/lib/Lampcms/Modules/Google/src/auth/apiOAuth.php

<?php

/*

 * Copyright 2008 Google Inc.

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */



require_once "external/OAuth.php";



/**

 * Authentication class that deals with 3-Legged OAuth 1.0a authentication

 *

 * This class uses the OAuth 1.0a spec which has a slightly different work flow in

 * how callback urls, request & access tokens are dealt with to prevent a possible

 * man in the middle attack.

 *

 * @author Chris Chabot <chabotc@google.com>

 *

 */

class apiOAuth extends apiAuth {

  public $cacheKey;

  protected $consumerToken;

  protected $accessToken;

  protected $privateKeyFile;

  protected $developerKey;

  public $service;



  /**

   * Instantiates the class, but does not initiate the login flow, leaving it

   * to the discretion of the caller.

   */

  public function __construct() {

    global $apiConfig;

    if (!empty($apiConfig['developer_key'])) {

      $this->setDeveloperKey($apiConfig['developer_key']);

    }

    $this->consumerToken = new apiClientOAuthConsumer($apiConfig['oauth_consumer_key'], $apiConfig['oauth_consumer_secret'], NULL);

    $this->signatureMethod = new apiClientOAuthSignatureMethod_HMAC_SHA1();

    $this->cacheKey = 'OAuth:' . $apiConfig['oauth_consumer_key']; // Scope data to the local user as well, or else multiple local users will share the same OAuth credentials.

  }



  /**

   * The 3 legged oauth class needs a way to store the access key and token

   * it uses the apiCache class to do so.

   *

   * Constructing this class will initiate the 3 legged oauth work flow, including redirecting

   * to the OAuth provider's site if required(!)

   *

   * @param string $consumerKey

   * @param string $consumerSecret

   * @return apiOAuth3Legged the logged-in provider instance

   */

  public function authenticate($service) {

    global $apiConfig;

    $this->service = $service;

    $this->service['authorization_token_url'] .= '?scope=' . apiClientOAuthUtil::urlencodeRFC3986($service['scope']) . '&domain=' . apiClientOAuthUtil::urlencodeRFC3986($apiConfig['site_name']) . '&oauth_token=';

    if (isset($_GET['oauth_verifier']) && isset($_GET['oauth_token'])  && isset($_GET['uid'])) {

      $uid = $_GET['uid'];

      $secret = apiClient::$cache->get($this->cacheKey.":nonce:" . $uid);

      apiClient::$cache->delete($this->cacheKey.":nonce:" . $uid);

      $token = $this->upgradeRequestToken($_GET['oauth_token'], $secret, $_GET['oauth_verifier']);

      return json_encode($token);

    } else {

      // Initialize the OAuth dance, first request a request token, then kick the client to the authorize URL

      // First we store the current URL in our cache, so that when the oauth dance is completed we can return there

      $callbackUrl = ((isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on') ? 'https://' : 'http://') . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];

      $uid = uniqid();

      $token = $this->obtainRequestToken($callbackUrl, $uid);

      apiClient::$cache->set($this->cacheKey.":nonce:" . $uid,  $token->secret);

      $this->redirectToAuthorization($token);

    }

  }



  /**

   * Sets the internal oauth access token (which is returned by the authenticate function), a user should only

   * go through the authenticate() flow once (which involces a bunch of browser redirections and authentication screens, not fun)

   * and every time the user comes back the access token from the authentication() flow should be re-used (it essentially never expires)

   * @param object $accessToken

   */

  public function setAccessToken($accessToken) {

    $accessToken = json_decode($accessToken, true);

    if ($accessToken == null) {

      throw new apiAuthException("Could not json decode the access token");

    }

    if (! isset($accessToken['key']) || ! isset($accessToken['secret'])) {

      throw new apiAuthException("Invalid OAuth token, missing key and/or secret");

    }

    $this->accessToken = new apiClientOAuthConsumer($accessToken['key'], $accessToken['secret']);

  }



  /**

   * Returns the current access token

   */

  public function getAccessToken() {

    return $this->accessToken;

  }





  /**

   * Set the developer key to use, these are obtained through the API Console

   */

  public function setDeveloperKey($developerKey) {

    $this->developerKey = $developerKey;

  }



  /**

   * Upgrades an existing request token to an access token.

   *

   * @param apiCache $cache cache class to use (file,apc,memcache,mysql)

   * @param oauthVerifier

   */

  public function upgradeRequestToken($requestToken, $requestTokenSecret, $oauthVerifier) {

    $ret = $this->requestAccessToken($requestToken, $requestTokenSecret, $oauthVerifier);

    $matches = array();

    @parse_str($ret, $matches);

    if (!isset($matches['oauth_token']) || !isset($matches['oauth_token_secret'])) {

      throw new apiAuthException("Error authorizing access key (result was: {$ret})");

    }

    // The token was upgraded to an access token, we can now continue to use it.

    $this->accessToken = new apiClientOAuthConsumer(apiClientOAuthUtil::urldecodeRFC3986($matches['oauth_token']), apiClientOAuthUtil::urldecodeRFC3986($matches['oauth_token_secret']));

    return $this->accessToken;

  }



  /**

   * Sends the actual request to exchange an existing request token for an access token.

   *

   * @param string $requestToken the existing request token

   * @param string $requestTokenSecret the request token secret

   * @return array('http_code' => HTTP response code (200, 404, 401, etc), 'data' => the html document)

   */

  protected function requestAccessToken($requestToken, $requestTokenSecret, $oauthVerifier) {

    $accessToken = new apiClientOAuthConsumer($requestToken, $requestTokenSecret);

    $accessRequest = apiClientOAuthRequest::from_consumer_and_token($this->consumerToken, $accessToken, "GET", $this->service['access_token_url'], array('oauth_verifier' => $oauthVerifier));

    $accessRequest->sign_request($this->signatureMethod, $this->consumerToken, $accessToken);

    $request = apiClient::$io->makeRequest(new apiHttpRequest($accessRequest));

    if ($request->getResponseHttpCode() != 200) {

      throw new apiAuthException("Could not fetch access token, http code: " . $request->getResponseHttpCode() . ', response body: '. $request->getResponseBody());

    }

    return $request->getResponseBody();

  }



  /**

   * Obtains a request token from the specified provider.

   */

  public function obtainRequestToken($callbackUrl, $uid) {

    $callbackParams = (strpos($_SERVER['REQUEST_URI'], '?') !== false ? '&' : '?') . 'uid=' . urlencode($uid);

    $ret = $this->requestRequestToken($callbackUrl . $callbackParams);

    $matches = array();

    preg_match('/oauth_token=(.*)&oauth_token_secret=(.*)&oauth_callback_confirmed=(.*)/', $ret, $matches);

    if (!is_array($matches) || count($matches) != 4) {

      throw new apiAuthException("Error retrieving request key ({$ret})");

    }

    return new apiClientOAuthToken(apiClientOAuthUtil::urldecodeRFC3986($matches[1]), apiClientOAuthUtil::urldecodeRFC3986($matches[2]));

  }



  /**

   * Sends the actual request to obtain a request token.

   *

   * @return array('http_code' => HTTP response code (200, 404, 401, etc), 'data' => the html document)

   */

  protected function requestRequestToken($callbackUrl) {

    $requestTokenRequest = apiClientOAuthRequest::from_consumer_and_token($this->consumerToken, NULL, "GET", $this->service['request_token_url'], array());

    $requestTokenRequest->set_parameter('scope', $this->service['scope']);

    $requestTokenRequest->set_parameter('oauth_callback', $callbackUrl);

    $requestTokenRequest->sign_request($this->signatureMethod, $this->consumerToken, NULL);

    $request = apiClient::$io->makeRequest(new apiHttpRequest($requestTokenRequest));

    if ($request->getResponseHttpCode() != 200) {

      throw new apiAuthException("Couldn't fetch request token, http code: " . $request->getResponseHttpCode() . ', response body: '. $request->getResponseBody());

    }

    return $request->getResponseBody();

  }



  /**

   * Redirect the uset to the (provider's) authorize page, if approved it should kick the user back to the call back URL

   * which hopefully means we'll end up in the constructor of this class again, but with oauth_continue=1 set

   *

   * @param OAuthToken $token the request token

   * @param string $callbackUrl the URL to return to post-authorization (passed to login site)

   */

  public function redirectToAuthorization($token) {

    $authorizeRedirect = $this->service['authorization_token_url']. $token->key;

    header("Location: $authorizeRedirect");

  }



  /**

   * Sign the request using OAuth. This uses the consumer token and key

   *

   * @param string $method the method (get/put/delete/post)

   * @param string $url the url to sign (http://site/social/rest/people/1/@me)

   * @param array $params the params that should be appended to the url (count=20 fields=foo, etc)

   * @param string $postBody for POST/PUT requests, the postBody is included in the signature

   * @return string the signed url

   */

  public function sign(apiHttpRequest $request) {

    // add the developer key to the request before signing it

    if ($this->developerKey) {

      $request->setUrl($request->getUrl() . ((strpos($request->getUrl(), '?') === false) ? '?' : '&') . 'key='.urlencode($this->developerKey));

    }

    // and sign the request

    $oauthRequest = apiClientOAuthRequest::from_request($request->getMethod(), $request->getBaseUrl(), $request->getQueryParams());

    $params = $this->mergeParameters($request->getQueryParams());

    foreach ($params as $key => $val) {

      if (is_array($val)) {

        $val = implode(',', $val);

      }

      $oauthRequest->set_parameter($key, $val);

    }

    $oauthRequest->sign_request($this->signatureMethod, $this->consumerToken, $this->accessToken);

    $authHeaders = $oauthRequest->to_header();

    $headers = $request->getHeaders();

    $headers[] = $authHeaders;

    $request->setHeaders($headers);

    // and add the access token key to it (since it doesn't include the secret, it's still secure to store this in cache)

    $request->accessKey = $this->accessToken->key;

    return $request;

  }



  /**

   * Merges the supplied parameters with reasonable defaults for 2 legged oauth. User-supplied parameters

   * will have precedent over the defaults.

   *

   * @param array $params the user-supplied params that will be appended to the url

   * @return array the combined parameters

   */

  protected function mergeParameters($params) {

    $defaults = array(

      'oauth_nonce' => md5(microtime() . mt_rand()),

      'oauth_version' => apiClientOAuthRequest::$version, 'oauth_timestamp' => time(),

      'oauth_consumer_key' => $this->consumerToken->key

    );

    if ($this->accessToken != null) {

      $params['oauth_token'] = $this->accessToken->key;

    }

    return array_merge($defaults, $params);

  }



  public function createAuthUrl($scope) {return null;}

  public function refreshToken($refreshToken) {/* noop*/}

  public function revokeToken() {/* noop*/}

}