Rails APP user auth with WordPress Cassava CAS Server

Question

Using Cassava CAS Server Plugin in WP to authenticate users from Rails app.

On Rails side:

 gem 'devise_cas_authenticatable'

On validation step:

https://www.example.com/wp-cas/proxyValidate?service=http%3A%2F%2Flocalhost%3A3000%2Fusers%2Fservice&ticket=ST-XXXXXXX

WordPress response:

<cas:serviceResponse><cas:authenticationFailure code="INVALID_TICKET">Expired ticket.</cas:authenticationFailure></cas:serviceResponse>

Maybe someone knows any solution for that?

I could use Plugin: wpCAS Server , but in this case my rails app gets only WP user_id and I would like to have them combined through email.