Re: [PATCH v8 3/4] doc: trusted-encrypted: updates with TEE as a new trust source

Jarkko Sakkinen
2020-12-08T17:49:06Z

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On Tue, Dec 08, 2020 at 10:02:57AM -0500, Mimi Zohar wrote:
> Hi Jarkko,
>
> On Fri, 2020-12-04 at 17:30 +0200, Jarkko Sakkinen wrote:
> > On Wed, Dec 02, 2020 at 02:34:07PM -0500, gmail Elaine Palmer wrote:
> > > Hi Sumit,
> > >
> > > Thank you for the detailed descriptions and examples of trust sources
> > > for Trusted Keys. A group of us in IBM (Stefan Berger, Ken Goldman,
> > > Zhongshu Gu, Nayna Jain, Elaine Palmer, George Wilson, Mimi Zohar)
> > > have been doing related work for quite some time, and we have one
> > > primary concern and some suggested changes to the document.
> > >
> > > Our primary concern is that describing a TEE as a Trust Source needs
> > > to be more specific. For example, "ARM TrustZone" is not sufficient,
> > > but "wolfSSL embedded SSL/TLS library with ARM TrustZone
> > > CryptoCell-310" is. Just because a key is protected by software
> > > running in a TEE is not enough to establish trust. Just like
> > > cryptographic modules, a Trust Source should be defined as a specific
> > > implementation on specific hardware with well-documented environmental
> > > assumptions, dependencies, and threats.
> > >
> > > In addition to the above concern, our suggested changes are inline
> > > below.
> >
> > In order to give a decent review comment it should have two ingredients:
> >
> > - Where the existing line of code / text / whatever goes wrong.
> > - How it should modified and why that makes sense. And use as plain
> > English and non-academic terms as possible, if it is documentation.
> > Further, scope is only the kernel implementation, no more or no
> > less.
> >
> > "do this" is not unfortunately an argument. Feedback is welcome when
> > it is supported by something common sensse.
>
> Even after the code is fully debugged, reviewed and tested, our concern
> is that people will assume the security guarantees of TEE based trusted
> keys to be equivalent to that of a discrete TPM.
>
> >
> > Some meta suggestion of related to email:
> >
> > Please also use a proper email client and split your paragraphs into
> > at most 80 character lines with new line characters when writing email.
> > I prefer to use 72 character line length so that there's some space
> > for longer email threads.
>
> Sure, we'll re-post the suggested documentation changes/additions.
>
> Mimi

So. Wouldn't it be a better idea to post a patch that Sumit could
squash to his (and add co-developed-by tag)?

/Jarkko