The SSH Protocol Version 1.5 Documented in the RFC file from the SSH1 distribution, this version of the protocol is obsolete, but still in wide use for historical reasons. The SSH-2 protocol is described in four separate documents. Architecture describes the overall design of SSH-2.
Authentication identifies the client to the server.
Connection provides richer, application-support services over the transport pipe, such as channel multiplexing, remote program execution, signal propagation, TCP port and X forwarding, etc. The proposed method allows a client to pick parameters from a set offered by the server. This memo also defines a new host public key algorithm which can be used when no operations are needed using a host's public key, and a new user authentication method which allows an authorization name to be used in conjunction with any authentication which has already occurred as a side-effect of key exchange. This document describes a general purpose authentication method for the SSH protocol, suitable for interactive authentications where the authentication data should be entered via a keyboard. The Secure Shell File Transfer Protocol provides secure file transfer functionality over any reliable data stream.