Subject: IETF 53 SASL bar BoF minutes

From: "RL 'Bob' Morgan" <[email-masked]>
Date: Sun, 24 Mar 2002 23:54:50 -0800 (PST)

Respectfully submitted,

 - RL "Bob"

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SASL bar BoF at IETF 53, 2002-03-18

Some SASL-interested folks met, yes, in the entirely too smoky back of
the bar at the Minneapolis Hilton.  Attendees included at least:
Alexei Melnikov, Kurt Zeilenga, John Myers, Larry Greenfield, Chris
Newman, Marshall Rose (who graciously paid for the drinks), RL "Bob"
Morgan, Walter Wong, and several others whose names I didn't get.
Here are some notes.  I apologize for any issue-mangling.

John will send the latest in-process draft revision of
draft-myers-saslrev to the list, in glorious nroff (done).  This will
update saslrev-01 when it's ready.

There was discussion of the buffer size issue.  Some application
protocols limit how much data can be sent in an application PDU, eg
NNTP and SMTP.  This is a problem if a security mechanism needs to
send more data than this in its message.  One approach is to say that
app profiles need to specify methods to send unlimited amounts of
data, but this opens up implementations to DoS attacks.  So a
"minimax" number needs to be picked: application profiles need to be
able to send at least N bytes, and mechanisms need to be able to work
while sending at most N bytes (or potentially fail with some compliant
app implementations).  A number of 4K was proposed, but this could
easily be too low if a security mechanism sends certificates, as some
do.  The group settled on 64K as being reasonable for this.  This
means 64K of decoded data, hence potentially more on the wire if, say,
base64 encoding is used.  In any case wording should be added to warn
implementors about potential DoS attacks.

The other main issues are about the authorization identifier.  The
saslrev doc specifies default handling of the authzid, so an
application profile only has to say something about it if it wants to
modify this default (but it can do this if needed).  It also specifies
the use of ISO 10646 and Unicode normalization form KC for authzids.
Question:  can an app profile (eg SACRED) mandate a null authzid?
Sure, though perhaps short-sighted.  Question:  can an app profile
say that authzid is, or can be, ignored?  No, not a good idea, if
authzid is present it has to be used for authorization, or the
authentication is rejected.

draft-josefsson-base-encoding-03 specifies a BASE32 that is different
from the BASE32 used in the GSSAPI draft for encoding mechanism OIDs,
so it will be proposed to change the SASL-GSSAPI doc to use the
josefsson-specified version.  May be a compatibility issue if anyone
has implemented to that draft.  Also the josefsson doc is too liberal
in accepting non-alphabet chars in input string; should say "reject
unless app profile specifically permits".

The Digest-MD5 SASL mechanism doc:  Chris Newman will either finish it
soon or hand it off to someone else who will.

ANONYMOUS and PLAIN mechanisms:  Kurt will do them both in one
document.  PLAIN will specify "must only use with appropriate data
protection", eg TLS.  EXTERNAL will stay in the base SASL document.
Note that the LDAP authmeth document shouldn't deprecate the use of
PLAIN.

There was discussion of sequence of START-TLS vs SASL AUTH.  Different
protocols do this differently (LDAP permits whatever, BEEP says TLS
comes first), so probably nothing to say in base doc.  Of course
specs also don't say much about TLS transitions in mid-stream.

Still need a Working Group?  Doesn't seem like it.  Need a T-shirt:
"SASL: WG free since 1997".  API doc should be Informational when it's
done.  It seems reasonable to complete the above core docs in the next
few weeks, have a "BoF last call" (or mailing-list last call), then
send to IESG.  (But, at SAAG, Jeff Schiller said the WG will be
started after all ...)

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From: Alexey Melnikov <[email-masked]>
Date: Wed, 27 Mar 2002 07:48:59 -0700

> soon or hand it off to someone else who will.

Most likely to me.

> comes first

Actually BEEP says that you can't have both.

> ), so probably nothing to say in base doc.  Of course

Alexey Melnikov
__________________________________________
R & D, ACI Worldwide/MessagingDirect
Richmond, Surrey, UK
Phone: +44 20 8332 4508

I speak for myself only, not for my employer.
__________________________________________

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From: Marshall Rose <[email-masked]>
Date: Wed, 27 Mar 2002 09:01:43 -0800

> Actually BEEP says that you can't have both.

no, beep says that if you're running TLS and if you decide to do sasl you may not negotiate a security layer... it also says that if you're going to do TLS, you have to do it before you do anything with SASL.

/mtr

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From: Tony Hansen <[email-masked]>
Date: Wed, 27 Mar 2002 23:18:57 -0500

> Here are some notes.  I apologize for any issue-mangling.

Pete Resnick, myself

> send to IESG.  (But, at SAAG, Jeff Schiller said the WG will be

If we finish the mailing list last call and get the docs sent to the
IESG before the next meeting, there won't be any need to start the WG.

	Tony Hansen
	[email-masked]

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From: "Raif S. Naffah" <[email-masked]>
Date: Thu, 28 Mar 2002 20:48:44 +1100

does this mean we don't need to work on SASL-SRP or others; eg. SM2?

cheers;
rsn

----- Original Message ----- 
From: "Tony Hansen" <[email-masked]>
To: "SASL list" <[email-masked]>
Sent: Thursday, March 28, 2002 3:18 PM
Subject: Re: IETF 53 SASL bar BoF minutes

> > ...

---

From: Alexey Melnikov <[email-masked]>
Date: Thu, 28 Mar 2002 06:03:44 -0700

> > Here are some notes.  I apologize for any issue-mangling.

Magnus Nystrom.

> IESG before the next meeting, there won't be any need to start the WG.

WG might end up taking on other SASL related stuff.

Alexey Melnikov

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From: Alexey Melnikov <[email-masked]>
Date: Thu, 28 Mar 2002 06:18:02 -0700

> does this mean we don't need to work on SASL-SRP or others; eg. SM2?

No, it doesn't.
I don't think DIGEST-MD5 will be ready before the next meeting. I think we
just carry on with what we are doing and let WG form simultaneously.

Alexey Melnikov

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From: Alexey Melnikov <[email-masked]>
Date: Thu, 28 Mar 2002 09:40:31 -0700

Marshall Rose wrote:

> no, beep says that if you're running TLS and if you decide to do sasl you may not negotiate a security layer...

That is what I meant (i.e. "you can't have both [security layers present simultaneously]").

> it also says that if you're going to do TLS, you have to do it before you do anything with SASL.

Alexey Melnikov

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From: Alexey Melnikov <[email-masked]>
Date: Wed, 27 Mar 2002 07:48:59 -0700

Most likely to me.

Alexey Melnikov

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From: Marshall Rose <[email-masked]>
Date: Wed, 27 Mar 2002 09:01:43 -0800

/mtr

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From: Tony Hansen <[email-masked]>
Date: Wed, 27 Mar 2002 23:18:57 -0500

Pete Resnick, myself

	Tony Hansen
	[email-masked]

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From: "Raif S. Naffah" <[email-masked]>
Date: Thu, 28 Mar 2002 20:48:44 +1100

cheers;
rsn

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From: Alexey Melnikov <[email-masked]>
Date: Thu, 28 Mar 2002 06:03:44 -0700

Magnus Nystrom.

Alexey Melnikov

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From: Alexey Melnikov <[email-masked]>
Date: Thu, 28 Mar 2002 06:18:02 -0700

No, it doesn't.

Alexey Melnikov

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From: Alexey Melnikov <[email-masked]>
Date: Thu, 28 Mar 2002 09:40:31 -0700

Alexey Melnikov