[GCP]Policy deny when set snp measurement as policy

[yuxisun1217]

Describe the bug

In GCP VM if use snp measurement as policy it always hit "PolicyDeny" error when get-resource.
The attestation step can pass.

Server policy:

package policy
default allow = false
input_tcb := input["tcb-status"]
allow {
    input_tcb["snp"]["measurement"] == "WerZtCZk1U/aVPcHZwOG9hsdO9NOLajI+awGfmF6Cq5GIzBKSqmLswdWr/tLbAoF"
}

Attestation token payload:

{
  "customized_claims": {
    "init_data": null,
    "runtime_data": {
      "nonce": "Pn26/CYqumELcdg0zIV989Nll5HEZ/rEF8pUGeiHAgQ=",
      "tee-pubkey": {
        "alg": "RSA1_5",
        "e": "AQAB",
        "kty": "RSA",
        "n": "pRw83NogaTIw4yV4dejWS7txWBPnt8lSh6kD_k_Sb76GXfSZutHNckPu8zEtepW4KP2z5qkUDpqKfgM0QLNOcLjDG6Vxok69ovLOPItdEg6x52VXrT6PGtBMIPmzcgxbVFhkVp2WoOiI6ZbejFyWxTqcR2SvivgdtfCTgFTKBQdRIFjjmGOfAwqHGZ-r91yoXGWpKOIcNtu7Bg9wZowikqoBndA8zCqRtaOC3q2k3B1uEPiUCHbvePsBOTnudTsDngxEmylA7L4sMtdm21JghjEi3i9Pton5K0WGQ4f7MVbVIfTK-hbOvpJwtqGp8C4lrmWaXf919XmF7W3-lFXEtQ"
      }
    }
  },
  "evaluation-reports": [
    {
      "policy-hash": "c0e7929671fb6780387f54760d84d65d2ce96093dfb33efda21f5eb05afcda77bba444c02cd177b23a5d350716726157",
      "policy-id": "default"
    }
  ],
  "exp": 1740477661,
  "iat": 1740477361,
  "iss": "CoCo-Attestation-Service",
  "jti": "NW16c3ZO3x",
  "nbf": 1740477361,
  "tcb-status": "{\"init_data\":\"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=\",\"report_data\":\"hnmityIPJY64Q0Dxk2KBLwVyIuB2lFju8QxCigbQPQVk59DUtQphGhIKeAIqW7XvAAAAAAAAAAAAAAAAAAAAAA==\",\"snp.measurement\":\"WerZtCZk1U/aVPcHZwOG9hsdO9NOLajI+awGfmF6Cq5GIzBKSqmLswdWr/tLbAoF\",\"snp.platform_smt_enabled\":\"1\",\"snp.platform_tsme_enabled\":\"0\",\"snp.policy_abi_major\":\"0\",\"snp.policy_abi_minor\":\"0\",\"snp.policy_debug_allowed\":\"0\",\"snp.policy_migrate_ma\":\"0\",\"snp.policy_single_socket\":\"0\",\"snp.policy_smt_allowed\":\"1\",\"snp.reported_tcb_bootloader\":\"4\",\"snp.reported_tcb_microcode\":\"219\",\"snp.reported_tcb_snp\":\"24\",\"snp.reported_tcb_tee\":\"0\"}",
  "tee": "snp"
}

How to reproduce

kbs-client --url https://trusteeserver:8080 --cert-file /root/host.crt get-resource --attestation-token /root/gcp_attestation_token --tee-key-file /root/trustee/kbs/test/tee_key.pem --path default/test/dummy_test

CoCo version information

kbs 0.1.0

What TEE are you seeing the problem on

Snp

Failing command and relevant log output

Server debug log:
debug.log

[fitzthum]

Hm, it would be useful to see the attestation token itself to make sure that it matches up with the policy. Can you get that via debug? (It's not the same as the attestation info that is currently being printed) You'll probably need to add a debug entry in the simple attestation token broker