[Summary view]

Differences Between: [Versions 310 and 402] [Versions 311 and 402] [Versions 39 and 402] [Versions 400 and 402] [Versions 401 and 402]

   1  <?php
   2  
   3  namespace IMSGlobal\LTI\OAuth;
   4  
   5  /**
   6   * Class to represent an %OAuth HMAC_SHA256 signature method
   7   *
   8   * @author  Stephen P Vickers <svickers@imsglobal.org>
   9   * @copyright  IMS Global Learning Consortium Inc
  10   * @date  2016
  11   * @version 2015-11-30
  12   * @license https://opensource.org/licenses/MIT The MIT License
  13   */
  14  /**
  15   * The HMAC-SHA256 signature method uses the HMAC-SHA256 signature algorithm as defined in [RFC6234]
  16   * where the Signature Base String is the text and the key is the concatenated values (each first
  17   * encoded per Parameter Encoding) of the Consumer Secret and Token Secret, separated by an '&'
  18   * character (ASCII code 38) even if empty.
  19   */
  20  #[\AllowDynamicProperties]
  21  class OAuthSignatureMethod_HMAC_SHA256 extends OAuthSignatureMethod {
  22  
  23      function get_name() {
  24          return "HMAC-SHA256";
  25      }
  26  
  27      public function build_signature($request, $consumer, $token) {
  28  
  29          $base_string = $request->get_signature_base_string();
  30          $request->base_string = $base_string;
  31  
  32          $key_parts = array(
  33            $consumer->secret,
  34            ($token) ? $token->secret : ""
  35          );
  36  
  37          $key_parts = OAuthUtil::urlencode_rfc3986($key_parts);
  38          $key = implode('&', $key_parts);
  39  
  40          return base64_encode(hash_hmac('sha256', $base_string, $key, true));
  41  
  42      }
  43  
  44  }