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

Milan Broz gmazyland at gmail.com
Thu Jun 20 12:09:17 UTC 2019


On 20/06/2019 13:54, Ard Biesheuvel wrote:
> 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?

Hm, seems that we are missing these in luks2-integrity-test. I'll add them there.

I also used this older test
https://gitlab.com/omos/dm-crypt-test-scripts/blob/master/root/test_dmintegrity.sh

(just aes-gcm-random need to be commented out, we never supported this format, it was
written for some devel version)

But seems ESSIV is there tested only without AEAD composition...

So yes, this AEAD part need more testing.

Milan




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