IETF RFC 4462 PDF

The Secure Shell protocol (SSH) is a protocol for secure remote login and other secure network services over an insecure network.

The Generic Security Service Application Program Interface (GSS-API) provides security services to callers in a mechanism-independent fashion.

This memo describes methods for using the GSS-API for authentication and key exchange in SSH. It defines an SSH user authentication method that uses a specified GSS-API mechanism to authenticate a user, and a family of SSH key exchange methods that use GSS-API to authenticate a Diffie-Hellman key exchange.

This memo also defines a new host public key algorithm that can be used when no operations are needed using a host's public key, and a new user authentication method that allows an authorization name to be used in conjunction with any authentication that has already occurred as a side-effect of GSS-API-based key exchange.