README

A Php implementation of JSON Web Token.

Installing

Install with composer

$ composer require mishal/jwt

Algorithms and Usage

The JWT spec supports NONE, HMAC, RSASSA, ECDSA and RSASSA-PSS algorithms for cryptographic signing.

Supported algorithms:

None
HMAC 256
RSA 256

NONE - unsigned token

<?php
    
use Jwt\Jwt;
use Jwt\Algorithm\NoneAlgorithm;
    
$token = Jwt::encode('string', new NoneAlgorithm());
  
echo $token; // eyJ0eXAiOiJKV1QiLCJhbGciOiJub25lIn0.eyJkYXRhIjoic3RyaW5nIn0.

HMAC

HS256 - HMAC using SHA-256 hash algorithm

HS256

<?php

use Jwt\Jwt;
use Jwt\Algorithm\HS256Algorithm;

$token = Jwt::encode('string', $alg = new HS256Algorithm('secret'));

echo $token; // eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJkYXRhIjoic3RyaW5nIn0.RncJbCyf4zd0pu1N02u_rKwEezkmd94r3i5sWLk1ceU

// decode, you must passed allowed algorithm(s) to prevent attackers to control the choice of algorithm
$decoded = Jwt::decode($token, ['algorithm' => $alg]);

echo $decoded['data']; // 'string'

RSA

RS256 - RSA using SHA-256 hash algorithm

RS256 - RSA using SHA-256 hash algorithm

<?php

use Jwt\Jwt;
use Jwt\Algorithm\RS256Algorithm;

$privateKey = __DIR__ . '/key.pem';
$publicKey = __DIR__ . '/key.pub';

$token = Jwt::encode('string', $alg = new RS256Algorithm($privateKey, $publicKey));

echo $token; // eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJkYXRhIjoic3RyaW5nIn0.RncJbCyf4zd0pu1N02u_rKwEezkmd94r3i5sWLk1ceU

// decode, you must passed allowed algorithm(s) to prevent attackers to control the choice of algorithm
$decoded = Jwt::decode($token, ['algorithm' => $alg]);

echo $decoded['data']; // 'string'

Support for reserved claim names

JSON Web Token defines some reserved claim names and defines how they should be used. JWT supports these reserved claim names:

'exp' (Expiration Time) Claim
'nbf' (Not Before Time) Claim
'iss' (Issuer) Claim
'aud' (Audience) Claim
'jti' (JWT ID) Claim
'iat' (Issued At) Claim
'sub' (Subject) Claim

Expiration Time Claim

The exp (expiration time) claim identifies the expiration time on or after which the JWT MUST NOT be accepted for processing. The processing of the exp claim requires that the current date/time MUST be before the expiration date/time listed in the exp claim. Implementers MAY provide for some small leeway, usually no more than a few minutes, to account for clock skew. Its value MUST be a number containing a NumericDate value. Use of this claim is OPTIONAL.

Handle Expiration Claim

<?php

use Jwt\Jwt;
use Jwt\Algorithm\HS256Algorithm;
use Jwt\Exception\ExpiredException;

$payload = [
    Jwt::CLAIM_EXPIRATION => strtotime('1 day'),
    'data' => 'my data'
];

$token = Jwt::encode($payload, $alg = new HS256Algorithm('secret'));

try {
    $token = Jwt::decode($token, ['algorithm' => $alg]);
} catch (ExpiredException $e) {
    // Handle expired token, e.g. logout user or deny access
}

Adding Leeway

<?php

use Jwt\Jwt;
use Jwt\Algorithm\HS256Algorithm;
use Jwt\Exception\ExpiredException;

$leeway = 30; // 30 sec

$payload = [
    Jwt::CLAIM_EXPIRATION => strtotime('1 day'),
    'data' => 'my data'
];

$token = Jwt::encode($payload, $alg = new HS256Algorithm('secret'));

try {
    $token = Jwt::decode($token, ['algorithm' => $alg, 'leeway' => $leeway]);
} catch (ExpiredException $e) {
    // Handle expired token, e.g. logout user or deny access
}

Not Before Time Claim

The nbf (not before) claim identifies the time before which the JWT MUST NOT be accepted for processing. The processing of the nbf claim requires that the current date/time MUST be after or equal to the not-before date/time listed in the nbf claim. Implementers MAY provide for some small leeway, usually no more than a few minutes, to account for clock skew. Its value MUST be a number containing a NumericDate value. Use of this claim is OPTIONAL.

Handle Not Before Claim

<?php

use Jwt\Jwt;
use Jwt\Algorithm\HS256Algorithm;
use Jwt\Exception\BeforeValidException;

$payload = [
    Jwt::CLAIM_NOT_BEFORE => strtotime('1 day'),
    'data' => 'my data'
];

$token = Jwt::encode($payload, $alg = new HS256Algorithm('secret'));

try {
    $token = Jwt::decode($token, ['algorithm' => $alg]);
} catch (BeforeValidException $e) {
    // Handle invalid token, e.g. logout user or deny access
}

Issuer Claim

The iss (issuer) claim identifies the principal that issued the JWT. The processing of this claim is generally application specific. The iss value is a case-sensitive string containing a StringOrURI value. Use of this claim is OPTIONAL.