JWT Artisan

Token auth for Laravel and Lumen web artisans

JWT is a great solution for authenticating API requests between various services. This package makes working with JWT super easy for both Laravel and Lumen.

Why JWT?

Because you have

That need to authenticate with each other so you can turn away bad requests like

Which is why JWT makes you feel like

Contents

• Setup
• Configure
• Working with Tokens

Setup

Install the package using composer

$ composer require generationtux/jwt-artisan

Add the appropriate service provider for Laravel/Lumen

// Laravel
// config/app.php
'providers' => [
    ...
    GenTux\Jwt\Support\LaravelServiceProvider::class,
]

// Lumen
// bootstrap/app.php
$app->register(GenTux\Jwt\Support\LumenServiceProvider::class);

Configure

All configuration for this package can be set using environment variables. The reason for using environment variables instead of config files is so that it can be integrated with both Laravel & Lumen as easily as possible. See the table below for the available config options and their defaults.

| Config | Default | Description | | ------------ | ------- | ---------------------------------------------------------------- | | JWT_SECRET | null | The secret key that will be used for sigining/validating tokens. | | JWT_ALGO | HS256 | The algorithm to use for sigining tokens. | | JWT_LEEWAY | 0 | Seconds of leeway for validating timestamps to account for time differences between systems | | JWT_INPUT | token | By default we will look for the token in the Authorization header. If it's not found there, then this value will be used to search the sent input from the request to find the token. | | JWT_HEADER | Authorization | By default the Authorization header key is used. This can be overridden with this value. |

If you're using the JwtExceptionHandler to handle exceptions, these environment variables can be set to customize the error messages. (see below for information on using the exception handler)

| Config | Default | Description | | ------------------------ | --------------------------------------------------------------- | ------------------------------------------------------------------ | | JWT_MESSAGE_ERROR | There was an error while validating the authorization token. | 500 A general error occured while working with the token. | | JWT_MESSAGE_INVALID | Authorization token is not valid. | 401 The provided token is invalid in some way: expired, mismatched signature, etc. | | JWT_MESSAGE_NOTOKEN | Authorization token is required. | 401 There was no token found with the request. | | JWT_MESSAGE_NOSECRET | No JWT secret defined. | 500 Unable to find the JWT secret for validating/signing tokens. |

Working with Tokens

• Creating Tokens
• Validating Tokens
• Payloads
• Handling Errors

Creating Tokens

Inject an instance of GenTux\Jwt\JwtToken into your controller or other service to create new tokens.

<?php

use GenTux\Jwt\JwtToken;

class TokensController extends controller
{
    public function create(JwtToken $jwt)
    {
        $payload = ['exp' => time() + 7200]; // expire in 2 hours
        $token = $jwt->createToken($payload); // new instance of JwtToken

        return (string) $token;
    }
}

Implement GenTux\Jwt\JwtPayloadInterface to pass other objects to createToken for a more dynamic payload.

<?php

use GenTux\Jwt\JwtPayloadInterface;

class User extends Model implements JwtPayloadInterface
{
    public function getPayload()
    {
        return [
            'sub' => $this->id,
            'exp' => time() + 7200,
            'context' => [
                'email' => $this->email
            ]
        ];
    }
}

Then simply pass that object when creating the token

<?php

use GenTux\Jwt\JwtToken;

class TokensController extends controller
{
    public function create(JwtToken $jwt)
    {
        $user = User::find(1);
        $token = $jwt->createToken($user);

        return $token->payload(); // ['sub' => 1, exp => '...', 'context' => ...]
    }
}

You can set a specific secret and algorithm to use if necessary

public function create(JwtToken $jwt)
{
    return $jwt
            ->setSecret('secret_123')
            ->setAlgorithm('custom')
            ->createToken('[...]');
}

Validating Tokens

The easiest way to validate a request with a JWT token is to use the provided middleware.

<?php

// Laravel
Route::group(['middleware' => 'jwt'], function() {
    Route::post('/foo', 'FooController');
});

// Lumen
$app->group(['middleware' => 'jwt', 'namespace' => 'App\Http\Controllers'], function($app)  {
    $app->post('/foo', 'FooController');
});

When a token is invalid, GenTux\Jwt\Exceptions\InvalidTokenException will be thrown. If no token is provided, then GenTux\Jwt\Exceptions\NoTokenException will be thrown.

To manually validate the token, you can get tokens in any class using the trait GenTux\Jwt\GetsJwtToken.

For example, in a Laravel request object

<?php

use GenTux\Jwt\GetsJwtToken;

class CreateUser extends FormRequest
{
    use GetsJwtToken;

    public function authorize()
    {
        return $this->jwtToken()->validate();
    }
}

Or in a controller for Lumen

<?php

use GenTux\Jwt\GetsJwtController;

class FooController extends controller
{
    use GetsJwtToken;

    public function store()
    {
        if( ! $this->jwtToken()->validate()) {
            return redirect('/nope');
        }

        ...
    }
}

Payloads

Once you have the token, working with the payload is easy.

<?php

use GenTux\Jwt\GetsJwtToken;

class TokenService
{

    use GetsJwtToken;

    public function getExpires()
    {
        $payload = $this->jwtPayload(); // shortcut for $this->jwtToken()->payload()

        return $payload['exp'];
    }
}

The payload method for JwtToken accepts a path that can be used to get specific data from the payload.

<?php

use GenTux\Jwt\GetsJwtToken;

class TokenService
{
    use GetsJwtToken;

    public function getData()
    {
        // ['exp' => '123', 'context' => ['foo' => 'bar']]

        $token = $this->jwtToken();
        $token->payload('exp'); // 123
        $token->payload('context.foo'); // bar
        $token->payload('context.baz'); // null
    }
}

Handling Errors

This package can handle JWT exceptions out of the box if you would like. It will take all JWT exceptions and return JSON error responses. If you would like to implements your own error handling, you can look at GenTux\Jwt\Exceptions\JwtExceptionHandler for an example.

To implement, add the following inside of app/Exceptions/Handler.php

<?php

use GenTux\Jwt\Exceptions\JwtException;
use GenTux\Jwt\Exceptions\JwtExceptionHandler;

class Handler extends ExceptionHandler
{
    use JwtExceptionHandler;

    public function render($request, Exception $e)
    {
        if($e instanceof JwtException) return $this->handleJwtException($e);

        ...
    }
}