An implementation of the JSON Web Token (JWT) draft in PHP. See jwt.io for more information on JWT.

Features include:

• Token serialization
• Token deserialization
• Token verification
  • aud, exp, iss, nbf, sub claims are verified
• Symmetric Encryption
  • NONE, HS256, HS384, HS512 algorithms supported
• Asymmetric Encryption
  • RS256, RS384, RS512 algorithms supported
  • ES256, ES384, ES512, PS256, PS384, PS512 algorithms are planned

⚠️ Versions of this library up to and including v1.0.2 are susceptible to timing attacks when using Symmetric encryption. See #20 for more information. Please update to >= v1.0.3 as soon as possible to address this vulnerability.

This library is not susceptible to a common encryption vulnerability.

Installation

composer require emarref/jwt

Usage

Create an instance of the Emarref\Jwt\Token class, then configure it.

use Emarref\Jwt\Claim;

$token = new Emarref\Jwt\Token();

// Standard claims are supported
$token->addClaim(new Claim\Audience(['audience_1', 'audience_2']));
$token->addClaim(new Claim\Expiration(new \DateTime('30 minutes')));
$token->addClaim(new Claim\IssuedAt(new \DateTime('now')));
$token->addClaim(new Claim\Issuer('your_issuer'));
$token->addClaim(new Claim\JwtId('your_id'));
$token->addClaim(new Claim\NotBefore(new \DateTime('now')));
$token->addClaim(new Claim\Subject('your_subject'));

// Custom claims are supported
$token->addClaim(new Claim\PublicClaim('claim_name', 'claim_value'));
$token->addClaim(new Claim\PrivateClaim('claim_name', 'claim_value'));

To use a token, create a JWT instance.

$jwt = new Emarref\Jwt\Jwt();

To retrieve the encoded token for transfer, call the serialize() method.

$algorithm = new Emarref\Jwt\Algorithm\None();
$encryption = Emarref\Jwt\Encryption\Factory::create($algorithm);
$serializedToken = $jwt->serialize($token, $encryption);

The $serializedToken variable now contains the unencrypted base64 encoded string representation of your token. To encrypt a token, pass an instance of Emarref\Jwt\Encryption\EncryptionInterface to the serialize() method as the second argument.

$algorithm = new Emarref\Jwt\Algorithm\Hs256('verysecret');
$encryption = Emarref\Jwt\Encryption\Factory::create($algorithm);
$serializedToken = $jwt->serialize($token, $encryption);

An example of using Rs256 encryption with a key pair can be found in the wiki - Using RS256 Encryption.

To use a serialized token, first deserialize it into a Emarref\Jwt\Token object using a Jwt instance.

$token = $jwt->deserialize($serializedToken);

To verify a token's claims, first set up the context that should be used to verify the token against. Encryption is the only required verification.

$context = new Emarref\Jwt\Verification\Context($encryption);
$context->setAudience('audience_1');
$context->setIssuer('your_issuer');

Then use the verify() method on a Jwt instance.

try {
    $jwt->verify($token, $context);
} catch (Emarref\Jwt\Exception\VerificationException $e) {
    echo $e->getMessage();
}

Testing

This library uses PHPUnit for unit testing. Make sure you've run composer install then call:

./bin/phpunit ./test

Further Reading

• JSON Web Encryption (JWE)
• JSON Web Signature (JWS)
• JSON Web Algorithms (JWA)
• JSON Web Key (JWK)
• http://self-issued.info/docs/draft-ietf-oauth-json-web-token.html