Add remote attestation support for the Authorization Enclave

[longtomjr]

Closes: #35

[PiDelport]

Looks good! @Nghondzweni and I gave this a walk-through, and the only thing I spotted was that PR #58's fix for the data enclave Makefile's Crate_Files declaration also needs to be applied for the auth enclave, now that it also depends on rtc_tenclave, but we can do that as a follow-up PR.

Update 1: Oh, wait, there was also an unexpected Cargo lockfile change. Let me investigate that quick…'

Update 2: Okay, the issue was an unexpected sgx_tcrypto version bump in the data enclave's lock file, because rtc_tenclave is pulling sgx_tcrypto without the patch from the old to new teaclave repositories. We should probably standardise these repository references across the enclaves, but that's a bit of a rabbithole at this point.

[longtomjr]

Looks good! @Nghondzweni and I gave this a walk-through, and the only thing I spotted was that PR #58's fix for the data enclave Makefile's Crate_Files declaration also needs to be applied for the auth enclave, now that it also depends on rtc_tenclave, but we can do that as a follow-up PR.

Lets do that in a follow up, and get this merged in. (#62)

Update 1: Oh, wait, there was also an unexpected Cargo lockfile change. Let me investigate that quick…'

Update 2: Okay, the issue was an unexpected sgx_tcrypto version bump in the data enclave's lock file, because rtc_tenclave is pulling sgx_tcrypto without the patch from the old to new teaclave repositories. We should probably standardise these repository references across the enclaves, but that's a bit of a rabbithole at this point.

I am currently considering a separate workspace for enclave, and non-enclave code, but I am not sure yet what the implications are for that. Will add a task to investigate. (#63)

[PiDelport]

I have a fix for #62 ready: I'll PR that shortly.

Consolidating the enclave code under a single workspace sounds like a great idea, if we can get that working!