<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\Security\Csrf;
use Symfony\Component\HttpFoundation\RequestStack;
use Symfony\Component\Security\Core\Exception\InvalidArgumentException;
use Symfony\Component\Security\Csrf\TokenGenerator\TokenGeneratorInterface;
use Symfony\Component\Security\Csrf\TokenGenerator\UriSafeTokenGenerator;
use Symfony\Component\Security\Csrf\TokenStorage\NativeSessionTokenStorage;
use Symfony\Component\Security\Csrf\TokenStorage\TokenStorageInterface;
/**
* Default implementation of {@link CsrfTokenManagerInterface}.
*
* @author Bernhard Schussek <bschussek@gmail.com>
* @author Kévin Dunglas <dunglas@gmail.com>
*/
class CsrfTokenManager implements CsrfTokenManagerInterface
{
private $generator;
private $storage;
private $namespace;
/**
* @param string|RequestStack|callable|null $namespace
* * null: generates a namespace using $_SERVER['HTTPS']
* * string: uses the given string
* * RequestStack: generates a namespace using the current main request
* * callable: uses the result of this callable (must return a string)
*/
public function __construct(TokenGeneratorInterface $generator = null, TokenStorageInterface $storage = null, $namespace = null)
{
$this->generator = $generator ?? new UriSafeTokenGenerator();
$this->storage = $storage ?? new NativeSessionTokenStorage();
$superGlobalNamespaceGenerator = function () {
return !empty($_SERVER['HTTPS']) && 'off' !== strtolower($_SERVER['HTTPS']) ? 'https-' : '';
};
if (null === $namespace) {
$this->namespace = $superGlobalNamespaceGenerator;
} elseif ($namespace instanceof RequestStack) {
$this->namespace = function () use ($namespace, $superGlobalNamespaceGenerator) {
if ($request = $namespace->getMainRequest()) {
return $request->isSecure() ? 'https-' : '';
}
return $superGlobalNamespaceGenerator();
};
} elseif (\is_callable($namespace) || \is_string($namespace)) {
$this->namespace = $namespace;
} else {
throw new InvalidArgumentException(sprintf('$namespace must be a string, a callable returning a string, null or an instance of "RequestStack". "%s" given.', get_debug_type($namespace)));
}
}
/**
* {@inheritdoc}
*/
public function getToken(string $tokenId)
{
$namespacedId = $this->getNamespace().$tokenId;
if ($this->storage->hasToken($namespacedId)) {
$value = $this->storage->getToken($namespacedId);
} else {
$value = $this->generator->generateToken();
$this->storage->setToken($namespacedId, $value);
}
return new CsrfToken($tokenId, $this->randomize($value));
}
/**
* {@inheritdoc}
*/
public function refreshToken(string $tokenId)
{
$namespacedId = $this->getNamespace().$tokenId;
$value = $this->generator->generateToken();
$this->storage->setToken($namespacedId, $value);
return new CsrfToken($tokenId, $this->randomize($value));
}
/**
* {@inheritdoc}
*/
public function removeToken(string $tokenId)
{
return $this->storage->removeToken($this->getNamespace().$tokenId);
}
/**
* {@inheritdoc}
*/
public function isTokenValid(CsrfToken $token)
{
$namespacedId = $this->getNamespace().$token->getId();
if (!$this->storage->hasToken($namespacedId)) {
return false;
}
return hash_equals($this->storage->getToken($namespacedId), $this->derandomize($token->getValue()));
}
private function getNamespace(): string
{
return \is_callable($ns = $this->namespace) ? $ns() : $ns;
}
private function randomize(string $value): string
{
$key = random_bytes(32);
$value = $this->xor($value, $key);
return sprintf('%s.%s.%s', substr(md5($key), 0, 1 + (\ord($key[0]) % 32)), rtrim(strtr(base64_encode($key), '+/', '-_'), '='), rtrim(strtr(base64_encode($value), '+/', '-_'), '='));
}
private function derandomize(string $value): string
{
$parts = explode('.', $value);
if (3 !== \count($parts)) {
return $value;
}
$key = base64_decode(strtr($parts[1], '-_', '+/'));
$value = base64_decode(strtr($parts[2], '-_', '+/'));
return $this->xor($value, $key);
}
private function xor(string $value, string $key): string
{
if (\strlen($value) > \strlen($key)) {
$key = str_repeat($key, ceil(\strlen($value) / \strlen($key)));
}
return $value ^ $key;
}
}