<?php
/**
* Nonce-related functionality.
*
* @package OpenID
*/
/**
* Need CryptUtil to generate random strings.
*/
require_once 'Auth/OpenID/CryptUtil.php';
/**
* This is the characters that the nonces are made from.
*/
define('Auth_OpenID_Nonce_CHRS',"abcdefghijklmnopqrstuvwxyz" .
"ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789");
// Keep nonces for five hours (allow five hours for the combination of
// request time and clock skew). This is probably way more than is
// necessary, but there is not much overhead in storing nonces.
global $Auth_OpenID_SKEW;
$Auth_OpenID_SKEW = 60 * 60 * 5;
define('Auth_OpenID_Nonce_REGEX',
'/(\d{4})-(\d\d)-(\d\d)T(\d\d):(\d\d):(\d\d)Z(.*)/');
define('Auth_OpenID_Nonce_TIME_FMT',
'%Y-%m-%dT%H:%M:%SZ');
function Auth_OpenID_splitNonce($nonce_string)
{
// Extract a timestamp from the given nonce string
$result = preg_match(Auth_OpenID_Nonce_REGEX, $nonce_string, $matches);
if ($result != 1 || count($matches) != 8) {
return null;
}
list($unused,
$tm_year,
$tm_mon,
$tm_mday,
$tm_hour,
$tm_min,
$tm_sec,
$uniquifier) = $matches;
$timestamp =
@gmmktime($tm_hour, $tm_min, $tm_sec, $tm_mon, $tm_mday, $tm_year);
if ($timestamp === false || $timestamp < 0) {
return null;
}
return array($timestamp, $uniquifier);
}
function Auth_OpenID_checkTimestamp($nonce_string,
$allowed_skew = null,
$now = null)
{
// Is the timestamp that is part of the specified nonce string
// within the allowed clock-skew of the current time?
global $Auth_OpenID_SKEW;
if ($allowed_skew === null) {
$allowed_skew = $Auth_OpenID_SKEW;
}
$parts = Auth_OpenID_splitNonce($nonce_string);
if ($parts == null) {
return false;
}
if ($now === null) {
$now = time();
}
$stamp = $parts[0];
// Time after which we should not use the nonce
$past = $now - $allowed_skew;
// Time that is too far in the future for us to allow
$future = $now + $allowed_skew;
// the stamp is not too far in the future and is not too far
// in the past
return (($past <= $stamp) && ($stamp <= $future));
}
function Auth_OpenID_mkNonce($when = null)
{
// Generate a nonce with the current timestamp
$salt = Auth_OpenID_CryptUtil::randomString(
6, Auth_OpenID_Nonce_CHRS);
if ($when === null) {
// It's safe to call time() with no arguments; it returns a
// GMT unix timestamp on PHP 4 and PHP 5. gmmktime() with no
// args returns a local unix timestamp on PHP 4, so don't use
// that.
$when = time();
}
$time_str = gmstrftime(Auth_OpenID_Nonce_TIME_FMT, $when);
return $time_str . $salt;
}
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