[messaging] Whiteout Secure PGP Key Sync

[Tankred Hase]

> I thought I'd mention this on-list, actually, for developers of other
> commercial applications: The Affero GPLv3 was written to be helpful in this
> case: it extends the GPL to server-side and web apps (users -- and thus the
> original developers -- have a right to the source). (And there's no
> particular need to release *all* of your app's source under that, even.)

Dual-licensing with AGPLv3+proprietary was discussed. I would be
interested in how this would allow for more community activity, since
it would allow non-commercial forks. Nothing decided on this front yet
though.

>> There is no easy answer here. I myself am a big fan of open source, but
>> most FLOSS tools like GPG tools cannot provide what many non-technical users
>> need, like professional support, hosting and other services. We're
>> explicitely building a commercial product that people will want to pay for,
>> since we're (hopefully) providing value to our users
>
>
> I agree completely. Alas, the story of open-source crypto projects (w.r.t.
> being adequately funded) has not historically been good. So I'm hoping you
> manage to find a business model that works.

Thanks :)

>> Not sure what attack you're suggesting. Can you provide a more elaborate
>> example.
>
>
> Okay, sure. I'm NSA/FBI/BND/ANSSI. I want a user's private key. So I hack
> into your servers, and get every encrypted private key you store.
>
> What do I do next? Is just taking a picture[*] of the user transferring the
> master key via the QR code option sufficient to decrypt what I got from your
> server. Or do I also have to MitM a connection between their device and your
> server? (The answer is hopefully the latter.)
>
> [*] Note that, for QR codes, it's easy to do this at large scale. E.g., do
> image processing of security camera footage.

What would protection against MitM add, if the attacker has full
access to the server as well as camera footage of the user endpoint?

I would also like to point out that the PGP key is passphrase
protected as well. The attacker would also need to know the
passphrase.

>> Currently only certs used for our IMAP/SMTP stack are pinned, which is why
>> you see a google ca for gmail. Since chrome support ssl pinning for the
>> https stack, we might add pinning for requests to our *whiteout.io servers
>> in a later version.
>
>
> Well, at the very least, get on the pinlist at some point.

Yes. That's in the backlog... we just haven't gotten to it yet. One
problem here is that pinning would work on Chrome, but not e.g. iOS.
So no silver bullets there.

>> The code and certs are deployed/installed via a packaged app (not
>> webserver). More on this here:
>> http://tankredhase.com/2014/04/13/heartbleed-and-javascript-crypto/
>
>
> (Right, sorry, I was unclear: I thought that your endpoints might be running
> on Appspot, and therefore that was your pin to the Google CA Appspot uses.)

Ok, Gotcha. That would obviously solve pinning in Chrome. But we're
not hosting on Appspot.

Kind regards,
Tankred

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