				$r2 = $this->mxor($l, $pcb);
				for($k = 0; $k < 32; $k++)
				{
					$l[$k] = $r[$k];
				}
				for($k = 0; $k < 32; $k++)
				{
					$r[$k] = $r2[$k];
				}
			}
			$rl = $r;
			for($i = 0; $i < sizeof($l); $i++)
			{
				$rl[] = $l[$i];
			}
			return $this->permute($rl, $this->perm6, 64);
		}

		function str_to_key($str)
		{
			$key[0] = $this->unsigned_shift_r($str[0], 1);
			$key[1] = (($str[0]&0x01)<<6) | $this->unsigned_shift_r($str[1], 2);
			$key[2] = (($str[1]&0x03)<<5) | $this->unsigned_shift_r($str[2], 3);
			$key[3] = (($str[2]&0x07)<<4) | $this->unsigned_shift_r($str[3], 4);
			$key[4] = (($str[3]&0x0F)<<3) | $this->unsigned_shift_r($str[4], 5);
			$key[5] = (($str[4]&0x1F)<<2) | $this->unsigned_shift_r($str[5], 6);
			$key[6] = (($str[5]&0x3F)<<1) | $this->unsigned_shift_r($str[6], 7);
			$key[7] = $str[6]&0x7F;
			for($i = 0; $i < 8; $i++)
			{
				$key[$i] = ($key[$i] << 1);
			}
			return $key;
		}

		function smb_hash($in, $key, $forw)
		{
			$key2 = $this->str_to_key($key);

			for($i = 0; $i < 64; $i++)
			{
				$inb[$i] = ($in[$i/8] & (1<<(7-($i%8)))) ? 1:0;
				$keyb[$i] = ($key2[$i/8] & (1<<(7-($i%8)))) ? 1:0;
				$outb[$i] = 0;
			}
			$outb = $this->dohash($inb, $keyb, $forw);
			for($i = 0; $i < 8; $i++)
			{
				$out[$i] = 0;
			}
			for($i = 0; $i < 65; $i++)
			{
				if(isset($outb[$i]) && $outb[$i])
				{
					$out[$i/8] |= (1<<(7-($i%8)));
				}
			}
			return $out;
		}

		function E_P16($in)
		{
			$p14 = array_values(unpack("C*",$in));
			$sp8 = array(0x4b, 0x47, 0x53, 0x21, 0x40, 0x23, 0x24, 0x25);
			$p14_1 = array();
			$p14_2 = array();
			for($i = 0; $i < 7; $i++)
			{
				$p14_1[$i] = $p14[$i];
				$p14_2[$i] = $p14[$i + 7];
			}
			$p16_1 = $this->smb_hash($sp8, $p14_1, true);
			$p16_2 = $this->smb_hash($sp8, $p14_2, true);
			$p16 = $p16_1;
			for($i = 0; $i < sizeof($p16_2); $i++)
			{
				$p16[] = $p16_2[$i];
			}
			return $p16;
		}

		/**
		* Calculates the LM hash of a given password.
		*
		* @param string $password password
		* @return string hash value
		*/
		function lmhash($password='')
		{
			$password = strtoupper($password);
			$password = substr($password,0,14);
			$password = str_pad($password, 14, chr(0));
			$p16 = $this->E_P16($password);
			for($i = 0; $i < sizeof($p16); $i++)
			{
				$p16[$i] = sprintf("%02X", $p16[$i]);
			}
			return join('', $p16);
		}

		/**
		* Calculates the NT hash of a given password.
		*
		* @param string $password password
		* @return string hash value
		*/
		function nthash($password='')
		{
			$password = substr($password,0,128);
			$password2 = '';
			for($i = 0; $i < strlen($password); $i++)
			{
				$password2 .= $password[$i] . chr(0);
			}
			$password = $password2;
			$hex = $this->mdfour($password);
			for($i = 0; $i < sizeof($hex); $i++)
			{
				$hex[$i] = sprintf("%02X", $hex[$i]);
			}
			return join('', $hex);
		}

		# Support functions
		# Ported from SAMBA/source/lib/md4.c:F,G and H respectfully

		function F($X, $Y, $Z)
		{
			return($X&$Y) | ((~$X)&$Z);
		}

		function G($X, $Y, $Z)
		{
			return($X&$Y) | ($X&$Z) | ($Y&$Z);
		}

		function H($X, $Y, $Z)
		{
			return $X^$Y^$Z;
		}

		# Ported from SAMBA/source/lib/md4.c:mdfour

		function mdfour($in)
		{
			$in = unpack("C*",$in);
			$in = array_values($in);
			$b = sizeof($in) * 8;
			$A = array(0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476);
			while(sizeof($in) > 64)
			{
				$M = $this->copy64($in);
				$this->mdfour64($A[0], $A[1], $A[2], $A[3], $M);
				$new_in = array();
				for($i = 64; $i < sizeof($in); $i++)
				{
					$new_in[] = $in[$i];
				}
				$in = $new_in;
			}
			$buf = $in;
			$buf[] = 0x80;
			for($i = sizeof($buf) - 1; $i < 127; $i++)
			{
				$buf[] = 0;
			}
			if(sizeof($in) <= 55)
			{
				$temp = $this->copy4($b);
				$buf[56] = $temp[0];
				$buf[57] = $temp[1];
				$buf[58] = $temp[2];
				$buf[59] = $temp[3];
				$M = $this->copy64($buf);
				$this->mdfour64($A[0], $A[1], $A[2], $A[3], $M);
			}
			else
			{
				$temp = $this->copy4($b);
				$buf[120] = $temp[0];
				$buf[121] = $temp[1];
				$buf[122] = $temp[2];
				$buf[123] = $temp[3];
				$M = $this->copy64($buf);
				$this->mdfour64($A[0], $A[1], $A[2], $A[3], $M);
				$temp = array();
				for($i = 64; $i < sizeof($buf); $i++)
				{
					$temp[] = $buf[$i];
				}
				$M = $this->copy64($temp);
				$this->mdfour64($A[0], $A[1], $A[2], $A[3], $M);
			}
			$out = array();
			$temp = $this->copy4($A[0]);
			for($i = 0; $i < 4; $i++)
			{
				$out[] = $temp[$i];
			}
			$temp = $this->copy4($A[1]);
			for($i = 0; $i < 4; $i++)
			{
				$out[] = $temp[$i];
			}
			$temp = $this->copy4($A[2]);
			for($i = 0; $i < 4; $i++)
			{
				$out[] = $temp[$i];
			}
			$temp = $this->copy4($A[3]);
			for($i = 0; $i < 4; $i++)
			{
				$out[] = $temp[$i];
			}
			return $out;
		}

		# Ported from SAMBA/source/lib/md4.c:copy4

		function copy4($x)
		{
			$out = array();
			$out[0] = $x&0xFF;
			$out[1] = $this->unsigned_shift_r($x, 8)&0xFF;
			$out[2] = $this->unsigned_shift_r($x, 16)&0xFF;
			$out[3] = $this->unsigned_shift_r($x, 24)&0xFF;
			return $out;
		}

		# Ported from SAMBA/source/lib/md4.c:copy64

		function copy64($in)
		{
			for($i = 0; $i < 16; $i++)
			{
				$M[$i] = ($in[$i*4+3]<<24) | ($in[$i*4+2]<<16) | ($in[$i*4+1]<<8) | ($in[$i*4+0]<<0);
			}
			return $M;
		}

		# Ported from SAMBA/source/lib/md4.c:mdfour64

		function mdfour64(&$A, &$B, &$C, &$D, $M)
		{
			$X = array();
			for($i = 0; $i < 16; $i++)
			{
				$X[] = $M[$i];
			}
			$AA=$A;
			$BB=$B;
			$CC=$C;
			$DD=$D;
			$this->ROUND1($A,$B,$C,$D, 0, 3, $X);
			$this->ROUND1($D,$A,$B,$C, 1, 7, $X);
			$this->ROUND1($C,$D,$A,$B, 2, 11, $X);
			$this->ROUND1($B,$C,$D,$A, 3, 19, $X);
			$this->ROUND1($A,$B,$C,$D, 4, 3, $X); $this->ROUND1($D,$A,$B,$C, 5, 7, $X);
			$this->ROUND1($C,$D,$A,$B, 6, 11, $X); $this->ROUND1($B,$C,$D,$A, 7, 19, $X);
			$this->ROUND1($A,$B,$C,$D, 8, 3, $X); $this->ROUND1($D,$A,$B,$C, 9, 7, $X);
			$this->ROUND1($C,$D,$A,$B, 10, 11, $X); $this->ROUND1($B,$C,$D,$A, 11, 19, $X);
			$this->ROUND1($A,$B,$C,$D, 12, 3, $X); $this->ROUND1($D,$A,$B,$C, 13, 7, $X);
			$this->ROUND1($C,$D,$A,$B, 14, 11, $X); $this->ROUND1($B,$C,$D,$A, 15, 19, $X);
			$this->ROUND2($A,$B,$C,$D, 0, 3, $X); $this->ROUND2($D,$A,$B,$C, 4, 5, $X);
			$this->ROUND2($C,$D,$A,$B, 8, 9, $X); $this->ROUND2($B,$C,$D,$A, 12, 13, $X);
			$this->ROUND2($A,$B,$C,$D, 1, 3, $X); $this->ROUND2($D,$A,$B,$C, 5, 5, $X);
			$this->ROUND2($C,$D,$A,$B, 9, 9, $X); $this->ROUND2($B,$C,$D,$A, 13, 13, $X);
			$this->ROUND2($A,$B,$C,$D, 2, 3, $X); $this->ROUND2($D,$A,$B,$C, 6, 5, $X);
			$this->ROUND2($C,$D,$A,$B, 10, 9, $X); $this->ROUND2($B,$C,$D,$A, 14, 13, $X);
			$this->ROUND2($A,$B,$C,$D, 3, 3, $X); $this->ROUND2($D,$A,$B,$C, 7, 5, $X);
			$this->ROUND2($C,$D,$A,$B, 11, 9, $X); $this->ROUND2($B,$C,$D,$A, 15, 13, $X);
			$this->ROUND3($A,$B,$C,$D, 0, 3, $X); $this->ROUND3($D,$A,$B,$C, 8, 9, $X);
			$this->ROUND3($C,$D,$A,$B, 4, 11, $X); $this->ROUND3($B,$C,$D,$A, 12, 15, $X);
			$this->ROUND3($A,$B,$C,$D, 2, 3, $X); $this->ROUND3($D,$A,$B,$C, 10, 9, $X);
			$this->ROUND3($C,$D,$A,$B, 6, 11, $X); $this->ROUND3($B,$C,$D,$A, 14, 15, $X);
			$this->ROUND3($A,$B,$C,$D, 1, 3, $X); $this->ROUND3($D,$A,$B,$C, 9, 9, $X);
			$this->ROUND3($C,$D,$A,$B, 5, 11, $X); $this->ROUND3($B,$C,$D,$A, 13, 15, $X);
			$this->ROUND3($A,$B,$C,$D, 3, 3, $X); $this->ROUND3($D,$A,$B,$C, 11, 9, $X);
			$this->ROUND3($C,$D,$A,$B, 7, 11, $X); $this->ROUND3($B,$C,$D,$A, 15, 15, $X);

			$A = $this->add32(array($A, $AA)); $B = $this->add32(array($B, $BB));
			$C = $this->add32(array($C, $CC)); $D = $this->add32(array($D, $DD));
		}

		# Needed? because perl seems to choke on overflowing when doing bitwise
		# operations on numbers larger than 32 bits. Well, it did on my machine =)

		function add32($v)
		{
			$sum = array();
			for($i = 0; $i < sizeof($v); $i++)
			{
				$v[$i] = array($this->unsigned_shift_r(($v[$i]&0xffff0000), 16), ($v[$i]&0xffff));
			}
			for($i = 0; $i < sizeof($v); $i++)
			{
				@$sum[0] += $v[$i][0];
				@$sum[1] += $v[$i][1];
			}
			$sum[0] += ($sum[1]&0xffff0000)>>16;
			$sum[1] &= 0xffff;
			$sum[0] &= 0xffff;
			$ret = ($sum[0]<<16) | $sum[1];
			return $ret;
		}

		# Ported from SAMBA/source/lib/md4.c:ROUND1

		function ROUND1(&$a,$b,$c,$d,$k,$s,$X)
		{
			$a = $this->md4lshift($this->add32(array($a, $this->F($b,$c,$d), $X[$k])), $s);
			return $a;
		}

		# Ported from SAMBA/source/lib/md4.c:ROUND2

		function ROUND2(&$a,$b,$c,$d,$k,$s,$X)
		{
			$a = $this->md4lshift($this->add32(array($a, $this->G($b,$c,$d), $X[$k] + 0x5A827999)), $s);
			return $a;
		}

		# Ported from SAMBA/source/lib/md4.c:ROUND3

		function ROUND3(&$a,$b,$c,$d,$k,$s,$X)
		{
			$a = $this->md4lshift($this->add32(array($a + $this->H($b,$c,$d) + $X[$k] + 0x6ED9EBA1)), $s);
			return $a;
		}

		# Ported from SAMBA/source/lib/md4.c:lshift
		# Renamed to prevent clash with SAMBA/source/libsmb/smbdes.c:lshift

		function md4lshift($x, $s)
		{
			$x &= 0xFFFFFFFF;
			return((($x<<$s)&0xFFFFFFFF) | $this->unsigned_shift_r($x, (32-$s)));
		}

		/**
		* Unsigned shift operation for 32bit values.
		*
		* PHP 4 only supports signed shifts by default.
		*/
		function unsigned_shift_r($a, $b)
		{
			$z = 0x80000000;
			if($z & $a)
			{
				$a = ($a >> 1);
				$a &= (~$z);
				$a |= 0x40000000;
				$a = ($a >> ($b - 1));
			}
			else
			{
				$a = ($a >> $b);
			}
			return $a;
		}
	}
?>