feature #6617 [WSSE] - Using a PSR6 cache instead of file cache (Nyholm)

This PR was submitted for the 3.0 branch but it was merged into the 3.1 branch instead (closes #6617).

Discussion
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[WSSE] - Using a PSR6 cache instead of file cache

I rewrote the WSSE example to use a PSR-6 cache instead. I did this because Symfony got a fancy new CacheComponent now and because using file cache will eventually fill up your inodes. (I just removed 2 million inodes from my server.)

Note: Im not sure about the service name for a cache pool. Is it just `cache`?

Commits
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1d6e267 [WSSE] - Using a PSR6 cache instead of file cache

Author: wouterj

cookbook/security/custom_authentication_provider.rst

@@ -208,6 +208,7 @@ the ``PasswordDigest`` header value matches with the user's password.
     // src/AppBundle/Security/Authentication/Provider/WsseProvider.php
     namespace AppBundle\Security\Authentication\Provider;
 
+    use Psr\Cache\CacheItemPoolInterface;
     use Symfony\Component\Security\Core\Authentication\Provider\AuthenticationProviderInterface;
     use Symfony\Component\Security\Core\User\UserProviderInterface;
     use Symfony\Component\Security\Core\Exception\AuthenticationException;
@@ -218,12 +219,12 @@ the ``PasswordDigest`` header value matches with the user's password.
     class WsseProvider implements AuthenticationProviderInterface
     {
         private $userProvider;
-        private $cacheDir;
+        private $cachePool;
 
-        public function __construct(UserProviderInterface $userProvider, $cacheDir)
+        public function __construct(UserProviderInterface $userProvider, CacheItemPoolInterface $cachePool)
         {
             $this->userProvider = $userProvider;
-            $this->cacheDir     = $cacheDir;
+            $this->cachePool = $cachePool;
         }
 
         public function authenticate(TokenInterface $token)
@@ -258,19 +259,18 @@ the ``PasswordDigest`` header value matches with the user's password.
                 return false;
             }
 
-            // Validate that the nonce is *not* used in the last 5 minutes
-            // if it has, this could be a replay attack
-            if (
-                file_exists($this->cacheDir.'/'.md5($nonce))
-                && file_get_contents($this->cacheDir.'/'.md5($nonce)) + 300 > time()
-            ) {
+            // Try to fetch the cache item from pool
+            $cacheItem = $this->cachePool->getItem(md5($nonce));
+            
+            // Validate that the nonce is *not* in cache
+            // if it is, this could be a replay attack
+            if ($cacheItem->isHit()) {
                 throw new NonceExpiredException('Previously used nonce detected');
             }
-            // If cache directory does not exist we create it
-            if (!is_dir($this->cacheDir)) {
-                mkdir($this->cacheDir, 0777, true);
-            }
-            file_put_contents($this->cacheDir.'/'.md5($nonce), time());
+            
+            // Store the item in cache for 5 minutes
+            $cacheItem->set(null)->expiresAfter(300);
+            $this->cachePool->save($cacheItem);
 
             // Validate Secret
             $expected = base64_encode(sha1(base64_decode($nonce).$created.$secret, true));
@@ -411,7 +411,7 @@ to service ids that do not exist yet: ``wsse.security.authentication.provider``
                 class: AppBundle\Security\Authentication\Provider\WsseProvider
                 arguments:
                     - '' # User Provider
-                    - '%kernel.cache_dir%/security/nonces'
+                    - '@cache.app'
                 public: false
 
             wsse.security.authentication.listener:
@@ -433,7 +433,7 @@ to service ids that do not exist yet: ``wsse.security.authentication.provider``
                     public="false"
                 >
                     <argument /> <!-- User Provider -->
-                    <argument>%kernel.cache_dir%/security/nonces</argument>
+                    <argument type="service" id="cache.app"></argument>
                 </service>
 
                 <service id="wsse.security.authentication.listener"
@@ -456,7 +456,7 @@ to service ids that do not exist yet: ``wsse.security.authentication.provider``
             'AppBundle\Security\Authentication\Provider\WsseProvider',
             array(
                 '', // User Provider
-                '%kernel.cache_dir%/security/nonces',
+                new Reference('cache.app'),
             )
         );
         $definition->setPublic(false);