Re: [PATCH] crypto: Make CRYPTO_CBC select CRYPTO_ECHAINIV

On 01/08/2016 10:48 AM, Herbert Xu wrote:

On Mon, Jan 04, 2016 at 09:43:53PM +0100, Thomas Egerer wrote:

quoted

Similar to CTR mode selecting CRYPTO_SEQIV, CBC mode requires echainiv
and has to select CRYPTO_ECHAINIV in order to work properly. This solves
the issues caused by a misconfiguration as described in [1].

[1] https://lists.strongswan.org/pipermail/users/2015-December/009074.html

Signed-off-by: Thomas Egerer <redacted>

Please patch net/ipvX/Kconfig instead as ECHAINIV is only used
by IPsec.

This does not seem right to me. By depending on CRYPTO_CBC in a particular
Kconfig, I would expect the 'default algorithm for CBC' to be transitively
selected with it. It's what CRYPTO_CTR does. There are a couple of places
that use select CRYPTO_CBC but not CRYPTO_ECHAINIV  (ext4, wusbcore, md
to mention a few). Wouldn't these end up unusable too, if CBC-mode doesn't
activate echainiv?

Cheers,
Thomas

Thanks,