From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Borislav Petkov <bp@alien8.de>,
x86@kernel.org, linux-sgx@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
Jethro Beekman <jethro@fortanix.com>,
Andy Lutomirski <luto@kernel.org>,
akpm@linux-foundation.org, andriy.shevchenko@linux.intel.com,
asapek@google.com, cedric.xing@intel.com,
chenalexchen@google.com, conradparker@google.com,
cyhanish@google.com, dave.hansen@intel.com,
haitao.huang@intel.com, josh@joshtriplett.org,
kai.huang@intel.com, kai.svahn@intel.com, kmoy@google.com,
ludloff@google.com, nhorman@redhat.com, npmccallum@redhat.com,
puiterwijk@redhat.com, rientjes@google.com, tglx@linutronix.de,
yaozhangx@google.com
Subject: Re: [PATCH v33 12/21] x86/sgx: Allow a limited use of ATTRIBUTE.PROVISIONKEY for attestation
Date: Fri, 3 Jul 2020 05:38:02 +0300 [thread overview]
Message-ID: <20200703023802.GB306897@linux.intel.com> (raw)
In-Reply-To: <20200629220400.GI12312@linux.intel.com>
On Mon, Jun 29, 2020 at 03:04:00PM -0700, Sean Christopherson wrote:
> On Mon, Jun 29, 2020 at 06:02:42PM +0200, Borislav Petkov wrote:
> > 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.
>
> Quoting Enclave.
>
> > > 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?
>
> /dev/sgx/provision is root-only by default, the expectation is that the admin
> will configure the system to grant only specific enclaves access to the
> PROVISION_KEY.
>
> > And in general, how does that whole flow look like: what calls
> > SGX_IOC_ENCLAVE_SET_ATTRIBUTE when?
>
> The basic gist is that the host process of an enclave that needs/wants access
> to the PROVISION_KEY will invoke SGX_IOC_ENCLAVE_SET_ATTRIBUTE when building
> the enclave. Any enclave can request access to PROVISION_KEY, but practically
> speaking only the PCE and QE (or their non-Intel equivalents) actually need
> access to the key. KVM (future series) will also respect /dev/sgx/provision,
> i.e. require a similar ioctl() to expose the PROVISION_KEY to a guest.
>
> E.g. for my own personal testing, I never do anything attestation related, so
> none of the enclaves I run request PROVISION_KEY, but I do expose it to VMs to
> test the KVM paths.
>
> In this series, access is fairly binary, i.e. there's no additional kernel
> infrastructure to help userspace make per-enclave decisions. There have been
> more than a few proposals on how to extend the kernel to help provide better
> granularity, e.g. LSM hooks, but it was generally agreed to punt that stuff
> to post-upstreaming to keep things "simple" once we went far enough down
> various paths to ensure we weren't painting ourselves into a corner.
>
> If you want super gory details, Intel's whitepaper on attestation in cloud
> environments is a good starting point[*], but I don't recommended doing much
> more than skimming unless you really like attestation stuff or are
> masochistic, which IMO amount to the same thing :-)
>
> [*] https://download.01.org/intel-sgx/dcap-1.0/docs/SGX_ECDSA_QuoteGenReference_DCAP_API_Linux_1.0.pdf
Section 3 in [*] is what describes the infrastructure. DCAP is only a
component in the whole attestation infrastructure.
[*] https://software.intel.com/sites/default/files/managed/f1/b8/intel-sgx-support-for-third-party-attestation.pdf
/Jarkko
next prev parent reply other threads:[~2020-07-03 2:38 UTC|newest]
Thread overview: 93+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-17 22:08 [PATCH v33 00/21] Intel SGX foundations Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 01/21] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Jarkko Sakkinen
2020-06-22 17:37 ` Borislav Petkov
2020-06-25 1:25 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 02/21] x86/cpufeatures: x86/msr: Add Intel SGX Launch Control " Jarkko Sakkinen
2020-06-24 13:04 ` Borislav Petkov
2020-06-24 14:34 ` Sean Christopherson
2020-06-25 1:28 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 03/21] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Jarkko Sakkinen
2020-06-25 8:59 ` Borislav Petkov
2020-06-25 15:34 ` Sean Christopherson
2020-06-25 16:49 ` Borislav Petkov
2020-06-25 20:52 ` Jarkko Sakkinen
2020-06-25 21:11 ` Borislav Petkov
2020-06-26 13:34 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 04/21] x86/sgx: Add SGX microarchitectural data structures Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 05/21] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 06/21] x86/cpu/intel: Detect SGX support Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 07/21] x86/cpu/intel: Add nosgx kernel parameter Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 08/21] x86/sgx: Initialize metadata for Enclave Page Cache (EPC) sections Jarkko Sakkinen
2020-06-25 10:14 ` Borislav Petkov
2020-06-25 20:11 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 09/21] x86/sgx: Add __sgx_alloc_epc_page() and sgx_free_epc_page() Jarkko Sakkinen
2020-06-25 17:06 ` Borislav Petkov
2020-06-25 20:55 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 10/21] mm: Introduce vm_ops->may_mprotect() Jarkko Sakkinen
2020-06-25 17:14 ` Borislav Petkov
2020-06-25 17:30 ` Matthew Wilcox
2020-06-25 18:06 ` Sean Christopherson
2020-06-25 22:40 ` Jarkko Sakkinen
2020-06-25 22:26 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 11/21] x86/sgx: Linux Enclave Driver Jarkko Sakkinen
2020-06-25 17:23 ` Borislav Petkov
2020-06-25 18:34 ` Sean Christopherson
2020-06-25 18:45 ` Borislav Petkov
2020-06-26 14:19 ` Jarkko Sakkinen
2020-06-25 20:21 ` Jarkko Sakkinen
2020-06-25 20:25 ` Borislav Petkov
2020-06-26 13:40 ` Jarkko Sakkinen
2020-06-25 18:53 ` Borislav Petkov
2020-06-26 14:17 ` Jarkko Sakkinen
2020-06-26 9:14 ` Borislav Petkov
2020-06-26 14:16 ` Sean Christopherson
2020-06-26 14:20 ` Borislav Petkov
2020-07-03 23:04 ` Jarkko Sakkinen
2020-07-03 3:09 ` Jarkko Sakkinen
2020-06-26 15:34 ` Borislav Petkov
2020-07-04 0:13 ` Jarkko Sakkinen
2020-10-26 21:26 ` Dave Hansen
2020-10-27 1:52 ` Jarkko Sakkinen
2020-10-27 10:05 ` Borislav Petkov
2020-10-27 15:20 ` Dave Hansen
2020-10-27 15:37 ` Borislav Petkov
2020-06-27 17:43 ` Borislav Petkov
2020-06-29 15:27 ` Sean Christopherson
2020-06-29 15:37 ` Borislav Petkov
2020-07-04 1:43 ` Jarkko Sakkinen
2020-07-07 1:38 ` Sean Christopherson
2020-07-07 3:29 ` Jarkko Sakkinen
2020-07-04 1:42 ` Jarkko Sakkinen
2020-07-02 3:59 ` Sean Christopherson
2020-07-04 3:31 ` Jarkko Sakkinen
2020-09-02 3:06 ` Haitao Huang
2020-09-02 16:10 ` Sean Christopherson
2020-09-02 18:40 ` Haitao Huang
2020-09-04 12:01 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 12/21] x86/sgx: Allow a limited use of ATTRIBUTE.PROVISIONKEY for attestation Jarkko Sakkinen
2020-06-29 16:02 ` Borislav Petkov
2020-06-29 22:04 ` Sean Christopherson
2020-06-30 8:49 ` Borislav Petkov
2020-06-30 14:20 ` Sean Christopherson
2020-06-30 17:13 ` Andy Lutomirski
2020-07-02 20:47 ` Dr. Greg
2020-07-03 2:43 ` Jarkko Sakkinen
2020-07-03 2:38 ` Jarkko Sakkinen [this message]
2020-07-03 2:32 ` Jarkko Sakkinen
2020-07-03 2:55 ` Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 13/21] x86/sgx: Add a page reclaimer Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 14/21] x86/sgx: ptrace() support for the SGX driver Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 15/21] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen
2020-06-29 17:10 ` Borislav Petkov
2020-06-30 6:00 ` Sean Christopherson
2020-06-30 8:41 ` Borislav Petkov
2020-06-30 14:55 ` Sean Christopherson
2020-06-30 16:48 ` Andy Lutomirski
2020-06-30 17:23 ` Sean Christopherson
2020-07-02 12:52 ` Thomas Gleixner
2020-06-17 22:08 ` [PATCH v33 16/21] x86/fault: Add helper function to sanitize error code Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 17/21] x86/traps: Attempt to fixup exceptions in vDSO before signaling Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 18/21] x86/vdso: Implement a vDSO for Intel SGX enclave call Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 19/21] selftests/x86: Add a selftest for SGX Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 20/21] docs: x86/sgx: Document SGX micro architecture and kernel internals Jarkko Sakkinen
2020-06-17 22:08 ` [PATCH v33 21/21] x86/sgx: Update MAINTAINERS Jarkko Sakkinen
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