KeyAuth
-------

Provides an API and a basic UI for key based authentication. Modeled after
services_keyauth module.


Requirements
------------

CTools
http://drupal.org/project/ctools

PHP 5.2.x


Installation
------------

Install module, go to admin/build/keys and create a new key or add an existing
key.


Basic usage
-----------

1) Generate a key through UI or through calling keyauth_save()

keyauth_include();
$key = keyauth_insert('Test key');

2) Sign a message

keyauth_include();
list($nonce, $timestamp, $hash) = keyauth_sign($key['public_key'], 'Lorem ipsum');

3) Verify a message

keyauth_include();
$verified = keyauth_verify($key['public_key'], 'Lorem ipsum', $nonce, $timestamp, $hash);


Sign URLs
---------

Key Authentication module comes with helper functions to sign URLs:

keyauth_include();
$signed = keyauth_sign_url($key['public_key'], 'http://example.com');
$verified = keyauth_verify_url($key['public_key'], $signed);


"Real world" example
--------------------

1) Set up Key Authorization on two Drupal sites, create a new key on one of the
   sites and add the same key (public key and private key) to the other site.

2) Create a module 'myresource' that exposes a path that should be protected, use
   keyauth_verify_url in the path's access check. Enable the module on one of
   the sites.

/**
 * Access callback for protected resource URLs.
 */
function myresource_access() {
  keyauth_include();
  return keyauth_verify_url($_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI']);
}

3) Create a module 'myconsumer' that pulls the protected path of 'myresource'
   using drupal_http_request() and keyauth_sign(). Enable myconsumer on the
   site where you have not enabled myresources module.

/**
 * Download URL, authenticate with Key Authentication module.
 * 7fb5490cce31840608ec635a931c00aa is the shared public key.
 */
function myconsumer_request($url) {
  return drupal_http_request(keyauth_sign_url('7fb5490cce31840608ec635a931c00aa', $url));
}