Crate az_tdx_vtpm
source ·Expand description
This library enables guest attestation flows for TDX CVMs on Azure.
A TD report can be retrieved in parsed form using report::get_report()
function, or as
raw bytes including the hcl envelope using vtpm::get_report()
. The library provides a
function to retrieve the TD quote from the Azure Instance Metadata Service (IMDS) using
imds::get_td_quote()
, produce returning a quote signed by a TDX Quoting Enclave.
Variable Data is part of the HCL envelope and holds the public part of the vTPM Attestation
Key (AK). A hash of the Variable Data block is included in the TD report as reportdata
.
TPM quotes retrieved with vtpm::get_quote()
should be signed by this AK. A verification
function would need to check this to ensure the TD report is linked to this unique TDX CVM.
§
use az_tdx_vtpm::{hcl, imds, report, tdx, vtpm};
use openssl::pkey::{PKey, Public};
use std::error::Error;
fn main() -> Result<(), Box<dyn Error>> {
let td_report = report::get_report()?;
let td_quote_bytes = imds::get_td_quote(&td_report)?;
std::fs::write("td_quote.bin", td_quote_bytes)?;
let bytes = vtpm::get_report()?;
let hcl_report = hcl::HclReport::new(bytes)?;
let var_data_hash = hcl_report.var_data_sha256();
let ak_pub = hcl_report.ak_pub()?;
let td_report: tdx::TdReport = hcl_report.try_into()?;
assert!(var_data_hash == td_report.report_mac.reportdata[..32]);
let nonce = "a nonce".as_bytes();
let tpm_quote = vtpm::get_quote(nonce)?;
let der = ak_pub.key.try_to_der()?;
let pub_key = PKey::public_key_from_der(&der)?;
tpm_quote.verify(&pub_key, nonce)?;
Ok(())
}
Modules§
Functions§
- Determines if the current VM is a TDX CVM. Returns
Ok(true)
if the VM is a TDX CVM,Ok(false)
if it is not, andErr
if an error occurs.