Re: [PATCH v3 1/4] crypto: add eboiv as a crypto API template

From: Milan Broz
Date: Fri Oct 30 2020 - 06:33:36 EST


On 29/10/2020 11:05, Gilad Ben-Yossef wrote:
>
> +config CRYPTO_EBOIV
> + tristate "EBOIV support for block encryption"
> + default DM_CRYPT
> + select CRYPTO_CBC
> + help
> + Encrypted byte-offset initialization vector (EBOIV) is an IV
> + generation method that is used in some cases by dm-crypt for
> + supporting the BitLocker volume encryption used by Windows 8
> + and onwards as a backwards compatible version in lieu of XTS
> + support.
> +
> + It uses the block encryption key as the symmetric key for a
> + block encryption pass applied to the sector offset of the block.
> + Additional details can be found at
> + https://www.jedec.org/sites/default/files/docs/JESD223C.pdf

This page is not available. Are you sure this is the proper documentation?

I think the only description we used (for dm-crypt) was original Ferguson's Bitlocker doc:
https://download.microsoft.com/download/0/2/3/0238acaf-d3bf-4a6d-b3d6-0a0be4bbb36e/bitlockercipher200608.pdf

IIRC EBOIV was a shortcut I added to dm-crypt because we found no official terminology for this IV.
And after lunchtime, nobody invented anything better, so it stayed as it is now :-)

Milan