Re: [PATCH v32 12/21] x86/sgx: Add provisioning

[Jarkko Sakkinen]

On Tue, Jun 16, 2020 at 10:55:11PM +0300, Jarkko Sakkinen wrote:
> On Fri, Jun 05, 2020 at 09:09:49PM +0100, Darren Kenny wrote:
> > TYPO: s/devilering/delivering/?
> 
> I decided to rewrite the whole thing:
> 
>   x86/sgx: Allow a limited use of ATTRIBUTE.PROVISIONKEY for attestation
> 
>   Provisioning Certification Enclave (PCE), the root of trust for other
>   enclaves, generates a signing key from a fused key called Provisioning
>   Certification Key. PCE can then use this key to certify an attestation key
>   of a QE, e.g. we get the chain of trust down to the hardware if the Intel
>   signed PCE is used.
> 
>   To use the needed keys, ATTRIBUTE.PROVISIONKEY is required but should be
>   only allowed for those who actually need it so that only the trusted
>   parties can certify QE's.
> 
>   Obviously the attestation service should know the public key of the used
>   PCE and that way detect illegit attestation, but whitelisting the legit
>   users still adds an additional layer of defence.
> 
>   Add new device file called /dev/sgx/provision. The sole purpose of this
>   file is to provide file descriptors that act as privilege tokens to allow
>   to build enclaves with ATTRIBUTE.PROVISIONKEY set. A new ioctl called
>   SGX_IOC_ENCLAVE_SET_ATTRIBUTE is used to assign this token to an enclave.

I also refined Documentation/x86/sgx.rst based on this in my tree [*].

[*] https://github.com/jsakkine-intel/linux-sgx.git

/Jarkko