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Re: [openpgp] Expected client behaviour ambiguity in signature verification

Andrew Gallagher <andrewg@andrewg.com> Thu, 07 July 2022 22:00 UTC

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From: Andrew Gallagher <andrewg@andrewg.com>
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Date: Thu, 07 Jul 2022 23:00:29 +0100
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To: Jonathan McDowell <noodles@earth.li>, openpgp@ietf.org
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Subject: Re: [openpgp] Expected client behaviour ambiguity in signature verification
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> On 7 Jul 2022, at 19:55, Jonathan McDowell <noodles@earth.li> wrote:
> 
> On Thu, Jul 07, 2022 at 07:39:33PM +0100, Andrew Gallagher wrote:
>> 
>> What should an implementation do in the case where these 16 bits are
>> incorrectly set but the signature is otherwise valid? It is implied that
>> failing hard on this test is allowed (otherwise why bother?) but it is
>> not specified as MUST or even SHOULD.
> 
> I know the GitHub key has this problem. I ended up dropping the check
> from onak as a result, but I'd be really interested to know what client
> software is generating the incorrect keys.

I wish it was as simple as dropping this check from Hockeypuck, but go-crypto doesn’t make it optional. It might in fact be easier to forcibly correct the error on submission, but that opens another question - what will (and what SHOULD) implementations do when faced with two conflicting signature packets that are identical in their signed data but differ in their unsigned components?

A

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