fleet-enrol: self-heal a stale non-ECC key at the enrol handle

Bench boot failed with "fleet-enrol: ensure key at 0x81010001: key at handle is not ECC: did not contain eccDetail (selector value was 1)": a real host had an RSA key persisted at 0x81010001 (left by an older tpm2-tools/openssl provisioning path), and EnsureKey fatally errored trying to read it as our ECC signing key — so enrolment died before the CSR/POST and the host fell through to a normal boot (no fingerprint, nothing at the broker). EnsureKey now evicts a wrong-type/unusable key at the handle and creates a fresh ECC key. Safe on the enrol path: it only runs on an empty-NV host, so no issued cert references the old key. A valid ECC key is still reused (idempotent retried enrol). Regression: simtest TestEnsureKeyEvictsStaleNonECC pre-plants an RSA key and asserts EnsureKey recreates a usable ECC signer (passes against the go-tpm simulator).
2026-07-02 11:43:03 +00:00
parent 1e1265b5a0
commit 63cd4049ff
2 changed files with 81 additions and 2 deletions
@@ -99,3 +99,67 @@ func TestNVWriteAndPresence(t *testing.T) {
 		t.Fatalf("WriteNVCert rewrite: %v", err)
 	}
 }
+
+// Regression for the bench failure "key at handle is not ECC ... selector value
+// was 1": an older provisioning path left an RSA key at 0x81010001, and EnsureKey
+// fatally failed trying to read it as ECC. It must now evict the stale key and
+// create a fresh ECC one.
+func TestEnsureKeyEvictsStaleNonECC(t *testing.T) {
+	tpm := openSim(t)
+	const h = tpm2.TPMHandle(0x81010001)
+
+	// Pre-populate the handle with an RSA key (mimics tpm2-tools/openssl default).
+	rsaTmpl := tpm2.TPMTPublic{
+		Type:    tpm2.TPMAlgRSA,
+		NameAlg: tpm2.TPMAlgSHA256,
+		ObjectAttributes: tpm2.TPMAObject{
+			FixedTPM: true, FixedParent: true, SensitiveDataOrigin: true,
+			UserWithAuth: true, SignEncrypt: true, NoDA: true,
+		},
+		Parameters: tpm2.NewTPMUPublicParms(tpm2.TPMAlgRSA, &tpm2.TPMSRSAParms{
+			Symmetric: tpm2.TPMTSymDefObject{Algorithm: tpm2.TPMAlgNull},
+			Scheme: tpm2.TPMTRSAScheme{
+				Scheme: tpm2.TPMAlgRSASSA,
+				Details: tpm2.NewTPMUAsymScheme(tpm2.TPMAlgRSASSA, &tpm2.TPMSSigSchemeRSASSA{
+					HashAlg: tpm2.TPMAlgSHA256,
+				}),
+			},
+			KeyBits: 2048,
+		}),
+	}
+	cp, err := tpm2.CreatePrimary{
+		PrimaryHandle: tpm2.TPMRHOwner, InPublic: tpm2.New2B(rsaTmpl),
+	}.Execute(tpm)
+	if err != nil {
+		t.Fatalf("create RSA primary: %v", err)
+	}
+	if _, err := (tpm2.EvictControl{
+		Auth:             tpm2.TPMRHOwner,
+		ObjectHandle:     &tpm2.NamedHandle{Handle: cp.ObjectHandle, Name: cp.Name},
+		PersistentHandle: h,
+	}).Execute(tpm); err != nil {
+		t.Fatalf("persist stale RSA key: %v", err)
+	}
+	_, _ = (tpm2.FlushContext{FlushHandle: cp.ObjectHandle}).Execute(tpm)
+
+	// EnsureKey must self-heal: evict the RSA key, create + persist a fresh ECC key.
+	signer, created, err := tpmkey.EnsureKey(tpm, h)
+	if err != nil {
+		t.Fatalf("EnsureKey over stale RSA key: %v", err)
+	}
+	if !created {
+		t.Errorf("EnsureKey should have recreated the key (created=true)")
+	}
+	if _, ok := signer.Public().(*ecdsa.PublicKey); !ok {
+		t.Fatalf("recreated signer is not ECDSA")
+	}
+	// and it must be usable for signing (the whole point of the recovery).
+	dig := sha256.Sum256([]byte("post-heal"))
+	sig, err := signer.Sign(rand.Reader, dig[:], nil)
+	if err != nil {
+		t.Fatalf("sign after heal: %v", err)
+	}
+	if !ecdsa.VerifyASN1(signer.Public().(*ecdsa.PublicKey), dig[:], sig) {
+		t.Fatalf("post-heal ECDSA signature did not verify")
+	}
+}