[cvs] [Wiki] changed: ImapSelect

[Wiki Guest]

guest [129.187.206.131]  Tue, 17 Jan 2006 07:50:49 -0800

Modified page: http://wiki.horde.org/ImapSelect
New Revision:  3.2
Change log:  adding IMAP select by realmed user

@@ -1,9 +1,13 @@
 + Dynamically selecting an IMAP server for authentication
 
 ++ Introduction
 
-During a migration from one IMAP server to another, the need arose to run both the old and the new IMAP servers in paralell. By default, Horde only allows a single primary server to be enabled in servers.php. Of course, we could have allowed our users to simply select their server by enabling IMAP server selection, but there is a better way. What follows are instructions on using a !MySQL backend to select an IMAP server for authentication, given a username:
+During a migration from one IMAP server to another, the need arose to run both the old and the new IMAP servers in paralell. By default, Horde only allows a single primary server to be enabled in servers.php. Of course, we could have allowed our users to simply select their server by enabling IMAP server selection, but there is a better way. 
+The first example shows a way using a !MySQL backend to select an IMAP server for authentication, given a username.
+The second example instead uses the realmed username to select the IMAP server \
+(i.e. the username used by Horde internally to prevent username clashes).
+----
 
 ++ The SQL table
 
 There are many ways to do this of course. In this example, we'll just be using a table with two rows:
@@ -51,4 +55,109 @@
 
 </code>
 
 All that's left to do, is to activate the preauthenticate hook in Horde's configuration.
+----
+
+++ IMAP server selection by realmed username
++++ Requirements
+* IMP is used to do the authentication
+* The usernames to authenticate against the mailserver may not have a domain part (separated with '@' from the username).
+* There is more than one active server entry in {{imp/config/servers.php}}. _
+ The realm values are different and the default server has an empty string as realm. _
+ //**Note:**// The default server is either the first server entry in the list or the one with the **preferred** value _
+ set.
+* Realm values are only lowercase strings (e.g. 'server1.example.com').
+
+++++ Examplary snippet of {{imp/config/servers.php}}
+<code>/* Example configuration: */
+
+$servers['imap'] = array(
+    'name' => 'IMAP Server',
+    'server' => 'imap.example.com',
+    'hordeauth' => true,
+    'protocol' => 'imap/notls',
+    'port' => 143,
+    'maildomain' => 'example.com',
+    'smtphost' => 'smtp.example.com',
+    'smtpport' => 25,
+    'realm' => '',
+    'preferred' => '',
+);
+
+$servers['imap1'] = array(
+    'name' => 'IMAP Server 1',
+    'server' => 'imap1.example.com',
+    'hordeauth' => true,
+    'protocol' => 'imap/ssl/novalidate-cert',
+    'port' => 993,
+    'maildomain' => 'example.com',
+    'smtphost' => 'smtp.example.com',
+    'smtpport' => 25,
+    'realm' => 'imap1.example.com',
+    'preferred' => '',
+);
+</code>
+
+++++ Functionality of the hook
+Entering the username {{smith}} in the login screen selects the necessary values given by {{$servers['imap']}}:
+* Authentication against {{imap.example.com}}
+* using protocol {{imap/notls}}
+* ...
+
+Entering the username {{smith at imap1.example.com}} instead selects the values of {{$servers['imap1']}}:
+* Authentication against {{imap1.example.com}}
+* using protocol {{imap/ssl/novalidate-cert}}
+* ...
+
+//**Note:**// 
+* Horde treats them as different users with their own preferences.
+* The selection of the server is done by the **realm** value **NOT** by the **server** value.
+
++++ The Preauthenticate-Hook
+The following hook has to be inserted in {{config/hooks.php}}:
+<code type="php">if (!function_exists('_horde_hook_preauthenticate')) {
+    function _horde_hook_preauthenticate($userID, $credential, $realm)
+    {
+        require dirname(__FILE__) . '/../imp/config/servers.php';
+
+        // Convert all to lower chars (even the possible domain part)
+        $userID=strtolower($userID);
+        // Strip domain part from user, if it exists.
+        if (($domainpart = strpos($userID, '@'))) {
+          $server=substr($userID, $domainpart+1);
+          $userID=substr($userID, 0, $domainpart);
+          // Change the values only if a domain part was found ...
+          if (!empty($server)) {
+            foreach ($servers as $serverkey => $curServer) {
+              if (!empty($curServer['realm']) && $server == $curServer['realm']) {
+                // We found an entry, now set IMAP server values.
+                foreach (array('server', 'folders', 'namespace',
+                  'protocol', 'port', 'smtphost', 'smtpport', 'maildomain') as $key) {
+                  if (isset($servers[$serverkey][$key])) {
+                    $_SESSION['imp'][$key] = $servers[$serverkey][$key];
+                  }
+                }
+                // Now use only the stripped version of the userID to logon to the server
+                $_SESSION['imp']['user'] = $userID;
+                // Setup the correct base_protocol
+                $_SESSION['imp']['base_protocol'] = $_SESSION['imp']['protocol'];
+                if (($pos = strpos($_SESSION['imp']['protocol'], '/'))) {
+                  $_SESSION['imp']['base_protocol'] = substr($_SESSION['imp']['protocol'], 0, $pos);
+                }
+              }
+            }
+          }
+        }
+        return true;
+    }
+}
+</code>
+
+Like in the first example, the hook has to be activated inside {{config/conf.php}}. 
+* Either use the administration user interface of Horde (recommended)
+* or set the following entry in {{config/conf.php}} with your favorite editor
+<code>...
+$conf['hooks']['preauthenticate'] = true;
+...
+</code> 
+