On Sun, Aug 04, 2019 at 03:20:24PM -0700, Andy Lutomirski wrote: > On Thu, Aug 1, 2019 at 9:38 AM Jarkko Sakkinen > <jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote: > > > > On Mon, Jul 15, 2019 at 03:29:23PM -0700, Andy Lutomirski wrote: > > > I would say it differently: regardless of exactly how /dev/sgx/enclave > > > is wired up under the hood, we want a way that a process can be > > > granted permission to usefully run enclaves without being granted > > > permission to execute whatever bytes of code it wants. Preferably > > > without requiring LSMs to maintain some form of enclave signature > > > whitelist. > > > > Would it be better to have a signer whitelist instead or some > > combination? E.g. you could whiteliste either by signer or > > enclave signature. > > > > I'm not sure, and also don't really think we need to commit to an > answer right now. I do think that the eventual solution should be > more flexible than just whitelisting the signers. In particular, it > should be possible to make secure enclaves, open-source or otherwise, > that are reproducibly buildable. This more or less requires that the > signing private key not be a secret, which means that no one would > want to whitelist the signing key. The enclave would be trusted, and > would seal data, on the basis of its MRENCLAVE, and the policy, if > any, would want to whitelist the MRENCLAVE or perhaps the whole > SIGSTRUCT. > > But my overall point is that it should be possible to have a conherent > policy that allows any enclave whatsoever to run but that still > respects EXECMEM and such. So could kernel embed a fixed signing key that would be made available through sysfs for signing? Already have one for my selftest. /Jarkko
