Herbert,

On Mon, Jun 14, 2021 at 10:18 PM Richard Weinberger [off-list ref] wrote:

DCP is capable to performing AES with hardware-bound keys.
These keys are not stored in main memory and are therefore not directly
accessible by the operating system.

So instead of feeding the key into DCP, we need to place a
reference to such a key before initiating the crypto operation.
Keys are referenced by a one byte identifiers.

DCP supports 6 different keys: 4 slots in the secure memory area,
a one time programmable key which can be burnt via on-chip fuses
and an unique device key.

Using these keys is restricted to in-kernel users that use them as building
block for other crypto tools such as trusted keys. Allowing userspace
(e.g. via AF_ALG) to use these keys to crypt or decrypt data is a security
risk, because there is no access control mechanism.

Cc: Ahmad Fatoum <a.fatoum@pengutronix.de>
Cc: David Gstir <david@sigma-star.at>
Cc: David Howells <dhowells@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: James Bottomley <redacted>
Cc: James Morris <jmorris@namei.org>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: keyrings@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-crypto@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-integrity@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: NXP Linux Team <redacted>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Richard Weinberger <richard@nod.at>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Co-developed-by: David Gstir <david@sigma-star.at>
Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Richard Weinberger <richard@nod.at>
---
 drivers/crypto/mxs-dcp.c | 110 ++++++++++++++++++++++++++++++++++-----
 include/linux/mxs-dcp.h  |  19 +++++++
 2 files changed, 117 insertions(+), 12 deletions(-)
 create mode 100644 include/linux/mxs-dcp.h

This patch was judged as not applicable in your patchwork.
Is something missing? How can we proceed?

-- 
Thanks,
//richard