Keycloak OAuth 2.0 Client Provider for The PHP League OAuth2-Client

authorization, client, oauth, oauth2, roles, authorisation, keycloak


Keycloak Provider for OAuth 2.0 Client

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This package provides Keycloak OAuth 2.0 support for the PHP League's OAuth 2.0 Client.


To install, use composer:

composer require pviojo/oauth2-keycloak


Usage is the same as The League's OAuth client, using \pviojo\OAuth2\Client\Provider\Keycloak as the provider.

Use authServerUrl to specify the Keycloak server URL. You can lookup the correct value from the Keycloak client installer JSON under auth-server-url, eg. http://localhost:8080/auth.

Use realm to specify the Keycloak realm name. You can lookup the correct value from the Keycloak client installer JSON under resource, eg. master.

Authorization Code Flow

$provider = new pviojo\OAuth2\Client\Provider\Keycloak([
    'authServerUrl'         => '{keycloak-server-url}',
    'realm'                 => '{keycloak-realm}',
    'clientId'              => '{keycloak-client-id}',
    'clientSecret'          => '{keycloak-client-secret}',
    'redirectUri'           => 'https://example.com/callback-url',
    'encryptionAlgorithm'   => 'RS256',                             // optional
    'encryptionKeyPath'     => '../key.pem'                         // optional
    'encryptionKey'         => 'contents_of_key_or_certificate'     // optional

if (!isset($_GET['code'])) {

    // If we don't have an authorization code then get one
    $authUrl = $provider->getAuthorizationUrl();
    $_SESSION['oauth2state'] = $provider->getState();
    header('Location: '.$authUrl);

// Check given state against previously stored one to mitigate CSRF attack
} elseif (empty($_GET['state']) || ($_GET['state'] !== $_SESSION['oauth2state'])) {

    exit('Invalid state, make sure HTTP sessions are enabled.');

} else {

    // Try to get an access token (using the authorization coe grant)
    try {
        $token = $provider->getAccessToken('authorization_code', [
            'code' => $_GET['code']
    } catch (Exception $e) {
        exit('Failed to get access token: '.$e->getMessage());

    // Optional: Now you have a token you can look up a users profile data
    try {

        // We got an access token, let's now get the user's details
        $user = $provider->getResourceOwner($token);

        // Use these details to create a new profile
        printf('Hello %s!', $user->getName());

    } catch (Exception $e) {
        exit('Failed to get resource owner: '.$e->getMessage());

    // Use this to interact with an API on the users behalf
    echo $token->getToken();

Refreshing a Token

$provider = new pviojo\OAuth2\Client\Provider\Keycloak([
    'authServerUrl'     => '{keycloak-server-url}',
    'realm'             => '{keycloak-realm}',
    'clientId'          => '{keycloak-client-id}',
    'clientSecret'      => '{keycloak-client-secret}',
    'redirectUri'       => 'https://example.com/callback-url',

$token = $provider->getAccessToken('refresh_token', ['refresh_token' => $token->getRefreshToken()]);

Getting user roles

After authenticating retrieve roles from the resource owner.

$user = $provider->getResourceOwner($token);
$roles = $user->getRoles(); //retrieve all roles
$rolesClient = $user->getRolesForClient($client); //retrieve all roles for given $client
$hasRole = $user->hasRoleForClient($client, $role); //check if user has the $role for  $client
$hasAccess = $user->hasAccessToClient($client, $role); //check if user has access to $client (at least one role)

Handling encryption

If you've configured your Keycloak instance to use encryption, there are some advanced options available to you.

Configure the provider to use the same encryption algorithm

$provider = new pviojo\OAuth2\Client\Provider\Keycloak([
    // ...
    'encryptionAlgorithm'   => 'RS256',



Configure the provider to use the expected decryption public key or certificate

By key value
$key = "-----BEGIN PUBLIC KEY-----\n....\n-----END PUBLIC KEY-----";
// or
// $key = "-----BEGIN CERTIFICATE-----\n....\n-----END CERTIFICATE-----";

$provider = new pviojo\OAuth2\Client\Provider\Keycloak([
    // ...
    'encryptionKey'   => $key,


By key path
$keyPath = '../key.pem';

$provider = new pviojo\OAuth2\Client\Provider\Keycloak([
    // ...
    'encryptionKeyPath'   => $keyPath,




$ ./vendor/bin/phpunit


Please see CONTRIBUTING for details.



The MIT License (MIT). Please see License File for more information.