Subject: RE: GSSAPI service registry

From: "Linn, John" <[email-masked]>
Date: Fri, 6 Feb 1998 11:53:21 -0500

Thanks, Chris, for investigating this.  Some initial thoughts:

In addition to the entries now in the preliminary registry, FTP security
(RFC-2228) also specifies "ftp" as first-use value with optional
fallback to "host".  There'd been discussion, though I'm not now sure
where/if it had been documented elsewhere, of encouraging use of "host"
as a more generic successor to "rcmd", for those cases where a single
host-based service name is applied (in all or selective cases) with
scope broader than an individual protocol.   Since it doesn't seem to
offer much utility to be able to derive the protocol-specific name that
should be used to connect to a particular protocol's server absent a
definition of how GSS was integrated into that protocol, I'm thinking
that the GSS-specific registry (perhaps subdivided into per-protocol vs.
cross-protocol entries, and hopefully we won't need many more of the
latter) seems usefully clarifying.   What do others think?

--jl

> ----------
> From: 	Chris Newman[SMTP:[email-masked]]
> Sent: 	Thursday, February 05, 1998 5:07 PM
> To: 	IETF Common Authentication Technology WG
> Subject: 	GSSAPI service registry
> 
> I was looking for the GSSAPI service registry for services used in the
> host-service name form, and couldn't find it.  So I asked IANA to
> create
> the registry after fishing through RFCs to find the ones which
> specified
> service names.  There is now a preliminary registry at:
> 
> <http://www.isi.edu/in-notes/iana/assignments/gssapi-service-names>
> 
> (note this is currently not linked to the top-level IANA assignments
> page).
> 
> It was then that I discovered there was also a reference to GSSAPI in
> the
> protocol and service name registry used by DNS WKS records:
> 
> <http://www.isi.edu/in-notes/iana/assignments/service-names>
> 
> This latter registry is really a registry of protocols.  Something
> like
> "rcmd" which reflects a service which can be provided by more than one
> protocol (on different ports) just doesn't fit DNS WKS intended use.
> In
> addition, this registry has no references to specifications of the
> protocols and it has a lot of junk entries.
> 
> This group should reach rough concensus on one of two actions:
> 
> (1) Ask IANA to strike the reference to GSSAPI from the protocol name
> list
> and to link the gssapi-service-name registry to their top-level
> registry
> list.
> 
> (2) Ask IANA to remove the gssapi-service-name registry, but add the
> values listed there to the protocol name registry.
> 
> I prefer (1) because I think it is semanticly cleaner.
> 
> 		- Chris
> 
>

---

From: Chris Newman <[email-masked]>
Date: Mon, 09 Feb 1998 10:29:42 -0800 (PST)

As this issue doesn't seem to be too controversial, I'll ask IANA to
remove the reference to GSSAPI in the DNS WKS protocol registry, add a
link the gssapi-service-name registry to their top-level registry list,
and add the "ftp" service defined in RFC 2228. 

On Fri, 6 Feb 1998, Linn, John wrote:
> scope broader than an individual protocol.

I do see the appeal of using "host" as "the fallback service name
referring to all services at the host."  But this is a pretty serious
interoperability issue, since it impacts all implementations of all 
servers and clients which use the host-service name form. I don't think
it's appropriate to make an incompatible change to the RFC 2228 fallback
rule from "ftp" to "rcmd" in a registry list.  If it's going to be done,
it should be documented in a standards track RFC.

>  Since it doesn't seem to

Sounds reasonable to me.  While cross-protocol service names don't bother
me, cross-service service names are a serious interoperability issue in
my book.  Seems like somebody needs to write some proper IANA
considerations for 2078bis, and probably define "host" there.

		- Chris