Re: [PATCH v6 1/7] crypto: essiv - create wrapper template for ESSIV generation

[Eric Biggers <ebiggers@kernel.org>]

On Fri, Jun 28, 2019 at 05:21:06PM +0200, Ard Biesheuvel wrote:
> Implement a template that wraps a (skcipher,cipher,shash) or
> (aead,cipher,shash) tuple so that we can consolidate the ESSIV handling
> in fscrypt and dm-crypt and move it into the crypto API. This will result
> in better test coverage, and will allow future changes to make the bare
> cipher interface internal to the crypto subsystem, in order to increase
> robustness of the API against misuse.
> 
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>  crypto/Kconfig  |   4 +
>  crypto/Makefile |   1 +
>  crypto/essiv.c  | 640 ++++++++++++++++++++
>  3 files changed, 645 insertions(+)
> 
> diff --git a/crypto/Kconfig b/crypto/Kconfig
> index 3d056e7da65f..1aa47087c1a2 100644
> --- a/crypto/Kconfig
> +++ b/crypto/Kconfig
> @@ -1917,6 +1917,10 @@ config CRYPTO_STATS
>  config CRYPTO_HASH_INFO
>  	bool
>  
> +config CRYPTO_ESSIV
> +	tristate
> +	select CRYPTO_AUTHENC
> +

One more request: can you make this symbol explicitly selectable, with prompt
string and help text?

As discussed earlier, to reduce bloat I don't really want FS_ENCRYPTION to
select this.  So the user will need a way to select CRYPTO_ESSIV if they need
it.

- Eric