Paul Hammant wrote on Wed, 15 May 2019 12:39 +00:00: > I'm suggesting phasing out SHA1, and during a v1.x to v1.x+1 upgrade > do a migration script for all content to gain (say) BLAKE2 hashes > *instead*, and for that install, client's with incompatible hashing > are rejected. > > There are alternates too, where up to a moment in time a repo has > SHA1s, and thence after has some other algo.
Hold your horses. *Why* are you proposing to phase out sha1? For example, is it out of general concerns that a cheap preimage attack will be discovered before long? Or do you see a specific way to use the new attack against working copies or repositories? Or something else? Once we've established that, we can discuss *what* to do... but you're getting ahead of yourself by discussing *how* to phase off sha1 before we understand *that* (arguendo) that's the right course of action. Cheers, Daniel
