bug 451 fixed: problem with auto login

- add an auto_login_key in users_table
- $conf['session_length'] is no more useful 
    and sessions length will be 0 (until browser closed)
- add $conf['remember_me_name'] for cookie remember name


git-svn-id: http://piwigo.org/svn/trunk@1493 68402e56-0260-453c-a942-63ccdbb3a9ee

include/config_default.inc.php

@@ -312,13 +312,13 @@ $conf['session_save_handler'] = 'db';
 // creates a cookie on client side.
 $conf['authorize_remembering'] = true;
 
+// remember_me_name: specifies the name of the cookie used to stay logged
+$conf['remember_me_name'] = 'pwg_remember';
+
 // remember_me_length : time of validity for "remember me" cookies, in
 // seconds.
 $conf['remember_me_length'] = 31536000;
 
-// session_length : time of validity for normal session, in seconds.
-$conf['session_length'] = 3600;
-
 // +-----------------------------------------------------------------------+
 // |                                debug                                  |
 // +-----------------------------------------------------------------------+

include/functions_session.inc.php

@@ -71,11 +71,8 @@ if (isset($conf['session_save_handler'])
     ini_set('session.use_only_cookies', $conf['session_use_only_cookies']);
     ini_set('session.use_trans_sid', intval($conf['session_use_trans_sid']));
   }
-  session_name( $conf['session_name'] );
-  session_set_cookie_params(
-      ini_get('session.cookie_lifetime'),
-      cookie_path()
-    );
+  session_name($conf['session_name']);
+  session_set_cookie_params(0, cookie_path());
 }
 
 // cookie_path returns the path to use for the PhpWebGallery cookie.

include/functions_user.inc.php

@@ -551,12 +551,34 @@ function get_language_filepath($filename)
 function log_user($user_id, $remember_me)
 {
   global $conf;
-  $session_length = $conf['session_length'];
+
   if ($remember_me)
   {
-    $session_length = $conf['remember_me_length'];
+    // search for an existing auto_login_key
+    $query = '
+SELECT auto_login_key 
+  FROM '.USERS_TABLE.'
+  WHERE '.$conf['user_fields']['id'].' = '.$user_id.'
+;';
+ 
+    $auto_login_key = current(mysql_fetch_assoc(pwg_query($query)));
+    if (empty($auto_login_key)) 
+    {
+      $auto_login_key = base64_encode(md5(uniqid(rand(), true)));
+      $query = '
+UPDATE '.USERS_TABLE.'
+  SET auto_login_key=\''.$auto_login_key.'\'
+  WHERE '.$conf['user_fields']['id'].' = '.$user_id.'
+;';
+      pwg_query($query);
+    }
+    $cookie = array('id' => $user_id, 'key' => $auto_login_key);
+    setcookie($conf['remember_me_name'],
+	      serialize($cookie), 
+	      time()+$conf['remember_me_length'],
+	      cookie_path()
+	      );
   }
-  session_set_cookie_params($session_length);
   session_start();
   $_SESSION['pwg_uid'] = $user_id;
 }