turnkey_proofs

This crate contains utilities to parse and verify Turnkey secure enclave proofs. As outlined in the Turnkey whitepaper there are two types of proofs:

• App proofs, signing structured data with enclave ephemeral keys.
• Boot proofs, which are proofs that a given enclave was provisioned correctly. Boot proofs reference via their public_key field the enclave ephemeral key. This links App and Boot proofs together.

Boot proofs

🚧 Experimental: Turnkey Boot proofs are not fully baked yet and may change significantly in the near future

If you have a Turnkey organization you can request a Boot proof from any enclave. This boot proof is an attestation document from Amazon, signed by a root certificate associated with AWS Nitro Attestation PKI (located in aws_root.pem). This top-level certificate can be downloaded from https://aws-nitro-enclaves.amazonaws.com/AWS_NitroEnclaves_Root-G1.zip.

Resources on AWS Nitro Enclaves, attestations, and verifying attestations can be found at the following:

• https://docs.aws.amazon.com/enclaves/latest/user/nitro-enclave.html
• https://docs.aws.amazon.com/enclaves/latest/user/set-up-attestation.html
• https://aws.amazon.com/blogs/compute/validating-attestation-documents-produced-by-aws-nitro-enclaves/
• https://docs.aws.amazon.com/enclaves/latest/user/verify-root.html

Usage

You may request a fresh attestation with the turnkey CLI (available here):

$ turnkey request --host api.turnkey.com --path /public/v1/query/get_attestation --body '{ "organizationId": "<your organization ID>", "enclaveType": "signer" }' --organization <your organization ID>

{
   "attestationDocument": "<base64-encoded attestation document>"
}

This crate contains a function to parse and verify this attestation: parse_and_verify_aws_nitro_attestation. This returns an AttestationDoc containing PCR values. You can display these values like so:

use hex;
use turnkey_proofs::parse_and_verify_aws_nitro_attestation;

let attestation_document = "<base64-encoded attestation doc>".to_string();
let attestation = parse_and_verify_aws_nitro_attestation(attestation_document)
   .expect("cannot parse and verify attestation document");

// Display PCR values
println!("PCR0: {}", hex::encode(attestation.pcrs.get(&0).unwrap()));
println!("PCR1: {}", hex::encode(attestation.pcrs.get(&1).unwrap()));
println!("PCR2: {}", hex::encode(attestation.pcrs.get(&2).unwrap()));
println!("PCR3: {}", hex::encode(attestation.pcrs.get(&3).unwrap()));

// Display user data and public key fields
println!("user_data: {}", hex::encode(attestation.user_data.unwrap()));
println!(
   "public_key: {}",
   hex::encode(attestation.public_key.unwrap())
);

Head over to the QuorumOS repository if you're looking to reproduce these PCR values independently.