linux-kernel - Re: [PATCH v33 12/21] x86/sgx: Allow a limited use of ATTRIBUTE.PROVISIONKEY for attestation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200629160242.GB32176@zn.tnic>
Date:   Mon, 29 Jun 2020 18:02:42 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
Cc:     x86@...nel.org, linux-sgx@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        linux-security-module@...r.kernel.org,
        Jethro Beekman <jethro@...tanix.com>,
        Andy Lutomirski <luto@...nel.org>, akpm@...ux-foundation.org,
        andriy.shevchenko@...ux.intel.com, asapek@...gle.com,
        cedric.xing@...el.com, chenalexchen@...gle.com,
        conradparker@...gle.com, cyhanish@...gle.com,
        dave.hansen@...el.com, haitao.huang@...el.com,
        josh@...htriplett.org, kai.huang@...el.com, kai.svahn@...el.com,
        kmoy@...gle.com, ludloff@...gle.com, nhorman@...hat.com,
        npmccallum@...hat.com, puiterwijk@...hat.com, rientjes@...gle.com,
        sean.j.christopherson@...el.com, tglx@...utronix.de,
        yaozhangx@...gle.com
Subject: Re: [PATCH v33 12/21] x86/sgx: Allow a limited use of
 ATTRIBUTE.PROVISIONKEY for attestation

On Thu, Jun 18, 2020 at 01:08:34AM +0300, Jarkko Sakkinen wrote:
> 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

What's a QE?

I don't see this acronym resolved anywhere in the whole patchset.

> 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.

So I'm sure I'm missing something here: what controls which
enclave can open /dev/sgx/provision and thus pass the FD to
SGX_IOC_ENCLAVE_SET_ATTRIBUTE?

And in general, how does that whole flow look like: what calls
SGX_IOC_ENCLAVE_SET_ATTRIBUTE when?

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette