Re: [Tails-dev] GUI for encrypted volumes from LUKS/TrueCryp…

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Author: sajolida
Date:  
To: The Tails public development discussion list
Subject: Re: [Tails-dev] GUI for encrypted volumes from LUKS/TrueCrypt container files
intrigeri:
> sajolida wrote (20 Mar 2015 12:34:35 GMT) :
>> I think that our long-term objective is to have people move out of
>> using TrueCrypt technologies in general (be it the software, the
>> volumes, or the containers).
>
> Now you make me curious: why do you think we should get rid of the
> TrueCrypt on-disk format?


I was saying this because I thought it was our vision when getting rid
of TrueCrypt, but I have no strong argument against TrueCrypt on-disk
format as such myself. My understanding was basically that we had no
good reasons for supporting it as we had LUKS already.

> The way I see it, we're stuck between a rock and a hard place:
>
> Ideally we'd like to be able to fully replace TrueCrypt volumes (I'm
> assuming that I'm missing information that makes you think we should)
> with something else, but nothing equivalent exists yet. Sadly, I'm not
> aware of any plan (let alone serious effort) towards making this
> a reality, when one takes into account the need for:
>
>  - inter-operability (which I'm tempted to disregard as a dangerous
>    way to share data with an untrusted OS, but then if we don't
>    support TrueCrypt volumes at all, perhaps users who won't/can't
>    fully give up proprietary software will just be forced to either
>    store and share the very same data in cleartext, or to use
>    something less safe than Tails)

>
>  - "hidden" volumes (which may be a false promise in TrueCrypt, but
>    still people want that and AFAIK there's nothing even approaching
>    it, be it in terms of peer-review of existing production-quality
>    implementations)


Thanks to Jasper we can add "containers" to that list.

All those are usability and interoperability issues that have real but
non-obvious security implications (not in terms of crypto but in terms
of user scenario). I'm not really convinced by containers and hidden
volumes as such in the context of a pure Tails setup, so we're left with
interoperability as the most interesting feature.

> With this in mind, supporting the TrueCrypt on-disk format (even
> minimally) still makes sense for the time being IMO. I doubt we'll
> actively patch out the corresponding code from cryptsetup, so I take
> for granted that we'll keep this support in Tails as long as
> cryptsetup has it.


Agreed.

> We had good reasons to get rid of the TrueCrypt software itself, but
> no existing GUI for TrueCrypt volumes is satisfying right now, in the
> context of Tails.
>
> Now, of course a CLI-only interface isn't encouraging for Tails users
> to go on using TrueCrypt volumes. This has both advantages (as
> a long-term strategy, hopefully it'll encourage people to either fully
> replace TrueCrypt volumes with a better design), and drawbacks (until
> our fancy long-term plans are made real by $someone $some_day, Tails
> users have the choice between using something we claim we don't really
> support, with poor usability, and doing something even worse).
>
> So, the question I'm coming to is: assuming there *was* satisfying GUI
> support for the TrueCrypt on-disk format (in GNOME Disks, Nautilus,
> etc.), would we want to explicitly support that, or still depict it as
> a suboptimal feature, and call it unsupported because we think it
> should ideally be replaced by something else on the long term?


We have a long tradition of advertising only one tool for one job. So
what would we advertise TrueCrypt for? Exchanging encrypted data with
other operating systems? With big fat warnings? Maybe...

> In other words: how hard should we push for adding support for the
> TrueCrypt on-disk format in udisks and friends? (Until 15 minutes ago,
> I was convinced that it was the way to go, and prepared to go ping the
> right folks about it, but now you've planted some non-negligible
> amount of doubt in my mind, so I'm a bit lost in terms of strategy.)


Me too :)

--
sajolida