Re: [PATCH v9 0/7] KEYS: trusted: Introduce support for NXP CAAM-based trusted keys

[Michael Walle <michael@walle.cc>]

Hi,

Am 2022-05-11 12:47, schrieb Ahmad Fatoum:
> On 06.05.22 12:52, Michael Walle wrote:
>> Am 2022-05-06 08:25, schrieb Ahmad Fatoum:
>>> Series applies on top of v5.18-rc5. Would be great if this could make 
>>> it
>>> into v5.19.
>>> 
>>> v8 was here:
>>> https://lore.kernel.org/linux-integrity/09e2552c-7392-e1da-926b-53c7db0b118d@pengutronix.de
>>> 
>>> Changelog is beneath each individual patch. Compared to v8, only code
>>> change is checking whether CAAM can support blobbing at init-time as
>>> apparently some Layerscape SoCs are available in a non-E(ncryption)
>>> variant that doesn't do AES. Previously, adding trusted keys on such
>>> SoCs would return an error with a cryptic error message.
>>> 
>>> 
>>> The Cryptographic Acceleration and Assurance Module (CAAM) is an IP 
>>> core
>>> built into many newer i.MX and QorIQ SoCs by NXP.
>>> 
>>> Its blob mechanism can AES encrypt/decrypt user data using a unique
>>> never-disclosed device-specific key.
>>> 
>>> There has been multiple discussions on how to represent this within 
>>> the kernel:
>>> 
>>> The Cryptographic Acceleration and Assurance Module (CAAM) is an IP 
>>> core
>>> built into many newer i.MX and QorIQ SoCs by NXP.
>>> 
>>> Its blob mechanism can AES encrypt/decrypt user data using a unique
>>> never-disclosed device-specific key. There has been multiple
>>> discussions on how to represent this within the kernel:
>>> 
>>>  - [RFC] crypto: caam - add red blobifier
>>>    Steffen implemented[1] a PoC sysfs driver to start a discussion on 
>>> how to
>>>    best integrate the blob mechanism.
>>>    Mimi suggested that it could be used to implement trusted keys.
>>>    Trusted keys back then were a TPM-only feature.
>>> 
>>>  - security/keys/secure_key: Adds the secure key support based on 
>>> CAAM.
>>>    Udit Agarwal added[2] a new "secure" key type with the CAAM as 
>>> backend.
>>>    The key material stays within the kernel only.
>>>    Mimi and James agreed that this needs a generic interface, not 
>>> specific
>>>    to CAAM. Mimi suggested trusted keys. Jan noted that this could 
>>> serve as
>>>    basis for TEE-backed keys.
>>> 
>>>  - [RFC] drivers: crypto: caam: key: Add caam_tk key type
>>>    Franck added[3] a new "caam_tk" key type based on Udit's work. 
>>> This time
>>>    it uses CAAM "black blobs" instead of "red blobs", so key material 
>>> stays
>>>    within the CAAM and isn't exposed to kernel in plaintext.
>>>    James voiced the opinion that there should be just one user-facing 
>>> generic
>>>    wrap/unwrap key type with multiple possible handlers.
>>>    David suggested trusted keys.
>>> 
>>>  - Introduce TEE based Trusted Keys support
>>>    Sumit reworked[4] trusted keys to support multiple possible 
>>> backends with
>>>    one chosen at boot time and added a new TEE backend along with 
>>> TPM.
>>>    This now sits in Jarkko's master branch to be sent out for v5.13
>>> 
>>> This patch series builds on top of Sumit's rework to have the CAAM as
>>> yet another
>>> trusted key backend.
>>> 
>>> The CAAM bits are based on Steffen's initial patch from 2015. His 
>>> work had been
>>> used in the field for some years now, so I preferred not to deviate
>>> too much from it.
>>> 
>>> This series has been tested with dmcrypt[5] on an i.MX6Q/DL and an 
>>> i.MX8M[6].
>>> 
>>> Looking forward to your feedback.
>> 
>> For the whole series:
>> 
>> Tested-by: Michael Walle <michael@walle.cc> # on ls1028a (non-E and E)
> 
> Thanks! Did you test checkpatch.pl and make htmldocs/pdfdocs too
> or should I add the Tested-by just for the first 5 patches?

I just tested the series on the mentioned hardware. So no htmldocs
or checkpatch.pl.

-michael