README

This package provides two PSR-15 middlewares.

The first middleware creates a signature of the payload. A secret key has to be provided as first argument. By default, SHA1 hashing algorithm is used and the HMAC signature will be added as x-signature header.

$signatureMiddleware = new Http\Middleware\HmacSignatureMiddleware('secret key'):

To validate the signature, use the verification middleware.

/** @var \Psr\Http\Message\ResponseFactoryInterface $responseFactory */
$signatureMiddleware = new Http\Middleware\HmacVerificationMiddleware('secret key', $responseFactory):

What's a HMAC

A HMAC is a hash-based message authentication code using a symmetric key.

If a user sees a message and a HMAC and knows the associated secret key, he can verify that the HMAC was produced by a principal that knows the key by doing the HMAC computation hisself. Therefore, if a message comes with a correct HMAC attached, it means this message was seen by a holder of the secret key at some point.

Installation

composer require manueldimmler/hmac-signature-middleware