public boolean confirmFailure ( String orderNumber , String timestamp , String authCode ) { String base = new StringBuilder ( ) . append ( orderNumber ) . append ( ' ' ) . append ( timestamp ) . append ( ' ' ) . append ( merchantSecret ) . toString ( ) ; return StringUtils . equals ( StringUtils . upperCase ( DigestUtils . md5Hex ( base ) ) , authCode ) ; }
This function can be used to validate parameters returned by failure request . Parameters must be validated in order to avoid hacking of payment failure .