CSPACE-ATT-03: Attestation token binds this deployment and resists replay/downgrade¶
| Property | Value |
|---|---|
| Severity | high |
| Platform | GCP Confidential Space (AMD SEV-SNP) |
| Lifecycle stage | attest |
| Policy | P-04: Attestation evidence is fresh and fully verified |
| Assurance | report-derived |
| Mode | Passive: reads only the files and values you pass to the scan. |
What it checks¶
It passes when:
- Token …, asserts secure boot, and binds project/zone/instance.
How to fix¶
- Request the token with a fresh nonce your verifier generated (eat_nonce), require secboot=true and a minimum swversion, and confirm submods.gce (project_id/zone/instance_name) matches the audited VM. This stops replay of an old or another deployment's genuine token.
After the fix, scan again: the check should report PASS.
When it is not assessed¶
SKIP:
- No --attestation-token provided; skipping token-binding check.
ERROR:
- Could not read/decode the attestation token: …
Scan inputs¶
The untrust scan options this check reads:
| Option | Description |
|---|---|
--attestation-token |
Path to a captured Confidential Space attestation token (JWT). |
--expected-nonce |
Verifier-issued eat_nonce the token must echo (CSPACE-ATT-03 replay check). |
--gcp-instance |
Confidential VM instance name. |
--gcp-project |
GCP project ID. |
--gcp-zone |
Zone of the Confidential VM. |
Permissions¶
None. The check reads only the files or values you pass to the scan.
Related¶
- Other checks for policy P-04: CCA-CERT-01, CSPACE-ATT-01, CSPACE-ATT-02, GPU-CERT-01, GPUCC-ATT-01, NITRO-ATT-02, NITRO-ATT-03, SE-CERT-01, SGX-CERT-01, SNP-CERT-01, TDX-CERT-01
Generated from untrust 1.3.0 (commit 7ef462d9a0c3).