<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Service_Amazon

 * @subpackage Authentication

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

/**

 * @see Zend_Service_Amazon_Authentication

 */

require_once 'Zend/Service/Amazon/Authentication.php';

/**

 * @see Zend_Crypt_Hmac

 */

require_once 'Zend/Crypt/Hmac.php';

/**

 * @category   Zend

 * @package    Zend_Service_Amazon

 * @subpackage Authentication

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_Service_Amazon_Authentication_V2 extends Zend_Service_Amazon_Authentication

{

    /**

     * Signature Version

     */

    protected $_signatureVersion = '2';

    /**

     * Signature Encoding Method

     */

    protected $_signatureMethod = 'HmacSHA256';

    /**

     * Type of http request

     * @var string

     */

    protected $_httpMethod = "POST";

    /**

     * Generate the required attributes for the signature

     * @param string $url

     * @param array $parameters

     * @return string

     */

    public function generateSignature($url, array &$parameters)

    {

        $parameters['AWSAccessKeyId']   = $this->_accessKey;

        $parameters['SignatureVersion'] = $this->_signatureVersion;

        $parameters['Version']          = $this->_apiVersion;

        $parameters['SignatureMethod']  = $this->_signatureMethod;

        if(!isset($parameters['Timestamp'])) {

            $parameters['Timestamp']    = gmdate('Y-m-d\TH:i:s\Z', time()+10);

        }

        $data = $this->_signParameters($url, $parameters);

        return $data;

    }

    /**

     * Set http request type to POST or GET

     * @param $method string

     */

    public function setHttpMethod($method = "POST") {

        $this->_httpMethod = strtoupper($method);

    }

    /**

     * Get the current http request type

     * @return string

     */

    public function getHttpMethod()

    {

        return $this->_httpMethod;

    }

    /**

     * Computes the RFC 2104-compliant HMAC signature for request parameters

     *

     * This implements the Amazon Web Services signature, as per the following

     * specification:

     *

     * 1. Sort all request parameters (including <tt>SignatureVersion</tt> and

     *    excluding <tt>Signature</tt>, the value of which is being created),

     *    ignoring case.

     *

     * 2. Iterate over the sorted list and append the parameter name (in its

     *    original case) and then its value. Do not URL-encode the parameter

     *    values before constructing this string. Do not use any separator

     *    characters when appending strings.

     *

     * @param  string $queue_url  Queue URL

     * @param  array  $parameters the parameters for which to get the signature.

     *

     * @return string the signed data.

     */

    protected function _signParameters($url, array &$paramaters)

    {

        $data = $this->_httpMethod . "\n";

        $data .= parse_url($url, PHP_URL_HOST) . "\n";

        $data .= ('' == $path = parse_url($url, PHP_URL_PATH)) ? '/' : $path;

        $data .= "\n";

        uksort($paramaters, 'strcmp');

        unset($paramaters['Signature']);

        $arrData = array();

        foreach($paramaters as $key => $value) {

            $arrData[] = $key . '=' . str_replace('%7E', '~', rawurlencode($value));

        }

        $data .= implode('&', $arrData);

        $hmac = Zend_Crypt_Hmac::compute($this->_secretKey, 'SHA256', $data, Zend_Crypt_Hmac::BINARY);

        $paramaters['Signature'] = base64_encode($hmac);

        return $data;

    }

}