Foiling MITM attacks on source and ports trees

cpghost cpghost at cordula.ws
Sat Jan 3 18:44:42 UTC 2009


On Sat, Jan 03, 2009 at 01:38:25AM +0000, RW wrote:
> On Fri, 02 Jan 2009 17:30:12 +0000
> Vincent Hoffman <vince at unsane.co.uk> wrote:
> > Admittedly this doesn't give a file by file checksum
> 
> That's not really a problem, it's no easier to create a collision
> in a .gz file than a patch file. 
> 
> The more substantial weakness is that the key is verified against a
> hash stored on the original installation media. If someone went to the
> trouble of diverting dns or routing to create a fake FreeBSD site they
> would presumably make it self-consistent down to the ISO checksums.

That's why I suggested that the list of checksums be digitally signed
by a private key belonging to The FreeBSD Project. It is assumed that
getting the corresponding public key would be possible by other means
not susceptible to MITM attacks (e.g. through endless replication all
over the net, fingerprint in books etc...).

-cpghost.

-- 
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