p2p/discover: remove type encPubkey (#30172)

The pubkey type was moved to package v4wire a long time ago. Remaining uses of
encPubkey were probably left in due to laziness.

p2p/discover/node.go

@@ -17,16 +17,10 @@
 package discover
 
 import (
-	"crypto/ecdsa"
-	"crypto/elliptic"
-	"errors"
-	"math/big"
 	"slices"
 	"sort"
 	"time"
 
-	"github.com/ethereum/go-ethereum/common/math"
-	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 )
 
@@ -48,33 +42,6 @@ type tableNode struct {
 	isValidatedLive bool      // true if existence of node is considered validated right now
 }
 
-type encPubkey [64]byte
-
-func encodePubkey(key *ecdsa.PublicKey) encPubkey {
-	var e encPubkey
-	math.ReadBits(key.X, e[:len(e)/2])
-	math.ReadBits(key.Y, e[len(e)/2:])
-	return e
-}
-
-func decodePubkey(curve elliptic.Curve, e []byte) (*ecdsa.PublicKey, error) {
-	if len(e) != len(encPubkey{}) {
-		return nil, errors.New("wrong size public key data")
-	}
-	p := &ecdsa.PublicKey{Curve: curve, X: new(big.Int), Y: new(big.Int)}
-	half := len(e) / 2
-	p.X.SetBytes(e[:half])
-	p.Y.SetBytes(e[half:])
-	if !p.Curve.IsOnCurve(p.X, p.Y) {
-		return nil, errors.New("invalid curve point")
-	}
-	return p, nil
-}
-
-func (e encPubkey) id() enode.ID {
-	return enode.ID(crypto.Keccak256Hash(e[:]))
-}
-
 func unwrapNodes(ns []*tableNode) []*enode.Node {
 	result := make([]*enode.Node, len(ns))
 	for i, n := range ns {

p2p/discover/table_util_test.go

@@ -30,6 +30,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/p2p/discover/v4wire"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
 )
@@ -284,7 +285,7 @@ func hexEncPrivkey(h string) *ecdsa.PrivateKey {
 }
 
 // hexEncPubkey decodes h as a public key.
-func hexEncPubkey(h string) (ret encPubkey) {
+func hexEncPubkey(h string) (ret v4wire.Pubkey) {
 	b, err := hex.DecodeString(h)
 	if err != nil {
 		panic(err)

p2p/discover/v4_lookup_test.go

@@ -34,7 +34,7 @@ func TestUDPv4_Lookup(t *testing.T) {
 	test := newUDPTest(t)
 
 	// Lookup on empty table returns no nodes.
-	targetKey, _ := decodePubkey(crypto.S256(), lookupTestnet.target[:])
+	targetKey, _ := v4wire.DecodePubkey(crypto.S256(), lookupTestnet.target)
 	if results := test.udp.LookupPubkey(targetKey); len(results) > 0 {
 		t.Fatalf("lookup on empty table returned %d results: %#v", len(results), results)
 	}
@@ -56,7 +56,7 @@ func TestUDPv4_Lookup(t *testing.T) {
 	results := <-resultC
 	t.Logf("results:")
 	for _, e := range results {
-		t.Logf("  ld=%d, %x", enode.LogDist(lookupTestnet.target.id(), e.ID()), e.ID().Bytes())
+		t.Logf("  ld=%d, %x", enode.LogDist(lookupTestnet.target.ID(), e.ID()), e.ID().Bytes())
 	}
 	if len(results) != bucketSize {
 		t.Errorf("wrong number of results: got %d, want %d", len(results), bucketSize)
@@ -142,7 +142,7 @@ func serveTestnet(test *udpTest, testnet *preminedTestnet) {
 			case *v4wire.Ping:
 				test.packetInFrom(nil, key, to, &v4wire.Pong{Expiration: futureExp, ReplyTok: hash})
 			case *v4wire.Findnode:
-				dist := enode.LogDist(n.ID(), testnet.target.id())
+				dist := enode.LogDist(n.ID(), testnet.target.ID())
 				nodes := testnet.nodesAtDistance(dist - 1)
 				test.packetInFrom(nil, key, to, &v4wire.Neighbors{Expiration: futureExp, Nodes: nodes})
 			}
@@ -156,12 +156,12 @@ func checkLookupResults(t *testing.T, tn *preminedTestnet, results []*enode.Node
 	t.Helper()
 	t.Logf("results:")
 	for _, e := range results {
-		t.Logf("  ld=%d, %x", enode.LogDist(tn.target.id(), e.ID()), e.ID().Bytes())
+		t.Logf("  ld=%d, %x", enode.LogDist(tn.target.ID(), e.ID()), e.ID().Bytes())
 	}
 	if hasDuplicates(results) {
 		t.Errorf("result set contains duplicate entries")
 	}
-	if !sortedByDistanceTo(tn.target.id(), results) {
+	if !sortedByDistanceTo(tn.target.ID(), results) {
 		t.Errorf("result set not sorted by distance to target")
 	}
 	wantNodes := tn.closest(len(results))
@@ -231,7 +231,7 @@ var lookupTestnet = &preminedTestnet{
 }
 
 type preminedTestnet struct {
-	target encPubkey
+	target v4wire.Pubkey
 	dists  [hashBits + 1][]*ecdsa.PrivateKey
 }
 
@@ -304,7 +304,7 @@ func (tn *preminedTestnet) closest(n int) (nodes []*enode.Node) {
 		}
 	}
 	slices.SortFunc(nodes, func(a, b *enode.Node) int {
-		return enode.DistCmp(tn.target.id(), a.ID(), b.ID())
+		return enode.DistCmp(tn.target.ID(), a.ID(), b.ID())
 	})
 	return nodes[:n]
 }
@@ -319,11 +319,11 @@ func (tn *preminedTestnet) mine() {
 		tn.dists[i] = nil
 	}
 
-	targetSha := tn.target.id()
+	targetSha := tn.target.ID()
 	found, need := 0, 40
 	for found < need {
 		k := newkey()
-		ld := enode.LogDist(targetSha, encodePubkey(&k.PublicKey).id())
+		ld := enode.LogDist(targetSha, v4wire.EncodePubkey(&k.PublicKey).ID())
 		if len(tn.dists[ld]) < 8 {
 			tn.dists[ld] = append(tn.dists[ld], k)
 			found++

p2p/discover/v4_udp.go

@@ -271,7 +271,7 @@ func (t *UDPv4) LookupPubkey(key *ecdsa.PublicKey) []*enode.Node {
 		// case and run the bootstrapping logic.
 		<-t.tab.refresh()
 	}
-	return t.newLookup(t.closeCtx, encodePubkey(key)).run()
+	return t.newLookup(t.closeCtx, v4wire.EncodePubkey(key)).run()
 }
 
 // RandomNodes is an iterator yielding nodes from a random walk of the DHT.
@@ -286,24 +286,24 @@ func (t *UDPv4) lookupRandom() []*enode.Node {
 
 // lookupSelf implements transport.
 func (t *UDPv4) lookupSelf() []*enode.Node {
-	return t.newLookup(t.closeCtx, encodePubkey(&t.priv.PublicKey)).run()
+	pubkey := v4wire.EncodePubkey(&t.priv.PublicKey)
+	return t.newLookup(t.closeCtx, pubkey).run()
 }
 
 func (t *UDPv4) newRandomLookup(ctx context.Context) *lookup {
-	var target encPubkey
+	var target v4wire.Pubkey
 	crand.Read(target[:])
 	return t.newLookup(ctx, target)
 }
 
-func (t *UDPv4) newLookup(ctx context.Context, targetKey encPubkey) *lookup {
+func (t *UDPv4) newLookup(ctx context.Context, targetKey v4wire.Pubkey) *lookup {
 	target := enode.ID(crypto.Keccak256Hash(targetKey[:]))
-	ekey := v4wire.Pubkey(targetKey)
 	it := newLookup(ctx, t.tab, target, func(n *enode.Node) ([]*enode.Node, error) {
 		addr, ok := n.UDPEndpoint()
 		if !ok {
 			return nil, errNoUDPEndpoint
 		}
-		return t.findnode(n.ID(), addr, ekey)
+		return t.findnode(n.ID(), addr, targetKey)
 	})
 	return it
 }

p2p/discover/v4_udp_test.go

@@ -314,7 +314,7 @@ func TestUDPv4_findnodeMultiReply(t *testing.T) {
 	// queue a pending findnode request
 	resultc, errc := make(chan []*enode.Node, 1), make(chan error, 1)
 	go func() {
-		rid := encodePubkey(&test.remotekey.PublicKey).id()
+		rid := v4wire.EncodePubkey(&test.remotekey.PublicKey).ID()
 		ns, err := test.udp.findnode(rid, test.remoteaddr, testTarget)
 		if err != nil && len(ns) == 0 {
 			errc <- err
@@ -433,7 +433,7 @@ func TestUDPv4_successfulPing(t *testing.T) {
 	// pong packet.
 	select {
 	case n := <-added:
-		rid := encodePubkey(&test.remotekey.PublicKey).id()
+		rid := v4wire.EncodePubkey(&test.remotekey.PublicKey).ID()
 		if n.ID() != rid {
 			t.Errorf("node has wrong ID: got %v, want %v", n.ID(), rid)
 		}

p2p/discover/v5_udp_test.go

@@ -31,6 +31,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/internal/testlog"
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/p2p/discover/v4wire"
 	"github.com/ethereum/go-ethereum/p2p/discover/v5wire"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
@@ -576,7 +577,7 @@ func TestUDPv5_lookup(t *testing.T) {
 	test := newUDPV5Test(t)
 
 	// Lookup on empty table returns no nodes.
-	if results := test.udp.Lookup(lookupTestnet.target.id()); len(results) > 0 {
+	if results := test.udp.Lookup(lookupTestnet.target.ID()); len(results) > 0 {
 		t.Fatalf("lookup on empty table returned %d results: %#v", len(results), results)
 	}
 
@@ -596,7 +597,7 @@ func TestUDPv5_lookup(t *testing.T) {
 	// Start the lookup.
 	resultC := make(chan []*enode.Node, 1)
 	go func() {
-		resultC <- test.udp.Lookup(lookupTestnet.target.id())
+		resultC <- test.udp.Lookup(lookupTestnet.target.ID())
 		test.close()
 	}()
 
@@ -793,7 +794,7 @@ func (test *udpV5Test) packetInFrom(key *ecdsa.PrivateKey, addr netip.AddrPort,
 
 // getNode ensures the test knows about a node at the given endpoint.
 func (test *udpV5Test) getNode(key *ecdsa.PrivateKey, addr netip.AddrPort) *enode.LocalNode {
-	id := encodePubkey(&key.PublicKey).id()
+	id := v4wire.EncodePubkey(&key.PublicKey).ID()
 	ln := test.nodesByID[id]
 	if ln == nil {
 		db, _ := enode.OpenDB("")