diff --git a/workflow/engine/classes/class.sso.php b/workflow/engine/classes/class.sso.php
new file mode 100644
index 000000000..d099b3bcd
--- /dev/null
+++ b/workflow/engine/classes/class.sso.php
@@ -0,0 +1,74 @@
+<?php
+/**
+ * class.sso.php
+ *  
+ */
+G::LoadClass ('pmFunctions');
+ 
+  class ssoClass extends PMPlugin {
+    function __construct() {
+    }
+
+    function setup()
+    {
+    }
+
+    function getFieldsForPageSetup()
+    {
+    }
+
+    function updateFieldsForPageSetup()
+    {
+    }
+
+    function ssocVerifyUser(){
+        $res = false;
+        $RBAC = RBAC::getSingleton();
+        $RBAC->initRBAC();		
+        $server = $_SERVER['SERVER_SOFTWARE'];		
+        $webserver = explode("/", $server);
+        if(isset($_SERVER['REMOTE_USER']) && $_SERVER['REMOTE_USER'] !=''){
+            // IIS Verification
+            if (!is_array($webserver) || (is_array($webserver) && ($webserver[0] == 'Microsoft-IIS'))){
+                $userFull = $_SERVER['REMOTE_USER'];
+                $userPN = explode("\\", $userFull);
+                if (is_array($userPN)){
+                    $user = $userPN[1];
+                } else {
+                    $user = $userFull;
+                }
+            } else {
+                $userFull = $_SERVER['REMOTE_USER'];
+                $user = $_SERVER['REMOTE_USER'];
+            }
+            // End IIS Verification
+
+            $resVerifyUser = $RBAC->verifyUser($user);
+            if ($resVerifyUser == 0) {
+                // Here we are checking if the automatic user Register is enabled, ioc return -1
+                $fakepswd = G::generate_password();
+                $res = $RBAC->checkAutomaticRegister($user, $fakepswd);
+                if ($res === -1) {
+                	return false; // No successful auto register, skipping the auto register and back to normal login form
+                }
+                $RBAC->verifyUser($user);
+            }
+            if (!isset($RBAC->userObj->fields['USR_STATUS']) || $RBAC->userObj->fields['USR_STATUS'] == 0) {
+                $errLabel = 'ID_USER_INACTIVE';
+                G::SendTemporalMessage($errLabel, "warning");
+                return false;
+            }
+            $sSQL = "SELECT USR_UID FROM USERS WHERE USR_USERNAME = '$user' ";
+            $aResSQL = executeQuery($sSQL);			
+            if(sizeof($aResSQL)){
+                $nUserId = $aResSQL[1]['USR_UID'];		
+                $RBAC->singleSignOn = true;
+                $RBAC->userObj->fields['USR_UID'] = $nUserId;
+                $RBAC->userObj->fields['USR_USERNAME'] = $user;
+                $res = true;
+            }
+        }
+        return $res;
+    }
+ }
+?>
\ No newline at end of file
diff --git a/workflow/engine/methods/login/login.php b/workflow/engine/methods/login/login.php
index d8d9aadea..83aa96f16 100755
--- a/workflow/engine/methods/login/login.php
+++ b/workflow/engine/methods/login/login.php
@@ -103,6 +103,22 @@ if (isset ($_SESSION['USER_LOGGED'])) {
     // Execute SSO trigger
     $pluginRegistry =& PMPluginRegistry::getSingleton();
     if (defined('PM_SINGLE_SIGN_ON')) {
+        //Check in SSO class
+        G::LoadClass("sso");
+        $oSso = new ssoClass();
+        $res = $oSso->ssocVerifyUser();
+        if($res){
+            // Start new session
+            @session_destroy();
+            session_start();
+            session_regenerate_id();
+
+            // Authenticate
+            require_once 'authentication.php';
+
+            die();
+        }
+        //Check in SSO class
         if ($pluginRegistry->existsTrigger(PM_SINGLE_SIGN_ON)) {
             if ($pluginRegistry->executeTriggers(PM_SINGLE_SIGN_ON, null)) {
                 // Start new session