[#229] netmap: Improve `UpdateState` in notary-enabled environment

Require `UpdateState` to be called by both storage node and the alphabet
in notary-enabled environment, fail if only one of the signatures is present.
`UpdateStateIR` can be use for force updates by the alphabet.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

netmap/netmap_contract.go

@@ -274,10 +274,19 @@ func AddPeer(nodeInfo []byte) {
 	addToNetmap(ctx, candidate)
 }
 
-// UpdateState method updates state of node from the network map candidate list
-// if it was invoked by Alphabet node. If it was invoked by public key owner,
-// then it produces UpdateState notification. Otherwise method throws panic.
+// UpdateState method updates state of node from the network map candidate list.
+// For notary-ENABLED environment tx must be signed by both storage node and the alphabet.
+// To force update without storage node signature, see `UpdateStateIR`.
 //
+// For notary-DISABLED environment the behaviour depends on who signed the transaction:
+// 1. If it was signed by alphabet, go into voting.
+// 2. If it was signed by a storage node, emit `UpdateState` notification.
+// 2. Fail in any other case.
+//
+// The behaviour can be summarized in the following table:
+// | notary \ Signer | Storage node | Alphabet | Both                  |
+// | ENABLED         | FAIL         | FAIL     | OK                    |
+// | DISABLED        | NOTIFICATION | OK       | OK (same as alphabet) |
 // State argument defines node state. The only supported state now is (2) --
 // offline state. Node is removed from network map candidate list.
 //
@@ -290,27 +299,18 @@ func UpdateState(state int, publicKey interop.PublicKey) {
 	ctx := storage.GetContext()
 	notaryDisabled := storage.Get(ctx, notaryDisabledKey).(bool)
 
-	var ( // for invocation collection without notary
-		alphabet []common.IRNode
-		nodeKey  []byte
-	)
-
 	if notaryDisabled {
-		alphabet = common.AlphabetNodes()
-		nodeKey = common.InnerRingInvoker(alphabet)
-	}
+		alphabet := common.AlphabetNodes()
+		nodeKey := common.InnerRingInvoker(alphabet)
 
-	// If notary is enabled or caller is not an alphabet node,
-	// just emit the notification for alphabet.
-	if !notaryDisabled || len(nodeKey) == 0 {
-		common.CheckWitness(publicKey)
-		if notaryDisabled {
+		// If caller is not an alphabet node,
+		// just emit the notification for alphabet.
+		if len(nodeKey) == 0 {
+			common.CheckWitness(publicKey)
 			runtime.Notify("UpdateState", state, publicKey)
+			return
 		}
-		return
-	}
 
-	if notaryDisabled {
 		threshold := len(alphabet)*2/3 + 1
 		id := common.InvokeID([]interface{}{state, publicKey}, []byte("update"))
 
@@ -320,6 +320,9 @@ func UpdateState(state int, publicKey interop.PublicKey) {
 		}
 
 		common.RemoveVotes(ctx, id)
+	} else {
+		common.CheckWitness(publicKey)
+		common.CheckAlphabetWitness(common.AlphabetAddress())
 	}
 
 	switch nodeState(state) {

tests/netmap_test.go

@@ -191,40 +191,71 @@ func checkSnapshot(t *testing.T, s *vm.Stack, nodes []testNodeInfo) {
 	require.ElementsMatch(t, expected, actual, "snapshot is different")
 }
 
-func TestUpdateState(t *testing.T) {
+func TestUpdateStateIR(t *testing.T) {
 	cNm := newNetmapInvoker(t)
 
 	acc := cNm.NewAccount(t)
-	cAcc := cNm.WithSigners(acc)
 	dummyInfo := dummyNodeInfo(acc)
-
-	cAcc.Invoke(t, stackitem.Null{}, "addPeer", dummyInfo.raw)
 	cNm.Invoke(t, stackitem.Null{}, "addPeerIR", dummyInfo.raw)
 
-	pub, ok := vm.ParseSignatureContract(acc.Script())
-	require.True(t, ok)
+	pub := acc.(neotest.SingleSigner).Account().PrivateKey().PublicKey().Bytes()
 
-	t.Run("missing witness", func(t *testing.T) {
-		cAcc.InvokeFail(t, common.ErrAlphabetWitnessFailed,
-			"updateStateIR", int64(2), pub)
-		cNm.InvokeFail(t, common.ErrWitnessFailed,
-			"updateState", int64(2), pub)
+	t.Run("must be signed by the alphabet", func(t *testing.T) {
+		cAcc := cNm.WithSigners(acc)
+		cAcc.InvokeFail(t, common.ErrAlphabetWitnessFailed, "updateStateIR", int64(2), pub)
+	})
+	t.Run("invalid state", func(t *testing.T) {
+		cNm.InvokeFail(t, "unsupported state", "updateStateIR", int64(42), pub)
 	})
 
-	h := cAcc.Invoke(t, stackitem.Null{}, "updateState", int64(2), pub)
-	aer := cAcc.CheckHalt(t, h)
-	require.Equal(t, 0, len(aer.Events))
+	checkNetmapCandidates(t, cNm, 1)
+	t.Run("good", func(t *testing.T) {
+		cNm.Invoke(t, stackitem.Null{}, "updateStateIR", int64(2), pub)
+		checkNetmapCandidates(t, cNm, 0)
+	})
+}
 
-	// Check that updating happens only after `updateState` is called by the alphabet.
-	s, err := cAcc.TestInvoke(t, "netmapCandidates")
+func TestUpdateState(t *testing.T) {
+	cNm := newNetmapInvoker(t)
+
+	accs := []neotest.Signer{cNm.NewAccount(t), cNm.NewAccount(t)}
+	pubs := make([][]byte, len(accs))
+	for i := range accs {
+		dummyInfo := dummyNodeInfo(accs[i])
+		cNm.Invoke(t, stackitem.Null{}, "addPeerIR", dummyInfo.raw)
+		pubs[i] = accs[i].(neotest.SingleSigner).Account().PrivateKey().PublicKey().Bytes()
+	}
+
+	t.Run("missing witness", func(t *testing.T) {
+		cAcc := cNm.WithSigners(accs[0])
+		cNm.InvokeFail(t, common.ErrWitnessFailed, "updateState", int64(2), pubs[0])
+		cAcc.InvokeFail(t, common.ErrAlphabetWitnessFailed, "updateState", int64(2), pubs[0])
+		cAcc.InvokeFail(t, common.ErrWitnessFailed, "updateState", int64(2), pubs[1])
+	})
+
+	checkNetmapCandidates(t, cNm, 2)
+
+	cBoth := cNm.WithSigners(accs[0], cNm.Committee)
+
+	cBoth.Invoke(t, stackitem.Null{}, "updateState", int64(2), pubs[0])
+	checkNetmapCandidates(t, cNm, 1)
+
+	t.Run("remove already removed node", func(t *testing.T) {
+		cBoth.Invoke(t, stackitem.Null{}, "updateState", int64(2), pubs[0])
+		checkNetmapCandidates(t, cNm, 1)
+	})
+
+	cBoth = cNm.WithSigners(accs[1], cNm.Committee)
+	cBoth.Invoke(t, stackitem.Null{}, "updateState", int64(2), pubs[1])
+	checkNetmapCandidates(t, cNm, 0)
+}
+
+func checkNetmapCandidates(t *testing.T, c *neotest.ContractInvoker, size int) {
+	s, err := c.TestInvoke(t, "netmapCandidates")
 	require.NoError(t, err)
 	require.Equal(t, 1, s.Len())
 
 	arr, ok := s.Pop().Value().([]stackitem.Item)
 	require.True(t, ok)
-	require.Equal(t, 1, len(arr))
-
-	cNm.Invoke(t, stackitem.Null{}, "updateStateIR", int64(2), pub)
-
-	cAcc.Invoke(t, stackitem.NewArray([]stackitem.Item{}), "netmapCandidates")
+	require.Equal(t, size, len(arr))
 }