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Re: [openpgp] Enigmail XSA issue with WKD and HTTP authentication

Daniel Kahn Gillmor <dkg@fifthhorseman.net> Fri, 14 December 2018 23:13 UTC

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From: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
To: Werner Koch <wk@gnupg.org>, Hanno Böck <hanno@hboeck.de>
Cc: openpgp@ietf.org
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Date: Fri, 14 Dec 2018 17:59:52 -0500
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Subject: Re: [openpgp] Enigmail XSA issue with WKD and HTTP authentication
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On Fri 2018-12-14 10:02:46 +0100, Werner Koch wrote:
> On Fri,  7 Dec 2018 15:44, hanno@hboeck.de said:
>
>> I think it would be good if the WKD draft would be updated to clarify
>> that a client should never answer to any 401 authentication requests
>> from the server.
>
> Is this okay:
>
>   A client MUST not accept a HTTP authentication challenge (HTTP code
>   401) because the information in the Web Key Directory is public and
>   needs no authentication.  Allowing an authentication challenge has the
>   problem to easily confuse a user with a password prompt and tricking
>   him into falsely entering the passphrase used to protect his private
>   key or to login to his mail provider.

The explanation and justification part here is very clear, and i agree
it should be included.  But is "accept an HTTP authentication challenge"
the same thing as "make an HTTP authentication prompt visible to the
user" ?

how about something more like "a WKD client MUST treat an HTTP response
code 401 the same way it treats a 404…"

   --dkg

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