[messaging] keys.gnupg.net returns random pages

[Daniel Roesler]

Thanks for the response! During the cryptoparty, I learned a lot about HKP.

First, you're right that the DNS entry for updates often with
different A and AAAA Records, and that makes sense for the
volunteer-operated, multi-organizational infrastructure.

Second, this thread was initiated by a UX misunderstanding. When I
publish my public key, I ran the following command:

$ gpg --send-key 72EFEE3D
gpg: sending key 72EFEE3D to hkp server keys.gnupg.net

I was curious about keys.gnupg.net, so I copied the domain into a
browser, and was met with a scary landing page[1]. As to be expected,
I was concerned and started asking around, and others confirmed
something strange was happening[2].

The big thing that we were missing was that HKP operates over port
11371. If we were to have visited http://keys.gnupg.net:11371/, it
would have been the standard keyserver interface. Most servers mirror
that interface on port 80, but some servers have entirely different
webservers listening to port 80 (like the one with the scary landing
page).

I don't think that there's anything particularly insecure with this
DNS round robin setup, but it is very confusing for new users and
comes off as pretty sketchy. I know we can't and shouldn't enforce
that the keyserver should have a port 80 mirror, so how about changing
the UX to set expectations better?

Would the experience be better if "gpg: sending key 72EFEE3D to hkp
server keys.gnupg.net" was changed to "gpg: sending key 72EFEE3D to
hkp server keys.gnupg.net:11371"? Would it be better to show the IP of
the particular server that was used (e.g. "104.37.104.142:11371")?

-Daniel

[1] - https://i.imgur.com/O1aRXUA.png
[2] - https://twitter.com/NotRhodey/status/523660838893133824

On Sun, Oct 19, 2014 at 6:21 PM, Andy Isaacson <adi at hexapodia.org> wrote:
> On Sat, Oct 18, 2014 at 10:25:19PM -0700, Daniel Roesler wrote:
>> Howdy all, as always, if this is off topic, please direct me to the
>> appropriate mailing list.
>
> Something more like cpunks or some gnupg list would probably be more on
> topic.
>
>> Today I randomly visited http://keys.gnupg.net/, which appears to be
>> loading various compromised and broken pages[1][2], which was
>> confirmed by Zaki and Rhodey[3].
>
> keys.gnupg.net is a DNS round robin pointing to several hosts run by
> different parties.  This works just fine if you depend on the PGP Web of
> Trust for your authenticity and privacy, because mutually untrusting
> hosts in different administrative domains can provide assertions and
> ones that misbehave can be ignored or whatever.
>
> This model works much less well when crossed with the TLS X.509
> certification scheme, where a Trusted Third Party is expected to attest
> that a specific Private Key entitles the posessor to complete control of
> traffic associated with the given name.
>
> As a result, https:// and hkps:// protocols are are more or less
> fundamentally incompatible with volunteer-operated multi-organizational
> load sharing schemes based on DNS round robin records.
>
>> keys.gnupg.net is the default keyserver for which GPG on my Xubuntu
>> 14.04 sends and receives keys, so I'd presume this is not expected
>> behavior.
>
> The catch is that most Internet users now assume that HTTP is the only
> (or at least the preeminent) way to use the internet.  DNS round robin
> application schemes harken back to an earlier, multiprotocol Internet.
>
> -andy