engelsystem/includes/sys_auth.php

<?php


// Testet ob ein User eingeloggt ist und lädt die entsprechenden Privilegien
function load_auth() {
	global $user, $privileges;

	$user = null;
	if (isset ($_SESSION['uid'])) {
		$user = sql_select("SELECT * FROM `User` WHERE `UID`=" . sql_escape($_SESSION['uid']) . " LIMIT 1");
		if (count($user) > 0) {
			// User ist eingeloggt, Datensatz zur Verfügung stellen und Timestamp updaten
			list ($user) = $user;
			sql_query("UPDATE `User` SET " . "`lastLogIn` = '" . time() . "'" . " WHERE `UID` = '" . sql_escape($_SESSION['uid']) . "' LIMIT 1;");
		} else
			unset ($_SESSION['uid']);
	}

	$privileges = isset ($user) ? privileges_for_user($user['UID']) : privileges_for_group(-1);
}

// generate a salt (random string) of arbitrary length suitable for the use with crypt()
function generate_salt($length = 16) {
	$alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
	$salt = "";
	for ($i = 0; $i < $length; $i++) {
		$salt .= $alphabet[rand(0, strlen($alphabet)-1)];
	}
	return $salt;
}

// set the password of a user
function set_password($uid, $password) {
	$res = sql_query("UPDATE `User` SET `Passwort` = '" . sql_escape(crypt($password, CRYPT_ALG . '$' . generate_salt(16) . '$')) . "' WHERE `UID` = " . intval($uid) . " LIMIT 1");
	return $res && (mysql_affected_rows() > 0);
}

// verify a password given a precomputed salt.
// if $uid is given and $salt is an old-style salt (plain md5), we convert it automatically
function verify_password($password, $salt, $uid = false) {
	$correct = false;
	if (substr($salt, 0, 1) == '$') // new-style crypt()
		$correct = crypt($password, $salt) == $salt;
	elseif (substr($salt, 0, 7) == '{crypt}') // old-style crypt() with DES and static salt - not used anymore
		$correct = crypt($password, '77') == $salt;
	elseif (strlen($salt) == 32) // old-style md5 without salt - not used anymore
		$correct = md5($password) == $salt;

	if($correct && substr($salt, 0, strlen(CRYPT_ALG)) != CRYPT_ALG && $uid) {
		// this password is stored in another format than we want it to be.
		// let's update it!
		// we duplicate the query from the above set_password() function to have the extra safety of checking the old hash
		sql_query("UPDATE `User` SET `Passwort` = '" . sql_escape(crypt($password, CRYPT_ALG . '$' . generate_salt() . '$')) . "' WHERE `UID` = " . intval($uid) . " AND `Passwort` = '" . sql_escape($salt) . "' LIMIT 1");
	}
	return $correct;
}

// JSON Authorisierungs-Schnittstelle
function json_auth_service() {
	global $CurrentExternAuthPass;

	header("Content-Type: application/json");

	$User = $_REQUEST['user'];
	$Pass = $_REQUEST['pw'];
	$SourceOuth = $_REQUEST['so'];

	if (isset ($CurrentExternAuthPass) && $SourceOuth == $CurrentExternAuthPass) {
		$sql = "SELECT `UID`, `Passwort` FROM `User` WHERE `Nick`='" . sql_escape($User) . "'";
		$Erg = sql_select($sql);

		if (count($Erg) == 1) {
			$Erg = $Erg[0];
			if (verify_password($Pass, $Erg["Passwort"], $Erg["UID"])) {
				$UID = mysql_result($Erg, 0, "UID");

				$user_privs = sql_select("SELECT `Privileges`.`name` FROM `User` JOIN `UserGroups` ON (`User`.`UID` = `UserGroups`.`uid`) JOIN `GroupPrivileges` ON (`UserGroups`.`group_id` = `GroupPrivileges`.`group_id`) JOIN `Privileges` ON (`GroupPrivileges`.`privilege_id` = `Privileges`.`id`) WHERE `User`.`UID`=" . sql_escape($UID) . ";");
				foreach ($user_privs as $user_priv)
					$privileges[] = $user_priv['name'];

				$msg = array (
					'status' => 'success',
					'rights' => $privileges
				);
				echo json_encode($msg);
				die();
			}
		}
	}

	echo json_encode(array (
		'status' => 'failed',
		'error' => "JSON Service GET syntax: https://engelsystem.de/?auth&user=<user>&pw=<password>&so=<key>, POST is possible too"
	));
	die();
}

function privileges_for_user($user_id) {
	$privileges = array ();
	$user_privs = sql_select("SELECT `Privileges`.`name` FROM `User` JOIN `UserGroups` ON (`User`.`UID` = `UserGroups`.`uid`) JOIN `GroupPrivileges` ON (`UserGroups`.`group_id` = `GroupPrivileges`.`group_id`) JOIN `Privileges` ON (`GroupPrivileges`.`privilege_id` = `Privileges`.`id`) WHERE `User`.`UID`=" . sql_escape($user_id) . ";");
	foreach ($user_privs as $user_priv)
		$privileges[] = $user_priv['name'];
	return $privileges;
}

function privileges_for_group($group_id) {
	$privileges = array ();
	$groups_privs = sql_select("SELECT * FROM `GroupPrivileges` JOIN `Privileges` ON (`GroupPrivileges`.`privilege_id` = `Privileges`.`id`) WHERE `group_id`=" . sql_escape($group_id));
	foreach ($groups_privs as $guest_priv)
		$privileges[] = $guest_priv['name'];
	return $privileges;
}
?>