Merge pull request openid#103 from vmattila/predis-store

Implemented PredisStore to provide association store for Redis servers.

Auth/OpenID/PredisStore.php

@@ -0,0 +1,208 @@
+<?php
+
+/**
+ * Supplies Redis server store backend for OpenID servers and consumers.
+ * Uses Predis library {@see https://github.com/nrk/predis}.
+ * Requires PHP >= 5.3.
+ *
+ * LICENSE: See the COPYING file included in this distribution.
+ *
+ * @package OpenID
+ * @author Ville Mattila <[email protected]>
+ * @copyright 2008 JanRain Inc., 2013 Eventio Oy / Ville Mattila
+ * @license http://www.apache.org/licenses/LICENSE-2.0 Apache
+ * Contributed by Eventio Oy <http://www.eventio.fi/>
+ */
+
+/**
+ * Import the interface for creating a new store class.
+ */
+require_once 'Auth/OpenID/Interface.php';
+
+/**
+ * Supplies Redis server store backend for OpenID servers and consumers.
+ * Uses Predis library {@see https://github.com/nrk/predis}.
+ * Requires PHP >= 5.3.
+ * 
+ * @package OpenID
+ */
+class Auth_OpenID_PredisStore extends Auth_OpenID_OpenIDStore {
+
+    /**
+     * @var \Predis\Client
+     */
+    protected $redis;
+
+    /**
+     * Prefix for Redis keys
+     * @var string
+     */
+    protected $prefix;
+
+    /**
+     * Initializes a new {@link Auth_OpenID_PredisStore} instance.
+     *
+     * @param \Predis\Client $redis  Predis client object
+     * @param string         $prefix Prefix for all keys stored to the Redis
+     */
+    function Auth_OpenID_PredisStore(\Predis\Client $redis, $prefix = '')
+    {
+        $this->prefix = $prefix;
+        $this->redis = $redis;
+    }
+
+    /**
+     * Store association until its expiration time in Redis server. 
+     * Overwrites any existing association with same server_url and 
+     * handle. Handles list of associations for every server. 
+     */
+    function storeAssociation($server_url, $association)
+    {
+        // create Redis keys for association itself 
+        // and list of associations for this server
+        $associationKey = $this->associationKey($server_url, 
+            $association->handle);
+        $serverKey = $this->associationServerKey($server_url);
+
+        // save association to server's associations' keys list
+        $this->redis->lpush(
+            $serverKey,
+            $associationKey
+        );
+
+        // Will touch the association list expiration, to avoid filling up
+        $newExpiration = ($association->issued + $association->lifetime);
+
+        $expirationKey = $serverKey.'_expires_at';
+        $expiration = $this->redis->get($expirationKey);
+        if (!$expiration || $newExpiration > $expiration) {
+            $this->redis->set($expirationKey, $newExpiration);
+            $this->redis->expiresat($serverKey, $newExpiration);
+            $this->redis->expiresat($expirationKey, $newExpiration);
+        }
+
+        // save association itself, will automatically expire
+        $this->redis->setex(
+            $associationKey,
+            $newExpiration - time(),
+            serialize($association)
+        );
+    }
+
+    /**
+     * Read association from Redis. If no handle given 
+     * and multiple associations found, returns latest issued
+     */
+    function getAssociation($server_url, $handle = null)
+    {
+        // simple case: handle given
+        if ($handle !== null) {
+            return $this->getAssociationFromServer(
+                $this->associationKey($server_url, $handle)
+            );
+        }
+
+        // no handle given, receiving the latest issued
+        $serverKey = $this->associationServerKey($server_url);
+        $lastKey = $this->redis->lpop($serverKey);
+        if (!$lastKey) { return null; }
+
+        // get association, return null if failed
+        return $this->getAssociationFromServer($lastKey);
+    }
+
+    /**
+     * Function to actually receive and unserialize the association
+     * from the server.
+     */
+    private function getAssociationFromServer($associationKey)
+    {
+        $association = $this->redis->get($associationKey);
+        return $association ? unserialize($association) : null;
+    }
+
+    /**
+     * Immediately delete association from Redis.
+     */
+    function removeAssociation($server_url, $handle)
+    {
+        // create Redis keys
+        $serverKey = $this->associationServerKey($server_url);
+        $associationKey = $this->associationKey($server_url, 
+            $handle);
+
+        // Removing the association from the server's association list
+        $removed = $this->redis->lrem($serverKey, 0, $associationKey);
+        if ($removed < 1) {
+            return false;
+        }
+
+        // Delete the association itself
+        return $this->redis->del($associationKey);
+    }
+
+    /**
+     * Create nonce for server and salt, expiring after 
+     * $Auth_OpenID_SKEW seconds.
+     */
+    function useNonce($server_url, $timestamp, $salt)
+    {
+        global $Auth_OpenID_SKEW;
+
+        // save one request to memcache when nonce obviously expired 
+        if (abs($timestamp - time()) > $Auth_OpenID_SKEW) {
+            return false;
+        }
+
+        // SETNX will set the value only of the key doesn't exist yet.
+        $nonceKey = $this->nonceKey($server_url, $salt);
+        $added = $this->predis->setnx($nonceKey);
+        if ($added) {
+            // Will set expiration
+            $this->predis->expire($nonceKey, $Auth_OpenID_SKEW);
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    /**
+     * Build up nonce key
+     */
+    private function nonceKey($server_url, $salt)
+    {
+        return $this->prefix .
+               'openid_nonce_' .
+               sha1($server_url) . '_' . sha1($salt);
+    }
+
+    /**
+     * Key is prefixed with $prefix and 'openid_association_' string
+     */
+    function associationKey($server_url, $handle = null) 
+    {
+        return $this->prefix .
+               'openid_association_' .
+               sha1($server_url) . '_' . sha1($handle);
+    }
+
+    /**
+     * Key is prefixed with $prefix and 'openid_association_server_' string
+     */
+    function associationServerKey($server_url) 
+    {
+        return $this->prefix .
+               'openid_association_server_' .
+               sha1($server_url);
+    }
+
+    /**
+     * Report that this storage doesn't support cleanup
+     */
+    function supportsCleanup()
+    {
+        return false;
+    }
+
+}
+