This middleware implements JSON Web Token Authentication for Slim Framework. It does not implement OAuth 2.0 authorization server nor does it provide ways to generate, issue or store authentication tokens. It only parses and authenticates a token when passed via header or cookie. This is useful for example when you want to use JSON Web Tokens as API keys.
Install Slim 3 version using composer.
$ composer require tuupola/slim-jwt-auth
Also add the following to the .htaccess
file. Otherwise PHP wont have access to Authorization: Bearer
header.
RewriteRule .* - [env=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
Configuration options are passed as an array. The only mandatory parameter is secret
which is used for verifying then token signature. For simplicity's sake examples show secret
hardcoded in code. In real life you should store it somewhere else. Good option is environment variable. You can use dotenv or something similar for development.
$app = new \Slim\App();
$app->add(new \Slim\Middleware\JwtAuthentication([
"secret" => "supersecretkeyyoushouldnotcommittogithub"
]));
An example where your secret is stored as an environment variable:
$app = new \Slim\App();
$app->add(new \Slim\Middleware\JwtAuthentication([
"secret" => getenv("JWT_SECRET")
]));
When a request is made, the middleware tries to validate and decode the token. If a token is not found or there is an error when validating and decoding it, the server will respond with 401 Unauthorized
.
Validation errors are triggered when the token has been tampered with or the token has expired. For all possible validation errors, see JWT library source.
The optional path
parameter allows you to specify the protected part of your website. It can be either a string or an array. You do not need to specify each URL. Instead think of path
setting as a folder. In the example below everything starting with /api
will be authenticated.
$app = new \Slim\App();
$app->add(new \Slim\Middleware\JwtAuthentication([
"path" => "/api", /* or ["/api", "/admin"] */
"secret" => "supersecretkeyyoushouldnotcommittogithub"
]));
With optional passthrough
parameter you can make exceptions to path
parameter. In the example below everything starting with /api
and /admin
will be authenticated with the exception of /api/token
and /admin/ping
which will not be authenticated.
$app = new \Slim\App();
$app->add(new \Slim\Middleware\JwtAuthentication([
"path" => ["/api", "/admin"],
"passthrough" => ["/api/token", "/admin/ping"],
"secret" => "supersecretkeyyoushouldnotcommittogithub"
]));
By default middleware tries to find the token from HTTP_AUTHORIZATION
and REDIRECT_HTTP_AUTHORIZATION
environments. You can change this using environment
parameter.
$app = new \Slim\App();
$app->add(new \Slim\Middleware\JwtAuthentication([
"environment" => ["HTTP_BRAWNDO", "HTTP_ELECTROLYTE"],
"secret" => "supersecretkeyyoushouldnotcommittogithub"
]));
If token is not found from environment middleware tries to find it from cookie name token
. You can change cookie name using cookie
parameter.
$app = new \Slim\App();
$app->add(new \Slim\Middleware\JwtAuthentication([
"cookie" => "nekot",
"secret" => "supersecretkeyyoushouldnotcommittogithub"
]));
When the token is decoded successfully and authentication succees the contents of decoded token as saved as token
attribute to the $request
object. You can change this with. attribute
parameter. Set to null
or false
to disable this behavour
$app = new \Slim\App();
$app->add(new \Slim\Middleware\JwtAuthentication([
"attribute" => "jwt",
"secret" => "supersecretkeyyoushouldnotcommittogithub"
]));
/* ... */
$decoded = $request->getAttribute("jwt");
The optional logger
parameter allows you to pass in a PSR-3 compatible logger to help with debugging or other application logging needs.
$app = new \Slim\App();
$logger = \Monolog\Logger("slim");
$rotating = new RotatingFileHandler(__DIR__ . "/logs/slim.log", 0, Logger::DEBUG);
$logger->pushHandler($rotating);
$app->add(new \Slim\Middleware\JwtAuthentication([
"path" => "/api",
"logger" => $logger,
"secret" => "supersecretkeyyoushouldnotcommittogithub"
]));
Callback is called only when authentication succeeds. It receives decoded token in arguments. If callback returns boolean false
authentication is forced to be failed.
You can also use callback for storing the value of decoded token for later use.
$app = new \Slim\App();
$container = $app->getContainer();
$container["jwt"] = function ($container) {
return new StdClass;
};
$app->add(new \Slim\Middleware\JwtAuthentication([
"secret" => "supersecretkeyyoushouldnotcommittogithub",
"callback" => function ($request, $response, $arguments) use ($container) {
$container["jwt"] = $arguments["decoded"];
}
]));
Error is called when authentication fails. It receives last error message in arguments.
$app = new \Slim\App();
$app->add(new \Slim\Middleware\JwtAuthentication([
"secret" => "supersecretkeyyoushouldnotcommittogithub",
"error" => function ($request, $response, $arguments) {
return $response->write("Error");
}
]));
The optional rules
parameter allows you to pass in rules which define whether the request should be authenticated or not. Rule is a callable which receives the Slim app as parameter. If the callable returns boolean false
request will not be authenticated.
By default middleware configuration looks like this. All paths are authenticated with all request methods except OPTIONS
.
$app = new \Slim\App();
$app->add(new \Slim\Middleware\JwtAuthentication([
"rules" => [
new \Slim\Middleware\JwtAuthentication\RequestPathRule([
"path" => "/",
"passthrough" => []
]),
new \Slim\Middleware\JwtAuthentication\RequestMethodRule([
"passthrough" => ["OPTIONS"]
])
]
]));
RequestPathRule contains both a path
parameter and a passthrough
parameter. Latter contains paths which should not be authenticated. RequestMethodRule contains passthrough
parameter of request methods which also should not be authenticated. Think of passthrough
as a whitelist.
Example use case for this is an API. Token can be retrieved via HTTP Basic Auth protected address. There also is an unprotected url for pinging. Rest of the API is protected by the JWT middleware.
$app = new \Slim\App();
$app->add(new \Slim\Middleware\JwtAuthentication([
"logger" => $logger,
"secret" => "supersecretkeyyoushouldnotcommittogithub",
"rules" => [
new RequestPathRule([
"path" => "/api",
"passthrough" => ["/api/token", "/api/ping"]
]),
new \Slim\Middleware\JwtAuthentication\RequestMethodRule([
"passthrough" => ["OPTIONS"]
])
]
]));
$app->add(new \Slim\Middleware\HttpBasicAuthentication([
"path" => "/api/token",
"users" => [
"user" => "password"
]
]));
$app->post("/token", function () {
/* Here generate and return JWT to the client. */
});
JSON Web Tokens are essentially passwords. You should treat them as such and you should always use HTTPS. If the middleware detects insecure usage over HTTP it will throw a RuntimeException
. This rule is relaxed for requests on localhost. To allow insecure usage you must enable it manually by setting secure
to false
.
$app->add(new \Slim\Middleware\JwtAuthentication([
"secure" => false,
"secret" => "supersecretkeyyoushouldnotcommittogithub"
]));
Alternatively you can list your development host to have relaxed security.
$app->add(new \Slim\Middleware\JwtAuthentication([
"secure" => true,
"relaxed" => ["localhost", "dev.example.com"],
"secret" => "supersecretkeyyoushouldnotcommittogithub"
]));
By default middleware only authenticates. This is not very interesting. Beauty of JWT is you can pass extra data in the token. This data can include for example scope which can be used for authorization.
It is up to you to implement how token data is stored or possible authorization implemented.
Let assume you have token which includes data for scope. In middleware callback you store the decoded token data to $app->jwt
and later use it for authorization.
[
"iat" => "1428819941",
"exp" => "1744352741",
"scope" => ["read", "write", "delete"]
]
$app = new \Slim\App();
$container = $app->getContainer();
$container["jwt"] = function ($container) {
return new StdClass;
};
$app->add(new \Slim\Middleware\JwtAuthentication([
"secret" => "supersecretkeyyoushouldnotcommittogithub",
"callback" => function ($request, $response, $arguments) use ($container) {
$container["jwt"] = $arguments["decoded"];
}
]));
$app->delete("/item/{id}", function ($request, $response, $arguments) {
if (in_array("delete", $this->jwt->scope)) {
/* Code for deleting item */
} else {
/* No scope so respond with 401 Unauthorized */
return $response->withStatus(401);
}
});
Tokens are like passwords and should be treated like one. Sometimes bad things happen. Maybe you accidentally leak internal token with full admin rights scope and expiration set to 10 years. Since there is no need to store tokens in database how can you revoke one? Changing the secret key would revoke all tokens in the wild.
Again it is up to you to implement how token blacklisting is done. This middleware intentionally only provides interface for blacklisting.
You can blacklist tokens by passing a callable blacklist
parameter. This callable receives the decoded token and instance of Slim application as parameters. If callable returns boolean true
the token is assumed to be blacklisted and server will response with 401 Unauthorized
.
One way of support blacklisting is to include jti
(JWT ID) claim in the token. This claim is unique identifier for the token and can be used for blacklisting.
[
"iat" => "1428819941",
"exp" => "1744352741",
"jti" => "24d4e5c5-5727-4b7f-bd1d-a8f0733f160b",
"scope" => ["read", "write", "delete"]
]
$app = new \Slim\App();
$app->add(new \Slim\Middleware\JwtAuthentication([
"secret" => "supersecretkeyyoushouldnotcommittogithub",
"blacklist" => function ($request, $response, $arguments) use ($app) {
$decoded = $arguments["decoded"];
return "24d4e5c5-5727-4b7f-bd1d-a8f0733f160b" === $decoded["jti"];
}
]));
You can run tests either manually...
$ vendor/bin/phpunit
$ vendor/bin/phpcs --standard=PSR2 src/ -p
... or automatically on every code change.
$ npm install
$ grunt watch
Please see CONTRIBUTING for details.
If you discover any security related issues, please email [email protected] instead of using the issue tracker.
The MIT License (MIT). Please see License File for more information.