How to make two -factor authentication PHP

Learn how to add two-factor authentication to your PHP app with an easy-to-follow example.

Two-Factor Authentication with PHP

Two-Factor Authentication (2FA) is an extra layer of security that can be added to your user accounts. It helps to ensure that the user is who they say they are by requiring a combination of two different types of authentication before allowing access. The two most common types of authentication are something you know, such as a password, and something you have, such as a code sent to your phone. In this guide, we'll be looking at how to implement two-factor authentication using PHP. We'll be using the PHP Google Authenticator library to create a time-based one-time password (TOTP) for users to enter when prompted.

Step 1: Install the PHP Google Authenticator Library

The first step is to install the PHP Google Authenticator library. You can do this by downloading the source code from the project's Github page or by using Composer. If you're using composer, you can do this by running the following command:

composer require pragmarx/google2fa

This will install the library and its dependencies into your project.

Step 2: Generate a TOTP Secret Key

The next step is to generate a TOTP secret key. This is a random string of characters that will be used to generate the one-time passwords. It should be kept secret and not shared with anyone. You can generate a secret key using the following code:

$secretKey = PragmaRXGoogle2FAGoogle2FA::generateSecretKey();

Step 3: Store the Secret Key

Now that you have a secret key, you need to store it somewhere. This should be done securely, as anyone who has the key can generate valid one-time passwords. You can store it in a database, or if you're using an authentication library such as Laravel, you can store it in the user's session.

Step 4: Generate a One-Time Password

Now that you have the secret key, you can generate a one-time password. This will be a six-digit number that the user needs to enter when prompted. You can generate a one-time password using the following code:

$oneTimePassword = PragmaRXGoogle2FAGoogle2FA::getCurrentOtp($secretKey);

Step 5: Verify the One-Time Password

The last step is to verify the one-time password. This should be done when the user attempts to log in. You can use the following code to check if the one-time password is valid:

$valid = PragmaRXGoogle2FAGoogle2FA::verifyKey($secretKey, $oneTimePassword);

If the one-time password is valid, the user will be allowed to log in.

Conclusion

Two-Factor Authentication is a great way to add an extra layer of security to your user accounts. It helps to ensure that the user is who they say they are by requiring a combination of two different types of authentication. In this guide, we looked at how to implement two-factor authentication using PHP. We used the PHP Google Authenticator library to generate a one-time password for users to enter when prompted. We also looked at how to store and verify the one-time password.