Prepare some small changes for SGX attestation

[lkatalin]

We will need an updated version of the SGX dependency and we'll need to use Intel's aesm-proto file to generate Rust structures during build.

[haraldh]

Suggested change

	protobuf_codegen_pure::Codegen::new()
	.out_dir("src/protobuf")
	.inputs(&["src/protobuf/aesm-proto.proto"])
	.include("src/protobuf")
	.run()
	.expect("Protobuf codegen failed");
	Command::new("mv")
	.current_dir(&Path::new(CRATE).join("src/protobuf"))
	.arg("aesm_proto.rs")
	.arg("mod.rs")
	.status()
	.unwrap_or_else(|_| panic!("Could not rename aesm proto file"));
	let out_dir = PathBuf::from(std::env::var("OUT_DIR").unwrap());
	let out_dir_bin = out_dir.join("bin");
	let out_dir = PathBuf::from(std::env::var("OUT_DIR").unwrap());
	let out_dir_proto = out_dir.join("protos");
	match std::fs::create_dir(&out_dir_proto) {
	Err(e) if e.kind() == std::io::ErrorKind::AlreadyExists => {}
	Err(e) => {
	eprintln!("Can't create {:#?} : {:#?}", out_dir_proto, e);
	std::process::exit(1);
	}
	Ok(_) => {}
	}
	protobuf_codegen_pure::Codegen::new()
	.out_dir(&out_dir_proto)
	.inputs(&["src/protobuf/aesm-proto.proto"])
	.include("src/protobuf")
	.customize(protobuf_codegen_pure::Customize {
	gen_mod_rs: Some(true),
	..Default::default()
	})
	.run()
	.expect("Protobuf codegen failed");
	let out_dir_bin = out_dir.join("bin");

We should not generate code into the current source code tree. Better generate into $OUT_DIR.

See also:
stepancheg/rust-protobuf#324

[lkatalin]

Thanks. I'm looking for info on gen_mod_rs but it's not very obvious. I assume it lets you name the output mod.rs, which is what I was trying to do.

[lkatalin]

Yeah, I see from the link this is how it's normally done: "And for now, you may generate that mod.rs in OUT_DIR file from build.rs, and include generated mod.rs from the src directory."

[haraldh]

Suggested change

	//! This is a placeholder file for the Rust stuctures generated from
	//! aesm-proto.proto during build.
	//! Provides all generated protobuf modules
	include!(concat!(env!("OUT_DIR"), "/protos/mod.rs"));

This then includes the generated protobuf modules.

You will then have to use crate::protobuf::aesm_proto.

[lkatalin]

I pulled the error handling for create_dir() out into its own function since we use it several times.

[connorkuehl]

I did not confirm the correctness of Intel's proto file