I am achieved the login functionality through REST API provided by sugarCRM ,
http://<url>/service/v2/rest.php?method=login&input_type=JSON&response_type=JSON&rest_data={"user_auth":{"user_name":"Vsree","password":"0141ffbe5e8d1cbaaeee96b3ca49cc49"}}
also updated the login response from
service\core\SugarWebServiceImpl.php
i am updated the response and its working fine . but it is a suiteCRM core module , i want to extend the login functionality with out affecting core modules, So how can i extend the modules inside suircrm .How can i achieve this