Re: [openpgp] New fingerprint: to v5 or not to v5

Werner Koch <wk@gnupg.org> Thu, 08 October 2015 15:46 UTC

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From: Werner Koch <wk@gnupg.org>
To: Peter Gutmann <pgut001@cs.auckland.ac.nz>
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Date: Thu, 08 Oct 2015 17:42:01 +0200
In-Reply-To: <9A043F3CF02CD34C8E74AC1594475C73F4B2D5B1@uxcn10-5.UoA.auckland.ac.nz> (Peter Gutmann's message of "Thu, 8 Oct 2015 15:16:50 +0000")
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Cc: Watson Ladd <watsonbladd@gmail.com>, Phillip Hallam-Baker <phill@hallambaker.com>, Daniel Kahn Gillmor <dkg@fifthhorseman.net>, IETF OpenPGP <openpgp@ietf.org>
Subject: Re: [openpgp] New fingerprint: to v5 or not to v5
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On Thu,  8 Oct 2015 17:16, pgut001@cs.auckland.ac.nz said:

> X.509 has been using this mechanism for about twenty years without any
> problems.  Sure, someone could do that, but what would they gain by it?  The

YMMV: I have seen serial number re-use for different keys done by
official CAs more than once.

>>I call this corrupt data.  The self-signature would not verify and thus the
>>key is unusable.  Time to remember where you stored the backup.
>
> It's not corrupted, someone just updated their key info, the signatures on the

What do you mean by "key info".

> new key data are all valid.  The fact that the exact same key that was used
> earlier, with the exact same name/email address attached to it, now has a
> totally different identifier associated with it, is a problem with how PGP
> identifiers are handled.  No data corruption has taken place.

You mean the binding signatures verify okay but the key is different?
If that is the case you found a bug in the software.  You can't change
the creation date, the key material, the user id or the hashed signature
subpackets without invalidating the corresponding self-signature.


Shalom-Salam,

   Werner

-- 
Die Gedanken sind frei.  Ausnahmen regelt ein Bundesgesetz.