yourls-ldap-auth/plugin.php

264 lines
8.7 KiB
PHP

<?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 ldapauth_environment_check() {
$required_params = array(
'LDAPAUTH_HOST', // ldap host
//'LDAAUTHP_PORT', // ldap port
'LDAPAUTH_BASE', // base ldap path
//'LDAPAUTH_USERNAME_FIELD', // field to check the username against
);
foreach ($required_params as $pname) {
if ( !defined( $pname ) ) {
$message = 'Missing defined parameter '.$pname.' in plugin '. $thisplugname;
error_log($message);
return false;
}
}
if ( !defined( 'LDAPAUTH_PORT' ) )
define( 'LDAPAUTH_PORT', 389 );
if ( !defined( 'LDAPAUTH_USERNAME_FIELD' ) )
define( 'LDAPAUTH_USERNAME_FIELD', 'uid' );
if ( !defined( 'LDAPAUTH_ALL_USERS_ADMIN' ) )
define( 'LDAPAUTH_ALL_USERS_ADMIN', true );
if ( !defined( 'LDAPAUTH_ADD_NEW' ) )
define( 'LDAPAUTH_ADD_NEW', false );
global $ldapauth_authorized_admins;
if ( !isset( $ldapauth_authorized_admins ) ) {
if ( !LDAPAUTH_ALL_USERS_ADMIN ) {
error_log('Undefined $ldapauth_authorized_admins');
}
$ldapauth_authorized_admins = array();
}
return true;
}
yourls_add_filter( 'is_valid_user', 'ldapauth_is_valid_user' );
// returns true/false
function ldapauth_is_valid_user( $value ) {
global $yourls_user_passwords;
global $ydb;
$ldapauth_usercache = $ydb->option['ldapauth_usercache'];
// no point in continuing if the user has already been validated by core
if ($value) {
ldapauth_debug("Returning from ldapauth_is_valid_user as user is already validated");
return $value;
}
@session_start();
// Always check & set early
if ( !ldapauth_environment_check() ) {
die( 'Invalid configuration for YOURLS LDAP plugin. Check PHP error log.' );
}
/* is the cookie needed anymore? Since the user cache is merged with $yourls_user_passwords
* core's yourls_check_auth_cookie should work. If so, a logged in user will arrive in this
* function with $value true, the function returns early and we never get here
*/
if ( isset( $_SESSION['LDAPAUTH_AUTH_USER'] ) ) {
// already authenticated...
$username = $_SESSION['LDAPAUTH_AUTH_USER'];
// why is this checked here, but not before the cookie is set?
if ( ldapauth_is_authorized_user( $username ) ) {
yourls_set_user( $_SESSION['LDAPAUTH_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'] ) ) {
// try to authenticate
$ldapConnection = ldap_connect(LDAPAUTH_HOST, LDAPAUTH_PORT);
if (!$ldapConnection) die("Cannot connect to LDAP " . LDAPAUTH_HOST);
ldap_set_option($ldapConnection, LDAP_OPT_PROTOCOL_VERSION, 3);
//ldap_set_option($ldapConnection, LDAP_OPT_REFERRALS, 0);
// should we to try and bind using the credentials being logged in with?
if (defined('LDAPAUTH_BIND_WITH_USER_TEMPLATE')) {
$bindRDN = sprintf(LDAPAUTH_BIND_WITH_USER_TEMPLATE, $_REQUEST['username']);
if (!($ldapSuccess = @ldap_bind($ldapConnection, $bindRDN, $_REQUEST['password']))) {
error_log('Couldn\'t bind to LDAP server with user ' . $bindRDN);
return $value;
}
}
// Check if using a privileged user account to search - only if not already bound with current user
if (defined('LDAPAUTH_SEARCH_USER') && defined('LDAPAUTH_SEARCH_PASS') && empty($ldapSuccess)) {
if (!@ldap_bind($ldapConnection, LDAPAUTH_SEARCH_USER, LDAPAUTH_SEARCH_PASS)) {
die('Couldn\'t bind search user ' . LDAPAUTH_SEARCH_USER);
}
}
// Limit the attrs to the ones we need
$attrs = array('dn', LDAPAUTH_USERNAME_FIELD);
if (defined('LDAPAUTH_GROUP_ATTR'))
array_push($attrs, LDAPAUTH_GROUP_ATTR);
$searchDn = ldap_search($ldapConnection, LDAPAUTH_BASE, LDAPAUTH_USERNAME_FIELD . "=" . $_REQUEST['username'], $attrs );
if (!$searchDn) return $value;
$searchResult = ldap_get_entries($ldapConnection, $searchDn);
if (!$searchResult) return $value;
$userDn = $searchResult[0]['dn'];
if (!$userDn && !$ldapSuccess) return $value;
if (empty($ldapSuccess)) { // we don't need to do this if we already bound using username and LDAPAUTH_BIND_WITH_USER_TEMPLATE
$ldapSuccess = @ldap_bind($ldapConnection, $userDn, $_REQUEST['password']);
}
@ldap_close($ldapConnection);
// success?
if ($ldapSuccess)
{
// are we checking group auth?
if (defined('LDAPAUTH_GROUP_ATTR') && defined('LDAPAUTH_GROUP_REQ')) {
if (!array_key_exists(LDAPAUTH_GROUP_ATTR, $searchResult[0])) die('Not in any LDAP groups');
$in_group = false;
$groups_to_check = explode(";", strtolower(LDAPAUTH_GROUP_REQ)); // This is now an array
foreach($searchResult[0][LDAPAUTH_GROUP_ATTR] as $grps) {
if (in_array(strtolower($grps), $groups_to_check)) { $in_group = true; break; }
}
if (!$in_group) die('Not in admin group');
}
// attribute index returned by ldap_get_entries is lowercased (http://php.net/manual/en/function.ldap-get-entries.php)
$username = $searchResult[0][strtolower(LDAPAUTH_USERNAME_FIELD)][0];
yourls_set_user($username);
if (LDAPAUTH_ADD_NEW && !array_key_exists($username, $yourls_user_passwords)) {
ldapauth_create_user( $username, $_REQUEST['password'] );
}
// store the current user credentials in our cache. This cuts down calls to the LDAP
// server, and allows API keys to work with LDAP users
$ldapauth_usercache[$username] = 'phpass:' . ldapauth_hash_password($_REQUEST['password']);
yourls_update_option('ldapauth_usercache', $ldapauth_usercache);
$yourls_user_passwords[$username] = ldapauth_hash_password($_REQUEST['password']);
$_SESSION['LDAPAUTH_AUTH_USER'] = $username;
return true;
} else {
error_log("No LDAP success");
}
}
return $value;
}
function ldapauth_is_authorized_user( $username ) {
// by default, anybody who can authenticate is also
// authorized as an administrator.
if ( LDAPAUTH_ALL_USERS_ADMIN ) {
return true;
}
// users listed in config.php are admin users. let them in.
global $ldapauth_authorized_admins;
if ( in_array( $username, $ldapauth_authorized_admins ) ) {
return true;
}
// not an admin user
return false;
}
yourls_add_action( 'logout', 'ldapauth_logout_hook' );
function ldapauth_logout_hook( $args ) {
unset($_SESSION['LDAPAUTH_AUTH_USER']);
setcookie('PHPSESSID', '', 0, '/');
}
/* This action, called as early as possible, retrieves our cache of LDAP users and
* merges it with $yourls_user_passwords. This enables core to do the authorisation
* of previously seen LDAP users, and also means that API signatures for LDAP users
* will work. Users that exist in both users/config.php and LDAP will need to use
* their LDAP passwords
*/
yourls_add_action ('plugins_loaded', 'ldapauth_merge_users');
function ldapauth_merge_users() {
global $ydb;
global $yourls_user_passwords;
if(isset($ydb->option['ldapauth_usercache'])) {
ldapauth_debug("Merging text file users and cached LDAP users");
$yourls_user_passwords = array_merge($yourls_user_passwords, $ydb->option['ldapauth_usercache']);
}
}
/**
* Create user in config file
* Code reused from yourls_hash_passwords_now()
*/
function ldapauth_create_user( $user, $new_password ) {
$configdata = file_get_contents( YOURLS_CONFIGFILE );
if ( $configdata == FALSE ) {
die('Couldn\'t read the config file');
}
if (!is_writable(YOURLS_CONFIGFILE))
die('Can\'t write to config file');
$pass_hash = ldapauth_hash_password($new_password);
$user_line = "\t'$user' => 'phpass:$pass_hash' /* Password encrypted by YOURLS */,";
// Add the user on a new line after the start of the passwords array
$new_contents = preg_replace('/(yourls_user_passwords\s=\sarray\()/', '$0 ' . PHP_EOL . $user_line, $configdata, -1, $count);
if ($count === 0) {
die('Couldn\'t add user, plugin may not be compatible with YourLS version');
} else if ($count > 1) {
die('Added user more than once. Check config file.');
}
$success = file_put_contents( YOURLS_CONFIGFILE, $new_contents );
if ( $success === false ) {
die('Unable to save config file');
}
return $pass_hash;
}
/**
* Hashes password the same way as yourls_hash_passwords_now()
**/
function ldapauth_hash_password ($password) {
$pass_hash = yourls_phpass_hash( $password );
// PHP would interpret $ as a variable, so replace it in storage.
$pass_hash = str_replace( '$', '!', $pass_hash );
return $pass_hash;
}
function ldapauth_debug ($msg) {
if (defined('LDAPAUTH_DEBUG') && LDAPAUTH_DEBUG) {
error_log("yourls_ldap_auth: " . $msg);
}
}