[otrs] auto-login for customers

Hello, I would like to auto-login into "customer.pl" by clicking on a link on an our CRM. I see that a quick way is it passing user/pass to the URL, but it's not a security best practice. Should be correct to obtain a auto-login without: - storing the password on the source system - passing it to the URL I searched on the documentation and found nothing. Does exist a native way to perform this or not? Thanks Matteo