diff --git a/plugin.php b/plugin.php
new file mode 100644
index 0000000..bcf06ed
--- /dev/null
+++ b/plugin.php
@@ -0,0 +1,126 @@
+<?php
+/*
+Plugin Name: Simple LDAP Auth
+Plugin URI: 
+Description: This plugin enables use of LDAP provider for authentication
+Version: 1.0
+Author: k3a
+Author URI: http://k3a.me
+*/
+// Thanks to nicwaller (https://github.com/nicwaller) for cas plugin I used as a reference!
+
+// No direct call
+if( !defined( 'YOURLS_ABSPATH' ) ) die();
+
+// returns true if the environment is set up right
+function ldap_environment_check() {
+	$required_params = array(
+		'LDAP_HOST', // ldap host
+		//'LDAP_PORT', // ldap port
+		'LDAP_BASE', // base ldap path
+		//'LDAP_USERNAME_FIELD', // field to check the username against
+	);
+
+	foreach ($required_params as $pname) {
+		if ( !defined( $pname ) ) {
+			$message = 'Missing defined parameter '.$pname.' in plugin '. $thisplugname;
+			error_log($message);
+			return false;
+		}
+	}
+
+	if ( !defined( 'LDAP_PORT' ) )
+		define( 'LDAP_PORT', 389 );
+
+	if ( !defined( 'LDAP_USERNAME_FIELD' ) )
+		define( 'LDAP_USERNAME_FIELD', 'uid' );
+
+	if ( !defined( 'LDAP_ALL_USERS_ADMIN' ) )
+		define( 'LDAP_ALL_USERS_ADMIN', true );
+
+	global $ldap_authorized_admins;
+	if ( !isset( $ldap_authorized_admins ) ) {
+		if ( !LDAP_ALL_USERS_ADMIN ) {
+			error_log('Undefined $ldap_authorized_admins');
+		}
+		$ldap_authorized_admins = array();
+	}
+
+	return true;
+}
+
+
+yourls_add_filter( 'is_valid_user', 'ldap_is_valid_user' );
+
+// returns true/false
+function ldap_is_valid_user( $value ) {
+	// doesn't work for API...
+	if (yourls_is_API())
+		return $value;
+
+	@session_start();
+
+	if ( isset( $_SESSION['LDAP_AUTH_USER'] ) ) {
+		// already authenticated...
+		$username = $_SESSION['LDAP_AUTH_USER'];
+		if ( ldap_is_authorized_user( $username ) ) {
+			yourls_set_user( $_SESSION['LDAP_AUTH_USER'] );
+			return true;
+		} else {
+			return $username.' is not admin user.';
+		}
+	} else if ( isset( $_REQUEST['username'] ) && isset( $_REQUEST['password'] )
+			&& !empty( $_REQUEST['username'] ) && !empty( $_REQUEST['password']  ) ) {
+
+		if ( !ldap_environment_check() ) {
+        	die( 'Invalid configuration for YOURLS LDAP plugin. Check PHP error log.' );
+    	}	
+
+		// try to authenticate
+		$ldapConnection = ldap_connect(LDAP_HOST, LDAP_PORT);
+		if (!$ldapConnection) Die("Cannot connect to LDAP " . LDAP_HOST);
+		$searchDn = ldap_search($ldapConnection, LDAP_BASE, LDAP_USERNAME_FIELD . "=" . $_REQUEST['username'] );
+		if (!$searchDn) return $value;
+		$searchResult = ldap_get_entries($ldapConnection, $searchDn);
+		if (!$searchResult) return $value;
+		$userDn = $searchResult[0]['dn'];
+		if (!$userDn) return $value;	
+		$ldap_login = @ldap_bind($ldapConnection, $userDn, $_REQUEST['password']);
+		@ldap_close($ldapConnection);
+
+		// success?
+		if ($ldap_login)
+		{
+			$username = $searchResult[0][LDAP_USERNAME_FIELD][0];
+			yourls_set_user($username);
+			$_SESSION['LDAP_AUTH_USER'] = $username;
+			return true;
+		}
+	}
+
+	return $value;
+}
+
+function ldap_is_authorized_user( $username ) {
+	// by default, anybody who can authenticate is also
+	// authorized as an administrator.
+	if ( LDAP_ALL_USERS_ADMIN ) {
+		return true;
+	}
+
+	// users listed in config.php are admin users. let them in.
+	global $ldap_authorized_admins;
+	if ( in_array( $username, $ldap_authorized_admins ) ) {
+		return true;
+	}
+
+	// not an admin user
+	return false;
+}
+
+yourls_add_action( 'logout', 'ldap_logout_hook' );
+
+function ldap_logout_hook( $args ) {
+	unset($_SESSION['LDAP_AUTH_USER']);
+	setcookie('PHPSESSID', '', 0, '/');
+}