feat(worker): enforce durable trust state

internal/distworker/trust_test.go

@@ -0,0 +1,63 @@
+package distworker
+
+import (
+	"crypto/ed25519"
+	"crypto/rand"
+	"encoding/base64"
+	"encoding/json"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"rocketgit.ru/rsmon/worker/internal/wire"
+)
+
+func signedInit(t *testing.T, private ed25519.PrivateKey, account, version int64) *wire.WorkerInit {
+	t.Helper()
+	init := &wire.WorkerInit{WorkerID: "w", SigningKeyID: "v1", AccountID: &account, ConfigVersion: version, ExpiresAt: time.Now().Add(time.Minute).Format(time.RFC3339Nano)}
+	body, err := json.Marshal(init)
+	require.NoError(t, err)
+	init.Signature = base64.StdEncoding.EncodeToString(ed25519.Sign(private, body))
+	return init
+}
+
+func TestVerifyInitRejectsTamperWrongKeyAndAccountChange(t *testing.T) {
+	pub, priv, err := ed25519.GenerateKey(rand.Reader)
+	require.NoError(t, err)
+	r := NewRunner(&Config{})
+	r.state = workerState{WorkerID: "w", VerificationKey: base64.StdEncoding.EncodeToString(pub), SigningKeyID: "v1", AccountID: 1}
+	init := signedInit(t, priv, 1, 1)
+	require.NoError(t, r.verifyInit(init))
+	init.ConfigVersion = 2
+	assert.Error(t, r.verifyInit(init), "tamper must invalidate signature")
+	_, other, err := ed25519.GenerateKey(rand.Reader)
+	require.NoError(t, err)
+	assert.Error(t, r.verifyInit(signedInit(t, other, 1, 2)), "wrong key")
+	assert.Error(t, r.verifyInit(signedInit(t, priv, 2, 2)), "account scope must be immutable")
+	unknown := signedInit(t, priv, 1, 2)
+	unknown.SigningKeyID = "unknown"
+	assert.Error(t, r.verifyInit(unknown), "unknown key id")
+}
+
+func TestVerifyInitAcceptsIdenticalRestartReplayOnly(t *testing.T) {
+	pub, priv, err := ed25519.GenerateKey(rand.Reader)
+	require.NoError(t, err)
+	first := NewRunner(&Config{})
+	first.state = workerState{WorkerID: "w", VerificationKey: base64.StdEncoding.EncodeToString(pub), SigningKeyID: "v1", AccountID: 1}
+	init := signedInit(t, priv, 1, 4)
+	require.NoError(t, first.verifyInit(init))
+	// Restart restores only durable identity state. The exact verified snapshot
+	// remains safe to replay at the same generation.
+	restarted := NewRunner(&Config{})
+	restarted.state = first.state
+	require.NoError(t, restarted.verifyInit(signedInit(t, priv, 1, 4)))
+	assert.Error(t, restarted.verifyInit(signedInit(t, priv, 1, 3)), "older generation")
+	different := signedInit(t, priv, 1, 4)
+	different.RegionCode = "other"
+	body, err := json.Marshal(&wire.WorkerInit{WorkerID: different.WorkerID, SigningKeyID: different.SigningKeyID, AccountID: different.AccountID, ConfigVersion: different.ConfigVersion, ExpiresAt: different.ExpiresAt, RegionCode: different.RegionCode})
+	require.NoError(t, err)
+	different.Signature = base64.StdEncoding.EncodeToString(ed25519.Sign(priv, body))
+	assert.Error(t, restarted.verifyInit(different), "same generation different content")
+	require.NoError(t, restarted.verifyInit(signedInit(t, priv, 1, 5)), "newer generation")
+}