Add a new crate for the AuthorizationEnclave

[longtomjr]

• Setup compile environment to mimic the rtc_data_enclave setup. Include:
  • Enclave.edl
  • Enclave.lds
  • Enclave_private.pem
  • Enclave.config.xml
  • rust-toolchain
  • x86_64-unknown-linux-sgx.json
• Add a build script with cbindgen to generate the bindings (see rtc_data_enclave/build.rs)
• Add Makefile based on the Makefile in rtc_data_enclave
• Add the following attributes to the lib.rs
  • #![no_std] -> Sets no_std (so rust does not add std prelude to the top of every file)
  • #![feature(unsafe_block_in_unsafe_fn)] -> Require unsafe blocks for unsafe code, even if the function is marked as unsafe
    • see Rust RFC 2585
  • #![deny(unsafe_op_in_unsafe_fn)] -> Sets the lint enabled by the above feature to error if the conditions are not met
  • #![deny(clippy::mem_forget)] -> Disallows (via clippy) the use of mem_forget. (This should not come up at all, but it is good to prevent obvious memory leaks)

[PiDelport]

For the crate name, rtc_auth_enclave?

[PiDelport]

Should we copy the Makefile, or try to factor out a common base Makefile again?