On Thu, Sep 13, 2018 at 1:45 AM Andy Lutomirski <luto@xxxxxxxxxx> wrote: > I'm not convinced that there's any real need for *all* crypto > algorithms to move into lib/zinc or to move at all. As I see it, > there are two classes of crypto algorithms in the kernel: > > a) Crypto that is used by code that chooses its algorithm statically > and wants synchronous operations. These include everything in > drivers/char/random.c, but also a bunch of various networking things > that are hardcoded and basically everything that uses stack buffers. > (This means it includes all the code that I broke when I did > VMAP_STACK. Sign.) Right, exactly. This is what will wind up using Zinc. I'm working on an example usage of this for v4 of the patch submission, which you can ogle in a preview here if you're curious: https://git.zx2c4.com/linux-dev/commit/?h=big_key_rewrite 28 insertions, 206 deletions :-D > b) Crypto that is used dynamically. This includes dm-crypt > (aes-xts-plain64, aes-cbc-essiv, etc), all the ALG_IF interfaces, a > lot of IPSEC stuff, possibly KCM, and probably many more. These will > get comparatively little benefit from being converted to a zinc-like > interface. For some of these cases, it wouldn't make any sense at all > to convert them. Certainly the ones that do async hardware crypto > using DMA engines will never look at all like zinc, even under the > hood. Right, this is what the crypto API will continue to be used for. > I think that, as a short-term goal, it makes a lot of sense to have > implementations of the crypto that *new* kernel code (like Wireguard) > wants to use in style (a) that live in /lib, and it obviously makes > sense to consolidate their implementations with the crypto/ > implementations in a timely manner. As a medium-term goal, adding > more algorithms as needed for things that could use the simpler APIs > (Bluetooth, perhaps) would make sense. Agreed 100%. With regards to "consolidate their implementations" -- I've actually already done this after your urging yesterday, and so that will be a part of v4. > But I see no reason at all that /lib should ever contain a grab-bag of > crypto implementations just for the heck of it. They should have real > in-kernel users IMO. And this means that there will probably always > be some crypto implementations in crypto/ for things like aes-xts. Right, precisely. Jason
