Signed tokens are loaded by a serializer or the serializer manager and verified by the JWSVerifier object. This JWSVerifier object just requires an algorithm manager.

Serializer And Verifier

In the following example, we will try to load a signed token. We will only use the HS256 algorithm.

<?php

use Jose\Component\Core\AlgorithmManager;
use Jose\Component\Signature\Algorithm\HS256;
use Jose\Component\Signature\JWSVerifier;

// The algorithm manager with the HS256 algorithm.
$algorithmManager = new AlgorithmManager([
    new HS256(),
]);

// We instantiate our JWS Verifier.
$jwsVerifier = new JWSVerifier(
    $algorithmManager
);

Now we can deserialize the input we receive and check the signature using our key. We will continue with the data we got in the JWS creation section.

<?php

use Jose\Component\Core\JWK;
use Jose\Component\Signature\Serializer\JWSSerializerManager;
use Jose\Component\Signature\Serializer\CompactSerializer;

// Our key.
$jwk = new JWK([
    'kty' => 'oct',
    'k' => 'dzI6nbW4OcNF-AtfxGAmuyz7IpHRudBI0WgGjZWgaRJt6prBn3DARXgUR8NVwKhfL43QBIU2Un3AvCGCHRgY4TbEqhOi8-i98xxmCggNjde4oaW6wkJ2NgM3Ss9SOX9zS3lcVzdCMdum-RwVJ301kbin4UtGztuzJBeg5oVN00MGxjC2xWwyI0tgXVs-zJs5WlafCuGfX1HrVkIf5bvpE0MQCSjdJpSeVao6-RSTYDajZf7T88a2eVjeW31mMAg-jzAWfUrii61T_bYPJFOXW8kkRWoa1InLRdG6bKB9wQs9-VdXZP60Q4Yuj_WZ-lO7qV9AEFrUkkjpaDgZT86w2g',
]);

// The serializer manager. We only use the JWS Compact Serialization Mode.
$serializerManager = new JWSSerializerManager([
    new CompactSerializer(),
]);

// The input we want to check
$token = 'eyJhbGciOiJIUzI1NiJ9.eyJpYXQiOjE1MDc4OTY5OTIsIm5iZiI6MTUwNzg5Njk5MiwiZXhwIjoxNTA3OTAwNTkyLCJpc3MiOiJNeSBzZXJ2aWNlIiwiYXVkIjoiWW91ciBhcHBsaWNhdGlvbiJ9.eycp9PTdgO4WA-68-AMoHPwsKDr68NhjIQKz4lUkiI0';

// We try to load the token.
$jws = $serializerManager->unserialize($token);

// We verify the signature. This method does NOT check the header.
// The arguments are:
// - The JWS object,
// - The key,
// - The index of the signature to check. See 
$isVerified = $jwsVerifier->verifyWithKey($jws, $jwk, 0);

The method verifyWithKey returns a boolean. If true, then your token signature is valid. You can then check the claims (if any) using the claim checker manager.

JWSLoader Object

To avoid duplication of code lines, you can create a JWSLoader object. This object contains a serializer, a verifier and an optional header checker (highly recommended).

In the following example, the JWSLoader object will try to unserialize the token $token, check the header parameters and verify the signature with the key $jwk. The variable $payload corresponds to the detached payload (null by default).

If the verification succeeded, the variable $signature will be set with the signature index and should be in case of multiple signatures. The method returns the JWS object.

<?php

use Jose\Component\Signature\JWSLoader;

$jwsLoader = new JWSLoader(
    $serializerManager,
    $jwsVerifier,
    $headerCheckerManager
);

$jws = $jwsLoader->loadAndVerifyWithKey($token, $jwk, $signature, $payload);

In case you use a key set, you can use the method loadAndVerifyWithKeySet.

JWSLoaderFactory Object

This feature was introduced in version 1.1.

The JWSLoaderFactory object is able to create JWSLoader objects on demand. It requires the following factories:

• JWSSerializerManagerFactory

• JWSVerifierFactory

• HeaderCheckerManagerFactory (optional)

<?php

use Jose\Component\Signature\JWSLoaderFactory;

$jwsLoaderFactory = new JWSLoaderFactory(
    $jwsSerializerManagerFactory,
    $jwsVerifierFactory,
    $headerCheckerManagerFactory
);

$jwsLoader = $jwsLoaderFactory->create(
    ['jws_compact'], // List of serializer aliases
    ['HS256'],       // List of signature algorithm aliases
    ['alg']          // Optional list of header checker aliases
);

This framework comes with several signature algorithms. These algorithms are in the following namespace: Jose\Component\Signature\Algorithm.

Experimental Algorithms

The following signature algorithms are experimental and must not be used in production unless you know what you are doing. They are proposed for testing purpose only.

They are provided throught the package web-token/jwt-experimental.

How To Use

These algorithms have to be used with the Algorithm Manager. They do not need any arguments.

Example:

<?php

use Jose\Component\Core\AlgorithmManager;
use Jose\Component\Signature\Algorithm\PS256;
use Jose\Component\Signature\Algorithm\ES512;
use Jose\Component\Signature\Algorithm\None;

$algorithm_manager = new AlgorithmManager([
    new PS256(),
    new ES512(),
    new None(),
]);

Now that you have an algorithm manager and a key, it is time to create your first signed token.

The computation is done by the JWSBuilder object. This object only requires the algorithm manager.

Now let's create our first JWS object.

Great! If everything is fine you will get a JWS object with one signature. We want to send it to the audience. Before that, it must be serialized.

We will use the compact serialization mode. This is the most common mode as it is URL safe and very compact. Perfect for a use in a web context!

All good! The variable $token now contains a string that should be something like this:

Other serialization modes exist. We will see them in the Advanced Topics section.

A very large number of signature algorithms is provided by the library. Please refer to to know what algorithms are available.

Then, you will find an and another incoming tokens.