silverstripe-framework/core/startup/ParameterConfirmationToken.php

200 lines
5.7 KiB
PHP

<?php
/**
* Class ParameterConfirmationToken
*
* When you need to use a dangerous GET parameter that needs to be set before core/Core.php is
* established, this class takes care of allowing some other code of confirming the parameter,
* by generating a one-time-use token & redirecting with that token included in the redirected URL
*
* WARNING: This class is experimental and designed specifically for use pre-startup in main.php
* It will likely be heavily refactored before the release of 3.2
*/
class ParameterConfirmationToken {
protected $parameterName = null;
protected $parameter = null;
protected $token = null;
protected function pathForToken($token) {
return TEMP_FOLDER.'/token_'.preg_replace('/[^a-z0-9]+/', '', $token);
}
protected function genToken() {
// Generate a new random token (as random as possible)
require_once(dirname(dirname(dirname(__FILE__))).'/security/RandomGenerator.php');
$rg = new RandomGenerator();
$token = $rg->randomToken('md5');
// Store a file in the session save path (safer than /tmp, as open_basedir might limit that)
file_put_contents($this->pathForToken($token), $token);
return $token;
}
protected function checkToken($token) {
$file = $this->pathForToken($token);
$content = null;
if (file_exists($file)) {
$content = file_get_contents($file);
unlink($file);
}
return $content == $token;
}
public function __construct($parameterName) {
// Store the parameter name
$this->parameterName = $parameterName;
// Store the parameter value
$this->parameter = isset($_GET[$parameterName]) ? $_GET[$parameterName] : null;
// Store the token
$this->token = isset($_GET[$parameterName.'token']) ? $_GET[$parameterName.'token'] : null;
// If a token was provided, but isn't valid, ignore it
if ($this->token && (!$this->checkToken($this->token))) $this->token = null;
}
/**
* Get the name of this token
*
* @return string
*/
public function getName() {
return $this->parameterName;
}
/**
* Is the parameter requested?
*
* @return bool
*/
public function parameterProvided() {
return $this->parameter !== null;
}
/**
* Is the necessary token provided for this parameter?
*
* @return bool
*/
public function tokenProvided() {
return $this->token !== null;
}
/**
* Is this parameter requested without a valid token?
*
* @return bool True if the parameter is given without a valid token
*/
public function reloadRequired() {
return $this->parameterProvided() && !$this->tokenProvided();
}
/**
* Suppress the current parameter by unsetting it from $_GET
*/
public function suppress() {
unset($_GET[$this->parameterName]);
}
public function params() {
return array(
$this->parameterName => $this->parameter,
$this->parameterName.'token' => $this->genToken()
);
}
/** What to use instead of BASE_URL. Must not contain protocol or host. @var string */
static public $alternateBaseURL = null;
protected function currentAbsoluteURL() {
global $url;
// Are we http or https? Replicates Director::is_https() without its dependencies/
$proto = 'http';
if(
TRUSTED_PROXY
&& isset($_SERVER['HTTP_X_FORWARDED_PROTO'])
&& strtolower($_SERVER['HTTP_X_FORWARDED_PROTO']) == 'https'
) {
// Convention for (non-standard) proxy signaling a HTTPS forward,
// see https://en.wikipedia.org/wiki/List_of_HTTP_header_fields
$proto = 'https';
} else if(
TRUSTED_PROXY
&& isset($_SERVER['HTTP_X_FORWARDED_PROTOCOL'])
&& strtolower($_SERVER['HTTP_X_FORWARDED_PROTOCOL']) == 'https'
) {
// Less conventional proxy header
$proto = 'https';
} else if(
isset($_SERVER['HTTP_FRONT_END_HTTPS'])
&& strtolower($_SERVER['HTTP_FRONT_END_HTTPS']) == 'on'
) {
// Microsoft proxy convention: https://support.microsoft.com/?kbID=307347
$proto = 'https';
} else if((!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] != 'off')) {
$proto = 'https';
} else if(isset($_SERVER['SSL'])) {
$proto = 'https';
}
if((!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] != 'off')) $proto = 'https';
if(isset($_SERVER['SSL'])) $proto = 'https';
$parts = array_filter(array(
// What's our host
$_SERVER['HTTP_HOST'],
// SilverStripe base
self::$alternateBaseURL !== null ? self::$alternateBaseURL : BASE_URL,
// And URL
$url
));
// Join together with protocol into our current absolute URL, avoiding duplicated "/" characters
return "$proto://" . preg_replace('#/{2,}#', '/', implode('/', $parts));
}
public function reloadWithToken() {
$location = $this->currentAbsoluteURL();
// What's our GET params (ensuring they include the original parameter + a new token)
$params = array_merge($_GET, $this->params());
unset($params['url']);
if ($params) $location .= '?'.http_build_query($params);
// And redirect
if (headers_sent()) {
echo "
<script>location.href='$location';</script>
<noscript><meta http-equiv='refresh' content='0; url=$location'></noscript>
You are being redirected. If you are not redirected soon, <a href='$location'>click here to continue the flush</a>
";
}
else header('location: '.$location, true, 302);
die;
}
/**
* Given a list of token names, suppress all tokens that have not been validated, and
* return the non-validated token with the highest priority
*
* @param type $keys List of token keys in ascending priority (low to high)
* @return ParameterConfirmationToken The token container for the unvalidated $key given with the highest priority
*/
public static function prepare_tokens($keys) {
$target = null;
foreach($keys as $key) {
$token = new ParameterConfirmationToken($key);
// Validate this token
if($token->reloadRequired()) {
$token->suppress();
$target = $token;
}
}
return $target;
}
}