Re: Migrating away from SHA-1?
- From
brian m. carlson <sandals@crustytoothpaste.net>
- Date
- Apr 15, 2016, 01:50 UTC
- Message-ID
- <20160415015004.GB140502@vauxhall.crustytoothpaste.net>
- In-Reply-To
- <8722D9F3-8A42-4BF7-A945-305F483E8364@zytor.com>
On Tue, Apr 12, 2016 at 06:58:10PM -0700, H. Peter Anvin wrote:
Show 13 quoted lines
> On April 12, 2016 6:51:12 PM PDT, Duy Nguyen <pclouds@gmail.com> wrote: > >On Wed, Apr 13, 2016 at 5:38 AM, H. Peter Anvin <hpa@zytor.com> wrote: > >> OK, I'm going to open this can of worms... > >> > >> At what point do we migrate from SHA-1? > > > >Brian Carlson has been slowly refactoring git code base, abstracting > >SHA-1 away. Once that work is done, I think we can talk about moving > >away from SHA-1. The process is slow because it likely causes > >conflicts with in-flight topics. A quick grep shows we still have > >about 300 SHA-1 references, so it'll be quite some time. > > Well, at least it sounds like work is underway. That is a big deal.
Yes, it's a bunch of slow manual refactoring, and I've been busy as we've been doing house- and car-related things recently. I'll try to spend a little more time on it this weekend.
The first step is to convert all of the individual places that use unsigned char [20] to use struct object_id, which can then be extended to use different hash algorithms. There are also constants, GIT_SHA1_RAWSZ and GIT_SHA1_HEXSZ, that abstract the 20 and 40 values in the codebase so they can be changed in the future.
While this is a project I've been mostly working on, I have no objection to other people sending in a patch or series as they feel like it.
-- brian m. carlson / brian with sandals: Houston, Texas, US +1 832 623 2791 | https://www.crustytoothpaste.net/~bmc | My opinion only OpenPGP: https://keybase.io/bk2204