Add Prosody XMPP MySQL authentication

Signed-off-by: Sebastian <sebastian@wiuwiu.de>

Change class name

Signed-off-by: Sebastian <sebastian@wiuwiu.de>

add prosody to title name

Signed-off-by: Sebastian <sebastian@wiuwiu.de>

integrate nextcloud code style guidelines

Signed-off-by: Sebastian <sebastian@wiuwiu.de>

clean up

Signed-off-by: Sebastian <sebastian@wiuwiu.de>

Applied nc code style

Signed-off-by: Sebastian <sebastian@wiuwiu.de>

README.md

@@ -146,6 +146,30 @@ Add the following to your `config.php`:
 
 [BasicAuth_0]: https://en.wikipedia.org/wiki/Basic_access_authentication
 
+
+XMPP (Prosody)
+----
+Authenticate Nextcloud users against a Prosody XMPP MySQL database.
+Prosody user and password need to be given for the Nextcloud login
+
+
+### Configuration
+Add the following to your `config.php`:
+
+    'user_backends' => array (
+        0 => array (
+            'class' => 'OC_User_XMPP',
+                'arguments' => array (
+                    0 => 'dbhost',
+                    1 => 'prosodydb',
+                    2 => 'dbuser',
+                    3 => 'dbuserpassword',
+                    4 => 'xmppdomain',
+                ),
+            ),
+    ),
+
+
 Alternatives
 ------------
 Other extensions allow connecting to external user databases directly via SQL, which may be faster:

appinfo/app.php

@@ -3,3 +3,4 @@ OC::$CLASSPATH['OC_User_IMAP']='user_external/lib/imap.php';
 OC::$CLASSPATH['OC_User_SMB']='user_external/lib/smb.php';
 OC::$CLASSPATH['OC_User_FTP']='user_external/lib/ftp.php';
 OC::$CLASSPATH['OC_User_BasicAuth']='user_external/lib/basicauth.php';
+OC::$CLASSPATH['OC_User_XMPP']='user_external/lib/xmpp.php';

appinfo/info.xml

@@ -3,8 +3,8 @@
 	  xsi:noNamespaceSchemaLocation="https://apps.nextcloud.com/schema/apps/info.xsd">
 	<id>user_external</id>
 	<name>External user support</name>
-	<summary>Use external user authentication methods like IMAP, SMB and FTP</summary>
+	<summary>Use external user authentication methods like IMAP, SMB, FTP, WebDAV, HTTP BasicAuth and XMPP</summary>
-	<description>Use external user authentication methods like IMAP, SMB and FTP</description>
+	<description>Use external user authentication methods like IMAP, SMB, FTP, WebDAV, HTTP BasicAuth and XMPP</description>
 	<version>0.6.0</version>
 	<licence>agpl</licence>
 	<author>Robin Appelman</author>

lib/xmpp.php

@@ -0,0 +1,102 @@
+<?php
+/**
+ * Copyright (c) 2019 Sebastian Sterk <sebastian@wiuwiu.de>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+/**
+ * User authentication against a XMPP Prosody MySQL database
+ *
+ * @category Apps
+ * @package  UserExternal
+ * @author   Sebastian Sterk https://wiuwiu.de/Imprint
+ * @license  http://www.gnu.org/licenses/agpl AGPL
+ */
+class OC_User_XMPP extends \OCA\user_external\Base {
+	private $host;
+	private $xmppDb;
+	private $xmppDbUser;
+	private $xmppDbPassword;
+	private $xmppDomain;
+
+	public function __construct($host, $xmppDb, $xmppDbUser, $xmppDbPassword, $xmppDomain) {
+		parent::__construct($host);
+		$this->host = $host;
+		$this->xmppDb = $xmppDb;
+		$this->xmppDbUser = $xmppDbUser;
+		$this->xmppDbPassword = $xmppDbPassword;
+		$this->xmppDomain = $xmppDomain;
+	}
+
+	public function hmacSha1($key, $data) {
+                if (strlen($key) > 64) {
+                        $key = str_pad(sha1($key, true), 64, chr(0));
+		}
+                if (strlen($key) < 64) {
+                        $key = str_pad($key, 64, chr(0));
+		}
+
+                $oPad = str_repeat(chr(0x5C), 64);
+                $iPad = str_repeat(chr(0x36), 64);
+
+                for ($i = 0; $i < strlen($key); $i++) {
+                        $oPad[$i] = $oPad[$i] ^ $key[$i];
+                        $iPad[$i] = $iPad[$i] ^ $key[$i];
+                }
+                return sha1($oPad.sha1($iPad.$data, true));
+        }
+	
+	public function checkPassword($uid, $password){
+		$pdo = new PDO("mysql:host=$this->host;dbname=$this->xmppDb", $this->xmppDbUser, $this->xmppDbPassword);
+		if(isset($uid) 
+		   && isset($password)) {
+        		if(!filter_var($uid, FILTER_VALIDATE_EMAIL) 
+			   || !strpos($uid, $this->xmppDomain) 
+			   || substr($uid, -strlen($this->xmppDomain)) !== $this->xmppDomain
+			  ) {
+				return false;
+			}
+			$user = explode("@", $uid);
+        		$userName = strtolower($user[0]);
+        		$submittedPassword = $password;
+        		$statement = $pdo->prepare("SELECT * FROM prosody WHERE user = :user AND host = :xmppDomain AND store = 'accounts'");
+        		$result = $statement->execute(array(
+				'user' => $userName, 
+				'xmppDomain' => $this->xmppDomain
+			));
+        		$user = $statement->fetchAll();
+        		if(empty($user)) {
+                		return false;
+			}
+        		foreach ($user as $key){
+                        	if($key[3] === "salt") {
+                        	        $internalSalt = $key['value'];
+				}
+                        	if($key[3] === "server_key") {
+                        	        $internalServerKey = $key['value'];
+				}
+                        	if($key[3] === "stored_key") {
+                        	        $internalStoredKey = $key['value'];
+				}
+		        }
+	        	unset($user);
+		        $internalIteration = '4096';
+
+		        $newSaltedPassword = hash_pbkdf2('sha1', $submittedPassword, $internalSalt, $internalIteration, 0, true);
+		        $newServerKey = $this->hmacSha1($newSaltedPassword, 'Server Key');
+		        $newClientKey = $this->hmacSha1($newSaltedPassword, 'Client Key');
+		        $newStoredKey = sha1(hex2bin($newClientKey));
+
+		        if ($newServerKey === $internalServerKey 
+			    && $newStoredKey === $internalStoredKey) {
+				$uid = mb_strtolower($uid);
+	                        $this->storeUser($uid);
+				return $uid;
+			} else {
+				return false;
+			}
+		}
+	}
+}