README

Hmac is a library for handling hmac authentication. Look at the source code for documentation.

Usage

<?php

use Krak\Hmac\Psr7HmacRequest,
    Krak\Hmac\HmacKeyPair,
    Krak\Hmac\ArrayHmacKeyPairProvider;

use function Krak\Hmac\hmac_sign_request,
    Krak\Hmac\hmac_auth_request;

// create the key pair of public and private keys
$keypair = new HmacKeyPair('public-key', 'private-key');

// wrap your request with the appropriate HmacRequest wrapper
$request = new Psr7HmacRequest($psr7_request);

// create the signer with default configuration
$sign = hmac_sign_request();

// sign the request
$request = $sign($request, $keypair);

// create a key pair provider for looking up the key pair used for the request
$provider = new ArrayHmacKeyPairProvider([$keypair]);

// we can authenticate a request now, by creating the authenticator with the
// same config as the signer (they need to match exactly)
$auth = hmac_auth_request($provider);

// authenticate the request
var_dump($auth($request));
// output: bool(true)

HmacConfig

The HmacConfig is passed at creation to the signer and authenticator to allow total configuration of how the request is authed or signed. The same config needs to be provided to the sign and the auth for them to inverse each other.

Here are the options:

<?php

use Krak\Hmac;

$config = Hmac\HmacConfig::create([
    'scheme' => 'CustomHmac', // authentication scheme. Authorization: <scheme> <public_key>:<hash>
    'hasher' => new Hmac\StdHmacHasher(), // any HmacHasher instance, defaults to Base64HmacHasher(StdHmacHasher)
    'hs_gen' => hmac\hmac_hashed_hs_gen(), // any hash string generator function
    'time_gen' => hmac\hmac_date_time_gen() // any time_gen function for generating a unit of time
    'time_header' => 'Date',
    'auth_header' => 'Authorization',
]);

$sign = hmac\hmac_sign_request($config);
$auth = hmac\hmac_auth_request($provider, $config);

Signers

hmac_sign_request(HmacConfing = null);
hmac_psr7_sign_request(HmacConfing = null);
hmac_psr7_sign($sign);

hmac_sign_request is the default signer which creates sign function that accepts an HmacRequest and HmacKeyPair.

hmac_psr7_sign_request is a decorated signer around the hmac_sign_request for accepting and returning Psr Http Requests. It simply just wraps hmac_sign_request around the hmac_psr7_sign decorator.

hmac_psr7_sign is a decorator sign function that accepts a sign function and wraps it and returns a sign function that will accept and return Psr Http Requests.

Hash String Generator

The hash string generators are functions that take the request and time value and generate the string that will end up being hashed.

provided hs_gen funcs:

// returns a hs_gen that will md5 hash the content and join everything by the given separator
hmac_hashed_hs_gen($sep = "\n");

example:

<?php

function concat_hs_gen() {
    return function(Krak\Hmac\HmacRequest $req, $time) {
        return $req->getUri() . $time;
    };
}

Time Generator

A time generator is just used to generate a time unit like a timestamp or date stamp.

provided time_gen funcs:

// returns the `time` function which creates a unix timestamp
hmac_ts_time_gen();

// returns a time_gen which creates an RFC 2822  formatted date
hmac_date_time_gen();

Integration

GuzzleHttp

Simple integration with Guzzle can be done via the Provider/guzzle.php functions.

<?php

use GuzzleHttp\HandlerStack,
    GuzzleHttp\Client,
    Krak\Hmac\HmacKeyPair;
use function Krak\Hmac\Provider\guzzle_hmac_middleware,
    Krak\Hmac\hmac_psr7_sign_request,

$handler = HandlerStack::create();
$handler->push(guzzle_hmac_middleware(hmac_psr7_sign_request(), $keypair));
$client = new Client(['handler' => $handler]);