test_utils.go

package peer

import (
	"bytes"
	crand "crypto/rand"
	"encoding/binary"
	"fmt"
	"io"
	"io/ioutil"
	"math/rand"
	"net"
	"os"
	"time"

	"github.com/btcsuite/btcd/btcec"
	"github.com/btcsuite/btcd/chaincfg"
	"github.com/btcsuite/btcd/chaincfg/chainhash"
	"github.com/btcsuite/btcd/txscript"
	"github.com/btcsuite/btcd/wire"
	"github.com/btcsuite/btcutil"
	"github.com/btcsuite/btcwallet/wallet/txauthor"
	"github.com/btcsuite/btcwallet/wtxmgr"
	"github.com/lightningnetwork/lnd/chainntnfs"
	"github.com/lightningnetwork/lnd/channeldb"
	"github.com/lightningnetwork/lnd/htlcswitch"
	"github.com/lightningnetwork/lnd/input"
	"github.com/lightningnetwork/lnd/keychain"
	"github.com/lightningnetwork/lnd/lnwallet"
	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
	"github.com/lightningnetwork/lnd/lnwire"
	"github.com/lightningnetwork/lnd/netann"
	"github.com/lightningnetwork/lnd/queue"
	"github.com/lightningnetwork/lnd/shachain"
	"github.com/lightningnetwork/lnd/ticker"
)

const (
	broadcastHeight = 100
)

var (
	alicesPrivKey = []byte{
		0x2b, 0xd8, 0x06, 0xc9, 0x7f, 0x0e, 0x00, 0xaf,
		0x1a, 0x1f, 0xc3, 0x32, 0x8f, 0xa7, 0x63, 0xa9,
		0x26, 0x97, 0x23, 0xc8, 0xdb, 0x8f, 0xac, 0x4f,
		0x93, 0xaf, 0x71, 0xdb, 0x18, 0x6d, 0x6e, 0x90,
	}

	bobsPrivKey = []byte{
		0x81, 0xb6, 0x37, 0xd8, 0xfc, 0xd2, 0xc6, 0xda,
		0x63, 0x59, 0xe6, 0x96, 0x31, 0x13, 0xa1, 0x17,
		0xd, 0xe7, 0x95, 0xe4, 0xb7, 0x25, 0xb8, 0x4d,
		0x1e, 0xb, 0x4c, 0xfd, 0x9e, 0xc5, 0x8c, 0xe9,
	}

	// Use a hard-coded HD seed.
	testHdSeed = [32]byte{
		0xb7, 0x94, 0x38, 0x5f, 0x2d, 0x1e, 0xf7, 0xab,
		0x4d, 0x92, 0x73, 0xd1, 0x90, 0x63, 0x81, 0xb4,
		0x4f, 0x2f, 0x6f, 0x25, 0x88, 0xa3, 0xef, 0xb9,
		0x6a, 0x49, 0x18, 0x83, 0x31, 0x98, 0x47, 0x53,
	}

	// Just use some arbitrary bytes as delivery script.
	dummyDeliveryScript = alicesPrivKey

	// testTx is used as the default funding txn for single-funder channels.
	testTx = &wire.MsgTx{
		Version: 1,
		TxIn: []*wire.TxIn{
			{
				PreviousOutPoint: wire.OutPoint{
					Hash:  chainhash.Hash{},
					Index: 0xffffffff,
				},
				SignatureScript: []byte{0x04, 0x31, 0xdc, 0x00, 0x1b, 0x01, 0x62},
				Sequence:        0xffffffff,
			},
		},
		TxOut: []*wire.TxOut{
			{
				Value: 5000000000,
				PkScript: []byte{
					0x41, // OP_DATA_65
					0x04, 0xd6, 0x4b, 0xdf, 0xd0, 0x9e, 0xb1, 0xc5,
					0xfe, 0x29, 0x5a, 0xbd, 0xeb, 0x1d, 0xca, 0x42,
					0x81, 0xbe, 0x98, 0x8e, 0x2d, 0xa0, 0xb6, 0xc1,
					0xc6, 0xa5, 0x9d, 0xc2, 0x26, 0xc2, 0x86, 0x24,
					0xe1, 0x81, 0x75, 0xe8, 0x51, 0xc9, 0x6b, 0x97,
					0x3d, 0x81, 0xb0, 0x1c, 0xc3, 0x1f, 0x04, 0x78,
					0x34, 0xbc, 0x06, 0xd6, 0xd6, 0xed, 0xf6, 0x20,
					0xd1, 0x84, 0x24, 0x1a, 0x6a, 0xed, 0x8b, 0x63,
					0xa6, // 65-byte signature
					0xac, // OP_CHECKSIG
				},
			},
		},
		LockTime: 5,
	}
)

// noUpdate is a function which can be used as a parameter in createTestPeer to
// call the setup code with no custom values on the channels set up.
var noUpdate = func(a, b *channeldb.OpenChannel) {}

type mockSigner struct {
	key *btcec.PrivateKey
}

func (m *mockSigner) SignOutputRaw(tx *wire.MsgTx,
	signDesc *input.SignDescriptor) (input.Signature, error) {
	amt := signDesc.Output.Value
	witnessScript := signDesc.WitnessScript
	privKey := m.key

	if !privKey.PubKey().IsEqual(signDesc.KeyDesc.PubKey) {
		return nil, fmt.Errorf("incorrect key passed")
	}

	switch {
	case signDesc.SingleTweak != nil:
		privKey = input.TweakPrivKey(privKey,
			signDesc.SingleTweak)
	case signDesc.DoubleTweak != nil:
		privKey = input.DeriveRevocationPrivKey(privKey,
			signDesc.DoubleTweak)
	}

	sig, err := txscript.RawTxInWitnessSignature(tx, signDesc.SigHashes,
		signDesc.InputIndex, amt, witnessScript, signDesc.HashType,
		privKey)
	if err != nil {
		return nil, err
	}

	return btcec.ParseDERSignature(sig[:len(sig)-1], btcec.S256())
}

func (m *mockSigner) ComputeInputScript(tx *wire.MsgTx,
	signDesc *input.SignDescriptor) (*input.Script, error) {

	// TODO(roasbeef): expose tweaked signer from lnwallet so don't need to
	// duplicate this code?

	privKey := m.key

	switch {
	case signDesc.SingleTweak != nil:
		privKey = input.TweakPrivKey(privKey,
			signDesc.SingleTweak)
	case signDesc.DoubleTweak != nil:
		privKey = input.DeriveRevocationPrivKey(privKey,
			signDesc.DoubleTweak)
	}

	witnessScript, err := txscript.WitnessSignature(tx, signDesc.SigHashes,
		signDesc.InputIndex, signDesc.Output.Value, signDesc.Output.PkScript,
		signDesc.HashType, privKey, true)
	if err != nil {
		return nil, err
	}

	return &input.Script{
		Witness: witnessScript,
	}, nil
}

var _ input.Signer = (*mockSigner)(nil)

type mockChainIO struct {
	bestHeight int32
}

func (m *mockChainIO) GetBestBlock() (*chainhash.Hash, int32, error) {
	return nil, m.bestHeight, nil
}

func (*mockChainIO) GetUtxo(op *wire.OutPoint, _ []byte,
	heightHint uint32, _ <-chan struct{}) (*wire.TxOut, error) {
	return nil, nil
}

func (*mockChainIO) GetBlockHash(blockHeight int64) (*chainhash.Hash, error) {
	return nil, nil
}

func (*mockChainIO) GetBlock(blockHash *chainhash.Hash) (*wire.MsgBlock, error) {
	return nil, nil
}

var _ lnwallet.BlockChainIO = (*mockChainIO)(nil)

type mockWalletController struct {
	rootKey       *btcec.PrivateKey
	publishedTxns chan *wire.MsgTx
}

func (*mockWalletController) FetchInputInfo(prevOut *wire.OutPoint) (
	*lnwallet.Utxo, error) {

	return nil, nil
}

func (*mockWalletController) ConfirmedBalance(confs int32) (btcutil.Amount,
	error) {

	return 0, nil
}

func (m *mockWalletController) NewAddress(addrType lnwallet.AddressType,
	change bool) (btcutil.Address, error) {

	addr, _ := btcutil.NewAddressPubKey(
		m.rootKey.PubKey().SerializeCompressed(), &chaincfg.MainNetParams,
	)
	return addr, nil
}

func (*mockWalletController) LastUnusedAddress(addrType lnwallet.AddressType) (
	btcutil.Address, error) {

	return nil, nil
}

func (*mockWalletController) IsOurAddress(a btcutil.Address) bool {
	return false
}

func (*mockWalletController) SendOutputs(outputs []*wire.TxOut,
	feeRate chainfee.SatPerKWeight, label string) (*wire.MsgTx, error) {

	return nil, nil
}

func (*mockWalletController) CreateSimpleTx(outputs []*wire.TxOut,
	feeRate chainfee.SatPerKWeight, dryRun bool) (*txauthor.AuthoredTx, error) {

	return nil, nil
}

func (*mockWalletController) ListUnspentWitness(minconfirms,
	maxconfirms int32) ([]*lnwallet.Utxo, error) {

	return nil, nil
}

func (*mockWalletController) ListTransactionDetails(startHeight,
	endHeight int32) ([]*lnwallet.TransactionDetail, error) {

	return nil, nil
}

func (*mockWalletController) LockOutpoint(o wire.OutPoint) {}

func (*mockWalletController) UnlockOutpoint(o wire.OutPoint) {}

func (m *mockWalletController) PublishTransaction(tx *wire.MsgTx,
	label string) error {
	m.publishedTxns <- tx
	return nil
}

func (*mockWalletController) LabelTransaction(hash chainhash.Hash,
	label string, overwrite bool) error {

	return nil
}

func (*mockWalletController) SubscribeTransactions() (
	lnwallet.TransactionSubscription, error) {

	return nil, nil
}

func (*mockWalletController) IsSynced() (bool, int64, error) {
	return false, 0, nil
}

func (*mockWalletController) Start() error {
	return nil
}

func (*mockWalletController) Stop() error {
	return nil
}

func (*mockWalletController) BackEnd() string {
	return ""
}

func (*mockWalletController) LeaseOutput(wtxmgr.LockID,
	wire.OutPoint) (time.Time, error) {

	return time.Now(), nil
}

func (*mockWalletController) ReleaseOutput(wtxmgr.LockID, wire.OutPoint) error {
	return nil
}

func (*mockWalletController) GetRecoveryInfo() (bool, float64, error) {
	return false, 0, nil
}

var _ lnwallet.WalletController = (*mockWalletController)(nil)

type mockNotifier struct {
	confChannel chan *chainntnfs.TxConfirmation
}

func (m *mockNotifier) RegisterConfirmationsNtfn(txid *chainhash.Hash,
	_ []byte, numConfs, heightHint uint32) (*chainntnfs.ConfirmationEvent,
	error) {

	return &chainntnfs.ConfirmationEvent{
		Confirmed: m.confChannel,
	}, nil
}

func (m *mockNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint, _ []byte,
	heightHint uint32) (*chainntnfs.SpendEvent, error) {

	return &chainntnfs.SpendEvent{
		Spend:  make(chan *chainntnfs.SpendDetail),
		Cancel: func() {},
	}, nil
}

func (m *mockNotifier) RegisterBlockEpochNtfn(
	bestBlock *chainntnfs.BlockEpoch) (*chainntnfs.BlockEpochEvent, error) {

	return &chainntnfs.BlockEpochEvent{
		Epochs: make(chan *chainntnfs.BlockEpoch),
		Cancel: func() {},
	}, nil
}

func (m *mockNotifier) Start() error {
	return nil
}

func (m *mockNotifier) Stop() error {
	return nil
}

func (m *mockNotifier) Started() bool {
	return true
}

var _ chainntnfs.ChainNotifier = (*mockNotifier)(nil)

// createTestPeer creates a channel between two nodes, and returns a peer for
// one of the nodes, together with the channel seen from both nodes. It takes
// an updateChan function which can be used to modify the default values on
// the channel states for each peer.
func createTestPeer(notifier chainntnfs.ChainNotifier,
	publTx chan *wire.MsgTx, updateChan func(a, b *channeldb.OpenChannel)) (
	*Brontide, *lnwallet.LightningChannel, func(), error) {

	aliceKeyPriv, aliceKeyPub := btcec.PrivKeyFromBytes(
		btcec.S256(), alicesPrivKey,
	)
	aliceKeySigner := &keychain.PrivKeyDigestSigner{PrivKey: aliceKeyPriv}
	bobKeyPriv, bobKeyPub := btcec.PrivKeyFromBytes(
		btcec.S256(), bobsPrivKey,
	)

	channelCapacity := btcutil.Amount(10 * 1e8)
	channelBal := channelCapacity / 2
	aliceDustLimit := btcutil.Amount(200)
	bobDustLimit := btcutil.Amount(1300)
	csvTimeoutAlice := uint32(5)
	csvTimeoutBob := uint32(4)

	prevOut := &wire.OutPoint{
		Hash:  chainhash.Hash(testHdSeed),
		Index: 0,
	}
	fundingTxIn := wire.NewTxIn(prevOut, nil, nil)

	aliceCfg := channeldb.ChannelConfig{
		ChannelConstraints: channeldb.ChannelConstraints{
			DustLimit:        aliceDustLimit,
			MaxPendingAmount: lnwire.MilliSatoshi(rand.Int63()),
			ChanReserve:      btcutil.Amount(rand.Int63()),
			MinHTLC:          lnwire.MilliSatoshi(rand.Int63()),
			MaxAcceptedHtlcs: uint16(rand.Int31()),
			CsvDelay:         uint16(csvTimeoutAlice),
		},
		MultiSigKey: keychain.KeyDescriptor{
			PubKey: aliceKeyPub,
		},
		RevocationBasePoint: keychain.KeyDescriptor{
			PubKey: aliceKeyPub,
		},
		PaymentBasePoint: keychain.KeyDescriptor{
			PubKey: aliceKeyPub,
		},
		DelayBasePoint: keychain.KeyDescriptor{
			PubKey: aliceKeyPub,
		},
		HtlcBasePoint: keychain.KeyDescriptor{
			PubKey: aliceKeyPub,
		},
	}
	bobCfg := channeldb.ChannelConfig{
		ChannelConstraints: channeldb.ChannelConstraints{
			DustLimit:        bobDustLimit,
			MaxPendingAmount: lnwire.MilliSatoshi(rand.Int63()),
			ChanReserve:      btcutil.Amount(rand.Int63()),
			MinHTLC:          lnwire.MilliSatoshi(rand.Int63()),
			MaxAcceptedHtlcs: uint16(rand.Int31()),
			CsvDelay:         uint16(csvTimeoutBob),
		},
		MultiSigKey: keychain.KeyDescriptor{
			PubKey: bobKeyPub,
		},
		RevocationBasePoint: keychain.KeyDescriptor{
			PubKey: bobKeyPub,
		},
		PaymentBasePoint: keychain.KeyDescriptor{
			PubKey: bobKeyPub,
		},
		DelayBasePoint: keychain.KeyDescriptor{
			PubKey: bobKeyPub,
		},
		HtlcBasePoint: keychain.KeyDescriptor{
			PubKey: bobKeyPub,
		},
	}

	bobRoot, err := chainhash.NewHash(bobKeyPriv.Serialize())
	if err != nil {
		return nil, nil, nil, err
	}
	bobPreimageProducer := shachain.NewRevocationProducer(*bobRoot)
	bobFirstRevoke, err := bobPreimageProducer.AtIndex(0)
	if err != nil {
		return nil, nil, nil, err
	}
	bobCommitPoint := input.ComputeCommitmentPoint(bobFirstRevoke[:])

	aliceRoot, err := chainhash.NewHash(aliceKeyPriv.Serialize())
	if err != nil {
		return nil, nil, nil, err
	}
	alicePreimageProducer := shachain.NewRevocationProducer(*aliceRoot)
	aliceFirstRevoke, err := alicePreimageProducer.AtIndex(0)
	if err != nil {
		return nil, nil, nil, err
	}
	aliceCommitPoint := input.ComputeCommitmentPoint(aliceFirstRevoke[:])

	aliceCommitTx, bobCommitTx, err := lnwallet.CreateCommitmentTxns(
		channelBal, channelBal, &aliceCfg, &bobCfg, aliceCommitPoint,
		bobCommitPoint, *fundingTxIn, channeldb.SingleFunderTweaklessBit,
	)
	if err != nil {
		return nil, nil, nil, err
	}

	alicePath, err := ioutil.TempDir("", "alicedb")
	if err != nil {
		return nil, nil, nil, err
	}

	dbAlice, err := channeldb.Open(alicePath)
	if err != nil {
		return nil, nil, nil, err
	}

	bobPath, err := ioutil.TempDir("", "bobdb")
	if err != nil {
		return nil, nil, nil, err
	}

	dbBob, err := channeldb.Open(bobPath)
	if err != nil {
		return nil, nil, nil, err
	}

	estimator := chainfee.NewStaticEstimator(12500, 0)
	feePerKw, err := estimator.EstimateFeePerKW(1)
	if err != nil {
		return nil, nil, nil, err
	}

	// TODO(roasbeef): need to factor in commit fee?
	aliceCommit := channeldb.ChannelCommitment{
		CommitHeight:  0,
		LocalBalance:  lnwire.NewMSatFromSatoshis(channelBal),
		RemoteBalance: lnwire.NewMSatFromSatoshis(channelBal),
		FeePerKw:      btcutil.Amount(feePerKw),
		CommitFee:     feePerKw.FeeForWeight(input.CommitWeight),
		CommitTx:      aliceCommitTx,
		CommitSig:     bytes.Repeat([]byte{1}, 71),
	}
	bobCommit := channeldb.ChannelCommitment{
		CommitHeight:  0,
		LocalBalance:  lnwire.NewMSatFromSatoshis(channelBal),
		RemoteBalance: lnwire.NewMSatFromSatoshis(channelBal),
		FeePerKw:      btcutil.Amount(feePerKw),
		CommitFee:     feePerKw.FeeForWeight(input.CommitWeight),
		CommitTx:      bobCommitTx,
		CommitSig:     bytes.Repeat([]byte{1}, 71),
	}

	var chanIDBytes [8]byte
	if _, err := io.ReadFull(crand.Reader, chanIDBytes[:]); err != nil {
		return nil, nil, nil, err
	}

	shortChanID := lnwire.NewShortChanIDFromInt(
		binary.BigEndian.Uint64(chanIDBytes[:]),
	)

	aliceChannelState := &channeldb.OpenChannel{
		LocalChanCfg:            aliceCfg,
		RemoteChanCfg:           bobCfg,
		IdentityPub:             aliceKeyPub,
		FundingOutpoint:         *prevOut,
		ShortChannelID:          shortChanID,
		ChanType:                channeldb.SingleFunderTweaklessBit,
		IsInitiator:             true,
		Capacity:                channelCapacity,
		RemoteCurrentRevocation: bobCommitPoint,
		RevocationProducer:      alicePreimageProducer,
		RevocationStore:         shachain.NewRevocationStore(),
		LocalCommitment:         aliceCommit,
		RemoteCommitment:        aliceCommit,
		Db:                      dbAlice,
		Packager:                channeldb.NewChannelPackager(shortChanID),
		FundingTxn:              testTx,
	}
	bobChannelState := &channeldb.OpenChannel{
		LocalChanCfg:            bobCfg,
		RemoteChanCfg:           aliceCfg,
		IdentityPub:             bobKeyPub,
		FundingOutpoint:         *prevOut,
		ChanType:                channeldb.SingleFunderTweaklessBit,
		IsInitiator:             false,
		Capacity:                channelCapacity,
		RemoteCurrentRevocation: aliceCommitPoint,
		RevocationProducer:      bobPreimageProducer,
		RevocationStore:         shachain.NewRevocationStore(),
		LocalCommitment:         bobCommit,
		RemoteCommitment:        bobCommit,
		Db:                      dbBob,
		Packager:                channeldb.NewChannelPackager(shortChanID),
	}

	// Set custom values on the channel states.
	updateChan(aliceChannelState, bobChannelState)

	aliceAddr := &net.TCPAddr{
		IP:   net.ParseIP("127.0.0.1"),
		Port: 18555,
	}

	if err := aliceChannelState.SyncPending(aliceAddr, 0); err != nil {
		return nil, nil, nil, err
	}

	bobAddr := &net.TCPAddr{
		IP:   net.ParseIP("127.0.0.1"),
		Port: 18556,
	}

	if err := bobChannelState.SyncPending(bobAddr, 0); err != nil {
		return nil, nil, nil, err
	}

	cleanUpFunc := func() {
		os.RemoveAll(bobPath)
		os.RemoveAll(alicePath)
	}

	aliceSigner := &mockSigner{aliceKeyPriv}
	bobSigner := &mockSigner{bobKeyPriv}

	alicePool := lnwallet.NewSigPool(1, aliceSigner)
	channelAlice, err := lnwallet.NewLightningChannel(
		aliceSigner, aliceChannelState, alicePool,
	)
	if err != nil {
		return nil, nil, nil, err
	}
	_ = alicePool.Start()

	bobPool := lnwallet.NewSigPool(1, bobSigner)
	channelBob, err := lnwallet.NewLightningChannel(
		bobSigner, bobChannelState, bobPool,
	)
	if err != nil {
		return nil, nil, nil, err
	}
	_ = bobPool.Start()

	chainIO := &mockChainIO{
		bestHeight: broadcastHeight,
	}
	wallet := &lnwallet.LightningWallet{
		WalletController: &mockWalletController{
			rootKey:       aliceKeyPriv,
			publishedTxns: publTx,
		},
	}

	_, currentHeight, err := chainIO.GetBestBlock()
	if err != nil {
		return nil, nil, nil, err
	}

	htlcSwitch, err := htlcswitch.New(htlcswitch.Config{
		DB:             dbAlice,
		SwitchPackager: channeldb.NewSwitchPackager(),
		Notifier:       notifier,
		FwdEventTicker: ticker.New(
			htlcswitch.DefaultFwdEventInterval),
		LogEventTicker: ticker.New(
			htlcswitch.DefaultLogInterval),
		AckEventTicker: ticker.New(
			htlcswitch.DefaultAckInterval),
	}, uint32(currentHeight))
	if err != nil {
		return nil, nil, nil, err
	}
	if err = htlcSwitch.Start(); err != nil {
		return nil, nil, nil, err
	}

	nodeSignerAlice := netann.NewNodeSigner(aliceKeySigner)

	const chanActiveTimeout = time.Minute

	chanStatusMgr, err := netann.NewChanStatusManager(&netann.ChanStatusConfig{
		ChanStatusSampleInterval: 30 * time.Second,
		ChanEnableTimeout:        chanActiveTimeout,
		ChanDisableTimeout:       2 * time.Minute,
		DB:                       dbAlice,
		Graph:                    dbAlice.ChannelGraph(),
		MessageSigner:            nodeSignerAlice,
		OurPubKey:                aliceKeyPub,
		IsChannelActive:          htlcSwitch.HasActiveLink,
		ApplyChannelUpdate:       func(*lnwire.ChannelUpdate) error { return nil },
	})
	if err != nil {
		return nil, nil, nil, err
	}
	if err = chanStatusMgr.Start(); err != nil {
		return nil, nil, nil, err
	}

	errBuffer, err := queue.NewCircularBuffer(ErrorBufferSize)
	if err != nil {
		return nil, nil, nil, err
	}

	var pubKey [33]byte
	copy(pubKey[:], aliceKeyPub.SerializeCompressed())

	cfgAddr := &lnwire.NetAddress{
		IdentityKey: aliceKeyPub,
		Address:     aliceAddr,
		ChainNet:    wire.SimNet,
	}

	cfg := &Config{
		Addr:        cfgAddr,
		PubKeyBytes: pubKey,
		ErrorBuffer: errBuffer,
		ChainIO:     chainIO,
		Switch:      htlcSwitch,

		ChanActiveTimeout: chanActiveTimeout,
		InterceptSwitch:   htlcswitch.NewInterceptableSwitch(htlcSwitch),

		ChannelDB:      dbAlice,
		FeeEstimator:   estimator,
		Wallet:         wallet,
		ChainNotifier:  notifier,
		ChanStatusMgr:  chanStatusMgr,
		DisconnectPeer: func(b *btcec.PublicKey) error { return nil },
	}

	alicePeer := NewBrontide(*cfg)

	chanID := lnwire.NewChanIDFromOutPoint(channelAlice.ChannelPoint())
	alicePeer.activeChannels[chanID] = channelAlice

	alicePeer.wg.Add(1)
	go alicePeer.channelManager()

	return alicePeer, channelBob, cleanUpFunc, nil
}