multi: use btcd's btcec/v2 and btcutil modules

This commit was previously split into the following parts to ease
review:
 - 2d746f68: replace imports
 - 4008f0fd: use ecdsa.Signature
 - 849e33d1: remove btcec.S256()
 - b8f6ebbd: use v2 library correctly
 - fa80bca9: bump go modules

netann/chan_status_manager.go

@@ -5,7 +5,7 @@ import (
 	"sync"
 	"time"
 
-	"github.com/btcsuite/btcd/btcec"
+	"github.com/btcsuite/btcd/btcec/v2"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/keychain"

netann/chan_status_manager_test.go

@@ -11,7 +11,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/btcsuite/btcd/btcec"
+	"github.com/btcsuite/btcd/btcec/v2"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/keychain"
@@ -80,7 +80,7 @@ func createEdgePolicies(t *testing.T, channel *channeldb.OpenChannel,
 	}
 
 	// Generate and set pubkey2 for THEIR pubkey.
-	privKey2, err := btcec.NewPrivateKey(btcec.S256())
+	privKey2, err := btcec.NewPrivateKey()
 	if err != nil {
 		t.Fatalf("unable to generate key pair: %v", err)
 	}
@@ -310,7 +310,7 @@ func newManagerCfg(t *testing.T, numChannels int,
 
 	t.Helper()
 
-	privKey, err := btcec.NewPrivateKey(btcec.S256())
+	privKey, err := btcec.NewPrivateKey()
 	if err != nil {
 		t.Fatalf("unable to generate key pair: %v", err)
 	}

netann/channel_announcement_test.go

@@ -4,9 +4,9 @@ import (
 	"bytes"
 	"testing"
 
+	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
-	"github.com/btcsuite/btcutil"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/stretchr/testify/assert"

netann/channel_update.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/btcsuite/btcd/btcec"
+	"github.com/btcsuite/btcd/btcec/v2"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/keychain"
 	"github.com/lightningnetwork/lnd/lnwallet"

netann/channel_update_test.go

@@ -5,7 +5,8 @@ import (
 	"testing"
 	"time"
 
-	"github.com/btcsuite/btcd/btcec"
+	"github.com/btcsuite/btcd/btcec/v2"
+	"github.com/btcsuite/btcd/btcec/v2/ecdsa"
 	"github.com/lightningnetwork/lnd/keychain"
 	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/lightningnetwork/lnd/lnwire"
@@ -18,7 +19,7 @@ type mockSigner struct {
 }
 
 func (m *mockSigner) SignMessage(_ keychain.KeyLocator,
-	_ []byte, _ bool) (*btcec.Signature, error) {
+	_ []byte, _ bool) (*ecdsa.Signature, error) {
 
 	if m.err != nil {
 		return nil, m.err
@@ -30,7 +31,7 @@ func (m *mockSigner) SignMessage(_ keychain.KeyLocator,
 var _ lnwallet.MessageSigner = (*mockSigner)(nil)
 
 var (
-	privKey, _    = btcec.NewPrivateKey(btcec.S256())
+	privKey, _    = btcec.NewPrivateKey()
 	privKeySigner = keychain.NewPrivKeyMessageSigner(privKey, testKeyLoc)
 
 	pubKey = privKey.PubKey()

netann/node_signer.go

@@ -3,7 +3,7 @@ package netann
 import (
 	"fmt"
 
-	"github.com/btcsuite/btcd/btcec"
+	"github.com/btcsuite/btcd/btcec/v2/ecdsa"
 	"github.com/lightningnetwork/lnd/keychain"
 	"github.com/lightningnetwork/lnd/lnwallet"
 )
@@ -26,7 +26,7 @@ func NewNodeSigner(keySigner keychain.SingleKeyMessageSigner) *NodeSigner {
 // resident node's private key described in the key locator. If the target key
 // locator is _not_ the node's private key, then an error will be returned.
 func (n *NodeSigner) SignMessage(keyLoc keychain.KeyLocator,
-	msg []byte, doubleHash bool) (*btcec.Signature, error) {
+	msg []byte, doubleHash bool) (*ecdsa.Signature, error) {
 
 	// If this isn't our identity public key, then we'll exit early with an
 	// error as we can't sign with this key.