Firebase Tokens

A library to work with Google Firebase tokens. You can use it to create custom tokens and verify ID Tokens.

Installation

composer require kreait/firebase-tokens

Create a custom token

use Firebase\Auth\Token\Generator;

$generator = new Generator($clientEmail, $privateKey);

$uid = 'a-uid';
$claims = ['foo' => 'bar'];

$token = $generator->createCustomToken($uid, $claims); // Returns a Lcobucci\JWT\Token instance

echo $token; // "eyJ0eXAiOiJKV1..."

Verify an ID token

use Firebase\Auth\Token\Verifier;

$verifier = new Verifier($projectId);

$idTokenString = 'eyJhbGciOiJSUzI1...';

try {
    $verifiedIdToken = $verifier->verifyIdToken($idTokenString);
    
    echo $verifiedIdToken->getClaim('sub'); // "a-uid"
} catch (\Firebase\Auth\Token\Exception\ExpiredToken $e) {
    echo $e->getMessage();
} catch (\Firebase\Auth\Token\Exception\IssuedInTheFuture $e) {
    echo $e->getMessage();
} catch (\Firebase\Auth\Token\Exception\InvalidToken $e) {
    echo $e->getMessage();
}

Cache results from the Google Secure Token Store

In order to verify ID tokens, the verifier makes a call to fetch Firebase's currently available public keys. The keys are cached in memory by default.

If you want to cache the public keys more effectively, you can use any implementation of psr/simple-cache.

Example using the Symfony Cache Component

use Firebase\Auth\Token\HttpKeyStore;
use Firebase\Auth\Token\Verifier;
use Symfony\Component\Cache\Simple\FilesystemCache;

$cache = new FilesystemCache();
$keyStore = new HttpKeyStore(null, $cache);

$verifier = new Verifier($projectId, $keyStore);