Add interface to verify trusted MailServers (#1112)

The goal of this PR is to add an interface to verify MailServers. In this PR, MailServers are hardcoded in status-go. The next iteration will use a smart contract.

node/node.go

@@ -327,6 +327,14 @@ func parseNodesV5(enodes []string) []*discv5.Node {
 	return nodes
 }
 
+func parseNodesToNodeID(enodes []string) []discover.NodeID {
+	nodeIDs := make([]discover.NodeID, 0, len(enodes))
+	for _, node := range parseNodes(enodes) {
+		nodeIDs = append(nodeIDs, node.ID)
+	}
+	return nodeIDs
+}
+
 // whisperTimeSource get timeSource to be used by whisper
 func whisperTimeSource(ctx *node.ServiceContext) (func() time.Time, error) {
 	var timeSource *timesource.NTPTimeSource

node/node_test.go

@@ -1,8 +1,10 @@
 package node
 
 import (
+	"fmt"
 	"testing"
 
+	"github.com/ethereum/go-ethereum/p2p/discover"
 	. "github.com/status-im/status-go/t/utils"
 	"github.com/stretchr/testify/require"
 	"github.com/syndtr/goleveldb/leveldb"
@@ -57,3 +59,12 @@ func TestMakeNodeMalformedBootnodes(t *testing.T) {
 	_, err = MakeNode(config, db)
 	require.NoError(t, err)
 }
+
+func TestParseNodesToNodeID(t *testing.T) {
+	nodeIDs := parseNodesToNodeID([]string{
+		"enode://badkey@127.0.0.1:30303",
+		fmt.Sprintf("enode://%s@127.0.0.1:30303", discover.NodeID{1}),
+	})
+	require.Len(t, nodeIDs, 1)
+	require.Equal(t, discover.NodeID{1}, nodeIDs[0])
+}

node/status_node.go

@@ -223,6 +223,7 @@ func (n *StatusNode) startDiscovery() error {
 	options := peers.NewDefaultOptions()
 	// TODO(dshulyak) consider adding a flag to define this behaviour
 	options.AllowStop = len(n.config.RegisterTopics) == 0
+	options.TrustedMailServers = parseNodesToNodeID(n.config.ClusterConfig.TrustedMailServers)
 	n.peerPool = peers.NewPeerPool(
 		n.discovery,
 		n.config.RequireTopics,

params/cluster.go

@@ -12,6 +12,7 @@ type cluster struct {
 	NetworkID   int      `json:"networkID"`
 	StaticNodes []string `json:"staticnodes"`
 	BootNodes   []string `json:"bootnodes"`
+	MailServers []string `json:"mailservers"` // list of trusted mail servers
 }
 
 var ropstenCluster = cluster{
@@ -26,6 +27,14 @@ var ropstenCluster = cluster{
 		"enode://a6a2a9b3a7cbb0a15da74301537ebba549c990e3325ae78e1272a19a3ace150d03c184b8ac86cc33f1f2f63691e467d49308f02d613277754c4dccd6773b95e8@206.189.243.176:30304", // node-01.do-ams3.eth.beta
 		"enode://207e53d9bf66be7441e3daba36f53bfbda0b6099dba9a865afc6260a2d253fb8a56a72a48598a4f7ba271792c2e4a8e1a43aaef7f34857f520c8c820f63b44c8@35.224.15.65:30304",    // node-01.gc-us-central1-a.eth.beta
 	},
+	MailServers: []string{
+		"enode://c42f368a23fa98ee546fd247220759062323249ef657d26d357a777443aec04db1b29a3a22ef3e7c548e18493ddaf51a31b0aed6079bd6ebe5ae838fcfaf3a49@206.189.108.78:30504", // mail-01.do-ams3.eth.beta
+		"enode://7aa648d6e855950b2e3d3bf220c496e0cae4adfddef3e1e6062e6b177aec93bc6cdcf1282cb40d1656932ebfdd565729da440368d7c4da7dbd4d004b1ac02bf8@206.189.108.63:30504", // mail-02.do-ams3.eth.beta
+		"enode://8a64b3c349a2e0ef4a32ea49609ed6eb3364be1110253c20adc17a3cebbc39a219e5d3e13b151c0eee5d8e0f9a8ba2cd026014e67b41a4ab7d1d5dd67ca27427@206.189.7.30:30504",   // mail-03.do-ams3.eth.beta
+		"enode://7de99e4cb1b3523bd26ca212369540646607c721ad4f3e5c821ed9148150ce6ce2e72631723002210fac1fd52dfa8bbdf3555e05379af79515e1179da37cc3db@35.188.19.210:30504",  // mail-01.gc-us-central1-a.eth.beta
+		"enode://015e22f6cd2b44c8a51bd7a23555e271e0759c7d7f52432719665a74966f2da456d28e154e836bee6092b4d686fe67e331655586c57b718be3997c1629d24167@35.226.21.19:30504",   // mail-02.gc-us-central1-a.eth.beta
+		"enode://531e252ec966b7e83f5538c19bf1cde7381cc7949026a6e499b6e998e695751aadf26d4c98d5a4eabfb7cefd31c3c88d600a775f14ed5781520a88ecd25da3c6@35.225.227.79:30504",  // mail-03.gc-us-central1-a.eth.beta
+	},
 }
 
 var rinkebyCluster = cluster{
@@ -40,6 +49,10 @@ var rinkebyCluster = cluster{
 		"enode://ba41aa829287a0a9076d9bffed97c8ce2e491b99873288c9e886f16fd575306ac6c656db4fbf814f5a9021aec004ffa9c0ae8650f92fd10c12eeb7c364593eb3@51.15.69.147:30303",
 		"enode://28ecf5272b560ca951f4cd7f1eb8bd62da5853b026b46db432c4b01797f5b0114819a090a72acd7f32685365ecd8e00450074fa0673039aefe10f3fb666e0f3f@51.15.76.249:30303",
 	},
+	MailServers: []string{
+		"enode://43829580446ad138386dadb7fa50b6bd4d99f7c28659a0bc08115f8c0380005922a340962496f6af756a42b94a1522baa38a694fa27de59c3a73d4e08d5dbb31@206.189.6.48:30504",
+		"enode://70a2004e78399075f566033c42e9a0b1d43c683d4742755bb5457d03191be66a1b48c2b4fb259696839f28646a5828a1958b900860e27897f984ad0fc8482404@206.189.56.154:30504",
+	},
 }
 
 var mainnetCluster = cluster{
@@ -54,6 +67,14 @@ var mainnetCluster = cluster{
 		"enode://a6a2a9b3a7cbb0a15da74301537ebba549c990e3325ae78e1272a19a3ace150d03c184b8ac86cc33f1f2f63691e467d49308f02d613277754c4dccd6773b95e8@206.189.243.176:30304", // node-01.do-ams3.eth.beta
 		"enode://207e53d9bf66be7441e3daba36f53bfbda0b6099dba9a865afc6260a2d253fb8a56a72a48598a4f7ba271792c2e4a8e1a43aaef7f34857f520c8c820f63b44c8@35.224.15.65:30304",    // node-01.gc-us-central1-a.eth.beta
 	},
+	MailServers: []string{
+		"enode://c42f368a23fa98ee546fd247220759062323249ef657d26d357a777443aec04db1b29a3a22ef3e7c548e18493ddaf51a31b0aed6079bd6ebe5ae838fcfaf3a49@206.189.108.78:30504", // mail-01.do-ams3.eth.beta
+		"enode://7aa648d6e855950b2e3d3bf220c496e0cae4adfddef3e1e6062e6b177aec93bc6cdcf1282cb40d1656932ebfdd565729da440368d7c4da7dbd4d004b1ac02bf8@206.189.108.63:30504", // mail-02.do-ams3.eth.beta
+		"enode://8a64b3c349a2e0ef4a32ea49609ed6eb3364be1110253c20adc17a3cebbc39a219e5d3e13b151c0eee5d8e0f9a8ba2cd026014e67b41a4ab7d1d5dd67ca27427@206.189.7.30:30504",   // mail-03.do-ams3.eth.beta
+		"enode://7de99e4cb1b3523bd26ca212369540646607c721ad4f3e5c821ed9148150ce6ce2e72631723002210fac1fd52dfa8bbdf3555e05379af79515e1179da37cc3db@35.188.19.210:30504",  // mail-01.gc-us-central1-a.eth.beta
+		"enode://015e22f6cd2b44c8a51bd7a23555e271e0759c7d7f52432719665a74966f2da456d28e154e836bee6092b4d686fe67e331655586c57b718be3997c1629d24167@35.226.21.19:30504",   // mail-02.gc-us-central1-a.eth.beta
+		"enode://531e252ec966b7e83f5538c19bf1cde7381cc7949026a6e499b6e998e695751aadf26d4c98d5a4eabfb7cefd31c3c88d600a775f14ed5781520a88ecd25da3c6@35.225.227.79:30504",  // mail-03.gc-us-central1-a.eth.beta
+	},
 }
 
 var betaCluster = []cluster{ropstenCluster, rinkebyCluster, mainnetCluster}

params/config.go

@@ -200,6 +200,9 @@ type ClusterConfig struct {
 	// for a given mode (production vs development)
 	BootNodes []string
 
+	// TrustedMailServers is a list of verified Mail Servers.
+	TrustedMailServers []string
+
 	// RendezvousNodes is a rendezvous discovery server.
 	RendezvousNodes []string
 }
@@ -644,6 +647,7 @@ func (c *NodeConfig) updateClusterConfig() error {
 			if len(cluster.BootNodes) == 0 {
 				c.NoDiscovery = true
 			}
+			c.ClusterConfig.TrustedMailServers = cluster.MailServers
 			break
 		}
 	}

peers/cotopicpool.go

@@ -1,6 +1,8 @@
 package peers
 
 import (
+	"context"
+
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/p2p/discover"
 	"github.com/ethereum/go-ethereum/p2p/discv5"
@@ -8,22 +10,29 @@ import (
 	"github.com/status-im/status-go/signal"
 )
 
+// Verifier verifies if a give node is trusted.
+type Verifier interface {
+	VerifyNode(context.Context, discover.NodeID) bool
+}
+
 // MailServerDiscoveryTopic topic name for mailserver discovery.
 const MailServerDiscoveryTopic = "whispermail"
 
 // MailServerDiscoveryLimits default mailserver discovery limits.
 var MailServerDiscoveryLimits = params.Limits{Min: 3, Max: 3}
 
-// newCacheOnlyTopicPool returns instance of CacheOnlyTopicPool.
-func newCacheOnlyTopicPool(t *TopicPool) *cacheOnlyTopicPool {
-	return &cacheOnlyTopicPool{
-		TopicPool: t,
-	}
-}
-
 // cacheOnlyTopicPool handles a mail server topic pool.
 type cacheOnlyTopicPool struct {
 	*TopicPool
+	verifier Verifier
+}
+
+// newCacheOnlyTopicPool returns instance of CacheOnlyTopicPool.
+func newCacheOnlyTopicPool(t *TopicPool, verifier Verifier) *cacheOnlyTopicPool {
+	return &cacheOnlyTopicPool{
+		TopicPool: t,
+		verifier:  verifier,
+	}
 }
 
 // MaxReached checks if the max allowed peers is reached or not. When true
@@ -45,14 +54,34 @@ var sendEnodeDiscovered = signal.SendEnodeDiscovered
 // ConfirmAdded calls base TopicPool ConfirmAdded method and sends a signal
 // confirming the enode has been discovered.
 func (t *cacheOnlyTopicPool) ConfirmAdded(server *p2p.Server, nodeID discover.NodeID) {
+	trusted := t.verifier.VerifyNode(context.TODO(), nodeID)
+	if trusted {
+		// add to cache only if trusted
 		t.TopicPool.ConfirmAdded(server, nodeID)
 		sendEnodeDiscovered(nodeID.String(), string(t.topic))
+		t.subtractToLimits()
+	}
 
 	id := discv5.NodeID(nodeID)
+
+	// If a peer was trusted, it was moved to connectedPeers,
+	// signal was sent and we can safely remove it.
 	if peer, ok := t.connectedPeers[id]; ok {
 		t.removeServerPeer(server, peer)
+		// Delete it from `connectedPeers` immediately to
+		// prevent removing it from the cache which logic is
+		// implemented in TopicPool.
 		delete(t.connectedPeers, id)
-		t.subtractToLimits()
+	}
+
+	// It a peer was not trusted, it is still in pendingPeers.
+	// We should remove it from the p2p.Server.
+	if peer, ok := t.pendingPeers[id]; ok {
+		t.removeServerPeer(server, peer.peerInfo)
+		// Delete it from `connectedPeers` immediately to
+		// prevent removing it from the cache which logic is
+		// implemented in TopicPool.
+		delete(t.pendingPeers, id)
 	}
 }
 

peers/cotopicpool_test.go

@@ -1,6 +1,7 @@
 package peers
 
 import (
+	"context"
 	"testing"
 	"time"
 
@@ -42,7 +43,7 @@ func (s *CacheOnlyTopicPoolSuite) SetupTest() {
 	cache, err := newInMemoryCache()
 	s.Require().NoError(err)
 	t := newTopicPool(nil, MailServerDiscoveryTopic, limits, 100*time.Millisecond, 200*time.Millisecond, cache)
-	s.topicPool = newCacheOnlyTopicPool(t)
+	s.topicPool = newCacheOnlyTopicPool(t, &testTrueVerifier{})
 	s.topicPool.running = 1
 	// This is a buffered channel to simplify testing.
 	// If your test generates more than 10 mode changes,
@@ -70,15 +71,15 @@ func (s *CacheOnlyTopicPoolSuite) TestReplacementPeerIsCounted() {
 	// When we stop searching for peers (when Max limit is reached)
 	s.topicPool.StopSearch(s.peer)
 	s.True(s.topicPool.MaxReached())
-	s.Equal(s.topicPool.limits.Max, 0)
+	s.Equal(0, s.topicPool.limits.Max)
-	s.Equal(s.topicPool.limits.Min, 0)
+	s.Equal(0, s.topicPool.limits.Min)
 
 	// Then we should drop all connected peers
 	s.Equal(len(s.topicPool.connectedPeers), 0)
 
 	// And cached peers should remain
 	cachedPeers := s.topicPool.cache.GetPeersRange(s.topicPool.topic, s.topicPool.maxCachedPeers)
-	s.Equal(len(cachedPeers), 1)
+	s.Equal(1, len(cachedPeers))
 }
 
 func (s *CacheOnlyTopicPoolSuite) TestConfirmAddedSignals() {
@@ -94,3 +95,35 @@ func (s *CacheOnlyTopicPoolSuite) TestConfirmAddedSignals() {
 	s.Equal((discv5.NodeID{1}).String(), sentNodeID)
 	s.Equal(MailServerDiscoveryTopic, sentTopic)
 }
+
+func (s *CacheOnlyTopicPoolSuite) TestNotTrustedPeer() {
+	var signalCalled bool
+	sendEnodeDiscovered = func(_, _ string) { signalCalled = true }
+
+	s.topicPool.limits = params.NewLimits(1, 1)
+	s.topicPool.maxCachedPeers = 1
+	s.topicPool.verifier = &testFalseVerifier{}
+
+	foundPeer := discv5.NewNode(discv5.NodeID{1}, s.peer.Self().IP, 32311, 32311)
+	s.topicPool.processFoundNode(s.peer, foundPeer)
+	s.topicPool.ConfirmAdded(s.peer, discover.NodeID(foundPeer.ID))
+
+	s.False(signalCalled)
+	// limits should not change
+	s.Equal(1, s.topicPool.limits.Max)
+	s.Equal(1, s.topicPool.limits.Min)
+	// not verified peer shoud not be added to the cache
+	s.Equal(0, len(s.topicPool.cache.GetPeersRange(s.topicPool.topic, s.topicPool.limits.Max)))
+}
+
+type testTrueVerifier struct{}
+
+func (v *testTrueVerifier) VerifyNode(context.Context, discover.NodeID) bool {
+	return true
+}
+
+type testFalseVerifier struct{}
+
+func (v *testFalseVerifier) VerifyNode(context.Context, discover.NodeID) bool {
+	return false
+}

peers/peerpool.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/status-im/status-go/discovery"
 	"github.com/status-im/status-go/params"
+	"github.com/status-im/status-go/peers/verifier"
 	"github.com/status-im/status-go/signal"
 )
 
@@ -53,6 +54,8 @@ type Options struct {
 	// TopicStopSearchDelay time stopSearch will be waiting for max cached peers to be
 	// filled before really stopping the search.
 	TopicStopSearchDelay time.Duration
+	// TrustedMailServers is a list of trusted nodes.
+	TrustedMailServers []discover.NodeID
 }
 
 // NewDefaultOptions returns a struct with default Options.
@@ -140,7 +143,7 @@ func (p *PeerPool) Start(server *p2p.Server) error {
 		var topicPool TopicPoolInterface
 		t := newTopicPool(p.discovery, topic, limits, p.opts.SlowSync, p.opts.FastSync, p.cache)
 		if topic == MailServerDiscoveryTopic {
-			topicPool = newCacheOnlyTopicPool(t)
+			topicPool = newCacheOnlyTopicPool(t, verifier.NewLocalVerifier(p.opts.TrustedMailServers))
 		} else {
 			topicPool = t
 		}

peers/peerpool_test.go

@@ -162,7 +162,7 @@ func (s *PeerPoolSimulationSuite) TestPeerPoolCacheEthV5() {
 	config := map[discv5.Topic]params.Limits{
 		topic: params.NewLimits(1, 1),
 	}
-	peerPoolOpts := &Options{100 * time.Millisecond, 100 * time.Millisecond, 0, true, 100 * time.Millisecond}
+	peerPoolOpts := &Options{100 * time.Millisecond, 100 * time.Millisecond, 0, true, 100 * time.Millisecond, nil}
 	cache, err := newInMemoryCache()
 	s.Require().NoError(err)
 	peerPool := NewPeerPool(s.discovery[1], config, cache, peerPoolOpts)
@@ -220,7 +220,7 @@ func (s *PeerPoolSimulationSuite) singleTopicDiscoveryWithFailover() {
 	config := map[discv5.Topic]params.Limits{
 		topic: params.NewLimits(1, 1), // limits are chosen for simplicity of the simulation
 	}
-	peerPoolOpts := &Options{100 * time.Millisecond, 100 * time.Millisecond, 0, true, 0}
+	peerPoolOpts := &Options{100 * time.Millisecond, 100 * time.Millisecond, 0, true, 0, nil}
 	cache, err := newInMemoryCache()
 	s.Require().NoError(err)
 	peerPool := NewPeerPool(s.discovery[1], config, cache, peerPoolOpts)
@@ -302,7 +302,7 @@ func TestPeerPoolMaxPeersOverflow(t *testing.T) {
 	defer func() { assert.NoError(t, discovery.Stop()) }()
 	require.True(t, discovery.Running())
 
-	poolOpts := &Options{DefaultFastSync, DefaultSlowSync, 0, true, 100 * time.Millisecond}
+	poolOpts := &Options{DefaultFastSync, DefaultSlowSync, 0, true, 100 * time.Millisecond, nil}
 	pool := NewPeerPool(discovery, nil, nil, poolOpts)
 	require.NoError(t, pool.Start(peer))
 	require.Equal(t, signal.EventDiscoveryStarted, <-signals)
@@ -355,7 +355,7 @@ func TestPeerPoolDiscV5Timeout(t *testing.T) {
 	require.True(t, discovery.Running())
 
 	// start PeerPool
-	poolOpts := &Options{DefaultFastSync, DefaultSlowSync, time.Millisecond * 100, true, 100 * time.Millisecond}
+	poolOpts := &Options{DefaultFastSync, DefaultSlowSync, time.Millisecond * 100, true, 100 * time.Millisecond, nil}
 	pool := NewPeerPool(discovery, nil, nil, poolOpts)
 	require.NoError(t, pool.Start(server))
 	require.Equal(t, signal.EventDiscoveryStarted, <-signals)
@@ -402,7 +402,7 @@ func TestPeerPoolNotAllowedStopping(t *testing.T) {
 	require.True(t, discovery.Running())
 
 	// start PeerPool
-	poolOpts := &Options{DefaultFastSync, DefaultSlowSync, time.Millisecond * 100, false, 100 * time.Millisecond}
+	poolOpts := &Options{DefaultFastSync, DefaultSlowSync, time.Millisecond * 100, false, 100 * time.Millisecond, nil}
 	pool := NewPeerPool(discovery, nil, nil, poolOpts)
 	require.NoError(t, pool.Start(server))
 
@@ -419,7 +419,7 @@ func (s *PeerPoolSimulationSuite) TestUpdateTopicLimits() {
 	config := map[discv5.Topic]params.Limits{
 		topic: params.NewLimits(1, 1),
 	}
-	peerPoolOpts := &Options{100 * time.Millisecond, 100 * time.Millisecond, 0, true, 100 * time.Millisecond}
+	peerPoolOpts := &Options{100 * time.Millisecond, 100 * time.Millisecond, 0, true, 100 * time.Millisecond, nil}
 	cache, err := newInMemoryCache()
 	s.Require().NoError(err)
 	peerPool := NewPeerPool(s.discovery[1], config, cache, peerPoolOpts)
@@ -447,3 +447,73 @@ func (s *PeerPoolSimulationSuite) TestUpdateTopicLimits() {
 		s.Equal(5, tp.limits.Min)
 	}
 }
+
+func (s *PeerPoolSimulationSuite) TestMailServerPeersDiscovery() {
+	s.setupEthV5()
+
+	// Buffered channels must be used because we expect the events
+	// to be in the same order. Use a buffer length greater than
+	// the expected number of events to avoid deadlock.
+	poolEvents := make(chan string, 10)
+	summaries := make(chan []*p2p.PeerInfo, 10)
+	signal.SetDefaultNodeNotificationHandler(func(jsonEvent string) {
+		var envelope struct {
+			Type  string
+			Event json.RawMessage
+		}
+		s.NoError(json.Unmarshal([]byte(jsonEvent), &envelope))
+
+		switch typ := envelope.Type; typ {
+		case signal.EventDiscoverySummary:
+			poolEvents <- envelope.Type
+			var summary []*p2p.PeerInfo
+			s.NoError(json.Unmarshal(envelope.Event, &summary))
+			summaries <- summary
+		}
+	})
+	defer signal.ResetDefaultNodeNotificationHandler()
+
+	// subscribe for peer events before starting the peer pool
+	events := make(chan *p2p.PeerEvent, 20)
+	subscription := s.peers[1].SubscribeEvents(events)
+	defer subscription.Unsubscribe()
+
+	// create and start topic registry
+	register := NewRegister(s.discovery[0], MailServerDiscoveryTopic)
+	s.Require().NoError(register.Start())
+
+	// create and start peer pool
+	config := map[discv5.Topic]params.Limits{
+		MailServerDiscoveryTopic: params.NewLimits(1, 1),
+	}
+	cache, err := newInMemoryCache()
+	s.Require().NoError(err)
+	peerPoolOpts := &Options{
+		100 * time.Millisecond,
+		100 * time.Millisecond,
+		0,
+		true,
+		100 * time.Millisecond,
+		[]discover.NodeID{s.peers[0].Self().ID},
+	}
+	peerPool := NewPeerPool(s.discovery[1], config, cache, peerPoolOpts)
+	s.Require().NoError(peerPool.Start(s.peers[1]))
+	defer peerPool.Stop()
+
+	// wait for and verify the mail server peer
+	connectedPeer := s.getPeerFromEvent(events, p2p.PeerEventTypeAdd)
+	s.Equal(s.peers[0].Self().ID, connectedPeer)
+
+	// wait for a summary event to be sure that ConfirmAdded() was called
+	s.Equal(signal.EventDiscoverySummary, s.getPoolEvent(poolEvents))
+	s.Equal(s.peers[0].Self().ID.String(), (<-summaries)[0].ID)
+
+	// check cache
+	cachedPeers := peerPool.cache.GetPeersRange(MailServerDiscoveryTopic, 5)
+	s.Require().Len(cachedPeers, 1)
+	s.Equal(s.peers[0].Self().ID[:], cachedPeers[0].ID[:])
+
+	// wait for another summary event as the peer should be removed
+	s.Equal(signal.EventDiscoverySummary, s.getPoolEvent(poolEvents))
+	s.Len(<-summaries, 0)
+}

peers/topicpool_test.go

@@ -325,6 +325,6 @@ func (s *TopicPoolSuite) TestNewTopicPoolInterface() {
 	s.IsType(&TopicPool{}, t)
 
 	tp := newTopicPool(nil, MailServerDiscoveryTopic, limits, 100*time.Millisecond, 200*time.Millisecond, cache)
-	cacheTP := newCacheOnlyTopicPool(tp)
+	cacheTP := newCacheOnlyTopicPool(tp, &testTrueVerifier{})
 	s.IsType(&cacheOnlyTopicPool{}, cacheTP)
 }

peers/verifier/verifier.go

@@ -0,0 +1,30 @@
+package verifier
+
+import (
+	"context"
+
+	"github.com/ethereum/go-ethereum/p2p/discover"
+)
+
+// LocalVerifier verifies nodes based on a provided local list.
+type LocalVerifier struct {
+	KnownPeers map[discover.NodeID]struct{}
+}
+
+// NewLocalVerifier returns a new LocalVerifier instance.
+func NewLocalVerifier(peers []discover.NodeID) *LocalVerifier {
+	knownPeers := make(map[discover.NodeID]struct{})
+	for _, peer := range peers {
+		knownPeers[peer] = struct{}{}
+	}
+
+	return &LocalVerifier{KnownPeers: knownPeers}
+}
+
+// VerifyNode checks if a given node is trusted using a local list.
+func (v *LocalVerifier) VerifyNode(_ context.Context, nodeID discover.NodeID) bool {
+	if _, ok := v.KnownPeers[nodeID]; ok {
+		return true
+	}
+	return false
+}

peers/verifier/verifier_test.go

@@ -0,0 +1,17 @@
+package verifier
+
+import (
+	"context"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/stretchr/testify/require"
+)
+
+func TestLocalVerifierForNodeIDTypes(t *testing.T) {
+	nodeID := discover.NodeID{1}
+
+	v := NewLocalVerifier([]discover.NodeID{{1}})
+	require.True(t, v.VerifyNode(context.TODO(), nodeID))
+	require.False(t, v.VerifyNode(context.TODO(), discover.NodeID{2}))
+}