Example PHP script for SSO for Zendesk

zendesk_sso_basic.php

<?
/*
 * Remote authentication stub for PHP
 *
 * This is meant as a template for your own customization. You can identify the user anyway you like,
 * integrate it into your intranet, web app or similar.
 *
 * You may call this script directly or have Zendesk redirect to it using the
 * Remote Authentication URL.
 * 
 */
 
/* The following values should be set from your source of information */
$sFullName = "Name"; 
$sEmail = "email@domain.com"; 
$sExternalID = ""; 
$sOrganization = "";
$sTags = "";
$sRemotePhotoURL = "";
$sReturnTo = "";

/* Insert the Autentication Token here */
$sToken = ""; 

/* Insert your account prefix here. If your account is yoursite.zendesk.com: */
$sUrlPrefix = "yoursite"; 

/* Build the message */
$sTimestamp = isset($_GET['timestamp']) ? $_GET['timestamp'] : time(); 
$sMessage = $sFullName."|".$sEmail."|".$sExternalID."|".$sOrganization."|".$sTags."|".$sRemotePhotoURL."|".$sToken."|".$sTimestamp; 
$sHash = MD5($sMessage); 

$sso_url = "https://".$sUrlPrefix.".zendesk.com/access/remoteauth/?name=".$sFullName."&email=".$sEmail."&external_id=".$sExternalID."&timestamp=".$sTimestamp."&hash=".$sHash."&return_to=".$sReturnTo;

header("Location: ".$sso_url);

?>

You forgot to add the organization parameter n the sso_url.