Public SourceMage Discussion List

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

Quoting Seth Alan Woolley <seth AT positivism.org>:

> size of tarball doing what exactly?

The first way that comes to mind to generate a hash collision is to add 
bytes to
the file until the collision is achieved. If we include both the hash 
value and
the tarball size in the DETAILS, we're drastically reducing chances of hash
collision going unnoticed.

> > This way, we will do exactly what is claimed on that Web page: sign package
> > receipt without signing the contents.
>
> a signature is merely an asymmetric encryption of a hash.

Technically, yes.

> What you propose is to make an asymmetric encryption of a hash which 
> includes a hash.
>
> Is this level of indirection that meaningful to you?

Yes. It's the same meaning as signing a package receipt for the neighbor,
without opening the contents.

> We're NOT doing that kind of validation.  Redhat signs their binaries
> and srpms -- are they attesting to the security?  Nope, just

Maybe. Can you prove otherwise? Where is the policy they use?

> transportation security.  In fact, Microsoft has been the greatest
> misinformer of the utility of digital signatures.  Digital signatures
> make not a secure system.
>
> FIPS 186, the DSA standard: http://www.itl.nist.gov/fipspubs/fip186.htm
>
> digital signatures = integrity, non-repudiatio

Good stuff. Please read my response to that here:
https://lists.ibiblio.org/sympa/arc/sm-discuss/2005-August/012133.html

I appreciate you going to all these lenghts to explain these things, but they
are not a deciding factor. This is a technical disucssion that does not 
reflect
how signatures are perceived by a wide public. I have all reasons to believe
that users will assign their own meaning to a signature, even knowing little
about PKI, PGP, or FIPS. Even people who don't know how a capacitor works use
electricity and AC current every day.

So, the bottom line is, I believe the compromise I suggest is a good one.
Thanks,

Sergey.