[dm-devel] dm-crypt error when CONFIG_CRYPTO_AUTHENC is disabled

[Mike Snitzer]

On Fri, Sep 20 2019 at 11:44am -0400,
Thibaut Sautereau <thibaut.sautereau at clip-os.org> wrote:

> Hi,
> 
> I just got a dm-crypt "crypt: Error allocating crypto tfm" error when
> trying to "cryptsetup open" a volume. I found out that it was only
> happening when I disabled CONFIG_CRYPTO_AUTHENC.
> 
> drivers/md/dm-crypt.c includes the crypto/authenc.h header and seems to
> use some CRYPTO_AUTHENC-related stuff. Therefore, shouldn't
> CONFIG_DM_CRYPT select CONFIG_CRYPTO_AUTHENC?

Yes, it looks like commit ef43aa38063a6 ("dm crypt: add cryptographic
data integrity protection (authenticated encryption)") should've added
'select CRYPTO_AUTHENC' to dm-crypt's Kconfig.  I'll let Milan weigh-in
but that seems like the right way forward.

Thanks for your report!
Mike