SSO through Webservice

Hello experts,

I have been asked to write a webservice which returns an SSO Ticket for given username,password and I would like to learn if this case is possible or not.

Here is the full scenario;
1- user enters username and password from Sapui5 application,
2- before connecting to the gateway, sapui5 calls for a webservice and pass these 2 parameters, get an SSO Ticket in return if authenticated.

3- with sso ticket, sapui5 app connects to gateway,

This was the given scenario so before digging into it, i would like to learn if this is possible if i may ?

Kindest Regards,

Yasin