Subject: Re: V5 signatures

From: "John W. Noerenberg" <[email-masked]>
Date: Wed, 7 Jul 1999 12:07:33 +0900

At 2:11 PM -0700 6/19/99, Jon Callas wrote:
>Bill, the only difference between a V4 sig and a V5 sig is changing the
>length field. The only place that really needs these is standalone
>signatures, (and arguably not even them -- you are after all making that
>very argument).

Well, you have to identify the signature type, too.  However the 
changes sound minimal.

How many implementors are interested in supporting this?  What bad 
thing happens when an implementation meets a v5 packet it doesn't 
know how to swallow?  Will implementations be able to skip over them?

john noerenberg
[email-masked]
   ----------------------------------------------------------------------
   The man that can most truly be accounted brave is he who best
   knows the meaning of what is sweet in life and what is terrible,
   and then goes out undeterred to meet what is to come.
   -- Pericles, "Funeral Oration", 479 B.C.
   ----------------------------------------------------------------------

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From: "William H. Geiger III" <[email-masked]>
Date: Wed, 07 Jul 1999 11:03:00 -0500

In <v04205504b3a8704d9f84@[199.106.106.131]>, on 07/07/99 

>Well, you have to identify the signature type, too.  However the  changes
>sound minimal.

>How many implementors are interested in supporting this?  What bad  thing
>happens when an implementation meets a v5 packet it doesn't  know how to
>swallow?  Will implementations be able to skip over them?

I don't know what other developers are doing but IMHO no program should
crash because of input data. It is a design failure if they do. Then again
in this day and age where program quality takes a back seat to marketing
it is an all too common problem. :(

-- 
---------------------------------------------------------------
William H. Geiger III  http://www.openpgp.net
Geiger Consulting    Cooking With Warp 4.0

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Hi Jeff!! :)
---------------------------------------------------------------

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From: Werner Koch <[email-masked]>
Date: Wed, 7 Jul 1999 18:43:19 +0200

> Well, you have to identify the signature type, too.  However the 

I still believe that putting large amounts of data into a signature
packet is not a good design - and therefore I don't think we really
need this.

What we need more, is an agreement on how to do the MDC packet and to
clarify some blocksize>64 issues.

> know how to swallow?  Will implementations be able to skip over them?

Sure, that's why we have version numbers.

-- 
Werner Koch at guug.de           www.gnupg.org           keyid 621CC013

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From: Jon Callas <[email-masked]>
Date: Wed, 7 Jul 1999 23:44:39 -0700

At 8:07 PM -0700 7/6/1999, John  W. Noerenberg said:

An implementation is flawed (in my opinion) if it does something horrid
with a future message. If a current implementation finds a V120 signature
today (which is either a data error, or evidence of time travel), it
shouldn't bus error, it should make some appropriate whimper. It's up to
the implementation what they do. Ignoring it is a fine response to my mind.
Other people may have other opinions. If they're implementors, they get to
do more than pontificate.

	Jon

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From: Paul Koning <[email-masked]>
Date: Thu, 8 Jul 1999 09:55:59 -0400

>>>>> "Jon" == Jon Callas <[email-masked]> writes:

 Jon> An implementation is flawed (in my opinion) if it does something
 Jon> horrid with a future message. If a current implementation finds
 Jon> a V120 signature today (which is either a data error, or
 Jon> evidence of time travel), it shouldn't bus error, it should make
 Jon> some appropriate whimper. 

I'd put it more strongly than that.  Any implementation of any
protocol is defective if it crashes when presented with ANY message,
including messages deliberately and maliciously constructed.  It's
always allowed to complain, or toss the message, or stuff like that,
but "you sent me an invalid message" will never excuse a crash.

	paul

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From: "John W. Noerenberg" <[email-masked]>
Date: Sat, 10 Jul 1999 06:52:45 +0200

>but "you sent me an invalid message" will never excuse a crash.

Crashing is right out.  But misinterpretation and wandering off into 
some odd corner mumbling to oneself isn't crashing, but equally 
useless.  Protocol changes that provoke massive misbehavior on the 
part of deployed implemenations aren't a real good idea.

If implementors don't squawk, or at least do no worse than shrug 
indifferently, I'm at ease.