[Summary view] [Print] [Text view]

   1  <?php
   2  /**
   3   * Zend Framework
   4   *
   5   * LICENSE
   6   *
   7   * This source file is subject to the new BSD license that is bundled
   8   * with this package in the file LICENSE.txt.
   9   * It is also available through the world-wide-web at this URL:
  10   * http://framework.zend.com/license/new-bsd
  11   * If you did not receive a copy of the license and are unable to
  12   * obtain it through the world-wide-web, please send an email
  13   * to [email protected] so we can send you a copy immediately.
  14   *
  15   * @category   Zend
  16   * @package    Zend_Service_Amazon
  17   * @subpackage Ec2
  18   * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
  19   * @license    http://framework.zend.com/license/new-bsd     New BSD License
  20   * @version    $Id$
  21   */
  22  
  23  /**
  24   * @see Zend_Service_Amazon_Abstract
  25   */
  26  require_once 'Zend/Service/Amazon/Abstract.php';
  27  
  28  /**
  29   * @see Zend_Service_Amazon_Ec2_Response
  30   */
  31  require_once 'Zend/Service/Amazon/Ec2/Response.php';
  32  
  33  /**
  34   * @see Zend_Service_Amazon_Ec2_Exception
  35   */
  36  require_once 'Zend/Service/Amazon/Ec2/Exception.php';
  37  
  38  /**
  39   * Provides the basic functionality to send a request to the Amazon Ec2 Query API
  40   *
  41   * @category   Zend
  42   * @package    Zend_Service_Amazon
  43   * @subpackage Ec2
  44   * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
  45   * @license    http://framework.zend.com/license/new-bsd     New BSD License
  46   */
  47  abstract class Zend_Service_Amazon_Ec2_Abstract extends Zend_Service_Amazon_Abstract
  48  {
  49      /**
  50       * The HTTP query server
  51       */
  52      protected $_ec2Endpoint = 'ec2.amazonaws.com';
  53  
  54      /**
  55       * The API version to use
  56       */
  57      protected $_ec2ApiVersion = '2009-04-04';
  58  
  59      /**
  60       * Signature Version
  61       */
  62      protected $_ec2SignatureVersion = '2';
  63  
  64      /**
  65       * Signature Encoding Method
  66       */
  67      protected $_ec2SignatureMethod = 'HmacSHA256';
  68  
  69      /**
  70       * Period after which HTTP request will timeout in seconds
  71       */
  72      protected $_httpTimeout = 10;
  73  
  74      /**
  75       * @var string Amazon Region
  76       */
  77      protected static $_defaultRegion = null;
  78  
  79      /**
  80       * @var string Amazon Region
  81       */
  82      protected $_region;
  83  
  84      /**
  85       * An array that contains all the valid Amazon Ec2 Regions.
  86       *
  87       * @var array
  88       */
  89      protected static $_validEc2Regions = array('eu-west-1', 'us-east-1');
  90  
  91      /**
  92       * Create Amazon client.
  93       *
  94       * @param  string $access_key       Override the default Access Key
  95       * @param  string $secret_key       Override the default Secret Key
  96       * @param  string $region           Sets the AWS Region
  97       * @return void
  98       */
  99      public function __construct($accessKey=null, $secretKey=null, $region=null)
 100      {
 101          if(!$region) {
 102              $region = self::$_defaultRegion;
 103          } else {
 104              // make rue the region is valid
 105              if(!empty($region) && !in_array(strtolower($region), self::$_validEc2Regions, true)) {
 106                  require_once 'Zend/Service/Amazon/Exception.php';
 107                  throw new Zend_Service_Amazon_Exception('Invalid Amazon Ec2 Region');
 108              }
 109          }
 110  
 111          $this->_region = $region;
 112  
 113          parent::__construct($accessKey, $secretKey);
 114      }
 115  
 116      /**
 117       * Set which region you are working in.  It will append the
 118       * end point automaticly
 119       *
 120       * @param string $region
 121       */
 122      public static function setRegion($region)
 123      {
 124          if(in_array(strtolower($region), self::$_validEc2Regions, true)) {
 125              self::$_defaultRegion = $region;
 126          } else {
 127              require_once 'Zend/Service/Amazon/Exception.php';
 128              throw new Zend_Service_Amazon_Exception('Invalid Amazon Ec2 Region');
 129          }
 130      }
 131  
 132      /**
 133       * Method to fetch the AWS Region
 134       *
 135       * @return string
 136       */
 137      protected function _getRegion()
 138      {
 139          return (!empty($this->_region)) ? $this->_region . '.' : '';
 140      }
 141  
 142      /**
 143       * Sends a HTTP request to the queue service using Zend_Http_Client
 144       *
 145       * @param array $params         List of parameters to send with the request
 146       * @return Zend_Service_Amazon_Ec2_Response
 147       * @throws Zend_Service_Amazon_Ec2_Exception
 148       */
 149      protected function sendRequest(array $params = array())
 150      {
 151          $url = 'https://' . $this->_getRegion() . $this->_ec2Endpoint . '/';
 152  
 153          $params = $this->addRequiredParameters($params);
 154  
 155          try {
 156              /* @var $request Zend_Http_Client */
 157              $request = self::getHttpClient();
 158              $request->resetParameters();
 159  
 160              $request->setConfig(array(
 161                  'timeout' => $this->_httpTimeout
 162              ));
 163  
 164              $request->setUri($url);
 165              $request->setMethod(Zend_Http_Client::POST);
 166              $request->setParameterPost($params);
 167  
 168              $httpResponse = $request->request();
 169  
 170  
 171          } catch (Zend_Http_Client_Exception $zhce) {
 172              $message = 'Error in request to AWS service: ' . $zhce->getMessage();
 173              throw new Zend_Service_Amazon_Ec2_Exception($message, $zhce->getCode(), $zhce);
 174          }
 175          $response = new Zend_Service_Amazon_Ec2_Response($httpResponse);
 176          $this->checkForErrors($response);
 177  
 178          return $response;
 179      }
 180  
 181      /**
 182       * Adds required authentication and version parameters to an array of
 183       * parameters
 184       *
 185       * The required parameters are:
 186       * - AWSAccessKey
 187       * - SignatureVersion
 188       * - Timestamp
 189       * - Version and
 190       * - Signature
 191       *
 192       * If a required parameter is already set in the <tt>$parameters</tt> array,
 193       * it is overwritten.
 194       *
 195       * @param array $parameters the array to which to add the required
 196       *                          parameters.
 197       *
 198       * @return array
 199       */
 200      protected function addRequiredParameters(array $parameters)
 201      {
 202          $parameters['AWSAccessKeyId']   = $this->_getAccessKey();
 203          $parameters['SignatureVersion'] = $this->_ec2SignatureVersion;
 204          $parameters['Timestamp']        = gmdate('Y-m-d\TH:i:s\Z');
 205          $parameters['Version']          = $this->_ec2ApiVersion;
 206          $parameters['SignatureMethod']  = $this->_ec2SignatureMethod;
 207          $parameters['Signature']        = $this->signParameters($parameters);
 208  
 209          return $parameters;
 210      }
 211  
 212      /**
 213       * Computes the RFC 2104-compliant HMAC signature for request parameters
 214       *
 215       * This implements the Amazon Web Services signature, as per the following
 216       * specification:
 217       *
 218       * 1. Sort all request parameters (including <tt>SignatureVersion</tt> and
 219       *    excluding <tt>Signature</tt>, the value of which is being created),
 220       *    ignoring case.
 221       *
 222       * 2. Iterate over the sorted list and append the parameter name (in its
 223       *    original case) and then its value. Do not URL-encode the parameter
 224       *    values before constructing this string. Do not use any separator
 225       *    characters when appending strings.
 226       *
 227       * @param array  $parameters the parameters for which to get the signature.
 228       * @param string $secretKey  the secret key to use to sign the parameters.
 229       *
 230       * @return string the signed data.
 231       */
 232      protected function signParameters(array $paramaters)
 233      {
 234          $data = "POST\n";
 235          $data .= $this->_getRegion() . $this->_ec2Endpoint . "\n";
 236          $data .= "/\n";
 237  
 238          uksort($paramaters, 'strcmp');
 239          unset($paramaters['Signature']);
 240  
 241          $arrData = array();
 242          foreach($paramaters as $key => $value) {
 243              $arrData[] = $key . '=' . str_replace("%7E", "~", rawurlencode($value));
 244          }
 245  
 246          $data .= implode('&', $arrData);
 247  
 248          require_once 'Zend/Crypt/Hmac.php';
 249          $hmac = Zend_Crypt_Hmac::compute($this->_getSecretKey(), 'SHA256', $data, Zend_Crypt_Hmac::BINARY);
 250  
 251          return base64_encode($hmac);
 252      }
 253  
 254      /**
 255       * Checks for errors responses from Amazon
 256       *
 257       * @param Zend_Service_Amazon_Ec2_Response $response the response object to
 258       *                                                   check.
 259       *
 260       * @return void
 261       *
 262       * @throws Zend_Service_Amazon_Ec2_Exception if one or more errors are
 263       *         returned from Amazon.
 264       */
 265      private function checkForErrors(Zend_Service_Amazon_Ec2_Response $response)
 266      {
 267          $xpath = new DOMXPath($response->getDocument());
 268          $list  = $xpath->query('//Error');
 269          if ($list->length > 0) {
 270              $node    = $list->item(0);
 271              $code    = $xpath->evaluate('string(Code/text())', $node);
 272              $message = $xpath->evaluate('string(Message/text())', $node);
 273              throw new Zend_Service_Amazon_Ec2_Exception($message, 0, $code);
 274          }
 275  
 276      }
 277  }