PHP Two-Factor Authentication
Example of two factor authentication login form using PHP without database.
The login data is stored on a PHP file, hidden from the user. Its content is also unreachable from direct access.
Configuration
The config.php file contains the settings and the translation of this script.
The data storage
You can register new users by accessing admin.php.
The data, including an encrypted password, is stored on a PHP file, which name is defined on settings.
If there is no data file, the script will create one.
The data file can also be deleted by clicking on a button on the same page.
Login process
The user is first prompted to enter his username and password. A reCAPTCHA verification is also required.
If username, password and reCAPTCHA are correct, the script will send an email to the respective user with a unique access code.
Then, the user is required to type and submit the access code to access the success page.
Any failures during the process results in a message error displayed to the user.