SMTP GSSAPI support (#6417)

* krb_authentication support for smtp_connect
* smtp GSSAPI support

plugins/krb_authentication/krb_authentication.php

@@ -25,6 +25,7 @@ class krb_authentication extends rcube_plugin
         $this->add_hook('login_after', array($this, 'login'));
         $this->add_hook('storage_connect', array($this, 'storage_connect'));
         $this->add_hook('managesieve_connect', array($this, 'managesieve_connect'));
+        $this->add_hook('smtp_connect', array($this, 'smtp_connect'));
     }
 
     /**
@@ -127,4 +128,24 @@ class krb_authentication extends rcube_plugin
 
         return $args;
     }
+    
+    /**
+     * smtp_connect hook handler
+     */
+    function smtp_connect($args)
+    {
+        if ((!isset($args['smtp_auth_type']) || $args['smtp_auth_type'] == 'GSSAPI') && !empty($_SERVER['REMOTE_USER']) && !empty($_SERVER['KRB5CCNAME'])) {
+            // Load plugin's config file
+            $this->load_config();
+
+            $rcmail  = rcmail::get_instance();
+            $context = $rcmail->config->get('krb_authentication_context');
+
+            $args['gssapi_context'] = $context ?: 'imap/kolab.example.org@EXAMPLE.ORG';
+            $args['gssapi_cn']      = $_SERVER['KRB5CCNAME'];
+            $args['smtp_auth_type'] = 'GSSAPI';
+        }
+
+        return $args;
+    }
 }

program/lib/Roundcube/rcube_smtp.php

@@ -108,7 +108,8 @@ class rcube_smtp
         // IDNA Support
         $smtp_host = rcube_utils::idn_to_ascii($smtp_host);
 
-        $this->conn = new Net_SMTP($smtp_host, $smtp_port, $helo_host, false, 0, $CONFIG['smtp_conn_options']);
+        $this->conn = new Net_SMTP($smtp_host, $smtp_port, $helo_host, false, 0, $CONFIG['smtp_conn_options'],
+            $CONFIG['gssapi_context'], $CONFIG['gssapi_cn']);
 
         if ($rcube->config->get('smtp_debug')) {
             $this->conn->setDebug(true, array($this, 'debug_handler'));
@@ -154,7 +155,7 @@ class rcube_smtp
         }
 
         // attempt to authenticate to the SMTP server
-        if ($smtp_user && $smtp_pass) {
+        if (($smtp_user && $smtp_pass) || ($smtp_auth_type == 'GSSAPI')) {
             // IDNA Support
             if (strpos($smtp_user, '@')) {
                 $smtp_user = rcube_utils::idn_to_ascii($smtp_user);