mishal / jwt
JWT - JSON Web Tokens
Requires
- php: >=5.4.0
This package is not auto-updated.
Last update: 2024-10-26 19:27:12 UTC
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.
Handle Issuer Claim
See the payload verification section.
Audience Claim
The aud
(audience) claim identifies the recipients that the JWT is intended for. Each principal intended to process the JWT MUST identify itself with a value in the audience claim. If the principal processing the claim does not identify itself with a value in the aud
claim when this claim is present, then the JWT MUST be rejected. In the general case, the aud
value is an array of case-sensitive strings, each containing a StringOrURI value. In the special case when the JWT has one audience, the aud
value MAY be a single case-sensitive string containing a StringOrURI value. The interpretation of audience values is generally application specific. Use of this claim is OPTIONAL.
Handle Audience Claim
See the payload verification section.
JWT ID Claim
The jti
(JWT ID) claim provides a unique identifier for the JWT. The identifier value MUST be assigned in a manner that ensures that there is a negligible probability that the same value will be accidentally assigned to a different data object; if the application uses multiple issuers, collisions MUST be prevented among values produced by different issuers as well. The jti
claim can be used to prevent the JWT from being replayed. The jti
value is a case-sensitive string. Use of this claim is OPTIONAL.
Handle JWT ID claim
See the payload verification section.
Issued At Claim
The iat
(issued at) claim identifies the time at which the JWT was issued. This claim can be used to determine the age of the JWT. Its value MUST be a number containing a NumericDate value. Use of this claim is OPTIONAL.
Handle Issued At Claim
See the payload verification section.
Subject Claim
The sub
(subject) claim identifies the principal that is the subject of the JWT. The Claims in a JWT are normally statements about the subject. The subject value MUST either be scoped to be locally unique in the context of the issuer or be globally unique. The processing of this claim is generally application specific. The sub value is a case-sensitive string containing a StringOrURI value. Use of this claim is OPTIONAL.
Handle Subject Claim
See the payload verification section.
Payload verification
Payload data can be verified when decoding the token using the verify
option.
Expiration
and Not Before
claims are ALWAYS checked.
<?php
use Jwt\Jwt;
use Jwt\Algorithm\HS256Algorithm;
use Jwt\Exception\VerificationException;
$payload = [
// expiration claim
Jwt::CLAIM_EXPIRATION => strtotime('1 day'),
// issuer claim
Jwt::CLAIM_ISSUER => 'my-web-app',
// custom claims
'user' => 'administrator'
];
$token = Jwt::encode($payload, $alg = new HS256Algorithm('secret'));
// Decode with verification of the payload
// Expiration, and Not before claims are verified automatically
// we will verify the token when decoding
$verify = [
Jwt::CLAIM_ISSUER => 'my-web-app',
// we can use closures for value verification
'user' => function ($value) {
if ($value === 'administrator') {
return true;
}
return false;
}
];
try {
$decoded = Jwt::decode($token, ['algorithm' => $alg, 'verify' => $verify]);
} catch (VerificationException $e) {
// something is wrong with the token
// do something!
switch ($e->getCode()) {
case VerificationException::CLAIM_IS_MISSING:
// claim is missing
break;
case VerificationException::CLAIM_VALUE_IS_INVALID:
// invalid claim value
break;
}
}
Tests
Run the tests using phpunit:
$ phpunit
Credits
Jwt was inspired by jwt for ruby and firebase/jwt for php.