By rout on
Would anyone be interested in assisting in developing a module to authenticate against iTunes U?
Aaron Axelsen, from the University of Wisconsin, has already developed a php script to do this work. I was curious if this was something that could be rolled into a module so that Drupal could be used for user access management to iTunes U.
Here is the code as contributed by Aaron:
<?php
##############################################
#
# iTunes Authentication Class
# URL: http://omega1.uww.edu/itunesu
# Version: 1.2 - 10/29/2007
#
# Written by Aaron Axelsen - axelsena@uww.edu
# University of Wisconsin - Whitewater
#
# Class based on the Apple provided ITunesU.pl
# example script.
#
# REQUIREMENTS:
#
# PHP: (Tested with 5.1.x and Newer)
# - php mhash support - http://mhash.sourceforge.net/
# - php curl support
#
#
##############################################
class itunes {
/**
* https://deimos.apple.com/WebObjects/Core.woa/Browse/example.edu
*
* @var string
*/
private $siteURL;
/**
* /abc1234
*
* @var string
*/
private $debugSuffix;
/**
* STRINGOFTHIRTYTWOLETTERSORDIGITS
*
* @var string;
*/
private $sharedSecret;
/**
* Array of credentials applied for the current user
*
* @var array
*/
private $credentials = array();
/**
* Array of roles passed in with config options
*
* @var array
*/
private $roles = array();
/**
* Create iTunes Object
*/
public function __construct($config = false) {
# Set Debug to False
$this->setDebug(false);
# If options are passed in at construct time, setup options
if ($config != false) {
$this->config($config);
}
}
/**
* Use Example Credentials
* This will setup the options to authenticate into Apple's example iTunes U instance
*/
public function setupExample() {
# Site URL - used for basic logins
$this->siteURL = 'https://deimos.apple.com/WebObjects/Core.woa/Browse/example.edu';
# Debug Suffix - needed to authenticate for debugging
$this->debugSuffix = '/abc1234';
# Shared Secret - needed for authentication
$this->sharedSecret = 'STRINGOFTHIRTYTWOLETTERSORDIGITS';
# Roles - array of roles used for credential strings - must correspond to what is set in iTunes U
$this->role['administrator'] = 'Administrator@urn:mace:itunesu.com:sites:example.edu';
$this->role['student'] = 'Student@urn:mace:itunesu.com:sites:example.edu:classes';
$this->role['instructor'] = 'Instructor@urn:mace:itunesu.com:sites:example.edu:classes';
# Set domain
$this->setDomain();
# Set Direct URL - used in conjunction with the handle (allows itunes U to launch directly into the specified course)
$this->setDirectURL();
}
/**
* Set Configuration Options
* Takes array as input, keys should correspond to variables above
*
* @config array $config iTunes configuration options passed into the class
*/
public function config($config) {
foreach ($config as $key=>$val) {
if (property_exists($this, $key))
$this->$key = $val;
else
trigger_error("Invalid config option: $key", E_USER_WARNING);
}
$this->setDomain();
$this->setDirectURL();
}
/**
* Add credentials
*
* @param string $role Name of the role to add
* @param string $unique Unique identifier for a course (Not required for Admin)
*/
public function add($role,$unique = -1) {
if ($unique == -1)
$this->addCredentials($this->roles[$role]);
else
$this->addCredentials($this->roles[$role].":$unique");
}
/**
* Add's admin credentials for a given user
* DEPRECATED - Convert to using array based credentials - add()
*/
public function addAdminCredentials() {
$this->addCredentials($this->administratorCredential);
}
/**
* Add Student Credential for a given course
* DEPRECATED - Convert to using array based credentials - add()
*/
public function addStudentCredential($unique) {
$this->addCredentials($this->studentCredential.":$unique");
}
/**
* Add Instructor Credential for a given course
* DEPRECATED - Convert to using style array credentials - add()
*/
public function addInstructorCredential($unique) {
$this->addCredentials($this->instructorCredential.":$unique");
}
/**
* Set User Information
*/
public function setUser($name, $email, $netid, $userid) {
$this->name = $name;
$this->email = $email;
$this->netid = $netid;
$this->userid = $userid;
return true;
}
/**
* Set the Domain
*
* Takes the siteURL and splits off the destination, hostname and action path.
*/
private function setDomain() {
$tmpArray = split("/",$this->siteURL);
$this->siteDomain = $tmpArray[sizeof($tmpArray)-1];
$this->actionPath = preg_replace("/https:\/\/(.+?)\/.*/",'$1',$this->siteURL);
$pattern = "/https:\/\/".$this->actionPath."(.*)/";
$this->hostName = preg_replace($pattern,'$1',$this->siteURL);
$this->destination = $this->siteDomain;
return true;
}
/**
* Set Direct URL
*
* Sets the Direct URL - If a handle is specified during the authentication process, this URL will be used to
* launch iTunes U directly into the specified course.
*/
private function setDirectURL() {
$this->directSiteURL = "https://deimos.apple.com/WebObjects/Core.woa/BrowsePrivately/".$this->siteDomain;
}
/**
* Set the Handle
*
* Takes the handle as input and forms the get upload url string
* This is needed for using the API to upload files directly to iTunes U
*/
public function setHandle($handleIn) {
$this->handle = $handleIn;
$this->getUploadUrl = "http://deimos.apple.com/WebObjects/Core.woa/API/GetUploadURL/".$this->siteDomain.'.'.$this->handle;
return true;
}
/**
* Get Identity String
*
* Combine user identity information into an appropriately formatted string.
* take the arguments passed into the function copy them to variables
*/
private function getIdentityString() {
# wrap the elements into the required delimiters.
return sprintf('"%s" <%s> (%s) [%s]', $this->name, $this->email, $this->netid, $this->userid);
}
/**
* Add Credentials to Array
*
* Allows to push multiple credientials for a user onto the array
*/
private function addCredentials($credentials) {
array_push($this->credentials,$credentials);
return true;
}
/**
* Get Credentials String
*
* this is equivalent to join(';', @_); this function is present
* for consistency with the Java example.
* concatenates all the passed in credentials into a string
* with a semicolon delimiting the credentials in the string.
*/
private function getCredentialsString() {
#make sure that at least one credential is passed in
if (sizeof($this->credentials) < 1)
return false;
return implode(";",$this->credentials);
}
private function getAuthorizationToken() {
# Create a buffer with which to generate the authorization token.
$buffer = "";
# create the POST Content and sign it
$buffer .= "credentials=" . urlencode($this->getCredentialsString());
$buffer .= "&identity=" . urlencode($this->identity);
$buffer .= "&time=" . urlencode(mktime());
# returns a signed message that is sent to the server
if (function_exists('hash_hmac'))
$signature = hash_hmac('SHA256', $buffer, $this->sharedSecret);
else {
require_once 'Message/Message.php';
$hmac = Message::createHMAC('SHA256', $this->sharedSecret);
$signature = $hmac->calc($buffer);
}
# append the signature to the POST content
return sprintf("%s&signature=%s", $buffer, $signature);
}
/**
* Invoke Action
*
* Send a request to iTunes U and record the response.
* Net:HTTPS is used to get better control of the encoding of the POST data
* as HTTP::Request::Common does not encode parentheses and Java's URLEncoder
* does.
*/
public function invokeAction() {
$this->identity = $this->getIdentityString();
$this->token = $this->getAuthorizationToken();
if (function_exists('curl_init')) {
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $this->generateURL() . '?' . $this->token);
curl_setopt($ch, CURLOPT_POST, 1);
if (curl_exec($ch)) {
// Echo Javascript to clear contents of popup window
echo "<script type=\"text/javascript\">
<!--
document.getElementById('loading').innerHTML = '';
-->
</script>";
curl_close($ch);
return true;
} else {
curl_close($ch);
return false;
}
} else {
require_once 'HTTP/Request.php';
$req = &new HTTP_Request($this->generateURL());;
$req->setMethod(HTTP_REQUEST_METHOD_POST);
$req->addHeader("Content-Type","application/x-www-form-urlencoded");
$req->addHeader("charset","UTF-8");
$req->addRawPostData($this->token, true);
$x = $req->sendRequest();
if (PEAR::isError($x)) {
echo $x->getMessage();
// Return false if error
return false;
} else {
echo $req->getResponseBody();
// Echo Javascript to clear contents of popup window
echo "<script type=\"text/javascript\">
<!--
document.getElementById('loading').innerHTML = '';
-->
</script>";
// Return true if success
return true;
}
}
}
/**
* Auth and Upload File to iTunes U
*
* This method is said to not be as heavily tested by apple, so you may have
* unexpected results.
*
* $fileIn - full system path to the file you desire to upload
*/
public function uploadFile($fileIn) {
$this->identity = $this->getIdentityString();
$this->token = $this->getAuthorizationToken();
// Escape the filename
$f = escapeshellcmd($fileIn);
// Contact Apple and Get the Upload URL
$upUrl = curl_init($this->getUploadUrl.'?'.$this->token);
curl_setopt($upUrl, CURLOPT_RETURNTRANSFER, true);
$uploadURL = curl_exec($upUrl);
$error = curl_error($upUrl);
$http_code = curl_getinfo($upUrl ,CURLINFO_HTTP_CODE);
curl_close($upUrl);
print $http_code;
print "<br /><br />$uploadURL";
if ($error) {
print "<br /><br />$error";
}
# Currently not working using php/curl functions. For now, we are just going to echo a system command .. see below
#// Push out the designated file to iTunes U
#// Build Post Fields
#$postfields = array("file" => "@$fileIn");
#$pushUrl = curl_init($uploadURL);
#curl_setopt($pushUrl, CURLOPT_FAILONERROR, 1);
#curl_setopt($pushUrl, CURLOPT_FOLLOWLOCATION, 1);// allow redirects
#curl_setopt($pushUrl, CURLOPT_VERBOSE, 1);
#curl_setopt($pushUrl, CURLOPT_RETURNTRANSFER, true);
#curl_setopt($pushUrl, CURLOPT_POST, true);
#curl_setopt($pushUrl, CURLOPT_POSTFILEDS, $postfields);
#$output = curl_exec($pushUrl);
#$error = curl_error($pushUrl);
#$http_code = curl_getinfo($pushUrl, CURLINFO_HTTP_CODE);
#curl_close($pushUrl);
#print "<br/>";
#print $http_code;
#print "<br /><br />$output";
#if ($error) {
# print "<br /><br />$error";
#}
// Set the php time limit higher so it doesnt time out.
set_time_limit(1200);
// System command to initiate curl and upload the file. (Temp until I figure out the php curl commands to do it)
$command = "curl -S -F file=@$f $uploadURL";
echo "<br/><br/>";
echo $command;
exec($command, $result, $error);
if ($error) {
echo "I'm busted";
} else {
print_r($result);
}
echo $command;
}
/**
* Set Debugging
*
* Enable/Disable debugging of iTunes U Authentication
*/
public function setDebug($bool) {
if ($bool) {
$this->debug = true;
} else {
$this->debug = false;
}
return true;
}
/**
* Generate Site URL
*
* Append debug suffix to end of url if debugging is enabled
*/
private function generateURL() {
if ($this->debug) {
return $this->siteURL.$this->debugSuffix;
} elseif ($this->isHandleSet()) {
return $this->directSiteURL.'.'.$this->handle;
} else {
return $this->siteURL;
}
}
/**
* Check to see if the handle is set
*/
private function isHandleSet() {
if (isset($this->handle))
return true;
else
return false;
}
}
?>
