OpenTokSDK.php

<?PHP

/**
* OpenTok PHP Library
* http://www.tokbox.com/
*
* Copyright (c) 2011, TokBox, Inc.
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the "Software"), 
* to deal in the Software without restriction, including without limitation 
* the rights to use, copy, modify, merge, publish, distribute, sublicense, 
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
* 
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
* THE SOFTWARE.
*/

require_once 'API_Config.php';
require_once 'OpenTokSession.php';
require_once 'OpenTokArchive.php';

//Generic OpenTok exception. Read the message to get more details
class OpenTokException extends Exception { };
//OpenTok exception related to authentication. Most likely an issue with your API key or secret
class AuthException extends OpenTokException { };
//OpenTok exception related to the HTTP request. Most likely due to a server error. (HTTP 500 error)
class RequestException extends OpenTokException { };

class RoleConstants {
    const SUBSCRIBER = "subscriber"; //Can only subscribe
    const PUBLISHER = "publisher";   //Can publish, subscribe, and signal
    const MODERATOR = "moderator";   //Can do the above along with  forceDisconnect and forceUnpublish
};

class OpenTokSDK {

    private $api_key;

    private $api_secret;

    public function __construct($api_key, $api_secret) {
        $this->api_key = $api_key;
        $this->api_secret = trim($api_secret);
    }

    /** - Generate a token
     *
     * $session_id  - If session_id is not blank, this token can only join the call with the specified session_id.
     * $role        - One of the constants defined in RoleConstants. Default is publisher, look in the documentation to learn more about roles.
     * $expire_time - Optional timestamp to change when the token expires. See documentation on token for details.
     */
    public function generate_token($session_id='', $role='', $expire_time=NULL, $connection_data='') {
        $create_time = time();

        $nonce = microtime(true) . mt_rand();

        if(!$role) {
            $role = RoleConstants::PUBLISHER;
        } else if (!in_array($role, array(RoleConstants::SUBSCRIBER, 
                RoleConstants::PUBLISHER, RoleConstants::MODERATOR))) {
            throw new OpenTokException("unknown role $role");
        }

        $data_string = "session_id=$session_id&create_time=$create_time&role=$role&nonce=$nonce";
        if(!is_null($expire_time)) {
            if(!is_numeric($expire_time))
                throw new OpenTokException("Expire time must be a number");
            if($expire_time < $create_time)
                throw new OpenTokException("Expire time must be in the future");
            if($expire_time > $create_time + 604800)
                throw new OpenTokException("Expire time must be in the next 7 days");
            $data_string .= "&expire_time=$expire_time";
        }
        if($connection_data != '') {
            if(strlen($connection_data) > 1000)
                throw new OpenTokException("Connection data must be less than 1000 characters");
            $data_string .= "&connection_data=" . urlencode($connection_data);
        }

        $sig = $this->_sign_string($data_string, $this->api_secret);
        $api_key = $this->api_key;

        return "T1==" . base64_encode("partner_id=$api_key&sig=$sig:$data_string");
    }
    
    /**
     * Creates a new session.
     * $location - IP address to geolocate the call around.
     * $properties - Optional array, keys are defined in SessionPropertyConstants
     */
    public function create_session($location='', $properties=array()) {
        $properties["location"] = $location;
        $properties["api_key"] = $this->api_key;

        $createSessionResult = $this->_do_request("/session/create", $properties);
        $createSessionXML = @simplexml_load_string($createSessionResult, 'SimpleXMLElement', LIBXML_NOCDATA);
        if(!$createSessionXML) {
            throw new OpenTokException("Failed to create session: Invalid response from server");
        }

        $errors = $createSessionXML->xpath("//error");
        if($errors) {
            $errMsg = $errors[0]->xpath("//@message");
            if($errMsg) {
                $errMsg = (string)$errMsg[0]['message'];
            } else {
                $errMsg = "Unknown error";
            }
            throw new AuthException("Error " . $createSessionXML->error['code'] ." ". $createSessionXML->error->children()->getName() . ": " . $errMsg );
        }
        if(!isset($createSessionXML->Session->session_id)) {
            echo"<pre>";print_r($createSessionXML);echo"</pre>";
            throw new OpenTokException("Failed to create session.");
        }
        $sessionId = $createSessionXML->Session->session_id;

        return new OpenTokSession($sessionId, null);
    }

    public function get_archive_manifest($archiveId, $token) {
        $auth = array('type' => 'token', 'token' => $token);

        $archiveManifestResult = $this->_do_request("/archive/getmanifest/$archiveId", array(), $auth);
        $archiveManifestXML = @simplexml_load_string($archiveManifestResult, 'SimpleXMLElement', LIBXML_NOCDATA);
        if(!$archiveManifestXML) {
            throw new OpenTokException("Failed to load manifest file associated with archive $archiveId");
        }

        return OpenTokArchive::parseManifest($archiveManifestXML);
    }

    //////////////////////////////////////////////
    //Signing functions, request functions, and other utility functions needed for the OpenTok
    //Server API. Developers should not edit below this line. Do so at your own risk.
    //////////////////////////////////////////////

    protected function _sign_string($string, $secret) {
        return hash_hmac("sha1", $string, $secret);
    }

    protected function _do_request($url, $data, $auth = array('type' => 'partner')) {
        $url = API_Config::API_SERVER . $url;

        $dataString = "";
        foreach($data as $key => $value){
            $value = urlencode($value);
            $dataString .= "$key=$value&";
        }

        $dataString = rtrim($dataString,"&");

        switch($auth['type']) {
            case 'token':
                $authString = "X-TB-TOKEN-AUTH: ".$auth['token'];
                break;
            case 'partner':
            default:
                $authString = "X-TB-PARTNER-AUTH: $this->api_key:$this->api_secret";
                break;
        }

        //Use file_get_contents if curl is not available for PHP
        if(function_exists("curl_init")) {            
            $ch = curl_init();

            $api_key = $this->api_key;
            $api_secret = $this->api_secret;

            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_HTTPHEADER, Array('Content-type: application/x-www-form-urlencoded'));
            curl_setopt($ch, CURLOPT_HTTPHEADER, Array($authString));   
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
            curl_setopt($ch, CURLOPT_HEADER, 0);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
            curl_setopt($ch, CURLOPT_POST, 1);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $dataString);

            $res = curl_exec($ch);
            if(curl_errno($ch)) {
                throw new RequestException('Request error: ' . curl_error($ch));
            }

            curl_close($ch);
        }
        else {        
            if (function_exists("file_get_contents")) {
                $context_source = array ('http' => array (
                                        'method' => 'POST',
                                        'header'=> Array("Content-type: application/x-www-form-urlencoded", $authString, "Content-Length: " . strlen($dataString), 'content' => $dataString)
                                        )
                                    );
                $context = stream_context_create($context_source);
                $res = @file_get_contents( $url ,false, $context);                
            }
            else{
                throw new RequestException("Your PHP installion neither supports the file_get_contents method nor cURL. Please enable one of these functions so that you can make API calls.");
            }        
        }        
        return $res;
    }
}