julienmonnerie/kirby/src/Cms/Auth.php
2022-06-17 17:51:59 +02:00

887 lines
28 KiB
PHP

<?php
namespace Kirby\Cms;
use Kirby\Cms\Auth\Status;
use Kirby\Data\Data;
use Kirby\Exception\InvalidArgumentException;
use Kirby\Exception\LogicException;
use Kirby\Exception\NotFoundException;
use Kirby\Exception\PermissionException;
use Kirby\Filesystem\F;
use Kirby\Http\Idn;
use Kirby\Http\Request\Auth\BasicAuth;
use Kirby\Toolkit\A;
use Throwable;
/**
* Authentication layer
*
* @package Kirby Cms
* @author Bastian Allgeier <bastian@getkirby.com>
* @link https://getkirby.com
* @copyright Bastian Allgeier
* @license https://getkirby.com/license
*/
class Auth
{
/**
* Available auth challenge classes
* from the core and plugins
*
* @var array
*/
public static $challenges = [];
/**
* Currently impersonated user
*
* @var \Kirby\Cms\User|null
*/
protected $impersonate;
/**
* Kirby instance
*
* @var \Kirby\Cms\App
*/
protected $kirby;
/**
* Cache of the auth status object
*
* @var \Kirby\Cms\Auth\Status
*/
protected $status;
/**
* Instance of the currently logged in user or
* `false` if the user was not yet determined
*
* @var \Kirby\Cms\User|null|false
*/
protected $user = false;
/**
* Exception that was thrown while
* determining the current user
*
* @var \Throwable
*/
protected $userException;
/**
* @param \Kirby\Cms\App $kirby
* @codeCoverageIgnore
*/
public function __construct(App $kirby)
{
$this->kirby = $kirby;
}
/**
* Creates an authentication challenge
* (one-time auth code)
* @since 3.5.0
*
* @param string $email
* @param bool $long If `true`, a long session will be created
* @param string $mode Either 'login' or 'password-reset'
* @return \Kirby\Cms\Auth\Status
*
* @throws \Kirby\Exception\LogicException If there is no suitable authentication challenge (only in debug mode)
* @throws \Kirby\Exception\NotFoundException If the user does not exist (only in debug mode)
* @throws \Kirby\Exception\PermissionException If the rate limit is exceeded
*/
public function createChallenge(string $email, bool $long = false, string $mode = 'login')
{
$email = $this->validateEmail($email);
// rate-limit the number of challenges for DoS/DDoS protection
$this->track($email, false);
$session = $this->kirby->session([
'createMode' => 'cookie',
'long' => $long === true
]);
$challenge = null;
if ($user = $this->kirby->users()->find($email)) {
$timeout = $this->kirby->option('auth.challenge.timeout', 10 * 60);
foreach ($this->enabledChallenges() as $name) {
$class = static::$challenges[$name] ?? null;
if (
$class &&
class_exists($class) === true &&
is_subclass_of($class, 'Kirby\Cms\Auth\Challenge') === true &&
$class::isAvailable($user, $mode) === true
) {
$challenge = $name;
$code = $class::create($user, compact('mode', 'timeout'));
$session->set('kirby.challenge.type', $challenge);
if ($code !== null) {
$session->set('kirby.challenge.code', password_hash($code, PASSWORD_DEFAULT));
$session->set('kirby.challenge.timeout', time() + $timeout);
}
break;
}
}
// if no suitable challenge was found, `$challenge === null` at this point;
// only leak this in debug mode
if ($challenge === null && $this->kirby->option('debug') === true) {
throw new LogicException('Could not find a suitable authentication challenge');
}
} else {
$this->kirby->trigger('user.login:failed', compact('email'));
// only leak the non-existing user in debug mode
if ($this->kirby->option('debug') === true) {
throw new NotFoundException([
'key' => 'user.notFound',
'data' => [
'name' => $email
]
]);
}
}
// always set the email, even if the challenge won't be
// created to avoid leaking whether the user exists
$session->set('kirby.challenge.email', $email);
// sleep for a random amount of milliseconds
// to make automated attacks harder and to
// avoid leaking whether the user exists
usleep(random_int(1000, 300000));
// clear the status cache
$this->status = null;
return $this->status($session, false);
}
/**
* Returns the csrf token if it exists and if it is valid
*
* @return string|false
*/
public function csrf()
{
// get the csrf from the header
$fromHeader = $this->kirby->request()->csrf();
// check for a predefined csrf or use the one from session
$fromSession = $this->csrfFromSession();
// compare both tokens
if (hash_equals((string)$fromSession, (string)$fromHeader) !== true) {
return false;
}
return $fromSession;
}
/**
* Returns either predefined csrf or the one from session
* @since 3.6.0
*
* @return string
*/
public function csrfFromSession(): string
{
$isDev = $this->kirby->option('panel.dev', false) !== false;
return $this->kirby->option('api.csrf', $isDev ? 'dev' : csrf());
}
/**
* Returns the logged in user by checking
* for a basic authentication header with
* valid credentials
*
* @param \Kirby\Http\Request\Auth\BasicAuth|null $auth
* @return \Kirby\Cms\User|null
* @throws \Kirby\Exception\InvalidArgumentException if the authorization header is invalid
* @throws \Kirby\Exception\PermissionException if basic authentication is not allowed
*/
public function currentUserFromBasicAuth(BasicAuth $auth = null)
{
if ($this->kirby->option('api.basicAuth', false) !== true) {
throw new PermissionException('Basic authentication is not activated');
}
// if logging in with password is disabled, basic auth cannot be possible either
$loginMethods = $this->kirby->system()->loginMethods();
if (isset($loginMethods['password']) !== true) {
throw new PermissionException('Login with password is not enabled');
}
// if any login method requires 2FA, basic auth without 2FA would be a weakness
foreach ($loginMethods as $method) {
if (isset($method['2fa']) === true && $method['2fa'] === true) {
throw new PermissionException('Basic authentication cannot be used with 2FA');
}
}
$request = $this->kirby->request();
$auth = $auth ?? $request->auth();
if (!$auth || $auth->type() !== 'basic') {
throw new InvalidArgumentException('Invalid authorization header');
}
// only allow basic auth when https is enabled or insecure requests permitted
if ($request->ssl() === false && $this->kirby->option('api.allowInsecure', false) !== true) {
throw new PermissionException('Basic authentication is only allowed over HTTPS');
}
return $this->validatePassword($auth->username(), $auth->password());
}
/**
* Returns the currently impersonated user
*
* @return \Kirby\Cms\User|null
*/
public function currentUserFromImpersonation()
{
return $this->impersonate;
}
/**
* Returns the logged in user by checking
* the current session and finding a valid
* valid user id in there
*
* @param \Kirby\Session\Session|array|null $session
* @return \Kirby\Cms\User|null
*/
public function currentUserFromSession($session = null)
{
$session = $this->session($session);
$id = $session->data()->get('kirby.userId');
if (is_string($id) !== true) {
return null;
}
if ($user = $this->kirby->users()->find($id)) {
// in case the session needs to be updated, do it now
// for better performance
$session->commit();
return $user;
}
return null;
}
/**
* Returns the list of enabled challenges in the
* configured order
* @since 3.5.1
*
* @return array
*/
public function enabledChallenges(): array
{
return A::wrap($this->kirby->option('auth.challenges', ['email']));
}
/**
* Become any existing user or disable the current user
*
* @param string|null $who User ID or email address,
* `null` to use the actual user again,
* `'kirby'` for a virtual admin user or
* `'nobody'` to disable the actual user
* @return \Kirby\Cms\User|null
* @throws \Kirby\Exception\NotFoundException if the given user cannot be found
*/
public function impersonate(?string $who = null)
{
// clear the status cache
$this->status = null;
switch ($who) {
case null:
return $this->impersonate = null;
case 'kirby':
return $this->impersonate = new User([
'email' => 'kirby@getkirby.com',
'id' => 'kirby',
'role' => 'admin',
]);
case 'nobody':
return $this->impersonate = new User([
'email' => 'nobody@getkirby.com',
'id' => 'nobody',
'role' => 'nobody',
]);
default:
if ($user = $this->kirby->users()->find($who)) {
return $this->impersonate = $user;
}
throw new NotFoundException('The user "' . $who . '" cannot be found');
}
}
/**
* Returns the hashed ip of the visitor
* which is used to track invalid logins
*
* @return string
*/
public function ipHash(): string
{
$hash = hash('sha256', $this->kirby->visitor()->ip());
// only use the first 50 chars to ensure privacy
return substr($hash, 0, 50);
}
/**
* Check if logins are blocked for the current ip or email
*
* @param string $email
* @return bool
*/
public function isBlocked(string $email): bool
{
$ip = $this->ipHash();
$log = $this->log();
$trials = $this->kirby->option('auth.trials', 10);
if ($entry = ($log['by-ip'][$ip] ?? null)) {
if ($entry['trials'] >= $trials) {
return true;
}
}
if ($this->kirby->users()->find($email)) {
if ($entry = ($log['by-email'][$email] ?? null)) {
if ($entry['trials'] >= $trials) {
return true;
}
}
}
return false;
}
/**
* Login a user by email and password
*
* @param string $email
* @param string $password
* @param bool $long
* @return \Kirby\Cms\User
*
* @throws \Kirby\Exception\PermissionException If the rate limit was exceeded or if any other error occurred with debug mode off
* @throws \Kirby\Exception\NotFoundException If the email was invalid
* @throws \Kirby\Exception\InvalidArgumentException If the password is not valid (via `$user->login()`)
*/
public function login(string $email, string $password, bool $long = false)
{
// session options
$options = [
'createMode' => 'cookie',
'long' => $long === true
];
// validate the user and log in to the session
$user = $this->validatePassword($email, $password);
$user->loginPasswordless($options);
// clear the status cache
$this->status = null;
return $user;
}
/**
* Login a user by email, password and auth challenge
* @since 3.5.0
*
* @param string $email
* @param string $password
* @param bool $long
* @return \Kirby\Cms\Auth\Status
*
* @throws \Kirby\Exception\PermissionException If the rate limit was exceeded or if any other error occurred with debug mode off
* @throws \Kirby\Exception\NotFoundException If the email was invalid
* @throws \Kirby\Exception\InvalidArgumentException If the password is not valid (via `$user->login()`)
*/
public function login2fa(string $email, string $password, bool $long = false)
{
$this->validatePassword($email, $password);
return $this->createChallenge($email, $long, '2fa');
}
/**
* Sets a user object as the current user in the cache
* @internal
*
* @param \Kirby\Cms\User $user
* @return void
*/
public function setUser(User $user): void
{
// stop impersonating
$this->impersonate = null;
$this->user = $user;
// clear the status cache
$this->status = null;
}
/**
* Returns the authentication status object
* @since 3.5.1
*
* @param \Kirby\Session\Session|array|null $session
* @param bool $allowImpersonation If set to false, only the actually
* logged in user will be returned
* @return \Kirby\Cms\Auth\Status
*/
public function status($session = null, bool $allowImpersonation = true)
{
// try to return from cache
if ($this->status && $session === null && $allowImpersonation === true) {
return $this->status;
}
$sessionObj = $this->session($session);
$props = ['kirby' => $this->kirby];
if ($user = $this->user($sessionObj, $allowImpersonation)) {
// a user is currently logged in
if ($allowImpersonation === true && $this->impersonate !== null) {
$props['status'] = 'impersonated';
} else {
$props['status'] = 'active';
}
$props['email'] = $user->email();
} elseif ($email = $sessionObj->get('kirby.challenge.email')) {
// a challenge is currently pending
$props['status'] = 'pending';
$props['email'] = $email;
$props['challenge'] = $sessionObj->get('kirby.challenge.type');
$props['challengeFallback'] = A::last($this->enabledChallenges());
} else {
// no active authentication
$props['status'] = 'inactive';
}
$status = new Status($props);
// only cache the default object
if ($session === null && $allowImpersonation === true) {
$this->status = $status;
}
return $status;
}
/**
* Ensures that email addresses with IDN domains are in Unicode format
* and that the rate limit was not exceeded
*
* @param string $email
* @return string The normalized Unicode email address
*
* @throws \Kirby\Exception\PermissionException If the rate limit was exceeded
*/
protected function validateEmail(string $email): string
{
// ensure that email addresses with IDN domains are in Unicode format
$email = Idn::decodeEmail($email);
// check for blocked ips
if ($this->isBlocked($email) === true) {
$this->kirby->trigger('user.login:failed', compact('email'));
if ($this->kirby->option('debug') === true) {
$message = 'Rate limit exceeded';
} else {
// avoid leaking security-relevant information
$message = ['key' => 'access.login'];
}
throw new PermissionException($message);
}
return $email;
}
/**
* Validates the user credentials and returns the user object on success;
* otherwise logs the failed attempt
*
* @param string $email
* @param string $password
* @return \Kirby\Cms\User
*
* @throws \Kirby\Exception\PermissionException If the rate limit was exceeded or if any other error occurred with debug mode off
* @throws \Kirby\Exception\NotFoundException If the email was invalid
* @throws \Kirby\Exception\InvalidArgumentException If the password is not valid (via `$user->login()`)
*/
public function validatePassword(string $email, string $password)
{
$email = $this->validateEmail($email);
// validate the user
try {
if ($user = $this->kirby->users()->find($email)) {
if ($user->validatePassword($password) === true) {
return $user;
}
}
throw new NotFoundException([
'key' => 'user.notFound',
'data' => [
'name' => $email
]
]);
} catch (Throwable $e) {
// log invalid login trial
$this->track($email);
// sleep for a random amount of milliseconds
// to make automated attacks harder
usleep(random_int(1000, 2000000));
// keep throwing the original error in debug mode,
// otherwise hide it to avoid leaking security-relevant information
if ($this->kirby->option('debug') === true) {
throw $e;
} else {
throw new PermissionException(['key' => 'access.login']);
}
}
}
/**
* Returns the absolute path to the logins log
*
* @return string
*/
public function logfile(): string
{
return $this->kirby->root('accounts') . '/.logins';
}
/**
* Read all tracked logins
*
* @return array
*/
public function log(): array
{
try {
$log = Data::read($this->logfile(), 'json');
$read = true;
} catch (Throwable $e) {
$log = [];
$read = false;
}
// ensure that the category arrays are defined
$log['by-ip'] = $log['by-ip'] ?? [];
$log['by-email'] = $log['by-email'] ?? [];
// remove all elements on the top level with different keys (old structure)
$log = array_intersect_key($log, array_flip(['by-ip', 'by-email']));
// remove entries that are no longer needed
$originalLog = $log;
$time = time() - $this->kirby->option('auth.timeout', 3600);
foreach ($log as $category => $entries) {
$log[$category] = array_filter(
$entries,
fn ($entry) => $entry['time'] > $time
);
}
// write new log to the file system if it changed
if ($read === false || $log !== $originalLog) {
if (count($log['by-ip']) === 0 && count($log['by-email']) === 0) {
F::remove($this->logfile());
} else {
Data::write($this->logfile(), $log, 'json');
}
}
return $log;
}
/**
* Logout the current user
*
* @return void
*/
public function logout(): void
{
// stop impersonating;
// ensures that we log out the actually logged in user
$this->impersonate = null;
// logout the current user if it exists
if ($user = $this->user()) {
$user->logout();
}
// clear the pending challenge
$session = $this->kirby->session();
$session->remove('kirby.challenge.code');
$session->remove('kirby.challenge.email');
$session->remove('kirby.challenge.timeout');
$session->remove('kirby.challenge.type');
// clear the status cache
$this->status = null;
}
/**
* Clears the cached user data after logout
* @internal
*
* @return void
*/
public function flush(): void
{
$this->impersonate = null;
$this->status = null;
$this->user = null;
}
/**
* Tracks a login
*
* @param string|null $email
* @param bool $triggerHook If `false`, no user.login:failed hook is triggered
* @return bool
*/
public function track(?string $email, bool $triggerHook = true): bool
{
if ($triggerHook === true) {
$this->kirby->trigger('user.login:failed', compact('email'));
}
$ip = $this->ipHash();
$log = $this->log();
$time = time();
if (isset($log['by-ip'][$ip]) === true) {
$log['by-ip'][$ip] = [
'time' => $time,
'trials' => ($log['by-ip'][$ip]['trials'] ?? 0) + 1
];
} else {
$log['by-ip'][$ip] = [
'time' => $time,
'trials' => 1
];
}
if ($email !== null && $this->kirby->users()->find($email)) {
if (isset($log['by-email'][$email]) === true) {
$log['by-email'][$email] = [
'time' => $time,
'trials' => ($log['by-email'][$email]['trials'] ?? 0) + 1
];
} else {
$log['by-email'][$email] = [
'time' => $time,
'trials' => 1
];
}
}
return Data::write($this->logfile(), $log, 'json');
}
/**
* Returns the current authentication type
*
* @param bool $allowImpersonation If set to false, 'impersonate' won't
* be returned as authentication type
* even if an impersonation is active
* @return string
*/
public function type(bool $allowImpersonation = true): string
{
$basicAuth = $this->kirby->option('api.basicAuth', false);
$auth = $this->kirby->request()->auth();
if ($basicAuth === true && $auth && $auth->type() === 'basic') {
return 'basic';
} elseif ($allowImpersonation === true && $this->impersonate !== null) {
return 'impersonate';
} else {
return 'session';
}
}
/**
* Validates the currently logged in user
*
* @param \Kirby\Session\Session|array|null $session
* @param bool $allowImpersonation If set to false, only the actually
* logged in user will be returned
* @return \Kirby\Cms\User|null
*
* @throws \Throwable If an authentication error occurred
*/
public function user($session = null, bool $allowImpersonation = true)
{
if ($allowImpersonation === true && $this->impersonate !== null) {
return $this->impersonate;
}
// return from cache
if ($this->user === null) {
// throw the same Exception again if one was captured before
if ($this->userException !== null) {
throw $this->userException;
}
return null;
} elseif ($this->user !== false) {
return $this->user;
}
try {
if ($this->type() === 'basic') {
return $this->user = $this->currentUserFromBasicAuth();
} else {
return $this->user = $this->currentUserFromSession($session);
}
} catch (Throwable $e) {
$this->user = null;
// capture the Exception for future calls
$this->userException = $e;
throw $e;
}
}
/**
* Verifies an authentication code that was
* requested with the `createChallenge()` method;
* if successful, the user is automatically logged in
* @since 3.5.0
*
* @param string $code User-provided auth code to verify
* @return \Kirby\Cms\User User object of the logged-in user
*
* @throws \Kirby\Exception\PermissionException If the rate limit was exceeded, the challenge timed out, the code
* is incorrect or if any other error occurred with debug mode off
* @throws \Kirby\Exception\NotFoundException If the user from the challenge doesn't exist
* @throws \Kirby\Exception\InvalidArgumentException If no authentication challenge is active
* @throws \Kirby\Exception\LogicException If the authentication challenge is invalid
*/
public function verifyChallenge(string $code)
{
try {
$session = $this->kirby->session();
// first check if we have an active challenge at all
$email = $session->get('kirby.challenge.email');
$challenge = $session->get('kirby.challenge.type');
if (is_string($email) !== true || is_string($challenge) !== true) {
throw new InvalidArgumentException('No authentication challenge is active');
}
$user = $this->kirby->users()->find($email);
if ($user === null) {
throw new NotFoundException([
'key' => 'user.notFound',
'data' => [
'name' => $email
]
]);
}
// rate-limiting
if ($this->isBlocked($email) === true) {
$this->kirby->trigger('user.login:failed', compact('email'));
throw new PermissionException('Rate limit exceeded');
}
// time-limiting
$timeout = $session->get('kirby.challenge.timeout');
if ($timeout !== null && time() > $timeout) {
throw new PermissionException('Authentication challenge timeout');
}
if (
isset(static::$challenges[$challenge]) === true &&
class_exists(static::$challenges[$challenge]) === true &&
is_subclass_of(static::$challenges[$challenge], 'Kirby\Cms\Auth\Challenge') === true
) {
$class = static::$challenges[$challenge];
if ($class::verify($user, $code) === true) {
$this->logout();
$user->loginPasswordless();
// clear the status cache
$this->status = null;
return $user;
} else {
throw new PermissionException(['key' => 'access.code']);
}
}
throw new LogicException('Invalid authentication challenge: ' . $challenge);
} catch (Throwable $e) {
if (empty($email) === false && $e->getMessage() !== 'Rate limit exceeded') {
$this->track($email);
}
// sleep for a random amount of milliseconds
// to make automated attacks harder and to
// avoid leaking whether the user exists
usleep(random_int(1000, 2000000));
// keep throwing the original error in debug mode,
// otherwise hide it to avoid leaking security-relevant information
if ($this->kirby->option('debug') === true) {
throw $e;
} else {
throw new PermissionException(['key' => 'access.code']);
}
}
}
/**
* Creates a session object from the passed options
*
* @param \Kirby\Session\Session|array|null $session
* @return \Kirby\Session\Session
*/
protected function session($session = null)
{
// use passed session options or session object if set
if (is_array($session) === true) {
return $this->kirby->session($session);
}
// try session in header or cookie
if (is_a($session, 'Kirby\Session\Session') === false) {
return $this->kirby->session(['detect' => true]);
}
return $session;
}
}