summaryrefslogtreecommitdiff
blob: 107858600c866b0bfb556f86ef2cb414adec64a6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
<?php

/**
 * This file supplies a memcached store backend for OpenID servers and
 * consumers.
 *
 * PHP versions 4 and 5
 *
 * LICENSE: See the COPYING file included in this distribution.
 *
 * @package OpenID
 * @author Artemy Tregubenko <me@arty.name>
 * @copyright 2008 JanRain, Inc.
 * @license http://www.apache.org/licenses/LICENSE-2.0 Apache
 * Contributed by Open Web Technologies <http://openwebtech.ru/>
 */

/**
 * Import the interface for creating a new store class.
 */
require_once 'Auth/OpenID/Interface.php';

/**
 * This is a memcached-based store for OpenID associations and
 * nonces. 
 * 
 * As memcache has limit of 250 chars for key length, 
 * server_url, handle and salt are hashed with sha1(). 
 *
 * Most of the methods of this class are implementation details.
 * People wishing to just use this store need only pay attention to
 * the constructor.
 *
 * @package OpenID
 */
class Auth_OpenID_MemcachedStore extends Auth_OpenID_OpenIDStore {

    /**
     * Initializes a new {@link Auth_OpenID_MemcachedStore} instance.
     * Just saves memcached object as property.
     *
     * @param resource connection Memcache connection resourse
     */
    function __construct($connection, $compress = false)
    {
        $this->connection = $connection;
        $this->compress = $compress ? MEMCACHE_COMPRESSED : 0;
    }

    /**
     * Store association until its expiration time in memcached. 
     * Overwrites any existing association with same server_url and 
     * handle. Handles list of associations for every server. 
     */
    function storeAssociation($server_url, $association)
    {
        // create memcached keys for association itself 
        // and list of associations for this server
        $associationKey = $this->associationKey($server_url, 
            $association->handle);
        $serverKey = $this->associationServerKey($server_url);
        
        // get list of associations 
        $serverAssociations = $this->connection->get($serverKey);
        
        // if no such list, initialize it with empty array
        if (!$serverAssociations) {
            $serverAssociations = array();
        }
        // and store given association key in it
        $serverAssociations[$association->issued] = $associationKey;
        
        // save associations' keys list 
        $this->connection->set(
            $serverKey,
            $serverAssociations,
            $this->compress
        );
        // save association itself
        $this->connection->set(
            $associationKey,
            $association, 
            $this->compress, 
            $association->issued + $association->lifetime);
    }

    /**
     * Read association from memcached. If no handle given 
     * and multiple associations found, returns latest issued
     */
    function getAssociation($server_url, $handle = null)
    {
        // simple case: handle given
        if ($handle !== null) {
            // get association, return null if failed
            $association = $this->connection->get(
                $this->associationKey($server_url, $handle));
            return $association ? $association : null;
        }
        
        // no handle given, working with list
        // create key for list of associations
        $serverKey = $this->associationServerKey($server_url);
        
        // get list of associations
        $serverAssociations = $this->connection->get($serverKey);
        // return null if failed or got empty list
        if (!$serverAssociations) {
            return null;
        }
        
        // get key of most recently issued association
        $keys = array_keys($serverAssociations);
        sort($keys);
        $lastKey = $serverAssociations[array_pop($keys)];
        
        // get association, return null if failed
        $association = $this->connection->get($lastKey);
        return $association ? $association : null;
    }

    /**
     * Immediately delete association from memcache.
     */
    function removeAssociation($server_url, $handle)
    {
        // create memcached keys for association itself 
        // and list of associations for this server
        $serverKey = $this->associationServerKey($server_url);
        $associationKey = $this->associationKey($server_url, 
            $handle);
        
        // get list of associations
        $serverAssociations = $this->connection->get($serverKey);
        // return null if failed or got empty list
        if (!$serverAssociations) {
            return false;
        }
        
        // ensure that given association key exists in list
        $serverAssociations = array_flip($serverAssociations);
        if (!array_key_exists($associationKey, $serverAssociations)) {
            return false;
        }
        
        // remove given association key from list
        unset($serverAssociations[$associationKey]);
        $serverAssociations = array_flip($serverAssociations);
        
        // save updated list
        $this->connection->set(
            $serverKey,
            $serverAssociations,
            $this->compress
        );

        // delete association 
        return $this->connection->delete($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;
        }
        
        // returns false when nonce already exists
        // otherwise adds nonce
        return $this->connection->add(
            'openid_nonce_' . sha1($server_url) . '_' . sha1($salt), 
            1, // any value here 
            $this->compress, 
            $Auth_OpenID_SKEW);
    }
    
    /**
     * Memcache key is prefixed with 'openid_association_' string. 
     */
    function associationKey($server_url, $handle = null) 
    {
        return 'openid_association_' . sha1($server_url) . '_' . sha1($handle);
    }
    
    /**
     * Memcache key is prefixed with 'openid_association_' string. 
     */
    function associationServerKey($server_url) 
    {
        return 'openid_association_server_' . sha1($server_url);
    }
    
    /**
     * Report that this storage doesn't support cleanup
     */
    function supportsCleanup()
    {
        return false;
    }
}