> During a report of the german news-website "Heise.de" experts
> (Christian Rechberger and Christophe De Cannihre) on the Crypto2006 (a
> conference) talked about at least one practical attack aggainst SHA-1.

Are you referring to a collision attack, or a second preimage attack?

i.e. can an attacker produce two files with the same SHA-1 hash,
or can they construct a file that matches a given SHA-1?

There's a huge difference, especially in the case of the ports tree.

> The Ports-System uses MD5 and SHA1 wich are both now, at least for
> cryptographic experts, brocken and not realy trustfull anymore. So 2 of
> 3 Algorithms used by the Ports-System are in fact weak.

Again, there's a distinction between the two attacks. A very important one,
since a collision attack doesn't really help a would-be ports-tree attacker.

> I think one of the Problems is that OpenSSL provides just a wide range
> of unsecure HASH-Functons like MD2/4/5 SHA and now also SHA1.
> The only algorithm considred as secure is the Ripe-MD (or rmd)
> algorithm.

says who?

> So no matter what you`ll do (as developers of OpenBSD) the question
> came up one more time and I think some peoples should start looking for
> alternative HASH-Algorithms used in the Ports.

And I think people should start looking for secure hash algorithms,
period, but that's going to take a while. A LONG while.

-kj