JWT with Laravel

JSON Web Tokens (JWTs) are a popular way to authenticate users and transmit information about them between systems. In this post, we’ll explore how to use JWTs with Laravel, a popular PHP framework for web application development.

First, let’s take a look at how JWTs work. JWTs are self-contained tokens that consist of three parts: a header, a payload, and a signature. The header specifies the algorithm used to generate the signature, and the payload contains the information being transmitted. The signature is used to verify that the sender of the JWT is who it claims to be and to ensure that the message wasn’t changed along the way.

To use JWTs with Laravel, we can use the tymon/jwt-auth package, which provides an easy-to-use interface for working with JWTs in Laravel. To install the package, we can run the following command:

composer require tymon/jwt-auth

Once the package is installed, we can set up the JWT authentication service provider in the config/app.php file. We can also publish the package’s configuration file using the following command:

php artisan vendor:publish --provider="Tymon\JWTAuth\Providers\LaravelServiceProvider"

With the service provider set up, we can use the JWT functions provided by the package to generate and verify JWTs. For example, to generate a JWT, we can use the JWTAuth::fromUser function:

$user = User::find(1);
$token = JWTAuth::fromUser($user);

To verify a JWT, we can use the JWTAuth::toUser function:

$user = JWTAuth::toUser($token);

For example, we can use the JWTAuth::attempt function to authenticate a user based on their login credentials:

$credentials = ['email' => $request->email, 'password' => $request->password];

if (JWTAuth::attempt($credentials)) {
    // credentials are valid, generate a token for the user
    $token = JWTAuth::fromUser(auth()->user());
    return response()->json(['token' => $token]);
} else {
    // invalid credentials
    return response()->json(['error' => 'invalid_credentials'], 401);
}

also use the JWTAuth::parseToken function to parse the JWT from an incoming request and authenticate the user based on the token:

$user = JWTAuth::parseToken()->authenticate();

Finally, we can use the JWTAuth::setToken and JWTAuth::invalidate functions to refresh a user’s token or log them out:

$newToken = JWTAuth::setToken($token)->refresh();