Re: [PATCH v6 08/11] intel_sgx: in-kernel launch enclave

[Jarkko Sakkinen]

On Sat, Nov 25, 2017 at 09:29:25PM +0200, Jarkko Sakkinen wrote:
> This commits implements the in-kernel launch enclave. It is wrapped into
> a user space program that reads SIGSTRUCT instances from stdin and
> outputs launch tokens to stdout.
> 
> The commit also adds enclave signing tool that is used by kbuild to
> measure and sign the launch enclave.
> 
> CONFIG_INTEL_SGX_SIGNING_KEY points to a PEM-file for the 3072-bit RSA
> key that is used as the LE public key pair. The default location is:
> 
>   drivers/platform/x86/intel_sgx/intel_sgx_signing_key.pem
> 
> If the default key does not exist kbuild will generate a random key and
> place it to this location. KBUILD_SGX_SIGN_PIN can be used to specify
> the passphrase for the LE public key.
> 
> TinyCrypt (https://github.com/01org/tinycrypt) is used as AES
> implementation, which is not timing resistant. Eventually this needs to
> be replaced with AES-NI based implementation that could be either
> 
> - re-use existing AES-NI code in the kernel
> - have its own hand written code

The AES is the biggest remaining open I think.

I'm starting look at how to re-use kernel aesni code by linking it as
part of the enclave binary i.e. aesni-intel_asm.S. This will render
away TinyCrypt's AES code that is used ATM.

I still need TinyCrypt CMAC, which I will modify to call CBC AES
encryption routine.

Does this sound like a sufficient plan?

/Jarkko