[dm-devel] [PATCH v3 0/6] crypto: switch to crypto API for ESSIV generation

[Ard Biesheuvel]

On Thu, 20 Jun 2019 at 13:22, Milan Broz <gmazyland at gmail.com> wrote:
>
> On 19/06/2019 18:29, Ard Biesheuvel wrote:
> > This series creates an ESSIV template that produces a skcipher or AEAD
> > transform based on a tuple of the form '<skcipher>,<cipher>,<shash>'
> > (or '<aead>,<cipher>,<shash>' for the AEAD case). It exposes the
> > encapsulated sync or async skcipher/aead by passing through all operations,
> > while using the cipher/shash pair to transform the input IV into an ESSIV
> > output IV.
> >
> > This matches what both users of ESSIV in the kernel do, and so it is proposed
> > as a replacement for those, in patches #2 and #4.
> >
> > This code has been tested using the fscrypt test suggested by Eric
> > (generic/549), as well as the mode-test script suggested by Milan for
> > the dm-crypt case. I also tested the aead case in a virtual machine,
> > but it definitely needs some wider testing from the dm-crypt experts.
> >
> > Changes since v2:
> > - fixed a couple of bugs that snuck in after I'd done the bulk of my
> >   testing
> > - some cosmetic tweaks to the ESSIV template skcipher setkey function
> >   to align it with the aead one
> > - add a test case for essiv(cbc(aes),aes,sha256)
> > - add an accelerated implementation for arm64 that combines the IV
> >   derivation and the actual en/decryption in a single asm routine
>
> I run tests for the whole patchset, including some older scripts and seems
> it works for dm-crypt now.
>

Thanks Milan, that is really helpful.

Does this include configurations that combine authenc with essiv?

> For the new CRYPTO_ESSIV option - dm-crypt must unconditionally
> select it (we rely on all IV generators availability in userspace),
> but that's already done in patch 4.
>

Indeed.