cannot ssh into linux host based on a private key 'key' and a certificate 'key-cert.pub'

[bbthekings]

I cannot find the function call to ssh into a linux host based on a private key 'key' and a certificate 'key-cert.pub' where the certificate is signed by a certification authority which is configured on the host as 'TrustedUserCAKeys /etc/ssh/user-ca-pubkey.pem'. Is this implemented or do I need to implement it by myself? If not implemented, how would you recommend to approach it? thanks

[mscdex]

Duplicate of #551