<?php

namespace SilverStripe\Security;

use Form;
use SilverStripe\ORM\ArrayList;
use SilverStripe\ORM\DataObject;
use SilverStripe\ORM\DB;
use Controller;
use SS_HTTPRequest;
use TemplateGlobalProvider;
use Deprecation;
use Director;
use SS_HTTPResponse;
use Session;
use Config;
use Exception;
use Page;
use Page_Controller;
use ArrayData;
use FieldList;
use EmailField;
use FormAction;
use Convert;
use Object;
use ClassInfo;

/**
 * Implements a basic security model
 * @package framework
 * @subpackage security
 */
class Security extends Controller implements TemplateGlobalProvider {

	private static $allowed_actions = array(
		'index',
		'login',
		'logout',
		'basicauthlogin',
		'lostpassword',
		'passwordsent',
		'changepassword',
		'ping',
		'LoginForm',
		'ChangePasswordForm',
		'LostPasswordForm',
	);

	/**
	 * Default user name. Only used in dev-mode by {@link setDefaultAdmin()}
	 *
	 * @var string
	 * @see setDefaultAdmin()
	 */
	protected static $default_username;

	/**
	 * Default password. Only used in dev-mode by {@link setDefaultAdmin()}
	 *
	 * @var string
	 * @see setDefaultAdmin()
	 */
	protected static $default_password;

	/**
	 * If set to TRUE to prevent sharing of the session across several sites
	 * in the domain.
	 *
	 * @config
	 * @var bool
	 */
	protected static $strict_path_checking = false;

	/**
	 * The password encryption algorithm to use by default.
	 * This is an arbitrary code registered through {@link PasswordEncryptor}.
	 *
	 * @config
	 * @var string
	 */
	private static $password_encryption_algorithm = 'blowfish';

	/**
	 * Showing "Remember me"-checkbox
	 * on loginform, and saving encrypted credentials to a cookie.
 	 *
 	 * @config
	 * @var bool
	 */
	private static $autologin_enabled = true;

	/**
	 * Determine if login username may be remembered between login sessions
	 * If set to false this will disable autocomplete and prevent username persisting in the session
	 *
	 * @config
	 * @var bool
	 */
	private static $remember_username = true;

	/**
	 * Location of word list to use for generating passwords
	 *
	 * @config
	 * @var string
	 */
	private static $word_list = './wordlist.txt';

	/**
	 * @config
	 * @var string
	 */
	private static $template = 'BlankPage';

	/**
	 * Template thats used to render the pages.
	 *
	 * @var string
	 * @config
	 */
	private static $template_main = 'Page';

	/**
	 * Default message set used in permission failures.
	 *
	 * @config
	 * @var array|string
	 */
	private static $default_message_set;

	/**
	 * Random secure token, can be used as a crypto key internally.
	 * Generate one through 'sake dev/generatesecuretoken'.
	 *
	 * @config
	 * @var String
	 */
	private static $token;

	/**
	 * The default login URL
	 *
	 * @config
	 *
	 * @var string
	 */
	private static $login_url = "Security/login";

	/**
	 * The default logout URL
	 *
	 * @config
	 *
	 * @var string
	 */
	private static $logout_url = "Security/logout";

	/**
	 * Get location of word list file
	 *
	 * @deprecated 4.0 Use the "Security.word_list" config setting instead
	 */
	public static function get_word_list() {
		Deprecation::notice('4.0', 'Use the "Security.word_list" config setting instead');
		return self::config()->word_list;
	}

	/**
	 * Enable or disable recording of login attempts
	 * through the {@link LoginRecord} object.
	 *
	 * @config
	 * @var boolean $login_recording
	 */
	private static $login_recording = false;

	/**
	 * @var boolean If set to TRUE or FALSE, {@link database_is_ready()}
	 * will always return FALSE. Used for unit testing.
	 */
	static $force_database_is_ready = null;

	/**
	 * When the database has once been verified as ready, it will not do the
	 * checks again.
	 *
	 * @var bool
	 */
	static $database_is_ready = false;

	/**
	 * Set location of word list file
	 *
	 * @deprecated 4.0 Use the "Security.word_list" config setting instead
	 * @param string $wordListFile Location of word list file
	 */
	public static function set_word_list($wordListFile) {
		Deprecation::notice('4.0', 'Use the "Security.word_list" config setting instead');
		self::config()->word_list = $wordListFile;
	}

	/**
	 * Set the default message set used in permissions failures.
	 *
	 * @deprecated 4.0 Use the "Security.default_message_set" config setting instead
	 * @param string|array $messageSet
	 */
	public static function set_default_message_set($messageSet) {
		Deprecation::notice('4.0', 'Use the "Security.default_message_set" config setting instead');
		self::config()->default_message_set = $messageSet;
	}


	/**
	 * Register that we've had a permission failure trying to view the given page
	 *
	 * This will redirect to a login page.
	 * If you don't provide a messageSet, a default will be used.
	 *
	 * @param Controller $controller The controller that you were on to cause the permission
	 *                               failure.
	 * @param string|array $messageSet The message to show to the user. This
	 *                                 can be a string, or a map of different
	 *                                 messages for different contexts.
	 *                                 If you pass an array, you can use the
	 *                                 following keys:
	 *                                   - default: The default message
	 *                                   - alreadyLoggedIn: The message to
	 *                                                      show if the user
	 *                                                      is already logged
	 *                                                      in and lacks the
	 *                                                      permission to
	 *                                                      access the item.
	 *
	 * The alreadyLoggedIn value can contain a '%s' placeholder that will be replaced with a link
	 * to log in.
	 * @return SS_HTTPResponse
	 */
	public static function permissionFailure($controller = null, $messageSet = null) {
		self::set_ignore_disallowed_actions(true);

		if(!$controller) $controller = Controller::curr();

		if(Director::is_ajax()) {
			$response = ($controller) ? $controller->getResponse() : new SS_HTTPResponse();
			$response->setStatusCode(403);
			if(!Member::currentUser()) {
				$response->setBody(_t('ContentController.NOTLOGGEDIN','Not logged in'));
				$response->setStatusDescription(_t('ContentController.NOTLOGGEDIN','Not logged in'));
				// Tell the CMS to allow re-aunthentication
				if(CMSSecurity::enabled()) {
					$response->addHeader('X-Reauthenticate', '1');
				}
			}
			return $response;
		}

		// Prepare the messageSet provided
		if(!$messageSet) {
			if($configMessageSet = static::config()->get('default_message_set')) {
				$messageSet = $configMessageSet;
			} else {
				$messageSet = array(
					'default' => _t(
						'Security.NOTEPAGESECURED',
						"That page is secured. Enter your credentials below and we will send "
							. "you right along."
					),
					'alreadyLoggedIn' => _t(
						'Security.ALREADYLOGGEDIN',
						"You don't have access to this page.  If you have another account that "
							. "can access that page, you can log in again below.",

						"%s will be replaced with a link to log in."
					)
				);
			}
		}

		if(!is_array($messageSet)) {
			$messageSet = array('default' => $messageSet);
		}

		$member = Member::currentUser();

		// Work out the right message to show
		if($member && $member->exists()) {
			$response = ($controller) ? $controller->getResponse() : new SS_HTTPResponse();
			$response->setStatusCode(403);

			//If 'alreadyLoggedIn' is not specified in the array, then use the default
			//which should have been specified in the lines above
			if(isset($messageSet['alreadyLoggedIn'])) {
				$message = $messageSet['alreadyLoggedIn'];
			} else {
				$message = $messageSet['default'];
			}

			// Somewhat hackish way to render a login form with an error message.
			$me = new Security();
			$form = $me->LoginForm();
			$form->sessionMessage($message, 'warning');
			Session::set('MemberLoginForm.force_message',1);
			$loginResponse = $me->login();
			if($loginResponse instanceof SS_HTTPResponse) {
				return $loginResponse;
			}

			$response->setBody((string)$loginResponse);

			$controller->extend('permissionDenied', $member);

			return $response;
		} else {
			$message = $messageSet['default'];
		}

		Session::set("Security.Message.message", $message);
		Session::set("Security.Message.type", 'warning');

		Session::set("BackURL", $_SERVER['REQUEST_URI']);

		// TODO AccessLogEntry needs an extension to handle permission denied errors
		// Audit logging hook
		$controller->extend('permissionDenied', $member);

		return $controller->redirect(
			Config::inst()->get('SilverStripe\\Security\\Security', 'login_url')
			. "?BackURL=" . urlencode($_SERVER['REQUEST_URI'])
		);
	}

	protected function init() {
		parent::init();

		// Prevent clickjacking, see https://developer.mozilla.org/en-US/docs/HTTP/X-Frame-Options
		$this->getResponse()->addHeader('X-Frame-Options', 'SAMEORIGIN');
	}

	public function index() {
		return $this->httpError(404); // no-op
	}

	/**
	 * Get the selected authenticator for this request
	 *
	 * @return string Class name of Authenticator
	 */
	protected function getAuthenticator() {
		$authenticator = $this->getRequest()->requestVar('AuthenticationMethod');
		if($authenticator) {
			$authenticators = Authenticator::get_authenticators();
			if(in_array($authenticator, $authenticators)) {
				return $authenticator;
			}
		} else {
			return Authenticator::get_default_authenticator();
		}

	}

	/**
	 * Get the login form to process according to the submitted data
	 *
	 * @return Form
	 * @throws Exception
	 */
	public function LoginForm() {
		$authenticator = $this->getAuthenticator();
		if($authenticator) return $authenticator::get_login_form($this);
		throw new Exception('Passed invalid authentication method');
	}

	/**
	 * Get the login forms for all available authentication methods
	 *
	 * @return array Returns an array of available login forms (array of Form
	 *               objects).
	 *
	 * @todo Check how to activate/deactivate authentication methods
	 */
	public function GetLoginForms() {
		$forms = array();

		$authenticators = Authenticator::get_authenticators();
		foreach($authenticators as $authenticator) {
			$forms[] = $authenticator::get_login_form($this);
		}

		return $forms;
	}


	/**
	 * Get a link to a security action
	 *
	 * @param string $action Name of the action
	 * @return string Returns the link to the given action
	 */
	public function Link($action = null) {
		/** @skipUpgrade */
		return Controller::join_links(Director::baseURL(), "Security", $action);
	}

	/**
	 * This action is available as a keep alive, so user
	 * sessions don't timeout. A common use is in the admin.
	 */
	public function ping() {
		return 1;
	}

	/**
	 * Log the currently logged in user out
	 *
	 * @param bool $redirect Redirect the user back to where they came.
	 *                       - If it's false, the code calling logout() is
	 *                         responsible for sending the user where-ever
	 *                         they should go.
	 */
	public function logout($redirect = true) {
		$member = Member::currentUser();
		if($member) $member->logOut();

		if($redirect && (!$this->getResponse()->isFinished())) {
			$this->redirectBack();
		}
	}

	/**
	 * Perform pre-login checking and prepare a response if available prior to login
	 *
	 * @return SS_HTTPResponse Substitute response object if the login process should be curcumvented.
	 * Returns null if should proceed as normal.
	 */
	protected function preLogin() {
		// Event handler for pre-login, with an option to let it break you out of the login form
		$eventResults = $this->extend('onBeforeSecurityLogin');
		// If there was a redirection, return
		if($this->redirectedTo()) return $this->getResponse();
		// If there was an SS_HTTPResponse object returned, then return that
		if($eventResults) {
			foreach($eventResults as $result) {
				if($result instanceof SS_HTTPResponse) return $result;
			}
		}

		// If arriving on the login page already logged in, with no security error, and a ReturnURL then redirect
		// back. The login message check is neccesary to prevent infinite loops where BackURL links to
		// an action that triggers Security::permissionFailure.
		// This step is necessary in cases such as automatic redirection where a user is authenticated
		// upon landing on an SSL secured site and is automatically logged in, or some other case
		// where the user has permissions to continue but is not given the option.
		if($this->getRequest()->requestVar('BackURL')
			&& !$this->getLoginMessage()
			&& ($member = Member::currentUser())
			&& $member->exists()
		) {
			return $this->redirectBack();
		}
	}

	/**
	 * Prepare the controller for handling the response to this request
	 *
	 * @param string $title Title to use
	 * @return Controller
	 */
	protected function getResponseController($title) {
		if(!class_exists('SiteTree')) return $this;

		// Use sitetree pages to render the security page
		$tmpPage = new Page();
		$tmpPage->Title = $title;
		/** @skipUpgrade */
		$tmpPage->URLSegment = "Security";
		// Disable ID-based caching  of the log-in page by making it a random number
		$tmpPage->ID = -1 * rand(1,10000000);

		$controller = Page_Controller::create($tmpPage);
		$controller->setDataModel($this->model);
		$controller->doInit();
		return $controller;
	}

	/**
	 * Determine the list of templates to use for rendering the given action
	 *
	 * @param string $action
	 * @return array Template list
	 */
	public function getTemplatesFor($action) {
		/** @skipUpgrade */
		return array("Security_{$action}", 'Security', $this->stat('template_main'), 'BlankPage');
	}

	/**
	 * Combine the given forms into a formset with a tabbed interface
	 *
	 * @param array $forms List of LoginForm instances
	 * @return string
	 */
	protected function generateLoginFormSet($forms) {
		$viewData = new ArrayData(array(
			'Forms' => new ArrayList($forms),
		));
		return $viewData->renderWith(
			$this->getIncludeTemplate('MultiAuthenticatorLogin')
		);
	}

	/**
	 * Get the HTML Content for the $Content area during login
	 *
	 * @param string &$messageType Type of message, if available, passed back to caller
	 * @return string Message in HTML format
	 */
	protected function getLoginMessage(&$messageType = null) {
		$message = Session::get('Security.Message.message');
		$messageType = null;
		if(empty($message)) return null;

		$messageType = Session::get('Security.Message.type');
		if($messageType === 'bad') {
			return "<p class=\"message $messageType\">$message</p>";
		} else {
			return "<p>$message</p>";
		}
	}


	/**
	 * Show the "login" page
	 *
	 * For multiple authenticators, Security_MultiAuthenticatorLogin is used.
	 * See getTemplatesFor and getIncludeTemplate for how to override template logic
	 *
	 * @return string|SS_HTTPResponse Returns the "login" page as HTML code.
	 */
	public function login() {
		// Check pre-login process
		if($response = $this->preLogin()) return $response;

		// Get response handler
		$controller = $this->getResponseController(_t('Security.LOGIN', 'Log in'));

		// if the controller calls Director::redirect(), this will break early
		if(($response = $controller->getResponse()) && $response->isFinished()) return $response;

		$forms = $this->GetLoginForms();
		if(!count($forms)) {
			user_error('No login-forms found, please use Authenticator::register_authenticator() to add one',
				E_USER_ERROR);
		}

		// Handle any form messages from validation, etc.
		$messageType = '';
		$message = $this->getLoginMessage($messageType);

		// We've displayed the message in the form output, so reset it for the next run.
		Session::clear('Security.Message');

		// only display tabs when more than one authenticator is provided
		// to save bandwidth and reduce the amount of custom styling needed
		if(count($forms) > 1) {
			$content = $this->generateLoginFormSet($forms);
		} else {
			$content = $forms[0]->forTemplate();
		}

		// Finally, customise the controller to add any form messages and the form.
		$customisedController = $controller->customise(array(
			"Content" => $message,
			"Message" => $message,
			"MessageType" => $messageType,
			"Form" => $content,
		));

		// Return the customised controller
		return $customisedController->renderWith(
			$this->getTemplatesFor('login')
		);
	}

	public function basicauthlogin() {
		$member = BasicAuth::requireLogin("SilverStripe login", 'ADMIN');
		$member->logIn();
	}

	/**
	 * Show the "lost password" page
	 *
	 * @return string Returns the "lost password" page as HTML code.
	 */
	public function lostpassword() {
		$controller = $this->getResponseController(_t('Security.LOSTPASSWORDHEADER', 'Lost Password'));

		// if the controller calls Director::redirect(), this will break early
		if(($response = $controller->getResponse()) && $response->isFinished()) return $response;

		$customisedController = $controller->customise(array(
			'Content' =>
				'<p>' .
				_t(
					'Security.NOTERESETPASSWORD',
					'Enter your e-mail address and we will send you a link with which you can reset your password'
				) .
				'</p>',
			'Form' => $this->LostPasswordForm(),
		));

		//Controller::$currentController = $controller;
		return $customisedController->renderWith($this->getTemplatesFor('lostpassword'));
	}


	/**
	 * Factory method for the lost password form
	 *
	 * @return Form Returns the lost password form
	 */
	public function LostPasswordForm() {
		return MemberLoginForm::create(
			$this,
			'LostPasswordForm',
			new FieldList(
				new EmailField('Email', _t('Member.EMAIL', 'Email'))
			),
			new FieldList(
				new FormAction(
					'forgotPassword',
					_t('Security.BUTTONSEND', 'Send me the password reset link')
				)
			),
			false
		);
	}


	/**
	 * Show the "password sent" page, after a user has requested
	 * to reset their password.
	 *
	 * @param SS_HTTPRequest $request The SS_HTTPRequest for this action.
	 * @return string Returns the "password sent" page as HTML code.
	 */
	public function passwordsent($request) {
		$controller = $this->getResponseController(_t('Security.LOSTPASSWORDHEADER', 'Lost Password'));

		// if the controller calls Director::redirect(), this will break early
		if(($response = $controller->getResponse()) && $response->isFinished()) return $response;

		$email = Convert::raw2xml(rawurldecode($request->param('ID')) . '.' . $request->getExtension());

		$customisedController = $controller->customise(array(
			'Title' => _t('Security.PASSWORDSENTHEADER', "Password reset link sent to '{email}'",
				array('email' => $email)),
			'Content' =>
				"<p>"
				. _t('Security.PASSWORDSENTTEXT',
					"Thank you! A reset link has been sent to '{email}', provided an account exists for this email"
					. " address.",
					array('email' => $email))
				. "</p>",
			'Email' => $email
		));

		//Controller::$currentController = $controller;
		return $customisedController->renderWith($this->getTemplatesFor('passwordsent'));
	}


	/**
	 * Create a link to the password reset form.
	 *
	 * GET parameters used:
	 * - m: member ID
	 * - t: plaintext token
	 *
	 * @param Member $member Member object associated with this link.
	 * @param string $autologinToken The auto login token.
	 * @return string
	 */
	public static function getPasswordResetLink($member, $autologinToken) {
		$autologinToken = urldecode($autologinToken);
		$selfControllerClass = __CLASS__;
		$selfController = new $selfControllerClass();
		return $selfController->Link('changepassword') . "?m={$member->ID}&t=$autologinToken";
	}

	/**
	 * Show the "change password" page.
	 * This page can either be called directly by logged-in users
	 * (in which case they need to provide their old password),
	 * or through a link emailed through {@link lostpassword()}.
	 * In this case no old password is required, authentication is ensured
	 * through the Member.AutoLoginHash property.
	 *
	 * @see ChangePasswordForm
	 *
	 * @return string Returns the "change password" page as HTML code.
	 */
	public function changepassword() {
		$controller = $this->getResponseController(_t('Security.CHANGEPASSWORDHEADER', 'Change your password'));

		// if the controller calls Director::redirect(), this will break early
		if(($response = $controller->getResponse()) && $response->isFinished()) return $response;

		// Extract the member from the URL.
		$member = null;
		if (isset($_REQUEST['m'])) {
			$member = Member::get()->filter('ID', (int)$_REQUEST['m'])->first();
		}

		// Check whether we are merely changin password, or resetting.
		if(isset($_REQUEST['t']) && $member && $member->validateAutoLoginToken($_REQUEST['t'])) {
			// On first valid password reset request redirect to the same URL without hash to avoid referrer leakage.

			// if there is a current member, they should be logged out
			if ($curMember = Member::currentUser()) {
				$curMember->logOut();
			}

			// Store the hash for the change password form. Will be unset after reload within the ChangePasswordForm.
			Session::set('AutoLoginHash', $member->encryptWithUserSettings($_REQUEST['t']));

			return $this->redirect($this->Link('changepassword'));
		} elseif(Session::get('AutoLoginHash')) {
			// Subsequent request after the "first load with hash" (see previous if clause).
			$customisedController = $controller->customise(array(
				'Content' =>
					'<p>' .
					_t('Security.ENTERNEWPASSWORD', 'Please enter a new password.') .
					'</p>',
				'Form' => $this->ChangePasswordForm(),
			));
		} elseif(Member::currentUser()) {
			// Logged in user requested a password change form.
			$customisedController = $controller->customise(array(
				'Content' => '<p>'
					. _t('Security.CHANGEPASSWORDBELOW', 'You can change your password below.') . '</p>',
				'Form' => $this->ChangePasswordForm()));

		} else {
			// Show friendly message if it seems like the user arrived here via password reset feature.
			if(isset($_REQUEST['m']) || isset($_REQUEST['t'])) {
				$customisedController = $controller->customise(
					array('Content' =>
						_t(
							'Security.NOTERESETLINKINVALID',
							'<p>The password reset link is invalid or expired.</p>'
							. '<p>You can request a new one <a href="{link1}">here</a> or change your password after'
							. ' you <a href="{link2}">logged in</a>.</p>',
							array('link1' => $this->Link('lostpassword'), 'link2' => $this->link('login'))
						)
					)
				);
			} else {
				self::permissionFailure(
					$this,
					_t('Security.ERRORPASSWORDPERMISSION', 'You must be logged in in order to change your password!')
				);
				return;
			}
		}

		return $customisedController->renderWith($this->getTemplatesFor('changepassword'));
	}

	/**
	 * Factory method for the lost password form
	 *
	 * @return ChangePasswordForm Returns the lost password form
	 */
	public function ChangePasswordForm() {
		/** @skipUpgrade */
		$formName = 'ChangePasswordForm';
		return \Injector::inst()->createWithArgs(
			'SilverStripe\\Security\\ChangePasswordForm',
			[ $this,  $formName]
		);
	}

	/**
	 * Gets the template for an include used for security.
	 * For use in any subclass.
	 *
	 * @param string $name
	 * @return array Returns the template(s) for rendering
	 */
	public function getIncludeTemplate($name) {
		return array('Security_' . $name);
	}

	/**
	 * Return an existing member with administrator privileges, or create one of necessary.
	 *
	 * Will create a default 'Administrators' group if no group is found
	 * with an ADMIN permission. Will create a new 'Admin' member with administrative permissions
	 * if no existing Member with these permissions is found.
	 *
	 * Important: Any newly created administrator accounts will NOT have valid
	 * login credentials (Email/Password properties), which means they can't be used for login
	 * purposes outside of any default credentials set through {@link Security::setDefaultAdmin()}.
	 *
	 * @return Member
	 */
	public static function findAnAdministrator() {
		// coupling to subsites module
		$origSubsite = null;
		if(is_callable('Subsite::changeSubsite')) {
			$origSubsite = \Subsite::currentSubsiteID();
			\Subsite::changeSubsite(0);
		}

		$member = null;

		// find a group with ADMIN permission
		$adminGroup = Permission::get_groups_by_permission('ADMIN')->first();

		if(is_callable('Subsite::changeSubsite')) {
			\Subsite::changeSubsite($origSubsite);
		}

		if ($adminGroup) {
			$member = $adminGroup->Members()->First();
		}

		if(!$adminGroup) {
			Group::singleton()->requireDefaultRecords();
			$adminGroup = Permission::get_groups_by_permission('ADMIN')->first();
		}

		if(!$member) {
			Member::singleton()->requireDefaultRecords();
			$member = Permission::get_members_by_permission('ADMIN')->first();
		}

		if(!$member) {
			$member = Member::default_admin();
		}

		if(!$member) {
			// Failover to a blank admin
			$member = Member::create();
			$member->FirstName = _t('Member.DefaultAdminFirstname', 'Default Admin');
			$member->write();
			// Add member to group instead of adding group to member
			// This bypasses the privilege escallation code in Member_GroupSet
			$adminGroup
				->DirectMembers()
				->add($member);
		}

		return $member;
	}

	/**
	 * Flush the default admin credentials
	 */
	public static function clear_default_admin() {
		self::$default_username = null;
		self::$default_password = null;
	}


	/**
	 * Set a default admin in dev-mode
	 *
	 * This will set a static default-admin which is not existing
	 * as a database-record. By this workaround we can test pages in dev-mode
	 * with a unified login. Submitted login-credentials are first checked
	 * against this static information in {@link Security::authenticate()}.
	 *
	 * @param string $username The user name
	 * @param string $password The password (in cleartext)
	 * @return bool
	 */
	public static function setDefaultAdmin($username, $password) {
		// don't overwrite if already set
		if(self::$default_username || self::$default_password) {
			return false;
		}

		self::$default_username = $username;
		self::$default_password = $password;
	}

	/**
	 * Checks if the passed credentials are matching the default-admin.
	 * Compares cleartext-password set through Security::setDefaultAdmin().
	 *
	 * @param string $username
	 * @param string $password
	 * @return bool
	 */
	public static function check_default_admin($username, $password) {
		return (
			self::$default_username === $username
			&& self::$default_password === $password
			&& self::has_default_admin()
		);
	}

	/**
	 * Check that the default admin account has been set.
	 */
	public static function has_default_admin() {
		return !empty(self::$default_username) && !empty(self::$default_password);
	}

	/**
	 * Get default admin username
	 *
	 * @return string
	 */
	public static function default_admin_username() {
		return self::$default_username;
	}

	/**
	 * Get default admin password
	 *
	 * @return string
	 */
	public static function default_admin_password() {
		return self::$default_password;
	}

	/**
	 * Set strict path checking
	 *
	 * This prevents sharing of the session across several sites in the
	 * domain.
	 *
	 * @deprecated 4.0 Use the "Security.strict_path_checking" config setting instead
	 * @param boolean $strictPathChecking To enable or disable strict patch
	 *                                    checking.
	 */
	public static function setStrictPathChecking($strictPathChecking) {
		Deprecation::notice('4.0', 'Use the "Security.strict_path_checking" config setting instead');
		self::config()->strict_path_checking = $strictPathChecking;
	}


	/**
	 * Get strict path checking
	 *
	 * @deprecated 4.0 Use the "Security.strict_path_checking" config setting instead
	 * @return boolean Status of strict path checking
	 */
	public static function getStrictPathChecking() {
		Deprecation::notice('4.0', 'Use the "Security.strict_path_checking" config setting instead');
		return self::config()->strict_path_checking;
	}


	/**
	 * Set the password encryption algorithm
	 *
	 * @deprecated 4.0 Use the "Security.password_encryption_algorithm" config setting instead
	 * @param string $algorithm One of the available password encryption
	 *  algorithms determined by {@link Security::get_encryption_algorithms()}
	 * @return bool Returns TRUE if the passed algorithm was valid, otherwise FALSE.
	 */
	public static function set_password_encryption_algorithm($algorithm) {
		Deprecation::notice('4.0', 'Use the "Security.password_encryption_algorithm" config setting instead');

		self::config()->password_encryption_algorithm = $algorithm;
	}

	/**
	 * @deprecated 4.0 Use the "Security.password_encryption_algorithm" config setting instead
	 * @return String
	 */
	public static function get_password_encryption_algorithm() {
		Deprecation::notice('4.0', 'Use the "Security.password_encryption_algorithm" config setting instead');
		return self::config()->password_encryption_algorithm;
	}

	/**
	 * Encrypt a password according to the current password encryption settings.
	 * If the settings are so that passwords shouldn't be encrypted, the
	 * result is simple the clear text password with an empty salt except when
	 * a custom algorithm ($algorithm parameter) was passed.
	 *
	 * @param string $password The password to encrypt
	 * @param string $salt Optional: The salt to use. If it is not passed, but
	 *  needed, the method will automatically create a
	 *  random salt that will then be returned as return value.
	 * @param string $algorithm Optional: Use another algorithm to encrypt the
	 *  password (so that the encryption algorithm can be changed over the time).
	 * @param Member $member Optional
	 * @return mixed Returns an associative array containing the encrypted
	 *  password and the used salt in the form:
	 * <code>
	 * 	array(
	 * 	'password' => string,
	 * 	'salt' => string,
	 * 	'algorithm' => string,
	 * 	'encryptor' => PasswordEncryptor instance
	 * 	)
	 * </code>
	 * If the passed algorithm is invalid, FALSE will be returned.
	 *
	 * @see encrypt_passwords()
	 */
	public static function encrypt_password($password, $salt = null, $algorithm = null, $member = null) {
		// Fall back to the default encryption algorithm
		if(!$algorithm) $algorithm = self::config()->password_encryption_algorithm;

		$e = PasswordEncryptor::create_for_algorithm($algorithm);

		// New salts will only need to be generated if the password is hashed for the first time
		$salt = ($salt) ? $salt : $e->salt($password);

		return array(
			'password' => $e->encrypt($password, $salt, $member),
			'salt' => $salt,
			'algorithm' => $algorithm,
			'encryptor' => $e
		);
	}

	/**
	 * Checks the database is in a state to perform security checks.
	 * See {@link DatabaseAdmin->init()} for more information.
	 *
	 * @return bool
	 */
	public static function database_is_ready() {
		// Used for unit tests
		if(self::$force_database_is_ready !== null) {
			return self::$force_database_is_ready;
		}

		if(self::$database_is_ready) {
			return self::$database_is_ready;
		}

		$requiredClasses = ClassInfo::dataClassesFor('SilverStripe\\Security\\Member');
		$requiredClasses[] = 'SilverStripe\\Security\\Group';
		$requiredClasses[] = 'SilverStripe\\Security\\Permission';

		foreach($requiredClasses as $class) {
			// Skip test classes, as not all test classes are scaffolded at once
			if(is_subclass_of($class, 'TestOnly')) {
				continue;
			}

			// if any of the tables aren't created in the database
			$table = DataObject::getSchema()->tableName($class);
			if(!ClassInfo::hasTable($table)) {
				return false;
			}

			// HACK: DataExtensions aren't applied until a class is instantiated for
			// the first time, so create an instance here.
			singleton($class);

			// if any of the tables don't have all fields mapped as table columns
			$dbFields = DB::field_list($table);
			if(!$dbFields) {
				return false;
			}

			$objFields = DataObject::database_fields($class);
			$missingFields = array_diff_key($objFields, $dbFields);

			if($missingFields) {
				return false;
			}
		}
		self::$database_is_ready = true;

		return true;
	}

	/**
	 * Enable or disable recording of login attempts
	 * through the {@link LoginRecord} object.
	 *
	 * @deprecated 4.0 Use the "Security.login_recording" config setting instead
	 * @param boolean $bool
	 */
	public static function set_login_recording($bool) {
		Deprecation::notice('4.0', 'Use the "Security.login_recording" config setting instead');
		self::$login_recording = (bool)$bool;
	}

	/**
	 * @deprecated 4.0 Use the "Security.login_recording" config setting instead
	 * @return boolean
	 */
	public static function login_recording() {
		Deprecation::notice('4.0', 'Use the "Security.login_recording" config setting instead');
		return self::$login_recording;
	}

	/**
	 * @config
	 * @var string Set the default login dest
	 * This is the URL that users will be redirected to after they log in,
	 * if they haven't logged in en route to access a secured page.
	 * By default, this is set to the homepage.
	 */
	private static $default_login_dest = "";

	/**
	 * @deprecated 4.0 Use the "Security.default_login_dest" config setting instead
	 */
	public static function set_default_login_dest($dest) {
		Deprecation::notice('4.0', 'Use the "Security.default_login_dest" config setting instead');
		self::config()->default_login_dest = $dest;
	}

	/**
	 * Get the default login dest.
	 *
	 * @deprecated 4.0 Use the "Security.default_login_dest" config setting instead
	 */
	public static function default_login_dest() {
		Deprecation::notice('4.0', 'Use the "Security.default_login_dest" config setting instead');
		return self::config()->default_login_dest;
	}

	protected static $ignore_disallowed_actions = false;

	/**
	 * Set to true to ignore access to disallowed actions, rather than returning permission failure
	 * Note that this is just a flag that other code needs to check with Security::ignore_disallowed_actions()
	 * @param $flag True or false
	 */
	public static function set_ignore_disallowed_actions($flag) {
		self::$ignore_disallowed_actions = $flag;
	}

	public static function ignore_disallowed_actions() {
		return self::$ignore_disallowed_actions;
	}


	/**
	 * Set a custom log-in URL if you have built your own log-in page.
	 *
	 * @deprecated 4.0 Use the "Security.login_url" config setting instead.
	 */
	public static function set_login_url($loginUrl) {
		Deprecation::notice('4.0', 'Use the "Security.login_url" config setting instead');
		self::config()->update("login_url", $loginUrl);
	}


	/**
	 * Get the URL of the log-in page.
	 *
	 * To update the login url use the "Security.login_url" config setting.
	 *
	 * @return string
	 */
	public static function login_url() {
		return self::config()->login_url;
	}


	/**
	 * Get the URL of the logout page.
	 *
	 * To update the logout url use the "Security.logout_url" config setting.
	 *
	 * @return string
	 */
	public static function logout_url() {
		return self::config()->logout_url;
	}


	/**
	 * Defines global accessible templates variables.
	 *
	 * @return array
	 */
	public static function get_template_global_variables() {
		return array(
			"LoginURL" => "login_url",
			"LogoutURL" => "logout_url",
		);
	}

}