Re: [PATCH v6 00/11] Intel SGX Driver

[Jarkko Sakkinen]

On Wed, Dec 20, 2017 at 01:33:46AM +0200, Jarkko Sakkinen wrote:
> On Tue, 2017-12-12 at 15:07 +0100, Pavel Machek wrote:
> > On Sat 2017-11-25 21:29:17, Jarkko Sakkinen wrote:
> > > Intel(R) SGX is a set of CPU instructions that can be used by applications to
> > > set aside private regions of code and data. The code outside the enclave is
> > > disallowed to access the memory inside the enclave by the CPU access control.
> > > In a way you can think that SGX provides inverted sandbox. It protects the
> > > application from a malicious host.
> > 
> > Would you list guarantees provided by SGX?
> > 
> > For example, host can still observe timing of cachelines being
> > accessed by "protected" app, right? Can it also introduce bit flips?
> > 
> > 								Pavel
> 
> I'll give a more proper response to this now that all the reported major
> issues in the code have been fixed in v9.
> 
> Yes, SGX is vulnerable to the L1 cacheline timing attacks. Jethro
> Beekman wrote a great summary about this on early March:
> 
>   https://jbeekman.nl/blog/2017/03/sgx-side-channel-attacks/
> 
> The counter measures are the same as without SGX. It really does not
> add or degrade security in this area.

This came up even in my patch set :-) I.e. I switched to kernel AES-NI
from TinyCrypt's AES because the latter is not timing resistant.

/Jarkko