<?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_WindowsAzure

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

 */

/**

 * @see Zend_Service_WindowsAzure_Credentials_CredentialsAbstract

 */

require_once 'Zend/Service/WindowsAzure/Credentials/CredentialsAbstract.php';

/**

 * @category   Zend

 * @package    Zend_Service_WindowsAzure

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

 */ 

class Zend_Service_WindowsAzure_Credentials_SharedKeyLite

    extends Zend_Service_WindowsAzure_Credentials_CredentialsAbstract

{

    /**

	 * Sign request URL with credentials

	 *

	 * @param string $requestUrl Request URL

	 * @param string $resourceType Resource type

	 * @param string $requiredPermission Required permission

	 * @return string Signed request URL

	 */

	public function signRequestUrl(

		$requestUrl = '',

		$resourceType = Zend_Service_WindowsAzure_Storage::RESOURCE_UNKNOWN,

		$requiredPermission = Zend_Service_WindowsAzure_Credentials_CredentialsAbstract::PERMISSION_READ

	) {

	    return $requestUrl;

	}

	/**

	 * Sign request headers with credentials

	 *

	 * @param string $httpVerb HTTP verb the request will use

	 * @param string $path Path for the request

	 * @param string $queryString Query string for the request

	 * @param array $headers x-ms headers to add

	 * @param boolean $forTableStorage Is the request for table storage?

	 * @param string $resourceType Resource type

	 * @param string $requiredPermission Required permission

	 * @param mixed  $rawData Raw post data

	 * @return array Array of headers

	 */

	public function signRequestHeaders(

		$httpVerb = Zend_Http_Client::GET,

		$path = '/',

		$queryString = '',

		$headers = null,

		$forTableStorage = false,

		$resourceType = Zend_Service_WindowsAzure_Storage::RESOURCE_UNKNOWN,

		$requiredPermission = Zend_Service_WindowsAzure_Credentials_CredentialsAbstract::PERMISSION_READ,

		$rawData = null

	) {

		// Table storage?

		if (!$forTableStorage) {

			throw new Zend_Service_WindowsAzure_Credentials_Exception('The Windows Azure SDK for PHP does not support SharedKeyLite authentication on blob or queue storage. Use SharedKey authentication instead.');

		}

		// Determine path

		if ($this->_usePathStyleUri) {

			$path = substr($path, strpos($path, '/'));

		}

		// Determine query

		$queryString = $this->_prepareQueryStringForSigning($queryString);

		// Build canonicalized resource string

		$canonicalizedResource  = '/' . $this->_accountName;

		if ($this->_usePathStyleUri) {

			$canonicalizedResource .= '/' . $this->_accountName;

		}

		$canonicalizedResource .= $path;

		if ($queryString !== '') {

		    $canonicalizedResource .= $queryString;

		}

		// Request date

		$requestDate = '';

		if (isset($headers[Zend_Service_WindowsAzure_Credentials_CredentialsAbstract::PREFIX_STORAGE_HEADER . 'date'])) {

		    $requestDate = $headers[Zend_Service_WindowsAzure_Credentials_CredentialsAbstract::PREFIX_STORAGE_HEADER . 'date'];

		} else {

		    $requestDate = gmdate('D, d M Y H:i:s', time()) . ' GMT'; // RFC 1123

		}

		// Create string to sign   

		$stringToSign   = array();

    	$stringToSign[] = $requestDate; // Date

    	$stringToSign[] = $canonicalizedResource;		 			// Canonicalized resource

    	$stringToSign   = implode("\n", $stringToSign);

    	$signString     = base64_encode(hash_hmac('sha256', $stringToSign, $this->_accountKey, true));

    	// Sign request

    	$headers[Zend_Service_WindowsAzure_Credentials_CredentialsAbstract::PREFIX_STORAGE_HEADER . 'date'] = $requestDate;

    	$headers['Authorization'] = 'SharedKeyLite ' . $this->_accountName . ':' . $signString;

    	// Return headers

    	return $headers;

	}

	/**

	 * Prepare query string for signing

	 * 

	 * @param  string $value Original query string

	 * @return string        Query string for signing

	 */

	protected function _prepareQueryStringForSigning($value)

	{

	    // Check for 'comp='

	    if (strpos($value, 'comp=') === false) {

	        // If not found, no query string needed

	        return '';

	    } else {

	        // If found, make sure it is the only parameter being used      

    		if (strlen($value) > 0 && strpos($value, '?') === 0) {

    			$value = substr($value, 1);

    		}

    		// Split parts

    		$queryParts = explode('&', $value);

    		foreach ($queryParts as $queryPart) {

    		    if (strpos($queryPart, 'comp=') !== false) {

    		        return '?' . $queryPart;

    		    }

    		}

    		// Should never happen...

			return '';

	    }

	}

}