On 09/04/2020 02:18, Chris Murphy wrote: > On Wed, Apr 8, 2020 at 5:17 AM Johannes Thumshirn > <Johannes.Thumshirn@xxxxxxx> wrote: >> >> On 07/04/2020 20:02, Chris Murphy wrote: >>> Hi, >>> >>> What's the status of this work? >>> https://lore.kernel.org/linux-btrfs/20191015121405.19066-1-jthumshirn@xxxxxxx/ >> >> It's done but no-one was interested in it and as I haven't received any >> answers from Dave if he's going to merge it, I did not bring it to >> attention again. After all it was for a specific use-case SUSE has/had >> and I left the company. > > I'm thinking of a way to verify that a non-encrypted generic > boot+startup data hasn't been tampered with. That is, a generic, > possibly read-only boot, can be authenticated on the fly. Basically, > it's fs-verity for Btrfs, correct? > Correct, example deployments would be embedded devices, or container images. I've written a paper [1] for the 2019 SUSE Labs Conference describing some of the scenarios, if you're interested. > Other use cases? > > >> If there is still interest in this work I can re-base my branches [1][2] >> and add blake2b as well, this /should/ be trivially done. >> >> [1] >> https://git.kernel.org/pub/scm/linux/kernel/git/jth/linux.git/log/?h=btrfs-integrity >> [2] https://github.com/morbidrsa/btrfs-progs/tree/mkfs-hmac > > I think 'btrfs check' also needs to be fed the hmac in order to verify > checksums and also rewrite out a new csum or extent tree and do > repairs? Check yes, I'm not so much with you with repairs. If a hmac of a block is corrupt, something altered the on-disk data, somehow. Either it's a bad block on disk or an attack. You can't be sure the data is still trusted. > >> I just don't want to spend time on it again when it's not going to be >> merged in the end (for what ever reason). > > Sure. Seems reasonable. > Let me see if I can carve out some time for this end of next week to re-base what I had. Maybe having someone in the community being interested in this work can accelerate it's upstream acceptance. [1] https://github.com/morbidrsa/btrfs-integrity-paper Byte, Johannes
