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From:   Janne Karhunen <janne.karhunen@gmail.com>
Date:   Thu, 1 Aug 2019 09:36:44 +0300
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Subject: Re: [RFC v2 0/6] Introduce TEE based Trusted Keys support
To:     Sumit Garg <sumit.garg@linaro.org>
Cc:     keyrings@vger.kernel.org, linux-integrity@vger.kernel.org,
        linux-security-module@vger.kernel.org,
        Jens Wiklander <jens.wiklander@linaro.org>,
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        jejb@linux.ibm.com,
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        Mimi Zohar <zohar@linux.ibm.com>,
        James Morris <jmorris@namei.org>,
        "Serge E. Hallyn" <serge@hallyn.com>,
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        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
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On Wed, Jul 31, 2019 at 5:23 PM Sumit Garg <sumit.garg@linaro.org> wrote:

> > I guess my wording was wrong, tried to say that physical TEEs in the
> > wild vary massively hardware wise. Generalizing these things is rough.
> >
>
> There are already well defined GlobalPlatform Standards to generalize
> the TEE interface. One of them is GlobalPlatform TEE Client API [1]
> which provides the basis for this TEE interface.

I'm aware of it - I have implemented a large part of the GP TEE APIs
earlier (primarily the crypto functions). Does the TEE you work with
actually support GP properly? Can I take a look at the code?

Normally the TEE implementations are well-guarded secrets and the
state of the implementation is quite random. In many cases keeping
things secret is fine from my point of view, given that it is a RoT
after all. The secrecy is the core business here. So, this is why I
opted the userspace 'secret' route - no secrets in the kernel, but
it's fine for the userspace. Umh was a logical fit to implement it.


--
Janne