[pacman-dev] md5sum's aren't used as cryptographic algorithm? (was: $ARCH suffix on packages)
roman.kyrylych at gmail.com
Wed Oct 11 16:57:45 EDT 2006
2006/10/11, Jason Chu <jason at archlinux.org>:
> On Wed, 11 Oct 2006 10:57:53 -0500
> "Aaron Griffin" <aaronmgriffin at gmail.com> wrote:
> > b) I don't feel that anything is gained from using sha1sums. md5 is
> > the defacto file integrity check. We're not using md5 as a
> > cryptographic algorithm, we're checking file integrity
> I talked to Judd about this one. I'd noticed it while at LinuxTag a
> couple years back...
> While, on the surface we use md5sums to check file integrity, during
> building we use it to verify that two downloads (at different time
> periods) are the same. In this situation, it's possible to craft a
> malicious tarball that matches the md5sum but has a different payload.
Yes, there were few security papers posted about MD5 collisions and
how to use them.
> JGC was the one who suggested we use md5sums and sha1sums together
> because it's much more difficult to craft something malicious that
> matches both of them. I wrote a patch for makepkg a long time ago, but
> Judd didn't accept it because sha1sums were a lot longer and looked
> ugly in a PKGBUILD.
Mmm... I don't think that using md5sum & sha1sum at the same time will
make things more secure. md5sum will not matters in that case, because
security will depend on the strongest part in such case, which is,
I propose to use SHA-512 instead which is basically a stronger version of SHA1.
I have much practical experience and theoretical knowledge to say that
this will be the best choice in terms of both security and simplicity
Roman Kyrylych (Роман Кирилич)
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