Subject: Esoterica (Was append writes)

From: Mike Eisler <[email-masked]>
Date: Mon, 19 Mar 2001 19:41:11 -0800 (PST)

"Neil Brown" <[email-masked]> writes

>     2/ authentication.  syslog would use nothing more than
>         reserved-port authentications.  NFS can (will in v4) give you
>         proper crypto security.  It would be a lot of work to add the
>         same to syslog

How hard is it to set up IPsec between a syslog client host and a
syslog server host? My understanding is that it can be enabled on
a per port basis. More than sufficient for syslog's host-based operational
model. NFS has a user-base doperational model, hence has more complex
security.

The logging example is strawman argument. What if my log requests
exceed buffer size on my application? The atomic append semantics
on local filesystems don't suffice? What if the log requests exceed the
NFS server's transfer size? In both cases, logging for end user is going
to have to use file locking.

> In summary, if O_APPEND is a valid filesystem operation it should be
> supported by NFSv4, and if not it should be removed from POSIX.

I like your standard for supporting a feature. So while we are at it,
lets support idempotent rename and link in NFSv4, or remove them from
POSIX too! After all if it's useless over the wire, it's useless on the
local filesystem.

Seriously, if people have solutions for APPEND that work, then let's
read about them; otherwise I don't see the point of this thread.

I do agree with you about the .nfs files in NFSv4. They should go away
in v4.0.

	-mre
	
p.s. While we are re-opening old cans of worms, anybody recall why
exclusive create semantics for directories, symlinks, and special
devices aren't in the NFSv4?

---

From: RJ Atkinson <[email-masked]>
Date: Tue, 20 Mar 2001 00:14:49 -0500

At 22:41 19/03/01, Mike Eisler wrote:
>a per port basis. More than sufficient for syslog's host-based operational model. 

For good or ill (I'm not following it closely), the IETF has 
a group working on standardising SYSLOG, with an intent 
to add "appropriate" security.  I do not know whether 
they are meeting this week.

>NFS has a user-based operational model, hence has more complex
>security.

(sidebar & free clue)
        IMHO, a clever NFS/Kerberos implementation would add the hooks
to use the Kerberos Key Distribution Centre (KDC) to distribute
Security Association information so that selected NFS sessions
could be authenticated with AH or encrypted with ESP.  The
Kerberos protocol details for this are (I think, not 100% sure)
being worked out in the KINK WG.  ESP and AH security associations
can be keyed per-user, per-host, or at several other granularities
without any changes to those protocols.
(end sidebar)

Ran