<?php
/**
 * Name: LDAP Authenticate
 * Description: Authenticate a user against an LDAP directory
 * Version: 1.1
 * Author: Mike Macgirvin <http://macgirvin.com/profile/mike>
 * Author: aymhce
 */
 
/**
 * Friendica addon
 * 
 * Module: LDAP Authenticate
 *
 * Authenticate a user against an LDAP directory
 * Useful for Windows Active Directory and other LDAP-based organisations
 * to maintain a single password across the organisation.
 *
 * Optionally authenticates only if a member of a given group in the directory.
 *
 * By default, the person must have registered with Friendica using the normal registration 
 * procedures in order to have a Friendica user record, contact, and profile.
 * However, it's possible with an option to automate the creation of a Friendica basic account.
 *
 * Note when using with Windows Active Directory: you may need to set TLS_CACERT in your site
 * ldap.conf file to the signing cert for your LDAP server. 
 * 
 * The required configuration options for this module may be set in the .htconfig.php file
 * e.g.:
 *
 * $a->config['ldapauth']['ldap_server'] = 'host.example.com';
 * ...etc.
 *
 */

require_once('include/user.php');


function ldapauth_install() {
	register_hook('authenticate', 'addon/ldapauth/ldapauth.php', 'ldapauth_hook_authenticate');
}


function ldapauth_uninstall() {
	unregister_hook('authenticate', 'addon/ldapauth/ldapauth.php', 'ldapauth_hook_authenticate');
}


function ldapauth_hook_authenticate($a,&$b) {
	if(ldapauth_authenticate($b['username'],$b['password']) && is_existing_account($b['username'])) {
		$b['user_record'] = $results[0];
		$b['authenticated'] = 1;
	}
	return;
}

function ldapauth_authenticate($username,$password) {

    $ldap_server   = get_config('ldapauth','ldap_server');
    $ldap_binddn   = get_config('ldapauth','ldap_binddn');
    $ldap_bindpw   = get_config('ldapauth','ldap_bindpw');
    $ldap_searchdn = get_config('ldapauth','ldap_searchdn');
    $ldap_userattr = get_config('ldapauth','ldap_userattr');
    $ldap_group    = get_config('ldapauth','ldap_group');
	$ldap_autocreateaccount = get_config('ldapauth','ldap_autocreateaccount');
	$ldap_autocreateaccount_emailattribute = get_config('ldapauth','ldap_autocreateaccount_emailattribute');
	$ldap_autocreateaccount_nameattribute = get_config('ldapauth','ldap_autocreateaccount_nameattribute');

	if(! strlen($ldap_autocreateaccount_emailattribute))
		$ldap_autocreateaccount_emailattribute = "mail";
	if(! strlen($ldap_autocreateaccount_nameattribute))
		$ldap_autocreateaccount_nameattribute = "givenName";
	
    if(! ((strlen($password))
            && (function_exists('ldap_connect'))
            && (strlen($ldap_server))))
            return false;

    $connect = @ldap_connect($ldap_server);

    if(! $connect)
        return false;

    @ldap_set_option($connect, LDAP_OPT_PROTOCOL_VERSION,3);
    @ldap_set_option($connect, LDAP_OPT_REFERRALS, 0);
    if((@ldap_bind($connect,$ldap_binddn,$ldap_bindpw)) === false) {
        return false;
    }

    $res = @ldap_search($connect,$ldap_searchdn, $ldap_userattr . '=' . $username);

    if(! $res) {
        return false;
    }

    $id = @ldap_first_entry($connect,$res);

    if(! $id) {
        return false;
    }

    $dn = @ldap_get_dn($connect,$id);

    if(! @ldap_bind($connect,$dn,$password))
        return false;
		
	$emailarray = @ldap_get_values($connect, $id, $ldap_autocreateaccount_emailattribute);
	$namearray = @ldap_get_values($connect, $id, $ldap_autocreateaccount_nameattribute);

    if(! strlen($ldap_group)){
		ldap_autocreateaccount($ldap_autocreateaccount,$username,$password,$emailarray[0],$namearray[0]);
        return true;
	}

    $r = @ldap_compare($connect,$ldap_group,'member',$dn);
    if ($r === -1) {
        $err = @ldap_error($connect);
        $eno = @ldap_errno($connect);
        @ldap_close($connect);

        if ($eno === 32) {
            logger("ldapauth: access control group Does Not Exist");
            return false;
        }
        elseif ($eno === 16) {
            logger('ldapauth: membership attribute does not exist in access control group');
            return false;
        }
        else {
            logger('ldapauth: error: ' . $err);
            return false;
        }
    }
    elseif ($r === false) {
        @ldap_close($connect);
        return false;
    }

	ldap_autocreateaccount($ldap_autocreateaccount,$username,$password,$emailarray[0],$namearray[0]);
    return true;
}

function ldap_autocreateaccount($ldap_autocreateaccount,$username,$password,$email,$name) {
	if($ldap_autocreateaccount == "true" && !is_existing_account($username)){
		if (strlen($email) > 0 && strlen($name) > 0){
			$arr = array('username'=>$name,'nickname'=>$username,'email'=>$email,'password'=>$password,'verified'=>1);
			$result = create_user($arr);
			if ($result['success']){
				logger("ldapauth: account " . $username . " created");
			}else{
				logger("ldapauth: account " . $username . " was not created ! : " . implode($result));
			}
		}else{
			logger("ldapauth: unable to create account, no email or nickname found");
		}
	}
}

function is_existing_account($username){
	$results = q("SELECT * FROM `user` WHERE `nickname` = '%s' AND `blocked` = 0 AND `verified` = 1 LIMIT 1",$username);
	if(count($results)) {
		return true;
	}
	return false;
}