JWT

A simple library to work with JSON Web Token and JSON Web Signature (requires PHP 5.6+). The implementation is based on the RFC 7519.

Installation

Package is available on Packagist, you can install it using Composer.

composer require lcobucci/jwt

Dependencies

• PHP 5.6+
• OpenSSL Extension

Basic usage

Creating

Just use the builder to create a new JWT/JWS tokens:

use Lcobucci\JWT\Builder;

$time = time();
$token = (new Builder())->issuedBy('http://example.com') // Configures the issuer (iss claim)
                        ->permittedFor('http://example.org') // Configures the audience (aud claim)
                        ->identifiedBy('4f1g23a12aa', true) // Configures the id (jti claim), replicating as a header item
                        ->issuedAt($time) // Configures the time that the token was issue (iat claim)
                        ->canOnlyBeUsedAfter($time + 60) // Configures the time that the token can be used (nbf claim)
                        ->expiresAt($time + 3600) // Configures the expiration time of the token (exp claim)
                        ->withClaim('uid', 1) // Configures a new claim, called "uid"
                        ->getToken(); // Retrieves the generated token


$token->getHeaders(); // Retrieves the token headers
$token->getClaims(); // Retrieves the token claims

echo $token->getHeader('jti'); // will print "4f1g23a12aa"
echo $token->getClaim('iss'); // will print "http://example.com"
echo $token->getClaim('uid'); // will print "1"
echo $token; // The string representation of the object is a JWT string (pretty easy, right?)

Parsing from strings

Use the parser to create a new token from a JWT string (using the previous token as example):

use Lcobucci\JWT\Parser;

$token = (new Parser())->parse((string) $token); // Parses from a string
$token->getHeaders(); // Retrieves the token header
$token->getClaims(); // Retrieves the token claims

echo $token->getHeader('jti'); // will print "4f1g23a12aa"
echo $token->getClaim('iss'); // will print "http://example.com"
echo $token->getClaim('uid'); // will print "1"

Validating

We can easily validate if the token is valid (using the previous token and time as example):

use Lcobucci\JWT\ValidationData;

$data = new ValidationData(); // It will use the current time to validate (iat, nbf and exp)
$data->setIssuer('http://example.com');
$data->setAudience('http://example.org');
$data->setId('4f1g23a12aa');

var_dump($token->validate($data)); // false, because token cannot be used before now() + 60

$data->setCurrentTime($time + 61); // changing the validation time to future

var_dump($token->validate($data)); // true, because current time is between "nbf" and "exp" claims

$data->setCurrentTime($time + 4000); // changing the validation time to future

var_dump($token->validate($data)); // false, because token is expired since current time is greater than exp

// We can also use the $leeway parameter to deal with clock skew (see notes below)
// If token's claimed time is invalid but the difference between that and the validation time is less than $leeway, 
// then token is still considered valid
$dataWithLeeway = new ValidationData($time, 20); 
$dataWithLeeway->setIssuer('http://example.com');
$dataWithLeeway->setAudience('http://example.org');
$dataWithLeeway->setId('4f1g23a12aa');

var_dump($token->validate($dataWithLeeway)); // false, because token can't be used before now() + 60, not within leeway

$dataWithLeeway->setCurrentTime($time + 51); // changing the validation time to future

var_dump($token->validate($dataWithLeeway)); // true, because current time plus leeway is between "nbf" and "exp" claims

$dataWithLeeway->setCurrentTime($time + 3610); // changing the validation time to future but within leeway

var_dump($token->validate($dataWithLeeway)); // true, because current time - 20 seconds leeway is less than exp

$dataWithLeeway->setCurrentTime($time + 4000); // changing the validation time to future outside of leeway

var_dump($token->validate($dataWithLeeway)); // false, because token is expired since current time is greater than exp

Important

• You have to configure ```ValidationData``` informing all claims you want to validate the token.
• If ```ValidationData``` contains claims that are not being used in token or token has claims that are not configured in ```ValidationData``` they will be ignored by ```Token::validate()```.

• with the current UNIX time (```time()```).
  
  

• The optional ```$leeway``` parameter of ```ValidationData``` will cause us to use that number of seconds of leeway when validating the time-based claims, pretending we are further in the future for the "Issued At" (```iat```) and "Not Before" (```nbf```) claims and pretending we are further in the past for the "Expiration Time" (```exp```) claim. This allows for situations where the clock of the issuing server has a different time than the clock of the verifying server, as mentioned in section 4.1 of RFC 7519.

use Lcobucci\JWT\Builder;
use Lcobucci\JWT\Signer\Key;
use Lcobucci\JWT\Signer\Hmac\Sha256;

$signer = new Sha256();
$time = time();

$token = (new Builder())->issuedBy('http://example.com') // Configures the issuer (iss claim)
                        ->permittedFor('http://example.org') // Configures the audience (aud claim)
                        ->identifiedBy('4f1g23a12aa', true) // Configures the id (jti claim), replicating as a header item
                        ->issuedAt($time) // Configures the time that the token was issue (iat claim)
                        ->canOnlyBeUsedAfter($time + 60) // Configures the time that the token can be used (nbf claim)
                        ->expiresAt($time + 3600) // Configures the expiration time of the token (exp claim)
                        ->withClaim('uid', 1) // Configures a new claim, called "uid"
                        ->getToken($signer, new Key('testing')); // Retrieves the generated token


var_dump($token->verify($signer, 'testing 1')); // false, because the key is different
var_dump($token->verify($signer, 'testing')); // true, because the key is the same

use Lcobucci\JWT\Builder;
use Lcobucci\JWT\Signer\Key;
use Lcobucci\JWT\Signer\Rsa\Sha256; // you can use Lcobucci\JWT\Signer\Ecdsa\Sha256 if you're using ECDSA keys

$signer = new Sha256();
$privateKey = new Key('file://{path to your private key}');
$time = time();

$token = (new Builder())->issuedBy('http://example.com') // Configures the issuer (iss claim)
                        ->permittedFor('http://example.org') // Configures the audience (aud claim)
                        ->identifiedBy('4f1g23a12aa', true) // Configures the id (jti claim), replicating as a header item
                        ->issuedAt($time) // Configures the time that the token was issue (iat claim)
                        ->canOnlyBeUsedAfter($time + 60) // Configures the time that the token can be used (nbf claim)
                        ->expiresAt($time + 3600) // Configures the expiration time of the token (exp claim)
                        ->withClaim('uid', 1) // Configures a new claim, called "uid"
                        ->getToken($signer,  $privateKey); // Retrieves the generated token

$publicKey = new Key('file://{path to your public key}');

var_dump($token->verify($signer, $publicKey)); // true when the public key was generated by the private one =)