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Subject: Re: [PATCH v1 0/3] KEYS: trusted: Introduce support for NXP
 CAAM-based trusted keys
To:     Richard Weinberger <richard@nod.at>
Cc:     Jarkko Sakkinen <jarkko@kernel.org>,
        horia geanta <horia.geanta@nxp.com>,
        Mimi Zohar <zohar@linux.ibm.com>,
        aymen sghaier <aymen.sghaier@nxp.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        davem <davem@davemloft.net>,
        James Bottomley <jejb@linux.ibm.com>,
        kernel <kernel@pengutronix.de>,
        David Howells <dhowells@redhat.com>,
        James Morris <jmorris@namei.org>,
        "Serge E. Hallyn" <serge@hallyn.com>,
        Steffen Trumtrar <s.trumtrar@pengutronix.de>,
        Udit Agarwal <udit.agarwal@nxp.com>,
        Jan Luebbe <j.luebbe@pengutronix.de>,
        david <david@sigma-star.at>,
        Franck Lenormand <franck.lenormand@nxp.com>,
        Sumit Garg <sumit.garg@linaro.org>,
        linux-integrity <linux-integrity@vger.kernel.org>,
        "open list, ASYMMETRIC KEYS" <keyrings@vger.kernel.org>,
        Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        LSM <linux-security-module@vger.kernel.org>
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From:   Ahmad Fatoum <a.fatoum@pengutronix.de>
Message-ID: <638717a5-a456-24a7-b0ab-9f71adb13687@pengutronix.de>
Date:   Thu, 1 Apr 2021 13:13:21 +0200
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Hello Richard,

On 01.04.21 13:05, Richard Weinberger wrote:
> Ahmad,
> 
> ----- Ursprüngliche Mail -----
>> Von: "Ahmad Fatoum" <a.fatoum@pengutronix.de>
>>> I don't want you to force to use cryptsetup.
>>
>> I'd love to use cryptsetup with LUKS and trusted keys eventually. I'll take
> 
> But using LUKS would mean that cryptsetup has access to the plain disc encryption key material?
> This would be a no-go for many systems out there, key material must not accessible to userspace.
> I know, distrusting userspace root is not easy, but doable. :)

The LUKS2 format supports tokens. I see no reason why the encrypted blob
couldn't be stored there along with the usual metadata. cryptsetup would
then load it as kernel trusted key and use it for dmcrypt decryption.

This will mean we have to part ways with features such as having multiple
keys, but I think it's worth it to have a plug and play solution for
trusted keys.

Of course, someone needs to implement this first ^^.

Cheers,
Ahmad

> 
> Thanks,
> //richard
> 

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