Document optional database name, schema or other qualifier in README

Use more expressive name 'deleteRememberDirectiveForUserById'

Database/MySQL.sql

@@ -1,24 +1,39 @@
+-- PHP-Auth (https://github.com/delight-im/PHP-Auth)
+-- Copyright (c) delight.im (https://www.delight.im/)
+-- Licensed under the MIT License (https://opensource.org/licenses/MIT)
+
+/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
+/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
+/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
+/*!40101 SET NAMES utf8mb4 */;
+
 CREATE TABLE IF NOT EXISTS `users` (
   `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
   `email` varchar(249) COLLATE utf8mb4_unicode_ci NOT NULL,
   `password` varchar(255) CHARACTER SET latin1 COLLATE latin1_general_cs NOT NULL,
   `username` varchar(100) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
+  `status` tinyint(2) unsigned NOT NULL DEFAULT '0',
   `verified` tinyint(1) unsigned NOT NULL DEFAULT '0',
+  `resettable` tinyint(1) unsigned NOT NULL DEFAULT '1',
+  `roles_mask` int(10) unsigned NOT NULL DEFAULT '0',
   `registered` int(10) unsigned NOT NULL,
   `last_login` int(10) unsigned DEFAULT NULL,
+  `force_logout` mediumint(7) unsigned NOT NULL DEFAULT '0',
   PRIMARY KEY (`id`),
   UNIQUE KEY `email` (`email`)
 ) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `users_confirmations` (
   `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
+  `user_id` int(10) unsigned NOT NULL,
   `email` varchar(249) COLLATE utf8mb4_unicode_ci NOT NULL,
   `selector` varchar(16) CHARACTER SET latin1 COLLATE latin1_general_cs NOT NULL,
   `token` varchar(255) CHARACTER SET latin1 COLLATE latin1_general_cs NOT NULL,
   `expires` int(10) unsigned NOT NULL,
   PRIMARY KEY (`id`),
   UNIQUE KEY `selector` (`selector`),
-  KEY `email_expires` (`email`,`expires`)
+  KEY `email_expires` (`email`,`expires`),
+  KEY `user_id` (`user_id`)
 ) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `users_remembered` (
@@ -35,20 +50,23 @@ CREATE TABLE IF NOT EXISTS `users_remembered` (
 CREATE TABLE IF NOT EXISTS `users_resets` (
   `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
   `user` int(10) unsigned NOT NULL,
-  `selector` varchar(24) CHARACTER SET latin1 COLLATE latin1_general_cs NOT NULL,
+  `selector` varchar(20) CHARACTER SET latin1 COLLATE latin1_general_cs NOT NULL,
   `token` varchar(255) CHARACTER SET latin1 COLLATE latin1_general_cs NOT NULL,
   `expires` int(10) unsigned NOT NULL,
   PRIMARY KEY (`id`),
   UNIQUE KEY `selector` (`selector`),
-  KEY `user` (`user`)
+  KEY `user_expires` (`user`,`expires`)
 ) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
 
 CREATE TABLE IF NOT EXISTS `users_throttling` (
-  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
-  `action_type` enum('login','register','confirm_email') COLLATE utf8mb4_unicode_ci NOT NULL,
-  `selector` varchar(44) CHARACTER SET latin1 COLLATE latin1_general_cs DEFAULT NULL,
-  `time_bucket` int(10) unsigned NOT NULL,
-  `attempts` mediumint(8) unsigned NOT NULL DEFAULT '1',
-  PRIMARY KEY (`id`),
-  UNIQUE KEY `action_type_selector_time_bucket` (`action_type`,`selector`,`time_bucket`)
+  `bucket` varchar(44) CHARACTER SET latin1 COLLATE latin1_general_cs NOT NULL,
+  `tokens` float unsigned NOT NULL,
+  `replenished_at` int(10) unsigned NOT NULL,
+  `expires_at` int(10) unsigned NOT NULL,
+  PRIMARY KEY (`bucket`),
+  KEY `expires_at` (`expires_at`)
 ) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
+/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
+/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;

Database/PostgreSQL.sql

@@ -0,0 +1,58 @@
+-- PHP-Auth (https://github.com/delight-im/PHP-Auth)
+-- Copyright (c) delight.im (https://www.delight.im/)
+-- Licensed under the MIT License (https://opensource.org/licenses/MIT)
+
+BEGIN;
+
+CREATE TABLE IF NOT EXISTS "users" (
+	"id" SERIAL PRIMARY KEY CHECK ("id" >= 0),
+	"email" VARCHAR(249) UNIQUE NOT NULL,
+	"password" VARCHAR(255) NOT NULL,
+	"username" VARCHAR(100) DEFAULT NULL,
+	"status" SMALLINT NOT NULL DEFAULT '0' CHECK ("status" >= 0),
+	"verified" SMALLINT NOT NULL DEFAULT '0' CHECK ("verified" >= 0),
+	"resettable" SMALLINT NOT NULL DEFAULT '1' CHECK ("resettable" >= 0),
+	"roles_mask" INTEGER NOT NULL DEFAULT '0' CHECK ("roles_mask" >= 0),
+	"registered" INTEGER NOT NULL CHECK ("registered" >= 0),
+	"last_login" INTEGER DEFAULT NULL CHECK ("last_login" >= 0),
+	"force_logout" INTEGER NOT NULL DEFAULT '0' CHECK ("force_logout" >= 0)
+);
+
+CREATE TABLE IF NOT EXISTS "users_confirmations" (
+	"id" SERIAL PRIMARY KEY CHECK ("id" >= 0),
+	"user_id" INTEGER NOT NULL CHECK ("user_id" >= 0),
+	"email" VARCHAR(249) NOT NULL,
+	"selector" VARCHAR(16) UNIQUE NOT NULL,
+	"token" VARCHAR(255) NOT NULL,
+	"expires" INTEGER NOT NULL CHECK ("expires" >= 0)
+);
+CREATE INDEX IF NOT EXISTS "email_expires" ON "users_confirmations" ("email", "expires");
+CREATE INDEX IF NOT EXISTS "user_id" ON "users_confirmations" ("user_id");
+
+CREATE TABLE IF NOT EXISTS "users_remembered" (
+	"id" BIGSERIAL PRIMARY KEY CHECK ("id" >= 0),
+	"user" INTEGER NOT NULL CHECK ("user" >= 0),
+	"selector" VARCHAR(24) UNIQUE NOT NULL,
+	"token" VARCHAR(255) NOT NULL,
+	"expires" INTEGER NOT NULL CHECK ("expires" >= 0)
+);
+CREATE INDEX IF NOT EXISTS "user" ON "users_remembered" ("user");
+
+CREATE TABLE IF NOT EXISTS "users_resets" (
+	"id" BIGSERIAL PRIMARY KEY CHECK ("id" >= 0),
+	"user" INTEGER NOT NULL CHECK ("user" >= 0),
+	"selector" VARCHAR(20) UNIQUE NOT NULL,
+	"token" VARCHAR(255) NOT NULL,
+	"expires" INTEGER NOT NULL CHECK ("expires" >= 0)
+);
+CREATE INDEX IF NOT EXISTS "user_expires" ON "users_resets" ("user", "expires");
+
+CREATE TABLE IF NOT EXISTS "users_throttling" (
+	"bucket" VARCHAR(44) PRIMARY KEY,
+	"tokens" REAL NOT NULL CHECK ("tokens" >= 0),
+	"replenished_at" INTEGER NOT NULL CHECK ("replenished_at" >= 0),
+	"expires_at" INTEGER NOT NULL CHECK ("expires_at" >= 0)
+);
+CREATE INDEX IF NOT EXISTS "expires_at" ON "users_throttling" ("expires_at");
+
+COMMIT;

Database/SQLite.sql

@@ -0,0 +1,60 @@
+-- PHP-Auth (https://github.com/delight-im/PHP-Auth)
+-- Copyright (c) delight.im (https://www.delight.im/)
+-- Licensed under the MIT License (https://opensource.org/licenses/MIT)
+
+PRAGMA foreign_keys = OFF;
+
+CREATE TABLE "users" (
+	"id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL CHECK ("id" >= 0),
+	"email" VARCHAR(249) NOT NULL,
+	"password" VARCHAR(255) NOT NULL,
+	"username" VARCHAR(100) DEFAULT NULL,
+	"status" INTEGER NOT NULL CHECK ("status" >= 0) DEFAULT "0",
+	"verified" INTEGER NOT NULL CHECK ("verified" >= 0) DEFAULT "0",
+	"resettable" INTEGER NOT NULL CHECK ("resettable" >= 0) DEFAULT "1",
+	"roles_mask" INTEGER NOT NULL CHECK ("roles_mask" >= 0) DEFAULT "0",
+	"registered" INTEGER NOT NULL CHECK ("registered" >= 0),
+	"last_login" INTEGER CHECK ("last_login" >= 0) DEFAULT NULL,
+	"force_logout" INTEGER NOT NULL CHECK ("force_logout" >= 0) DEFAULT "0",
+	CONSTRAINT "email" UNIQUE ("email")
+);
+
+CREATE TABLE "users_confirmations" (
+	"id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL CHECK ("id" >= 0),
+	"user_id" INTEGER NOT NULL CHECK ("user_id" >= 0),
+	"email" VARCHAR(249) NOT NULL,
+	"selector" VARCHAR(16) NOT NULL,
+	"token" VARCHAR(255) NOT NULL,
+	"expires" INTEGER NOT NULL CHECK ("expires" >= 0),
+	CONSTRAINT "selector" UNIQUE ("selector")
+);
+CREATE INDEX "users_confirmations.email_expires" ON "users_confirmations" ("email", "expires");
+CREATE INDEX "users_confirmations.user_id" ON "users_confirmations" ("user_id");
+
+CREATE TABLE "users_remembered" (
+	"id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL CHECK ("id" >= 0),
+	"user" INTEGER NOT NULL CHECK ("user" >= 0),
+	"selector" VARCHAR(24) NOT NULL,
+	"token" VARCHAR(255) NOT NULL,
+	"expires" INTEGER NOT NULL CHECK ("expires" >= 0),
+	CONSTRAINT "selector" UNIQUE ("selector")
+);
+CREATE INDEX "users_remembered.user" ON "users_remembered" ("user");
+
+CREATE TABLE "users_resets" (
+	"id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL CHECK ("id" >= 0),
+	"user" INTEGER NOT NULL CHECK ("user" >= 0),
+	"selector" VARCHAR(20) NOT NULL,
+	"token" VARCHAR(255) NOT NULL,
+	"expires" INTEGER NOT NULL CHECK ("expires" >= 0),
+	CONSTRAINT "selector" UNIQUE ("selector")
+);
+CREATE INDEX "users_resets.user_expires" ON "users_resets" ("user", "expires");
+
+CREATE TABLE "users_throttling" (
+	"bucket" VARCHAR(44) PRIMARY KEY NOT NULL,
+	"tokens" REAL NOT NULL CHECK ("tokens" >= 0),
+	"replenished_at" INTEGER NOT NULL CHECK ("replenished_at" >= 0),
+	"expires_at" INTEGER NOT NULL CHECK ("expires_at" >= 0)
+);
+CREATE INDEX "users_throttling.expires_at" ON "users_throttling" ("expires_at");

LICENSE

@@ -1,201 +1,21 @@
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Migration.md

@@ -1,35 +1,220 @@
 # Migration
 
- * `v1.x.x` to `v2.x.x`
-   * The MySQL schema has been changed from charset `utf8` to charset `utf8mb4` and from collation `utf8_general_ci` to collation `utf8mb4_unicode_ci`. Use the statements below to update the database schema:
+ * [General](#general)
+ * [From `v7.x.x` to `v8.x.x`](#from-v7xx-to-v8xx)
+ * [From `v6.x.x` to `v7.x.x`](#from-v6xx-to-v7xx)
+ * [From `v5.x.x` to `v6.x.x`](#from-v5xx-to-v6xx)
+ * [From `v4.x.x` to `v5.x.x`](#from-v4xx-to-v5xx)
+ * [From `v3.x.x` to `v4.x.x`](#from-v3xx-to-v4xx)
+ * [From `v2.x.x` to `v3.x.x`](#from-v2xx-to-v3xx)
+ * [From `v1.x.x` to `v2.x.x`](#from-v1xx-to-v2xx)
+
+## General
+
+Update your version of this library using Composer and its `composer update` or `composer require` commands [[?]](https://github.com/delight-im/Knowledge/blob/master/Composer%20(PHP).md#how-do-i-update-libraries-or-modules-within-my-application).
+
+## From `v7.x.x` to `v8.x.x`
+
+ * The database schema has changed.
+
+   * The MySQL database schema has changed. Use the statement below to update your database:
 
      ```sql
-     ALTER TABLE `users` CHANGE `email` `email` VARCHAR(249) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL;
-     ALTER TABLE `users_confirmations` CHANGE `email` `email` VARCHAR(249) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL;
-
-     -- ALTER DATABASE `<DATABASE_NAME>` CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci;
-
-     ALTER TABLE `users` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
-     ALTER TABLE `users_confirmations` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
-     ALTER TABLE `users_remembered` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
-     ALTER TABLE `users_resets` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
-     ALTER TABLE `users_throttling` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
-
-     ALTER TABLE `users` CHANGE `email` `email` VARCHAR(249) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL;
-     ALTER TABLE `users` CHANGE `username` `username` VARCHAR(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NULL DEFAULT NULL;
-
-     ALTER TABLE `users_confirmations` CHANGE `email` `email` VARCHAR(249) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL;
-
-     ALTER TABLE `users_throttling` CHANGE `action_type` `action_type` ENUM('login','register','confirm_email') CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL;
-
-     REPAIR TABLE users;
-     OPTIMIZE TABLE users;
-     REPAIR TABLE users_confirmations;
-     OPTIMIZE TABLE users_confirmations;
-     REPAIR TABLE users_remembered;
-     OPTIMIZE TABLE users_remembered;
-     REPAIR TABLE users_resets;
-     OPTIMIZE TABLE users_resets;
-     REPAIR TABLE users_throttling;
-     OPTIMIZE TABLE users_throttling;
+     ALTER TABLE users
+         ADD COLUMN `force_logout` mediumint(7) unsigned NOT NULL DEFAULT '0' AFTER `last_login`;
      ```
+
+   * The PostgreSQL database schema has changed. Use the statement below to update your database:
+
+     ```sql
+     ALTER TABLE users
+         ADD COLUMN "force_logout" INTEGER NOT NULL DEFAULT '0' CHECK ("force_logout" >= 0);
+     ```
+
+   * The SQLite database schema has changed. Use the statement below to update your database:
+
+     ```sql
+     ALTER TABLE users
+         ADD COLUMN "force_logout" INTEGER NOT NULL CHECK ("force_logout" >= 0) DEFAULT "0";
+     ```
+
+ * The method `logOutAndDestroySession` has been removed from class `Auth`. Instead, call the two separate methods `logOut` and `destroySession` from class `Auth` one after another for the same effect.
+
+ * If you have been using the return values of the methods `confirmEmail` or `confirmEmailAndSignIn` from class `Auth`, these return values have changed. Instead of only returning the new email address (which has just been verified), both methods now return an array with the old email address (if any) at index zero and the new email address (which has just been verified) at index one.
+
+## From `v6.x.x` to `v7.x.x`
+
+ * The method `logOutButKeepSession` from class `Auth` is now simply called `logOut`. Therefore, the former method `logout` is now called `logOutAndDestroySession`.
+
+ * The second argument of the `Auth` constructor, which was named `$useHttps`, has been removed. If you previously had it set to `true`, make sure to set the value of the `session.cookie_secure` directive to `1` now. You may do so either directly in your [PHP configuration](http://php.net/manual/en/configuration.file.php) (`php.ini`), via the `\ini_set` method or via the `\session_set_cookie_params` method. Otherwise, make sure that directive is set to `0`.
+
+ * The third argument of the `Auth` constructor, which was named `$allowCookiesScriptAccess`, has been removed. If you previously had it set to `true`, make sure to set the value of the `session.cookie_httponly` directive to `0` now. You may do so either directly in your [PHP configuration](http://php.net/manual/en/configuration.file.php) (`php.ini`), via the `\ini_set` method or via the `\session_set_cookie_params` method. Otherwise, make sure that directive is set to `1`.
+
+ * Only if *both* of the following two conditions are met:
+
+   * The directive `session.cookie_domain` is set to an empty value. It may have been set directly in your [PHP configuration](http://php.net/manual/en/configuration.file.php) (`php.ini`), via the `\ini_set` method or via the `\session_set_cookie_params` method. You can check the value of that directive by executing the following statement somewhere in your application:
+
+     ```php
+     \var_dump(\ini_get('session.cookie_domain'));
+     ```
+
+   * Your application is accessed via a registered or registrable *domain name*, either by yourself during development and testing or by your visitors and users in production. That means your application is *not*, or *not only*, accessed via `localhost` or via an IP address.
+
+   Then the domain scope for the [two cookies](README.md#cookies) used by this library has changed. You can handle this change in one of two different ways:
+
+   * Restore the old behavior by placing the following statement as early as possible in your application, and before you create the `Auth` instance:
+
+     ```php
+     \ini_set('session.cookie_domain', \preg_replace('/^www\./', '', $_SERVER['HTTP_HOST']));
+     ```
+
+     You may also evaluate the complete second parameter and put its value directly into your [PHP configuration](http://php.net/manual/en/configuration.file.php) (`php.ini`).
+
+   * Use the new domain scope for your application. To do so, you only need to [rename the cookies](README.md#renaming-the-librarys-cookies) used by this library in order to prevent conflicts with old cookies that have been created previously. Renaming the cookies is critically important here. We recommend a versioned name such as `session_v1` for the session cookie.
+
+ * Only if *both* of the following two conditions are met:
+
+   * The directive `session.cookie_domain` is set to a value that starts with the `www` subdomain. It may have been set directly in your [PHP configuration](http://php.net/manual/en/configuration.file.php) (`php.ini`), via the `\ini_set` method or via the `\session_set_cookie_params` method. You can check the value of that directive by executing the following statement somewhere in your application:
+
+     ```php
+     \var_dump(\ini_get('session.cookie_domain'));
+     ```
+
+   * Your application is accessed via a registered or registrable *domain name*, either by yourself during development and testing or by your visitors and users in production. That means your application is *not*, or *not only*, accessed via `localhost` or via an IP address.
+
+   Then the domain scope for [one of the cookies](README.md#cookies) used by this library has changed. To make your application work correctly with the new scope, [rename the cookies](README.md#renaming-the-librarys-cookies) used by this library in order to prevent conflicts with old cookies that have been created previously. Renaming the cookies is critically important here. We recommend a versioned name such as `session_v1` for the session cookie.
+
+ * If the directive `session.cookie_path` is set to an empty value, then the path scope for [one of the cookies](README.md#cookies) used by this library has changed. To make your application work correctly with the new scope, [rename the cookies](README.md#renaming-the-librarys-cookies) used by this library in order to prevent conflicts with old cookies that have been created previously. Renaming the cookies is critically important here. We recommend a versioned name such as `session_v1` for the session cookie.
+
+   The directive may have been set directly in your [PHP configuration](http://php.net/manual/en/configuration.file.php) (`php.ini`), via the `\ini_set` method or via the `\session_set_cookie_params` method. You can check the value of that directive by executing the following statement somewhere in your application:
+
+   ```php
+   \var_dump(\ini_get('session.cookie_path'));
+   ```
+
+## From `v5.x.x` to `v6.x.x`
+
+ * The database schema has changed.
+
+   * The MySQL database schema has changed. Use the statements below to update your database:
+
+     ```sql
+     ALTER TABLE users
+         ADD COLUMN roles_mask INT(10) UNSIGNED NOT NULL DEFAULT 0 AFTER verified,
+         ADD COLUMN resettable TINYINT(1) UNSIGNED NOT NULL DEFAULT 1 AFTER verified;
+
+     ALTER TABLE users_confirmations
+         ADD COLUMN user_id INT(10) UNSIGNED NULL DEFAULT NULL AFTER id;
+
+     UPDATE users_confirmations SET user_id = (
+         SELECT id FROM users WHERE email = users_confirmations.email
+     ) WHERE user_id IS NULL;
+
+     ALTER TABLE users_confirmations
+         CHANGE COLUMN user_id user_id INT(10) UNSIGNED NOT NULL;
+
+     ALTER TABLE users_confirmations
+         ADD INDEX user_id (user_id ASC);
+
+     DROP TABLE users_throttling;
+
+     CREATE TABLE users_throttling (
+         bucket varchar(44) CHARACTER SET latin1 COLLATE latin1_general_cs NOT NULL,
+         tokens float unsigned NOT NULL,
+         replenished_at int(10) unsigned NOT NULL,
+         expires_at int(10) unsigned NOT NULL,
+         PRIMARY KEY (bucket),
+         KEY expires_at (expires_at)
+     ) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+     ```
+
+   * The SQLite database schema has changed. Use the statements below to update your database:
+
+     ```sql
+     ALTER TABLE users
+         ADD COLUMN "roles_mask" INTEGER NOT NULL CHECK ("roles_mask" >= 0) DEFAULT "0",
+         ADD COLUMN "resettable" INTEGER NOT NULL CHECK ("resettable" >= 0) DEFAULT "1";
+
+     ALTER TABLE users_confirmations
+         ADD COLUMN "user_id" INTEGER CHECK ("user_id" >= 0);
+
+     UPDATE users_confirmations SET user_id = (
+         SELECT id FROM users WHERE email = users_confirmations.email
+     ) WHERE user_id IS NULL;
+
+     CREATE INDEX "users_confirmations.user_id" ON "users_confirmations" ("user_id");
+
+     DROP TABLE users_throttling;
+
+     CREATE TABLE "users_throttling" (
+         "bucket" VARCHAR(44) PRIMARY KEY NOT NULL,
+         "tokens" REAL NOT NULL CHECK ("tokens" >= 0),
+         "replenished_at" INTEGER NOT NULL CHECK ("replenished_at" >= 0),
+         "expires_at" INTEGER NOT NULL CHECK ("expires_at" >= 0)
+     );
+
+     CREATE INDEX "users_throttling.expires_at" ON "users_throttling" ("expires_at");
+     ```
+
+ * The method `setThrottlingOptions` has been removed.
+
+ * The method `changePassword` may now throw an additional `\Delight\Auth\TooManyRequestsException` if too many attempts have been made without the correct old password.
+
+ * The two methods `confirmEmail` and `confirmEmailAndSignIn` may now throw an additional `\Delight\Auth\UserAlreadyExistsException` if an attempt has been made to change the email address to an address that has become occupied in the meantime.
+
+ * The two methods `forgotPassword` and `resetPassword` may now throw an additional `\Delight\Auth\ResetDisabledException` if the user has disabled password resets for their account.
+
+ * The `Base64` class is now an external module and has been moved from the namespace `Delight\Auth` to the namespace `Delight\Base64`. The interface and the return values are not compatible with those from previous versions anymore.
+
+## From `v4.x.x` to `v5.x.x`
+
+ * The MySQL database schema has changed. Use the statement below to update your database:
+
+   ```sql
+   ALTER TABLE `users` ADD COLUMN `status` TINYINT(2) UNSIGNED NOT NULL DEFAULT 0 AFTER `username`;
+   ```
+
+ * The two classes `Auth` and `Base64` are now `final`, i.e. they can't be extended anymore, which has never been a good idea, anyway. If you still need to wrap your own methods around these classes, consider [object composition instead of class inheritance](https://en.wikipedia.org/wiki/Composition_over_inheritance).
+
+## From `v3.x.x` to `v4.x.x`
+
+ * PHP 5.6.0 or higher is now required.
+
+## From `v2.x.x` to `v3.x.x`
+
+ * The license has been changed from the [Apache License 2.0](http://www.apache.org/licenses/LICENSE-2.0) to the [MIT License](https://opensource.org/licenses/MIT).
+
+## From `v1.x.x` to `v2.x.x`
+
+ * The MySQL schema has been changed from charset `utf8` to charset `utf8mb4` and from collation `utf8_general_ci` to collation `utf8mb4_unicode_ci`. Use the statements below to update the database schema:
+
+   ```sql
+   ALTER TABLE `users` CHANGE `email` `email` VARCHAR(249) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL;
+   ALTER TABLE `users_confirmations` CHANGE `email` `email` VARCHAR(249) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL;
+
+   -- ALTER DATABASE `<DATABASE_NAME>` CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci;
+
+   ALTER TABLE `users` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
+   ALTER TABLE `users_confirmations` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
+   ALTER TABLE `users_remembered` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
+   ALTER TABLE `users_resets` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
+   ALTER TABLE `users_throttling` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
+
+   ALTER TABLE `users` CHANGE `email` `email` VARCHAR(249) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL;
+   ALTER TABLE `users` CHANGE `username` `username` VARCHAR(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NULL DEFAULT NULL;
+
+   ALTER TABLE `users_confirmations` CHANGE `email` `email` VARCHAR(249) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL;
+
+   ALTER TABLE `users_throttling` CHANGE `action_type` `action_type` ENUM('login','register','confirm_email') CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL;
+
+   REPAIR TABLE users;
+   OPTIMIZE TABLE users;
+   REPAIR TABLE users_confirmations;
+   OPTIMIZE TABLE users_confirmations;
+   REPAIR TABLE users_remembered;
+   OPTIMIZE TABLE users_remembered;
+   REPAIR TABLE users_resets;
+   OPTIMIZE TABLE users_resets;
+   REPAIR TABLE users_throttling;
+   OPTIMIZE TABLE users_throttling;
+   ```

NOTICE

@@ -1,5 +0,0 @@
-PHP-Auth
-Copyright (c) delight.im <info@delight.im>
-
-This product includes software developed by
-delight.im (http://www.delight.im/).

composer.json

@@ -2,14 +2,16 @@
 	"name": "delight-im/auth",
 	"description": "Authentication for PHP. Simple, lightweight and secure.",
 	"require": {
-		"php": ">=5.5.0",
+		"php": ">=5.6.0",
 		"ext-openssl": "*",
-		"delight-im/cookie": "^1.3"
+		"delight-im/base64": "^1.0",
+		"delight-im/cookie": "^3.1",
+		"delight-im/db": "^1.3"
 	},
 	"type": "library",
 	"keywords": [ "auth", "authentication", "login", "security" ],
 	"homepage": "https://github.com/delight-im/PHP-Auth",
-	"license": "Apache-2.0",
+	"license": "MIT",
 	"autoload": {
 		"psr-4": {
 			"Delight\\Auth\\": "src/"

composer.lock

@@ -4,28 +4,68 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "hash": "32e4912115e164a1a86227d49db9ac29",
-    "content-hash": "1a5c0056d726ae6195da0faa38f37fdd",
+    "content-hash": "e4acd9e4ba13c4d0692f07a03a454859",
     "packages": [
         {
-            "name": "delight-im/cookie",
-            "version": "v1.3.0",
+            "name": "delight-im/base64",
+            "version": "v1.0.0",
             "source": {
                 "type": "git",
-                "url": "https://github.com/delight-im/PHP-Cookie.git",
-                "reference": "481c569d6f4bcb0391f56203f078d425b3339001"
+                "url": "https://github.com/delight-im/PHP-Base64.git",
+                "reference": "687b2a49f663e162030a8d27b32838bbe7f91c78"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/delight-im/PHP-Cookie/zipball/481c569d6f4bcb0391f56203f078d425b3339001",
-                "reference": "481c569d6f4bcb0391f56203f078d425b3339001",
+                "url": "https://api.github.com/repos/delight-im/PHP-Base64/zipball/687b2a49f663e162030a8d27b32838bbe7f91c78",
+                "reference": "687b2a49f663e162030a8d27b32838bbe7f91c78",
                 "shasum": ""
             },
             "require": {
-                "delight-im/http": "^1.1",
                 "php": ">=5.3.0"
             },
             "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "Delight\\Base64\\": "src/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "description": "Simple and convenient Base64 encoding and decoding for PHP",
+            "homepage": "https://github.com/delight-im/PHP-Base64",
+            "keywords": [
+                "URL-safe",
+                "base-64",
+                "base64",
+                "decode",
+                "decoding",
+                "encode",
+                "encoding",
+                "url"
+            ],
+            "time": "2017-07-24T18:59:51+00:00"
+        },
+        {
+            "name": "delight-im/cookie",
+            "version": "v3.1.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/delight-im/PHP-Cookie.git",
+                "reference": "76ef2a21817cf7a034f85fc3f4d4bfc60f873947"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/delight-im/PHP-Cookie/zipball/76ef2a21817cf7a034f85fc3f4d4bfc60f873947",
+                "reference": "76ef2a21817cf7a034f85fc3f4d4bfc60f873947",
+                "shasum": ""
+            },
+            "require": {
+                "delight-im/http": "^2.0",
+                "php": ">=5.4.0"
+            },
+            "type": "library",
             "autoload": {
                 "psr-4": {
                     "Delight\\Cookie\\": "src/"
@@ -33,7 +73,7 @@
             },
             "notification-url": "https://packagist.org/downloads/",
             "license": [
-                "Apache-2.0"
+                "MIT"
             ],
             "description": "Modern cookie management for PHP",
             "homepage": "https://github.com/delight-im/PHP-Cookie",
@@ -46,20 +86,61 @@
                 "samesite",
                 "xss"
             ],
-            "time": "2016-07-19 22:20:24"
+            "time": "2017-10-18T19:48:59+00:00"
         },
         {
-            "name": "delight-im/http",
-            "version": "v1.1.0",
+            "name": "delight-im/db",
+            "version": "v1.3.0",
             "source": {
                 "type": "git",
-                "url": "https://github.com/delight-im/PHP-HTTP.git",
-                "reference": "2ca9001f047c8b4e1b7ca7281823a1a9437850f8"
+                "url": "https://github.com/delight-im/PHP-DB.git",
+                "reference": "7a03da20b5592fa445c10cd6c7245d51037292c4"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/delight-im/PHP-HTTP/zipball/2ca9001f047c8b4e1b7ca7281823a1a9437850f8",
-                "reference": "2ca9001f047c8b4e1b7ca7281823a1a9437850f8",
+                "url": "https://api.github.com/repos/delight-im/PHP-DB/zipball/7a03da20b5592fa445c10cd6c7245d51037292c4",
+                "reference": "7a03da20b5592fa445c10cd6c7245d51037292c4",
+                "shasum": ""
+            },
+            "require": {
+                "ext-pdo": "*",
+                "php": ">=5.6.0"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "Delight\\Db\\": "src/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "description": "Safe and convenient SQL database access in a driver-agnostic way",
+            "homepage": "https://github.com/delight-im/PHP-DB",
+            "keywords": [
+                "database",
+                "mysql",
+                "pdo",
+                "pgsql",
+                "postgresql",
+                "sql",
+                "sqlite"
+            ],
+            "time": "2018-08-28T18:23:01+00:00"
+        },
+        {
+            "name": "delight-im/http",
+            "version": "v2.0.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/delight-im/PHP-HTTP.git",
+                "reference": "0a19a72a7eac8b1301aa972fb20cff494ac43e09"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/delight-im/PHP-HTTP/zipball/0a19a72a7eac8b1301aa972fb20cff494ac43e09",
+                "reference": "0a19a72a7eac8b1301aa972fb20cff494ac43e09",
                 "shasum": ""
             },
             "require": {
@@ -73,7 +154,7 @@
             },
             "notification-url": "https://packagist.org/downloads/",
             "license": [
-                "Apache-2.0"
+                "MIT"
             ],
             "description": "Hypertext Transfer Protocol (HTTP) utilities for PHP",
             "homepage": "https://github.com/delight-im/PHP-HTTP",
@@ -82,7 +163,7 @@
                 "http",
                 "https"
             ],
-            "time": "2016-07-08 21:19:02"
+            "time": "2016-07-21T15:05:01+00:00"
         }
     ],
     "packages-dev": [],
@@ -92,7 +173,7 @@
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": {
-        "php": ">=5.5.0",
+        "php": ">=5.6.0",
         "ext-openssl": "*"
     },
     "platform-dev": []

src/Administration.php

@@ -0,0 +1,577 @@
+<?php
+
+/*
+ * PHP-Auth (https://github.com/delight-im/PHP-Auth)
+ * Copyright (c) delight.im (https://www.delight.im/)
+ * Licensed under the MIT License (https://opensource.org/licenses/MIT)
+ */
+
+namespace Delight\Auth;
+
+use Delight\Db\PdoDatabase;
+use Delight\Db\PdoDsn;
+use Delight\Db\Throwable\Error;
+
+require_once __DIR__ . '/Exceptions.php';
+
+/** Component that can be used for administrative tasks by privileged and authorized users */
+final class Administration extends UserManager {
+
+	/**
+	 * @param PdoDatabase|PdoDsn|\PDO $databaseConnection the database connection to operate on
+	 * @param string|null $dbTablePrefix (optional) the prefix for the names of all database tables used by this component
+	 * @param string|null $dbSchema (optional) the schema name for all database tables used by this component
+	 */
+	public function __construct($databaseConnection, $dbTablePrefix = null, $dbSchema = null) {
+		parent::__construct($databaseConnection, $dbTablePrefix, $dbSchema);
+	}
+
+	/**
+	 * Creates a new user
+	 *
+	 * @param string $email the email address to register
+	 * @param string $password the password for the new account
+	 * @param string|null $username (optional) the username that will be displayed
+	 * @return int the ID of the user that has been created (if any)
+	 * @throws InvalidEmailException if the email address was invalid
+	 * @throws InvalidPasswordException if the password was invalid
+	 * @throws UserAlreadyExistsException if a user with the specified email address already exists
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	public function createUser($email, $password, $username = null) {
+		return $this->createUserInternal(false, $email, $password, $username, null);
+	}
+
+	/**
+	 * Creates a new user while ensuring that the username is unique
+	 *
+	 * @param string $email the email address to register
+	 * @param string $password the password for the new account
+	 * @param string|null $username (optional) the username that will be displayed
+	 * @return int the ID of the user that has been created (if any)
+	 * @throws InvalidEmailException if the email address was invalid
+	 * @throws InvalidPasswordException if the password was invalid
+	 * @throws UserAlreadyExistsException if a user with the specified email address already exists
+	 * @throws DuplicateUsernameException if the specified username wasn't unique
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	public function createUserWithUniqueUsername($email, $password, $username = null) {
+		return $this->createUserInternal(true, $email, $password, $username, null);
+	}
+
+	/**
+	 * Deletes the user with the specified ID
+	 *
+	 * This action cannot be undone
+	 *
+	 * @param int $id the ID of the user to delete
+	 * @throws UnknownIdException if no user with the specified ID has been found
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	public function deleteUserById($id) {
+		$numberOfDeletedUsers = $this->deleteUsersByColumnValue('id', (int) $id);
+
+		if ($numberOfDeletedUsers === 0) {
+			throw new UnknownIdException();
+		}
+	}
+
+	/**
+	 * Deletes the user with the specified email address
+	 *
+	 * This action cannot be undone
+	 *
+	 * @param string $email the email address of the user to delete
+	 * @throws InvalidEmailException if no user with the specified email address has been found
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	public function deleteUserByEmail($email) {
+		$email = self::validateEmailAddress($email);
+
+		$numberOfDeletedUsers = $this->deleteUsersByColumnValue('email', $email);
+
+		if ($numberOfDeletedUsers === 0) {
+			throw new InvalidEmailException();
+		}
+	}
+
+	/**
+	 * Deletes the user with the specified username
+	 *
+	 * This action cannot be undone
+	 *
+	 * @param string $username the username of the user to delete
+	 * @throws UnknownUsernameException if no user with the specified username has been found
+	 * @throws AmbiguousUsernameException if multiple users with the specified username have been found
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	public function deleteUserByUsername($username) {
+		$userData = $this->getUserDataByUsername(
+			\trim($username),
+			[ 'id' ]
+		);
+
+		$this->deleteUsersByColumnValue('id', (int) $userData['id']);
+	}
+
+	/**
+	 * Assigns the specified role to the user with the given ID
+	 *
+	 * A user may have any number of roles (i.e. no role at all, a single role, or any combination of roles)
+	 *
+	 * @param int $userId the ID of the user to assign the role to
+	 * @param int $role the role as one of the constants from the {@see Role} class
+	 * @throws UnknownIdException if no user with the specified ID has been found
+	 *
+	 * @see Role
+	 */
+	public function addRoleForUserById($userId, $role) {
+		$userFound = $this->addRoleForUserByColumnValue(
+			'id',
+			(int) $userId,
+			$role
+		);
+
+		if ($userFound === false) {
+			throw new UnknownIdException();
+		}
+	}
+
+	/**
+	 * Assigns the specified role to the user with the given email address
+	 *
+	 * A user may have any number of roles (i.e. no role at all, a single role, or any combination of roles)
+	 *
+	 * @param string $userEmail the email address of the user to assign the role to
+	 * @param int $role the role as one of the constants from the {@see Role} class
+	 * @throws InvalidEmailException if no user with the specified email address has been found
+	 *
+	 * @see Role
+	 */
+	public function addRoleForUserByEmail($userEmail, $role) {
+		$userEmail = self::validateEmailAddress($userEmail);
+
+		$userFound = $this->addRoleForUserByColumnValue(
+			'email',
+			$userEmail,
+			$role
+		);
+
+		if ($userFound === false) {
+			throw new InvalidEmailException();
+		}
+	}
+
+	/**
+	 * Assigns the specified role to the user with the given username
+	 *
+	 * A user may have any number of roles (i.e. no role at all, a single role, or any combination of roles)
+	 *
+	 * @param string $username the username of the user to assign the role to
+	 * @param int $role the role as one of the constants from the {@see Role} class
+	 * @throws UnknownUsernameException if no user with the specified username has been found
+	 * @throws AmbiguousUsernameException if multiple users with the specified username have been found
+	 *
+	 * @see Role
+	 */
+	public function addRoleForUserByUsername($username, $role) {
+		$userData = $this->getUserDataByUsername(
+			\trim($username),
+			[ 'id' ]
+		);
+
+		$this->addRoleForUserByColumnValue(
+			'id',
+			(int) $userData['id'],
+			$role
+		);
+	}
+
+	/**
+	 * Takes away the specified role from the user with the given ID
+	 *
+	 * A user may have any number of roles (i.e. no role at all, a single role, or any combination of roles)
+	 *
+	 * @param int $userId the ID of the user to take the role away from
+	 * @param int $role the role as one of the constants from the {@see Role} class
+	 * @throws UnknownIdException if no user with the specified ID has been found
+	 *
+	 * @see Role
+	 */
+	public function removeRoleForUserById($userId, $role) {
+		$userFound = $this->removeRoleForUserByColumnValue(
+			'id',
+			(int) $userId,
+			$role
+		);
+
+		if ($userFound === false) {
+			throw new UnknownIdException();
+		}
+	}
+
+	/**
+	 * Takes away the specified role from the user with the given email address
+	 *
+	 * A user may have any number of roles (i.e. no role at all, a single role, or any combination of roles)
+	 *
+	 * @param string $userEmail the email address of the user to take the role away from
+	 * @param int $role the role as one of the constants from the {@see Role} class
+	 * @throws InvalidEmailException if no user with the specified email address has been found
+	 *
+	 * @see Role
+	 */
+	public function removeRoleForUserByEmail($userEmail, $role) {
+		$userEmail = self::validateEmailAddress($userEmail);
+
+		$userFound = $this->removeRoleForUserByColumnValue(
+			'email',
+			$userEmail,
+			$role
+		);
+
+		if ($userFound === false) {
+			throw new InvalidEmailException();
+		}
+	}
+
+	/**
+	 * Takes away the specified role from the user with the given username
+	 *
+	 * A user may have any number of roles (i.e. no role at all, a single role, or any combination of roles)
+	 *
+	 * @param string $username the username of the user to take the role away from
+	 * @param int $role the role as one of the constants from the {@see Role} class
+	 * @throws UnknownUsernameException if no user with the specified username has been found
+	 * @throws AmbiguousUsernameException if multiple users with the specified username have been found
+	 *
+	 * @see Role
+	 */
+	public function removeRoleForUserByUsername($username, $role) {
+		$userData = $this->getUserDataByUsername(
+			\trim($username),
+			[ 'id' ]
+		);
+
+		$this->removeRoleForUserByColumnValue(
+			'id',
+			(int) $userData['id'],
+			$role
+		);
+	}
+
+	/**
+	 * Returns whether the user with the given ID has the specified role
+	 *
+	 * @param int $userId the ID of the user to check the roles for
+	 * @param int $role the role as one of the constants from the {@see Role} class
+	 * @return bool
+	 * @throws UnknownIdException if no user with the specified ID has been found
+	 *
+	 * @see Role
+	 */
+	public function doesUserHaveRole($userId, $role) {
+		if (empty($role) || !\is_numeric($role)) {
+			return false;
+		}
+
+		$userId = (int) $userId;
+
+		$rolesBitmask = $this->db->selectValue(
+			'SELECT roles_mask FROM ' . $this->makeTableName('users') . ' WHERE id = ?',
+			[ $userId ]
+		);
+
+		if ($rolesBitmask === null) {
+			throw new UnknownIdException();
+		}
+
+		$role = (int) $role;
+
+		return ($rolesBitmask & $role) === $role;
+	}
+
+	/**
+	 * Returns the roles of the user with the given ID, mapping the numerical values to their descriptive names
+	 *
+	 * @param int $userId the ID of the user to return the roles for
+	 * @return array
+	 * @throws UnknownIdException if no user with the specified ID has been found
+	 *
+	 * @see Role
+	 */
+	public function getRolesForUserById($userId) {
+		$userId = (int) $userId;
+
+		$rolesBitmask = $this->db->selectValue(
+			'SELECT roles_mask FROM ' . $this->makeTableName('users') . ' WHERE id = ?',
+			[ $userId ]
+		);
+
+		if ($rolesBitmask === null) {
+			throw new UnknownIdException();
+		}
+
+		return \array_filter(
+			Role::getMap(),
+			function ($each) use ($rolesBitmask) {
+				return ($rolesBitmask & $each) === $each;
+			},
+			\ARRAY_FILTER_USE_KEY
+		);
+	}
+
+	/**
+	 * Signs in as the user with the specified ID
+	 *
+	 * @param int $id the ID of the user to sign in as
+	 * @throws UnknownIdException if no user with the specified ID has been found
+	 * @throws EmailNotVerifiedException if the user has not verified their email address via a confirmation method yet
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	public function logInAsUserById($id) {
+		$numberOfMatchedUsers = $this->logInAsUserByColumnValue('id', (int) $id);
+
+		if ($numberOfMatchedUsers === 0) {
+			throw new UnknownIdException();
+		}
+	}
+
+	/**
+	 * Signs in as the user with the specified email address
+	 *
+	 * @param string $email the email address of the user to sign in as
+	 * @throws InvalidEmailException if no user with the specified email address has been found
+	 * @throws EmailNotVerifiedException if the user has not verified their email address via a confirmation method yet
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	public function logInAsUserByEmail($email) {
+		$email = self::validateEmailAddress($email);
+
+		$numberOfMatchedUsers = $this->logInAsUserByColumnValue('email', $email);
+
+		if ($numberOfMatchedUsers === 0) {
+			throw new InvalidEmailException();
+		}
+	}
+
+	/**
+	 * Signs in as the user with the specified display name
+	 *
+	 * @param string $username the display name of the user to sign in as
+	 * @throws UnknownUsernameException if no user with the specified username has been found
+	 * @throws AmbiguousUsernameException if multiple users with the specified username have been found
+	 * @throws EmailNotVerifiedException if the user has not verified their email address via a confirmation method yet
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	public function logInAsUserByUsername($username) {
+		$numberOfMatchedUsers = $this->logInAsUserByColumnValue('username', \trim($username));
+
+		if ($numberOfMatchedUsers === 0) {
+			throw new UnknownUsernameException();
+		}
+		elseif ($numberOfMatchedUsers > 1) {
+			throw new AmbiguousUsernameException();
+		}
+	}
+
+	/**
+	 * Changes the password for the user with the given ID
+	 *
+	 * @param int $userId the ID of the user whose password to change
+	 * @param string $newPassword the new password to set
+	 * @throws UnknownIdException if no user with the specified ID has been found
+	 * @throws InvalidPasswordException if the desired new password has been invalid
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	public function changePasswordForUserById($userId, $newPassword) {
+		$userId = (int) $userId;
+		$newPassword = self::validatePassword($newPassword);
+
+		$this->updatePasswordInternal(
+			$userId,
+			$newPassword
+		);
+
+		$this->forceLogoutForUserById($userId);
+	}
+
+	/**
+	 * Changes the password for the user with the given username
+	 *
+	 * @param string $username the username of the user whose password to change
+	 * @param string $newPassword the new password to set
+	 * @throws UnknownUsernameException if no user with the specified username has been found
+	 * @throws AmbiguousUsernameException if multiple users with the specified username have been found
+	 * @throws InvalidPasswordException if the desired new password has been invalid
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	public function changePasswordForUserByUsername($username, $newPassword) {
+		$userData = $this->getUserDataByUsername(
+			\trim($username),
+			[ 'id' ]
+		);
+
+		$this->changePasswordForUserById(
+			(int) $userData['id'],
+			$newPassword
+		);
+	}
+
+	/**
+	 * Deletes all existing users where the column with the specified name has the given value
+	 *
+	 * You must never pass untrusted input to the parameter that takes the column name
+	 *
+	 * @param string $columnName the name of the column to filter by
+	 * @param mixed $columnValue the value to look for in the selected column
+	 * @return int the number of deleted users
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	private function deleteUsersByColumnValue($columnName, $columnValue) {
+		try {
+			return $this->db->delete(
+				$this->makeTableNameComponents('users'),
+				[
+					$columnName => $columnValue
+				]
+			);
+		}
+		catch (Error $e) {
+			throw new DatabaseError($e->getMessage());
+		}
+	}
+
+	/**
+	 * Modifies the roles for the user where the column with the specified name has the given value
+	 *
+	 * You must never pass untrusted input to the parameter that takes the column name
+	 *
+	 * @param string $columnName the name of the column to filter by
+	 * @param mixed $columnValue the value to look for in the selected column
+	 * @param callable $modification the modification to apply to the existing bitmask of roles
+	 * @return bool whether any user with the given column constraints has been found
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 *
+	 * @see Role
+	 */
+	private function modifyRolesForUserByColumnValue($columnName, $columnValue, callable $modification) {
+		try {
+			$userData = $this->db->selectRow(
+				'SELECT id, roles_mask FROM ' . $this->makeTableName('users') . ' WHERE ' . $columnName . ' = ?',
+				[ $columnValue ]
+			);
+		}
+		catch (Error $e) {
+			throw new DatabaseError($e->getMessage());
+		}
+
+		if ($userData === null) {
+			return false;
+		}
+
+		$newRolesBitmask = $modification($userData['roles_mask']);
+
+		try {
+			$this->db->exec(
+				'UPDATE ' . $this->makeTableName('users') . ' SET roles_mask = ? WHERE id = ?',
+				[
+					$newRolesBitmask,
+					(int) $userData['id']
+				]
+			);
+
+			return true;
+		}
+		catch (Error $e) {
+			throw new DatabaseError($e->getMessage());
+		}
+	}
+
+	/**
+	 * Assigns the specified role to the user where the column with the specified name has the given value
+	 *
+	 * You must never pass untrusted input to the parameter that takes the column name
+	 *
+	 * @param string $columnName the name of the column to filter by
+	 * @param mixed $columnValue the value to look for in the selected column
+	 * @param int $role the role as one of the constants from the {@see Role} class
+	 * @return bool whether any user with the given column constraints has been found
+	 *
+	 * @see Role
+	 */
+	private function addRoleForUserByColumnValue($columnName, $columnValue, $role) {
+		$role = (int) $role;
+
+		return $this->modifyRolesForUserByColumnValue(
+			$columnName,
+			$columnValue,
+			function ($oldRolesBitmask) use ($role) {
+				return $oldRolesBitmask | $role;
+			}
+		);
+	}
+
+	/**
+	 * Takes away the specified role from the user where the column with the specified name has the given value
+	 *
+	 * You must never pass untrusted input to the parameter that takes the column name
+	 *
+	 * @param string $columnName the name of the column to filter by
+	 * @param mixed $columnValue the value to look for in the selected column
+	 * @param int $role the role as one of the constants from the {@see Role} class
+	 * @return bool whether any user with the given column constraints has been found
+	 *
+	 * @see Role
+	 */
+	private function removeRoleForUserByColumnValue($columnName, $columnValue, $role) {
+		$role = (int) $role;
+
+		return $this->modifyRolesForUserByColumnValue(
+			$columnName,
+			$columnValue,
+			function ($oldRolesBitmask) use ($role) {
+				return $oldRolesBitmask & ~$role;
+			}
+		);
+	}
+
+	/**
+	 * Signs in as the user for which the column with the specified name has the given value
+	 *
+	 * You must never pass untrusted input to the parameter that takes the column name
+	 *
+	 * @param string $columnName the name of the column to filter by
+	 * @param mixed $columnValue the value to look for in the selected column
+	 * @return int the number of matched users (where only a value of one means that the login may have been successful)
+	 * @throws EmailNotVerifiedException if the user has not verified their email address via a confirmation method yet
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	private function logInAsUserByColumnValue($columnName, $columnValue) {
+		try {
+			$users = $this->db->select(
+				'SELECT verified, id, email, username, status, roles_mask FROM ' . $this->makeTableName('users') . ' WHERE ' . $columnName . ' = ? LIMIT 2 OFFSET 0',
+				[ $columnValue ]
+			);
+		}
+		catch (Error $e) {
+			throw new DatabaseError($e->getMessage());
+		}
+
+		$numberOfMatchingUsers = ($users !== null) ? \count($users) : 0;
+
+		if ($numberOfMatchingUsers === 1) {
+			$user = $users[0];
+
+			if ((int) $user['verified'] === 1) {
+				$this->onLoginSuccessful($user['id'], $user['email'], $user['username'], $user['status'], $user['roles_mask'], \PHP_INT_MAX, false);
+			}
+			else {
+				throw new EmailNotVerifiedException();
+			}
+		}
+
+		return $numberOfMatchingUsers;
+	}
+
+}

src/Base64.php

@@ -1,44 +0,0 @@
-<?php
-
-/*
- * Copyright (c) delight.im <info@delight.im>
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-namespace Delight\Auth;
-
-class Base64 {
-
-	const SPECIAL_CHARS_ORIGINAL = '+/=';
-	const SPECIAL_CHARS_SAFE = '._-';
-
-	public static function encode($data, $safeChars = false) {
-		$result = base64_encode($data);
-
-		if ($safeChars) {
-			$result = strtr($result, self::SPECIAL_CHARS_ORIGINAL, self::SPECIAL_CHARS_SAFE);
-		}
-
-		return $result;
-	}
-
-	public static function decode($data) {
-		$data = strtr($data, self::SPECIAL_CHARS_SAFE, self::SPECIAL_CHARS_ORIGINAL);
-
-		$result = base64_decode($data, true);
-
-		return $result;
-	}
-
-}

src/Exceptions.php

@@ -1,27 +1,21 @@
 <?php
 
 /*
- * Copyright (c) delight.im <info@delight.im>
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ * PHP-Auth (https://github.com/delight-im/PHP-Auth)
+ * Copyright (c) delight.im (https://www.delight.im/)
+ * Licensed under the MIT License (https://opensource.org/licenses/MIT)
  */
 
 namespace Delight\Auth;
 
 class AuthException extends \Exception {}
 
+class UnknownIdException extends AuthException {}
+
 class InvalidEmailException extends AuthException {}
 
+class UnknownUsernameException extends AuthException {}
+
 class InvalidPasswordException extends AuthException {}
 
 class EmailNotVerifiedException extends AuthException {}
@@ -36,6 +30,16 @@ class TokenExpiredException extends AuthException {}
 
 class TooManyRequestsException extends AuthException {}
 
+class DuplicateUsernameException extends AuthException {}
+
+class AmbiguousUsernameException extends AuthException {}
+
+class AttemptCancelledException extends AuthException {}
+
+class ResetDisabledException extends AuthException {}
+
+class ConfirmationRequestNotFound extends AuthException {}
+
 class AuthError extends \Exception {}
 
 class DatabaseError extends AuthError {}
@@ -43,3 +47,5 @@ class DatabaseError extends AuthError {}
 class MissingCallbackError extends AuthError {}
 
 class HeadersAlreadySentError extends AuthError {}
+
+class EmailOrUsernameRequiredError extends AuthError {}

src/Role.php

@@ -0,0 +1,79 @@
+<?php
+
+/*
+ * PHP-Auth (https://github.com/delight-im/PHP-Auth)
+ * Copyright (c) delight.im (https://www.delight.im/)
+ * Licensed under the MIT License (https://opensource.org/licenses/MIT)
+ */
+
+namespace Delight\Auth;
+
+final class Role {
+
+	const ADMIN = 1;
+	const AUTHOR = 2;
+	const COLLABORATOR = 4;
+	const CONSULTANT = 8;
+	const CONSUMER = 16;
+	const CONTRIBUTOR = 32;
+	const COORDINATOR = 64;
+	const CREATOR = 128;
+	const DEVELOPER = 256;
+	const DIRECTOR = 512;
+	const EDITOR = 1024;
+	const EMPLOYEE = 2048;
+	const MAINTAINER = 4096;
+	const MANAGER = 8192;
+	const MODERATOR = 16384;
+	const PUBLISHER = 32768;
+	const REVIEWER = 65536;
+	const SUBSCRIBER = 131072;
+	const SUPER_ADMIN = 262144;
+	const SUPER_EDITOR = 524288;
+	const SUPER_MODERATOR = 1048576;
+	const TRANSLATOR = 2097152;
+	// const XYZ = 4194304;
+	// const XYZ = 8388608;
+	// const XYZ = 16777216;
+	// const XYZ = 33554432;
+	// const XYZ = 67108864;
+	// const XYZ = 134217728;
+	// const XYZ = 268435456;
+	// const XYZ = 536870912;
+
+	/**
+	 * Returns an array mapping the numerical role values to their descriptive names
+	 *
+	 * @return array
+	 */
+	public static function getMap() {
+		$reflectionClass = new \ReflectionClass(static::class);
+
+		return \array_flip($reflectionClass->getConstants());
+	}
+
+	/**
+	 * Returns the descriptive role names
+	 *
+	 * @return string[]
+	 */
+	public static function getNames() {
+		$reflectionClass = new \ReflectionClass(static::class);
+
+		return \array_keys($reflectionClass->getConstants());
+	}
+
+	/**
+	 * Returns the numerical role values
+	 *
+	 * @return int[]
+	 */
+	public static function getValues() {
+		$reflectionClass = new \ReflectionClass(static::class);
+
+		return \array_values($reflectionClass->getConstants());
+	}
+
+	private function __construct() {}
+
+}

src/Status.php

@@ -0,0 +1,20 @@
+<?php
+
+/*
+ * PHP-Auth (https://github.com/delight-im/PHP-Auth)
+ * Copyright (c) delight.im (https://www.delight.im/)
+ * Licensed under the MIT License (https://opensource.org/licenses/MIT)
+ */
+
+namespace Delight\Auth;
+
+final class Status {
+
+	const NORMAL = 0;
+	const ARCHIVED = 1;
+	const BANNED = 2;
+	const LOCKED = 3;
+	const PENDING_REVIEW = 4;
+	const SUSPENDED = 5;
+
+}

src/UserManager.php

@@ -0,0 +1,456 @@
+<?php
+
+/*
+ * PHP-Auth (https://github.com/delight-im/PHP-Auth)
+ * Copyright (c) delight.im (https://www.delight.im/)
+ * Licensed under the MIT License (https://opensource.org/licenses/MIT)
+ */
+
+namespace Delight\Auth;
+
+use Delight\Base64\Base64;
+use Delight\Cookie\Session;
+use Delight\Db\PdoDatabase;
+use Delight\Db\PdoDsn;
+use Delight\Db\Throwable\Error;
+use Delight\Db\Throwable\IntegrityConstraintViolationException;
+
+require_once __DIR__ . '/Exceptions.php';
+
+/**
+ * Abstract base class for components implementing user management
+ *
+ * @internal
+ */
+abstract class UserManager {
+
+	/** @var string session field for whether the client is currently signed in */
+	const SESSION_FIELD_LOGGED_IN = 'auth_logged_in';
+	/** @var string session field for the ID of the user who is currently signed in (if any) */
+	const SESSION_FIELD_USER_ID = 'auth_user_id';
+	/** @var string session field for the email address of the user who is currently signed in (if any) */
+	const SESSION_FIELD_EMAIL = 'auth_email';
+	/** @var string session field for the display name (if any) of the user who is currently signed in (if any) */
+	const SESSION_FIELD_USERNAME = 'auth_username';
+	/** @var string session field for the status of the user who is currently signed in (if any) as one of the constants from the {@see Status} class */
+	const SESSION_FIELD_STATUS = 'auth_status';
+	/** @var string session field for the roles of the user who is currently signed in (if any) as a bitmask using constants from the {@see Role} class */
+	const SESSION_FIELD_ROLES = 'auth_roles';
+	/** @var string session field for whether the user who is currently signed in (if any) has been remembered (instead of them having authenticated actively) */
+	const SESSION_FIELD_REMEMBERED = 'auth_remembered';
+	/** @var string session field for the UNIX timestamp in seconds of the session data's last resynchronization with its authoritative source in the database */
+	const SESSION_FIELD_LAST_RESYNC = 'auth_last_resync';
+	/** @var string session field for the counter that keeps track of forced logouts that need to be performed in the current session */
+	const SESSION_FIELD_FORCE_LOGOUT = 'auth_force_logout';
+
+	/** @var PdoDatabase the database connection to operate on */
+	protected $db;
+	/** @var string|null the schema name for all database tables used by this component */
+	protected $dbSchema;
+	/** @var string the prefix for the names of all database tables used by this component */
+	protected $dbTablePrefix;
+
+	/**
+	 * Creates a random string with the given maximum length
+	 *
+	 * With the default parameter, the output should contain at least as much randomness as a UUID
+	 *
+	 * @param int $maxLength the maximum length of the output string (integer multiple of 4)
+	 * @return string the new random string
+	 */
+	public static function createRandomString($maxLength = 24) {
+		// calculate how many bytes of randomness we need for the specified string length
+		$bytes = \floor((int) $maxLength / 4) * 3;
+
+		// get random data
+		$data = \openssl_random_pseudo_bytes($bytes);
+
+		// return the Base64-encoded result
+		return Base64::encodeUrlSafe($data);
+	}
+
+	/**
+	 * @param PdoDatabase|PdoDsn|\PDO $databaseConnection the database connection to operate on
+	 * @param string|null $dbTablePrefix (optional) the prefix for the names of all database tables used by this component
+	 * @param string|null $dbSchema (optional) the schema name for all database tables used by this component
+	 */
+	protected function __construct($databaseConnection, $dbTablePrefix = null, $dbSchema = null) {
+		if ($databaseConnection instanceof PdoDatabase) {
+			$this->db = $databaseConnection;
+		}
+		elseif ($databaseConnection instanceof PdoDsn) {
+			$this->db = PdoDatabase::fromDsn($databaseConnection);
+		}
+		elseif ($databaseConnection instanceof \PDO) {
+			$this->db = PdoDatabase::fromPdo($databaseConnection, true);
+		}
+		else {
+			$this->db = null;
+
+			throw new \InvalidArgumentException('The database connection must be an instance of either `PdoDatabase`, `PdoDsn` or `PDO`');
+		}
+
+		$this->dbSchema = $dbSchema !== null ? (string) $dbSchema : null;
+		$this->dbTablePrefix = (string) $dbTablePrefix;
+	}
+
+	/**
+	 * Creates a new user
+	 *
+	 * If you want the user's account to be activated by default, pass `null` as the callback
+	 *
+	 * If you want to make the user verify their email address first, pass an anonymous function as the callback
+	 *
+	 * The callback function must have the following signature:
+	 *
+	 * `function ($selector, $token)`
+	 *
+	 * Both pieces of information must be sent to the user, usually embedded in a link
+	 *
+	 * When the user wants to verify their email address as a next step, both pieces will be required again
+	 *
+	 * @param bool $requireUniqueUsername whether it must be ensured that the username is unique
+	 * @param string $email the email address to register
+	 * @param string $password the password for the new account
+	 * @param string|null $username (optional) the username that will be displayed
+	 * @param callable|null $callback (optional) the function that sends the confirmation email to the user
+	 * @return int the ID of the user that has been created (if any)
+	 * @throws InvalidEmailException if the email address has been invalid
+	 * @throws InvalidPasswordException if the password has been invalid
+	 * @throws UserAlreadyExistsException if a user with the specified email address already exists
+	 * @throws DuplicateUsernameException if it was specified that the username must be unique while it was *not*
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 *
+	 * @see confirmEmail
+	 * @see confirmEmailAndSignIn
+	 */
+	protected function createUserInternal($requireUniqueUsername, $email, $password, $username = null, callable $callback = null) {
+		\ignore_user_abort(true);
+
+		$email = self::validateEmailAddress($email);
+		$password = self::validatePassword($password);
+
+		$username = isset($username) ? \trim($username) : null;
+
+		// if the supplied username is the empty string or has consisted of whitespace only
+		if ($username === '') {
+			// this actually means that there is no username
+			$username = null;
+		}
+
+		// if the uniqueness of the username is to be ensured
+		if ($requireUniqueUsername) {
+			// if a username has actually been provided
+			if ($username !== null) {
+				// count the number of users who do already have that specified username
+				$occurrencesOfUsername = $this->db->selectValue(
+					'SELECT COUNT(*) FROM ' . $this->makeTableName('users') . ' WHERE username = ?',
+					[ $username ]
+				);
+
+				// if any user with that username does already exist
+				if ($occurrencesOfUsername > 0) {
+					// cancel the operation and report the violation of this requirement
+					throw new DuplicateUsernameException();
+				}
+			}
+		}
+
+		$password = \password_hash($password, \PASSWORD_DEFAULT);
+		$verified = \is_callable($callback) ? 0 : 1;
+
+		try {
+			$this->db->insert(
+				$this->makeTableNameComponents('users'),
+				[
+					'email' => $email,
+					'password' => $password,
+					'username' => $username,
+					'verified' => $verified,
+					'registered' => \time()
+				]
+			);
+		}
+		// if we have a duplicate entry
+		catch (IntegrityConstraintViolationException $e) {
+			throw new UserAlreadyExistsException();
+		}
+		catch (Error $e) {
+			throw new DatabaseError($e->getMessage());
+		}
+
+		$newUserId = (int) $this->db->getLastInsertId();
+
+		if ($verified === 0) {
+			$this->createConfirmationRequest($newUserId, $email, $callback);
+		}
+
+		return $newUserId;
+	}
+
+	/**
+	 * Updates the given user's password by setting it to the new specified password
+	 *
+	 * @param int $userId the ID of the user whose password should be updated
+	 * @param string $newPassword the new password
+	 * @throws UnknownIdException if no user with the specified ID has been found
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	protected function updatePasswordInternal($userId, $newPassword) {
+		$newPassword = \password_hash($newPassword, \PASSWORD_DEFAULT);
+
+		try {
+			$affected = $this->db->update(
+				$this->makeTableNameComponents('users'),
+				[ 'password' => $newPassword ],
+				[ 'id' => $userId ]
+			);
+
+			if ($affected === 0) {
+				throw new UnknownIdException();
+			}
+		}
+		catch (Error $e) {
+			throw new DatabaseError($e->getMessage());
+		}
+	}
+
+	/**
+	 * Called when a user has successfully logged in
+	 *
+	 * This may happen via the standard login, via the "remember me" feature, or due to impersonation by administrators
+	 *
+	 * @param int $userId the ID of the user
+	 * @param string $email the email address of the user
+	 * @param string $username the display name (if any) of the user
+	 * @param int $status the status of the user as one of the constants from the {@see Status} class
+	 * @param int $roles the roles of the user as a bitmask using constants from the {@see Role} class
+	 * @param int $forceLogout the counter that keeps track of forced logouts that need to be performed in the current session
+	 * @param bool $remembered whether the user has been remembered (instead of them having authenticated actively)
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	protected function onLoginSuccessful($userId, $email, $username, $status, $roles, $forceLogout, $remembered) {
+		// re-generate the session ID to prevent session fixation attacks (requests a cookie to be written on the client)
+		Session::regenerate(true);
+
+		// save the user data in the session variables maintained by this library
+		$_SESSION[self::SESSION_FIELD_LOGGED_IN] = true;
+		$_SESSION[self::SESSION_FIELD_USER_ID] = (int) $userId;
+		$_SESSION[self::SESSION_FIELD_EMAIL] = $email;
+		$_SESSION[self::SESSION_FIELD_USERNAME] = $username;
+		$_SESSION[self::SESSION_FIELD_STATUS] = (int) $status;
+		$_SESSION[self::SESSION_FIELD_ROLES] = (int) $roles;
+		$_SESSION[self::SESSION_FIELD_FORCE_LOGOUT] = (int) $forceLogout;
+		$_SESSION[self::SESSION_FIELD_REMEMBERED] = $remembered;
+		$_SESSION[self::SESSION_FIELD_LAST_RESYNC] = \time();
+	}
+
+	/**
+	 * Returns the requested user data for the account with the specified username (if any)
+	 *
+	 * You must never pass untrusted input to the parameter that takes the column list
+	 *
+	 * @param string $username the username to look for
+	 * @param array $requestedColumns the columns to request from the user's record
+	 * @return array the user data (if an account was found unambiguously)
+	 * @throws UnknownUsernameException if no user with the specified username has been found
+	 * @throws AmbiguousUsernameException if multiple users with the specified username have been found
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	protected function getUserDataByUsername($username, array $requestedColumns) {
+		try {
+			$projection = \implode(', ', $requestedColumns);
+
+			$users = $this->db->select(
+				'SELECT ' . $projection . ' FROM ' . $this->makeTableName('users') . ' WHERE username = ? LIMIT 2 OFFSET 0',
+				[ $username ]
+			);
+		}
+		catch (Error $e) {
+			throw new DatabaseError($e->getMessage());
+		}
+
+		if (empty($users)) {
+			throw new UnknownUsernameException();
+		}
+		else {
+			if (\count($users) === 1) {
+				return $users[0];
+			}
+			else {
+				throw new AmbiguousUsernameException();
+			}
+		}
+	}
+
+	/**
+	 * Validates an email address
+	 *
+	 * @param string $email the email address to validate
+	 * @return string the sanitized email address
+	 * @throws InvalidEmailException if the email address has been invalid
+	 */
+	protected static function validateEmailAddress($email) {
+		if (empty($email)) {
+			throw new InvalidEmailException();
+		}
+
+		$email = \trim($email);
+
+		if (!\filter_var($email, \FILTER_VALIDATE_EMAIL)) {
+			throw new InvalidEmailException();
+		}
+
+		return $email;
+	}
+
+	/**
+	 * Validates a password
+	 *
+	 * @param string $password the password to validate
+	 * @return string the sanitized password
+	 * @throws InvalidPasswordException if the password has been invalid
+	 */
+	protected static function validatePassword($password) {
+		if (empty($password)) {
+			throw new InvalidPasswordException();
+		}
+
+		$password = \trim($password);
+
+		if (\strlen($password) < 1) {
+			throw new InvalidPasswordException();
+		}
+
+		return $password;
+	}
+
+	/**
+	 * Creates a request for email confirmation
+	 *
+	 * The callback function must have the following signature:
+	 *
+	 * `function ($selector, $token)`
+	 *
+	 * Both pieces of information must be sent to the user, usually embedded in a link
+	 *
+	 * When the user wants to verify their email address as a next step, both pieces will be required again
+	 *
+	 * @param int $userId the user's ID
+	 * @param string $email the email address to verify
+	 * @param callable $callback the function that sends the confirmation email to the user
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	protected function createConfirmationRequest($userId, $email, callable $callback) {
+		$selector = self::createRandomString(16);
+		$token = self::createRandomString(16);
+		$tokenHashed = \password_hash($token, \PASSWORD_DEFAULT);
+		$expires = \time() + 60 * 60 * 24;
+
+		try {
+			$this->db->insert(
+				$this->makeTableNameComponents('users_confirmations'),
+				[
+					'user_id' => (int) $userId,
+					'email' => $email,
+					'selector' => $selector,
+					'token' => $tokenHashed,
+					'expires' => $expires
+				]
+			);
+		}
+		catch (Error $e) {
+			throw new DatabaseError($e->getMessage());
+		}
+
+		if (\is_callable($callback)) {
+			$callback($selector, $token);
+		}
+		else {
+			throw new MissingCallbackError();
+		}
+	}
+
+	/**
+	 * Clears an existing directive that keeps the user logged in ("remember me")
+	 *
+	 * @param int $userId the ID of the user who shouldn't be kept signed in anymore
+	 * @param string $selector (optional) the selector which the deletion should be restricted to
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	protected function deleteRememberDirectiveForUserById($userId, $selector = null) {
+		$whereMappings = [];
+
+		if (isset($selector)) {
+			$whereMappings['selector'] = (string) $selector;
+		}
+
+		$whereMappings['user'] = (int) $userId;
+
+		try {
+			$this->db->delete(
+				$this->makeTableNameComponents('users_remembered'),
+				$whereMappings
+			);
+		}
+		catch (Error $e) {
+			throw new DatabaseError($e->getMessage());
+		}
+	}
+
+	/**
+	 * Triggers a forced logout in all sessions that belong to the specified user
+	 *
+	 * @param int $userId the ID of the user to sign out
+	 * @throws AuthError if an internal problem occurred (do *not* catch)
+	 */
+	protected function forceLogoutForUserById($userId) {
+		$this->deleteRememberDirectiveForUserById($userId);
+		$this->db->exec(
+			'UPDATE ' . $this->makeTableName('users') . ' SET force_logout = force_logout + 1 WHERE id = ?',
+			[ $userId ]
+		);
+	}
+
+	/**
+	 * Builds a (qualified) full table name from an optional qualifier, an optional prefix, and the table name itself
+	 *
+	 * The optional qualifier may be a database name or a schema name, for example
+	 *
+	 * @param string $name the name of the table
+	 * @return string[] the components of the (qualified) full name of the table
+	 */
+	protected function makeTableNameComponents($name) {
+		$components = [];
+
+		if (!empty($this->dbSchema)) {
+			$components[] = $this->dbSchema;
+		}
+
+		if (!empty($name)) {
+			if (!empty($this->dbTablePrefix)) {
+				$components[] = $this->dbTablePrefix . $name;
+			}
+			else {
+				$components[] = $name;
+			}
+		}
+
+		return $components;
+	}
+
+	/**
+	 * Builds a (qualified) full table name from an optional qualifier, an optional prefix, and the table name itself
+	 *
+	 * The optional qualifier may be a database name or a schema name, for example
+	 *
+	 * @param string $name the name of the table
+	 * @return string the (qualified) full name of the table
+	 */
+	protected function makeTableName($name) {
+		$components = $this->makeTableNameComponents($name);
+
+		return \implode('.', $components);
+	}
+
+}