From: Eric Biggers <ebiggers@kernel.org>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: linux-usb@vger.kernel.org, gregkh@linuxfoundation.org,
linux-crypto@vger.kernel.org, herbert@gondor.apana.org.au
Subject: Re: [PATCH v3] wusb: switch to cbcmac transform
Date: Sat, 15 Jun 2019 18:20:56 -0700 [thread overview]
Message-ID: <20190616012056.GA698@sol.localdomain> (raw)
In-Reply-To: <20190615091745.3100-1-ard.biesheuvel@linaro.org>
On Sat, Jun 15, 2019 at 11:17:45AM +0200, Ard Biesheuvel wrote:
> The wusb code takes a very peculiar approach at implementing CBC-MAC,
> by using plain CBC into a scratch buffer, and taking the output IV
> as the MAC.
>
> We can clean up this code substantially by switching to the cbcmac
> shash, as exposed by the CCM template. To ensure that the module is
> loaded on demand, add the cbcmac template name as a module alias.
>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
> v3: - add missing #include to fix build error spotted by kbuild test robot
> v2: - use finup()/digest() where possible, and process b0+b1 using a single
> call to update()
> - make 'stv_hsmic_hs' static const and remove comment regarding GCC 4.1
>
> NOTE: I don't have any hardware to test this, but the built-in selftest
> still passes.
>
> crypto/ccm.c | 1 +
> drivers/usb/wusbcore/crypto.c | 169 +++++---------------
> 2 files changed, 45 insertions(+), 125 deletions(-)
>
drivers/usb/wusbcore/Kconfig also needs to be updated:
diff --git a/drivers/usb/wusbcore/Kconfig b/drivers/usb/wusbcore/Kconfig
index 12e89189ca7d..2ec17d6af1f8 100644
--- a/drivers/usb/wusbcore/Kconfig
+++ b/drivers/usb/wusbcore/Kconfig
@@ -6,9 +6,7 @@ config USB_WUSB
tristate "Enable Wireless USB extensions"
depends on UWB
select CRYPTO
- select CRYPTO_BLKCIPHER
- select CRYPTO_CBC
- select CRYPTO_MANAGER
+ select CRYPTO_CCM
select CRYPTO_AES
help
Enable the host-side support for Wireless USB.
> diff --git a/drivers/usb/wusbcore/crypto.c b/drivers/usb/wusbcore/crypto.c
> index edb7263bff40..9ee66483ee54 100644
> --- a/drivers/usb/wusbcore/crypto.c
> +++ b/drivers/usb/wusbcore/crypto.c
Other than that, this patch looks correct. There are a massive number of things
that need to be cleaned up in this code, but I guess we don't really care since
as Greg said, this driver is planned to be removed anyway. (It also seems the
wireless USB specification is no longer available at usb.org.) So I'm not going
to bother being very picky...
- Eric
next prev parent reply other threads:[~2019-06-16 1:21 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-15 9:17 [PATCH v3] wusb: switch to cbcmac transform Ard Biesheuvel
2019-06-16 1:20 ` Eric Biggers [this message]
2019-06-16 6:52 ` Ard Biesheuvel
2019-06-16 7:19 ` Eric Biggers
2019-06-16 18:25 ` Ard Biesheuvel
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