gnu-social/vendor/openid/php-openid/Auth/OpenID/DiffieHellman.php

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<?php
/**
* The OpenID library's Diffie-Hellman implementation.
*
* PHP versions 4 and 5
*
* LICENSE: See the COPYING file included in this distribution.
*
* @access private
* @package OpenID
* @author JanRain, Inc. <openid@janrain.com>
* @copyright 2005-2008 Janrain, Inc.
* @license http://www.apache.org/licenses/LICENSE-2.0 Apache
*/
require_once 'Auth/OpenID.php';
require_once 'Auth/OpenID/BigMath.php';
function Auth_OpenID_getDefaultMod()
{
return '155172898181473697471232257763715539915724801'.
'966915404479707795314057629378541917580651227423'.
'698188993727816152646631438561595825688188889951'.
'272158842675419950341258706556549803580104870537'.
'681476726513255747040765857479291291572334510643'.
'245094715007229621094194349783925984760375594985'.
'848253359305585439638443';
}
function Auth_OpenID_getDefaultGen()
{
return '2';
}
/**
* The Diffie-Hellman key exchange class. This class relies on
* {@link Auth_OpenID_MathLibrary} to perform large number operations.
*
* @access private
* @package OpenID
*/
class Auth_OpenID_DiffieHellman {
var $mod;
var $gen;
var $private;
var $lib = null;
function Auth_OpenID_DiffieHellman($mod = null, $gen = null,
$private = null, $lib = null)
{
if ($lib === null) {
$this->lib = Auth_OpenID_getMathLib();
} else {
$this->lib = $lib;
}
if ($mod === null) {
$this->mod = $this->lib->init(Auth_OpenID_getDefaultMod());
} else {
$this->mod = $mod;
}
if ($gen === null) {
$this->gen = $this->lib->init(Auth_OpenID_getDefaultGen());
} else {
$this->gen = $gen;
}
if ($private === null) {
$r = $this->lib->rand($this->mod);
$this->private = $this->lib->add($r, 1);
} else {
$this->private = $private;
}
$this->public = $this->lib->powmod($this->gen, $this->private,
$this->mod);
}
function getSharedSecret($composite)
{
return $this->lib->powmod($composite, $this->private, $this->mod);
}
function getPublicKey()
{
return $this->public;
}
function usingDefaultValues()
{
return ($this->mod == Auth_OpenID_getDefaultMod() &&
$this->gen == Auth_OpenID_getDefaultGen());
}
function xorSecret($composite, $secret, $hash_func)
{
$dh_shared = $this->getSharedSecret($composite);
$dh_shared_str = $this->lib->longToBinary($dh_shared);
$hash_dh_shared = $hash_func($dh_shared_str);
$xsecret = "";
for ($i = 0; $i < Auth_OpenID::bytes($secret); $i++) {
$xsecret .= chr(ord($secret[$i]) ^ ord($hash_dh_shared[$i]));
}
return $xsecret;
}
}