A library to work with Google Firebase tokens. You can use it to create custom tokens and verify ID Tokens.
Achieve more with the Firebase Admin SDK for PHP (which uses this library).
composer require kreait/firebase-tokensMore information on what a custom token is and how it can be used can be found in Google's official documentation.
<?php
use Kreait\Firebase\JWT\CustomTokenGenerator;
$clientEmail = '...';
$privateKey = '...';
$generator = CustomTokenGenerator::withClientEmailAndPrivateKey($clientEmail, $privateKey);
$token = $generator->createCustomToken('uid', ['first_claim' => 'first_value' /* ... */]);
echo $token;
// Output: eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.e...The ID token verification methods included in the Firebase Admin SDKs are meant to verify ID tokens that come from the client SDKs, not the custom tokens that you create with the Admin SDKs. See Auth tokens for more information.
<?php
use Kreait\Firebase\JWT\Error\IdTokenVerificationFailed;
use Kreait\Firebase\JWT\IdTokenVerifier;
$projectId = '...';
$idToken = 'eyJhb...'; // An ID token given to your backend by a Client application
$verifier = IdTokenVerifier::createWithProjectId($projectId);
try {
$token = $verifier->verifyIdToken($idToken);
} catch (IdTokenVerificationFailed $e) {
echo $e->getMessage();
// Example Output:
// The value 'eyJhb...' is not a verified ID token:
// - The token is expired.
exit;
}
try {
$token = $verifier->verifyIdTokenWithLeeway($idToken, $leewayInSeconds = 10000000);
} catch (IdTokenVerificationFailed $e) {
print $e->getMessage();
exit;
}Tokens returned from the Generator and Verifier are instances of Kreait\Firebase\JWT\Token and
represent a JWT. The displayed outputs are examples and vary depending on
the information associated with the given user in your project's auth database.
According to the JWT specification, you can expect the following payload fields to be always
available: iss, aud, auth_time, sub, iat, exp. Other fields depend on the
authentication method of the given account and the information stored in your project's
Auth database.
$token = $verifier->verifyIdToken('eyJhb...'); // An ID token given to your backend by a Client application
echo json_encode($token->headers(), JSON_PRETTY_PRINT);
// {
// "alg": "RS256",
// "kid": "e5a91d9f39fa4de254a1e89df00f05b7e248b985",
// "typ": "JWT"
// }
echo json_encode($token->payload(), JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
// {
// "name": "Jane Doe",
// "picture": "https://domain.tld/picture.jpg",
// "iss": "https://securetoken.google.com/your-project-id",
// "aud": "your-project-id",
// "auth_time": 1580063945,
// "user_id": "W0IturDwy4TYTmX6ilkd2ZbAXRp2",
// "sub": "W0IturDwy4TYTmX6ilkd2ZbAXRp2",
// "iat": 1580063945,
// "exp": 1580067545,
// "email": "jane@doe.tld",
// "email_verified": true,
// "phone_number": "+1234567890",
// "firebase": {
// "identities": {
// "phone": [
// "+1234567890"
// ],
// "email": [
// "jane@doe.tld"
// ]
// },
// "sign_in_provider": "custom"
// }
// }
echo $token->toString();
// eyJhb...
$tokenString = (string) $token; // string
// eyJhb...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 initialize the verifier with an implementation of psr/simple-cache or psr/cache to reduce the amount of HTTP requests to Google's servers.
Here's an example using the Symfony Cache Component:
use Kreait\Firebase\JWT\IdTokenVerifier;
use Symfony\Component\Cache\Simple\FilesystemCache;
$cache = new FilesystemCache();
$verifier = IdTokenVerifier::createWithProjectIdAndCache($projectId, $cache);The MIT License (MIT). Please see License File for more information.