Public SourceMage Discussion List

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

Eric,

You're now trying to mislead everyone even further by calling a hash value a
signature. It's the same tactics you guys are trying to use to redefine the
purpose of signature to mean something else. "Correct wording" that you
describe will not be read by anyone who ought to read it; even if it were, it
would be contrary to what most people are used to.

At least try to answer one question: find me a major OSS project that has a
policy disclaiming authenticity and non-repudiation of the code signed 
by their
GPG signatures, and claiming only integrity must be verified. You and 
Jeremy and
others keep ignoring the questions I ask and try to find nonexistent 
gaps in my
logic, and that's not how I like the discussions to be held.

If you have anything else to say, I'm listening. Playing games with 
words is not
the best use of my time as well as yours.

Sergey.

Quoting Eric Sandall <eric AT sandall.us>:

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> On Tue, 30 Aug 2005, Sergey A. Lipnevich wrote:
> > Quoting Eric Sandall <eric AT sandall.us>:
> >
> > > We're not asking you to sign your soul away. I cannot see how you are
> > > completely missing the point of what we're saying. You are /not/
> > > signing tarballs saying that you have audited the code (unless you
> > > have, then you can say that), nor that you guarantee this tarball
> > > won't break your computer, nor that this tarball has no viruses,
> > > trojans, worms, wife beaters, etc. in it, nor that this tarball has no
> > > bugs, nor many other things. The only thing the GPG signatures are for
> > > is to replace the dependency on specific hashsums (md5sum, sha1sum,
> > > etc.) and to allow for trusting the vendor's as much as we currently
> > > trust them (I don't recall anyone doing audits of source code of any
> > > packages for SMGL and no one complained that signing (yes, it's
> > > technically a signature) with the md5sum said that you had done that).
> >
> > Let me explain it differently because we keep walking around the same
> > issue. The
> > users don't care no matter how you describe your use of signatures. I
> > as a user
> > don't care how for example Apache Software Foundation describes their use of
> > signatures. When I, as a user, see a signature, I assume that they vouch for
> > contents of file, not just this file's integrity. That's how I treat
> > signatures. Tell me if I'm wrong, but you better have a good reason for it.
> > Maybe I as a user can go and read the authors' key policy, but 
> > ususally I'd do
> > that only when the actual problem comes up that prompts me to do so.
> >
> > Even more so, Apache for example doesn't have any explanation. I tried
> > searching
> > the site and I can't find a policy. Please find me a policy on some 
> > major OSS
> > vendor site that says: GPG signatures are used for integrity only 
> > and do *not*
> > mean non-repudiation and authenticity *of the code*. This file for
> > example says
> > "signatures are used for code signing:"
> >
> > http://svn.apache.org/repos/asf/lenya/trunk/KEYS
> >
> > Did I make myself clear on why I don't care about what's written on our
> > Web site
> > about signatures, and nobody else does? I hope I did. Please understand that
> > *this* point is the beef of my argument. I tried to express it as item
> > #4 of my
> > original email, which was not understood well.
> >
> > Now, as a maintainer, I am worried about perceived meaning of 
> > signatures. I do
> > not want my users to have a false feeling of security because the tarball is
> > signed. Moreover, I am not taking the responsibility of signing 
> > things I don't
> > read, even though you try to tell me that we have a disclaimer. With or
> > without
> > this disclaimer, I can't do that.
> >
> > Finally, I'm saying, and we agree on that at least with you Eric, that hash
> > values do allow for detection of integrity problems. I argue that they are
> > sufficient, and there's no reason to go further. If package authors 
> > sign their
> > packages, we support GPG verification, otherwise all bets are off. 
> > But please
> > understand that this is just a secondary reason of why I can't sign 
> > a tarball.
> > If there were no such thing as hash value, I couldn't sign an alien tarball
> > anyway.
> >
> > Finally, Seth here is telling us that signatures do not mean security.
> > Regardless of whether I agree or disagree with this, please understand that
> > signatures are perceived as means to provide additional layer of... what?
> > correct, *security*! Why do I think so? Let me put our friend Andrew on the
> > spot (I'm sorry Andrew, you made it too easy with your email to make my
> > point).
> > He recently wrote this:
> > https://lists.ibiblio.org/sympa/arc/sm-discuss/2005-August/011907.html
> >
> > Citing it: "This is part of my new security policy I'm implementing for
> > myself.
> > This key expires end of the year and I will issue a new one then."
> >
> > So, people do perceive digital keys as a means of security. Not the
> > only means,
> > of course, but definitely an important one. In the U.S., you can sign
> > your name
> > now with the help of digital signature. Not GPG I think. 
> > Nevertheless, in the
> > public eye digital signature is very much alike the real deal. You can't try
> > and change this meaning just by posting a disclaimer on the site.
>
> That doesn't mean that they see keys as /only/ for security, that's a
> fallacy if that's how your logic is working.
>
> > The question is, are we clear now on what I am objecting to?
>
> I think so. You're objecting to using something use see as only
> allowable for one task (GPG signing saying I verified everything
> inside this signage), where we are saying we can use it for whatever
> we say we're using it for.
>
> I don't think users will be confused, especially if we word it
> correctly. Most probably won't even notice the difference (other than
> faster checking since we no long uncompress the tarball to verify, but
> that goes for the new SOURCE_HASH as well) until they get a corrupted
> tarball and see that there was a GPG signature instead of an md5sum
> signature that failed. Note: md5sum /signature/. That's basically what
> an md5sum is: a signature. Same with sha{1,256,512,infinity*42)sum and
> gpg.
>
> This is where I'm having the problem with your argument. We're
> replacing one type of signature (specific hashsum (e.g. md5, sha, blah
> blah) with a hashum agnostic signature (gpg, currently using sha512,
> but easily changed if that is easily broken). You seem to be trying to
> say that the /only/ use for GPG is to say that we've checked over and
> agree with all the contents of the signed file and that users will
> become confused if we use any other method. What others have pointed
> out is that GPG is used for other methods (the kernel.org people don't
> say there are no bugs in the kernel sources they've signed, but that,
> if you have the correct signature and it verifies the tarball you are
> getting the /same/ tarball that they signed and uploaded. Nothing
> more).
>
> When I sign this e-mail I'm not saying I agree with everything in it
> (as I obviously am disagreeing with your point ;)) and that there are
> no errors in it (me fail English?), but that I sent this e-mail and,
> if your e-mail reader verifies my GPG key, that this is the same
> e-mail I intended you to receive and it hasn't been modified.
>
> - -sandalle
>
> - --
> Eric Sandall                     |  Source Mage GNU/Linux Developer
> eric AT sandall.us                  |  http://www.sourcemage.org/
> http://eric.sandall.us/          |  SysAdmin @ Inst. Shock Physics @ WSU
> http://counter.li.org/  #196285  |  http://www.shock.wsu.edu/
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