Public SourceMage Discussion List

["Sergey A. Lipnevich" <sergey AT optimaltec.com>]

Quoting Eric Sandall <eric AT sandall.us>:

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> On Mon, 29 Aug 2005, Sergey A. Lipnevich wrote:
> > Quoting Seth Alan Woolley <seth AT positivism.org>:
> >
> > > DRAFT, although this is one case where we're actually moving on it
> > > quickly, so it's more of a last call for objections.
> >
> > So here goes: I object.
> >
> > 1. Hash collision is not a problem when it comes to source tarballs, 
> > so please
> > don't use it as a reason to switch to signatures. We could've as 
> > easily hashed
> > them with CRC32 or with 10K-bit hash. *Either* way provides *no* security.
>
> Care to explain? The nice part about GPG is that we can change
> hashsums without changing which tool (GPG) we're using.

The reasoning on why GPG signing must be mandatory is convoluted. I would like
to remove this particular reason from the list, because it's simply 
wrong. Hash
collision doesn't mean we have to move to GPG signatures. It doesn't 
consitute a
security hazard or absence of it.

> > 2. There's no way I can sign a bunch of code I didn't read through and
> > understand. It's an impossible task in a distribution, so it's 
> > shorter to say
> > that I can't sign a bunch of code, period.
>
> You must have forgotten to read the prior conversations. We are /not/
> guaranteeing that these files are trojan/virus/malware/whatever-free.
> What we are guaranteeing is that the tarball the user downloaded is
> the same as the one the guru tested with. Nothing less, nothing more.

So let's use the appropriate means of soing that. Hash is appropriate and
sufficient, GPG signatures are too much.

> > 3. Let's be frank Seth, tarballs that you, or anyone else besides 
> > the authors,
> > signed are as *insecure* as they were before you did that. It didn't format
> > your hard drive? Good for you. Maybe it's designed to format only *mine*. Or
> > the drive of the guy who works for CIA ot Chinese government. You don't know
> > that.
>
> We have that problem now. Your point?

My point is that regardless of the disclaimer, we're accepting responsibility
for what we sign. I don't want this responsibility. Moreover, the disclaimer
doesn't change perception: you signed it, so you know a) it's good, b) what's
inside, c) it's not malicious. But a-c are relative and are very difficult to
ascertain.

> > 4. Combination of #2 and #3 leads me to believe that we do not provide *any*
> > additional security over unsigned tarballs, so let's focus on *integrity*.
> > Integrity is *perfectly* verified by the hash. Stronger hash if 
> > necessary, but
> > nevertheless a hash. Non-personified piece of information.
> > 5. What people keep saying on the list amounts to: let's call it blue even
> > though it's black. Meaning, let's call GPG signature a means to verify
> > integrity even though it's a means to verify source and integrity. I 
> > don't buy
> > that.
> >
> > Don't get me wrong, I believe that PGP and GPG are one of the most 
> > overlooked
> > technologies of the present time, in the light of PKI having so many
> > unresolved
> > and abandoned issues. So, I support use of GPG signatures, but for 
> > the correct
> > purpose. Verifying integrity of the source tarballs is not a sufficient
> > purpose.
> >
> > Sergey.
>
> You seem to have missed the entire conversation. That's exactly what
> we've been saying the entire time and we've corrected people who
> posted misunderstandings: GPG is being used to verify the tarball is
> what the guru used, nothing more, nothing less.

No I didn't. And my answer to this is as I said before: you're trying to
substitute a different meaning for something that already has a 
meaning. Please
read my original item #4. Using Jeremy's analogy, signing an email 
doesn't mean
that you always agree with it, in 10 years or otherwise. But, it *does* mean
that whatever is written is coming from *you* and you vouch for it. If you
wrote that you wanted to rob a bank, in ten years you might regret it, 
but your
malicios intent will be beyong doubt.

Moreover, in Jeremy's analogy with mail package and a neighbor, I think 
now the
package corresponds to a tarball, and our *spell* corresponds to a wrapping,
backtrace, etc. So, I would agree to sign the *spell* that I altered, but not
the *source* coming from a 3rd party web site.

Sergey.