Mechanisms
RFC1961: GSS-API Authentication Method for SOCKS Version 5
RFC1964: GSSAPI Keberos V5 mechanism augmented by draft-ietf-cat-krb5gss-mech2-02.txt: The Keberos Version 5 GSSAPI Mechanism
RFC2025: The Simple Public-Key GSS-API Mechanism (SPKM)
Define tokens formats, encoding, error codes mappings, etcand occasionally semantics