package htlcswitch import ( "bytes" "crypto/rand" "crypto/sha256" "fmt" "testing" "time" "io/ioutil" "os" "io" "math/big" "net" "github.com/btcsuite/fastsha256" "github.com/go-errors/errors" "github.com/lightningnetwork/lnd/chainntnfs" "github.com/lightningnetwork/lnd/channeldb" "github.com/lightningnetwork/lnd/lnwallet" "github.com/lightningnetwork/lnd/lnwire" "github.com/lightningnetwork/lnd/shachain" "github.com/roasbeef/btcd/btcec" "github.com/roasbeef/btcd/chaincfg/chainhash" "github.com/roasbeef/btcd/wire" "github.com/roasbeef/btcutil" ) var ( alicePrivKey = []byte("alice priv key") bobPrivKey = []byte("bob priv key") carolPrivKey = []byte("carol priv key") testPrivKey = []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, } _, testPubKey = btcec.PrivKeyFromBytes(btcec.S256(), testPrivKey) testSig = &btcec.Signature{ R: new(big.Int), S: new(big.Int), } _, _ = testSig.R.SetString("6372440660162918006277497454296753625158993"+ "5445068131219452686511677818569431", 10) _, _ = testSig.S.SetString("1880105606924982582529128710493133386286603"+ "3135609736119018462340006816851118", 10) ) // mockGetChanUpdateMessage helper function which returns topology update // of the channel func mockGetChanUpdateMessage() (*lnwire.ChannelUpdate, error) { return &lnwire.ChannelUpdate{ Signature: testSig, }, nil } // generateRandomBytes returns securely generated random bytes. // It will return an error if the system's secure random // number generator fails to function correctly, in which // case the caller should not continue. func generateRandomBytes(n int) ([]byte, error) { b := make([]byte, n) // TODO(roasbeef): should use counter in tests (atomic) rather than // this _, err := rand.Read(b[:]) // Note that Err == nil only if we read len(b) bytes. if err != nil { return nil, err } return b, nil } // createTestChannel creates the channel and returns our and remote channels // representations. // // TODO(roasbeef): need to factor out, similar func re-used in many parts of codebase func createTestChannel(alicePrivKey, bobPrivKey []byte, aliceAmount, bobAmount btcutil.Amount, chanID lnwire.ShortChannelID) (*lnwallet.LightningChannel, *lnwallet.LightningChannel, func(), func() (*lnwallet.LightningChannel, *lnwallet.LightningChannel, error), error) { aliceKeyPriv, aliceKeyPub := btcec.PrivKeyFromBytes(btcec.S256(), alicePrivKey) bobKeyPriv, bobKeyPub := btcec.PrivKeyFromBytes(btcec.S256(), bobPrivKey) channelCapacity := aliceAmount + bobAmount aliceDustLimit := btcutil.Amount(200) bobDustLimit := btcutil.Amount(800) csvTimeoutAlice := uint32(5) csvTimeoutBob := uint32(4) var hash [sha256.Size]byte randomSeed, err := generateRandomBytes(sha256.Size) if err != nil { return nil, nil, nil, nil, err } copy(hash[:], randomSeed) prevOut := &wire.OutPoint{ Hash: chainhash.Hash(hash), Index: 0, } fundingTxIn := wire.NewTxIn(prevOut, nil, nil) aliceCfg := channeldb.ChannelConfig{ ChannelConstraints: channeldb.ChannelConstraints{ DustLimit: aliceDustLimit, }, CsvDelay: uint16(csvTimeoutAlice), MultiSigKey: aliceKeyPub, RevocationBasePoint: aliceKeyPub, PaymentBasePoint: aliceKeyPub, DelayBasePoint: aliceKeyPub, HtlcBasePoint: aliceKeyPub, } bobCfg := channeldb.ChannelConfig{ ChannelConstraints: channeldb.ChannelConstraints{ DustLimit: bobDustLimit, }, CsvDelay: uint16(csvTimeoutBob), MultiSigKey: bobKeyPub, RevocationBasePoint: bobKeyPub, PaymentBasePoint: bobKeyPub, DelayBasePoint: bobKeyPub, HtlcBasePoint: bobKeyPub, } bobRoot := lnwallet.DeriveRevocationRoot(bobKeyPriv, hash, aliceKeyPub) bobPreimageProducer := shachain.NewRevocationProducer(bobRoot) bobFirstRevoke, err := bobPreimageProducer.AtIndex(0) if err != nil { return nil, nil, nil, nil, err } bobCommitPoint := lnwallet.ComputeCommitmentPoint(bobFirstRevoke[:]) aliceRoot := lnwallet.DeriveRevocationRoot(aliceKeyPriv, hash, bobKeyPub) alicePreimageProducer := shachain.NewRevocationProducer(aliceRoot) aliceFirstRevoke, err := alicePreimageProducer.AtIndex(0) if err != nil { return nil, nil, nil, nil, err } aliceCommitPoint := lnwallet.ComputeCommitmentPoint(aliceFirstRevoke[:]) aliceCommitTx, bobCommitTx, err := lnwallet.CreateCommitmentTxns(aliceAmount, bobAmount, &aliceCfg, &bobCfg, aliceCommitPoint, bobCommitPoint, fundingTxIn) if err != nil { return nil, nil, nil, nil, err } alicePath, err := ioutil.TempDir("", "alicedb") dbAlice, err := channeldb.Open(alicePath) if err != nil { return nil, nil, nil, nil, err } bobPath, err := ioutil.TempDir("", "bobdb") dbBob, err := channeldb.Open(bobPath) if err != nil { return nil, nil, nil, nil, err } estimator := &lnwallet.StaticFeeEstimator{ FeeRate: 24, } feePerWeight, err := estimator.EstimateFeePerWeight(1) if err != nil { return nil, nil, nil, nil, err } feePerKw := btcutil.Amount(feePerWeight * 1000) commitFee := (feePerKw * btcutil.Amount(724)) / 1000 const broadcastHeight = 1 bobAddr := &net.TCPAddr{ IP: net.ParseIP("127.0.0.1"), Port: 18555, } aliceAddr := &net.TCPAddr{ IP: net.ParseIP("127.0.0.1"), Port: 18556, } aliceCommit := channeldb.ChannelCommitment{ CommitHeight: 0, LocalBalance: lnwire.NewMSatFromSatoshis(aliceAmount - commitFee), RemoteBalance: lnwire.NewMSatFromSatoshis(bobAmount), CommitFee: commitFee, FeePerKw: feePerKw, CommitTx: aliceCommitTx, CommitSig: bytes.Repeat([]byte{1}, 71), } bobCommit := channeldb.ChannelCommitment{ CommitHeight: 0, LocalBalance: lnwire.NewMSatFromSatoshis(bobAmount), RemoteBalance: lnwire.NewMSatFromSatoshis(aliceAmount - commitFee), CommitFee: commitFee, FeePerKw: feePerKw, CommitTx: bobCommitTx, CommitSig: bytes.Repeat([]byte{1}, 71), } aliceChannelState := &channeldb.OpenChannel{ LocalChanCfg: aliceCfg, RemoteChanCfg: bobCfg, IdentityPub: aliceKeyPub, FundingOutpoint: *prevOut, ChanType: channeldb.SingleFunder, IsInitiator: true, Capacity: channelCapacity, RemoteCurrentRevocation: bobCommitPoint, RevocationProducer: alicePreimageProducer, RevocationStore: shachain.NewRevocationStore(), LocalCommitment: aliceCommit, RemoteCommitment: aliceCommit, ShortChanID: chanID, Db: dbAlice, } bobChannelState := &channeldb.OpenChannel{ LocalChanCfg: bobCfg, RemoteChanCfg: aliceCfg, IdentityPub: bobKeyPub, FundingOutpoint: *prevOut, ChanType: channeldb.SingleFunder, IsInitiator: false, Capacity: channelCapacity, RemoteCurrentRevocation: aliceCommitPoint, RevocationProducer: bobPreimageProducer, RevocationStore: shachain.NewRevocationStore(), LocalCommitment: bobCommit, RemoteCommitment: bobCommit, ShortChanID: chanID, Db: dbBob, } if err := aliceChannelState.SyncPending(bobAddr, broadcastHeight); err != nil { return nil, nil, nil, nil, err } if err := bobChannelState.SyncPending(aliceAddr, broadcastHeight); err != nil { return nil, nil, nil, nil, err } cleanUpFunc := func() { os.RemoveAll(bobPath) os.RemoveAll(alicePath) } aliceSigner := &mockSigner{aliceKeyPriv} bobSigner := &mockSigner{bobKeyPriv} channelAlice, err := lnwallet.NewLightningChannel(aliceSigner, nil, estimator, aliceChannelState) if err != nil { return nil, nil, nil, nil, err } channelBob, err := lnwallet.NewLightningChannel(bobSigner, nil, estimator, bobChannelState) if err != nil { return nil, nil, nil, nil, err } // Now that the channel are open, simulate the start of a session by // having Alice and Bob extend their revocation windows to each other. aliceNextRevoke, err := channelAlice.NextRevocationKey() if err != nil { return nil, nil, nil, nil, err } if err := channelBob.InitNextRevocation(aliceNextRevoke); err != nil { return nil, nil, nil, nil, err } bobNextRevoke, err := channelBob.NextRevocationKey() if err != nil { return nil, nil, nil, nil, err } if err := channelAlice.InitNextRevocation(bobNextRevoke); err != nil { return nil, nil, nil, nil, err } restore := func() (*lnwallet.LightningChannel, *lnwallet.LightningChannel, error) { aliceStoredChannels, err := dbAlice.FetchOpenChannels(aliceKeyPub) if err != nil { return nil, nil, errors.Errorf("unable to fetch alice channel: "+ "%v", err) } var aliceStoredChannel *channeldb.OpenChannel for _, channel := range aliceStoredChannels { if channel.FundingOutpoint.String() == prevOut.String() { aliceStoredChannel = channel break } } if aliceStoredChannel == nil { return nil, nil, errors.New("unable to find stored alice channel") } newAliceChannel, err := lnwallet.NewLightningChannel(aliceSigner, nil, estimator, aliceStoredChannel) if err != nil { return nil, nil, errors.Errorf("unable to create new channel: %v", err) } bobStoredChannels, err := dbBob.FetchOpenChannels(bobKeyPub) if err != nil { return nil, nil, errors.Errorf("unable to fetch bob channel: "+ "%v", err) } var bobStoredChannel *channeldb.OpenChannel for _, channel := range bobStoredChannels { if channel.FundingOutpoint.String() == prevOut.String() { bobStoredChannel = channel break } } if bobStoredChannel == nil { return nil, nil, errors.New("unable to find stored bob channel") } newBobChannel, err := lnwallet.NewLightningChannel(bobSigner, nil, estimator, bobStoredChannel) if err != nil { return nil, nil, errors.Errorf("unable to create new channel: %v", err) } return newAliceChannel, newBobChannel, nil } return channelAlice, channelBob, cleanUpFunc, restore, nil } // getChanID retrieves the channel point from nwire message. func getChanID(msg lnwire.Message) (lnwire.ChannelID, error) { var chanID lnwire.ChannelID switch msg := msg.(type) { case *lnwire.UpdateAddHTLC: chanID = msg.ChanID case *lnwire.UpdateFufillHTLC: chanID = msg.ChanID case *lnwire.UpdateFailHTLC: chanID = msg.ChanID case *lnwire.RevokeAndAck: chanID = msg.ChanID case *lnwire.CommitSig: chanID = msg.ChanID case *lnwire.ChannelReestablish: chanID = msg.ChanID case *lnwire.FundingLocked: chanID = msg.ChanID default: return chanID, fmt.Errorf("unknown type: %T", msg) } return chanID, nil } // generatePayment generates the htlc add request by given path blob and // invoice which should be added by destination peer. func generatePayment(invoiceAmt, htlcAmt lnwire.MilliSatoshi, timelock uint32, blob [lnwire.OnionPacketSize]byte) (*channeldb.Invoice, *lnwire.UpdateAddHTLC, error) { var preimage [sha256.Size]byte r, err := generateRandomBytes(sha256.Size) if err != nil { return nil, nil, err } copy(preimage[:], r) rhash := fastsha256.Sum256(preimage[:]) invoice := &channeldb.Invoice{ CreationDate: time.Now(), Terms: channeldb.ContractTerm{ Value: invoiceAmt, PaymentPreimage: preimage, }, } htlc := &lnwire.UpdateAddHTLC{ PaymentHash: rhash, Amount: htlcAmt, Expiry: timelock, OnionBlob: blob, } return invoice, htlc, nil } // generateRoute generates the path blob by given array of peers. func generateRoute(hops ...ForwardingInfo) ([lnwire.OnionPacketSize]byte, error) { var blob [lnwire.OnionPacketSize]byte if len(hops) == 0 { return blob, errors.New("empty path") } iterator := newMockHopIterator(hops...) w := bytes.NewBuffer(blob[0:0]) if err := iterator.EncodeNextHop(w); err != nil { return blob, err } return blob, nil } // threeHopNetwork is used for managing the created cluster of 3 hops. type threeHopNetwork struct { aliceServer *mockServer aliceChannelLink *channelLink firstBobChannelLink *channelLink bobServer *mockServer secondBobChannelLink *channelLink carolChannelLink *channelLink carolServer *mockServer globalPolicy ForwardingPolicy } // generateHops creates the per hop payload, the total amount to be sent, and // also the time lock value needed to route a HTLC with the target amount over // the specified path. func generateHops(payAmt lnwire.MilliSatoshi, startingHeight uint32, path ...*channelLink) (lnwire.MilliSatoshi, uint32, []ForwardingInfo) { lastHop := path[len(path)-1] totalTimelock := startingHeight runningAmt := payAmt hops := make([]ForwardingInfo, len(path)) for i := len(path) - 1; i >= 0; i-- { // If this is the last hop, then the next hop is the special // "exit node". Otherwise, we look to the "prior" hop. nextHop := exitHop if i != len(path)-1 { nextHop = path[i+1].channel.ShortChanID() } // If this is the last, hop, then the time lock will be their // specified delta policy plus our starting height. totalTimelock += lastHop.cfg.FwrdingPolicy.TimeLockDelta timeLock := totalTimelock // Otherwise, the outgoing time lock should be the incoming // timelock minus their specified delta. if i != len(path)-1 { delta := path[i].cfg.FwrdingPolicy.TimeLockDelta timeLock = totalTimelock - delta } // Finally, we'll need to calculate the amount to forward. For // the last hop, it's just the payment amount. amount := payAmt if i != len(path)-1 { prevHop := hops[i+1] prevAmount := prevHop.AmountToForward fee := ExpectedFee(path[i].cfg.FwrdingPolicy, prevAmount) runningAmt += fee // Otherwise, for a node to forward an HTLC, then // following inequality most hold true: // * amt_in - fee >= amt_to_forward amount = runningAmt - fee } hops[i] = ForwardingInfo{ Network: BitcoinHop, NextHop: nextHop, AmountToForward: amount, OutgoingCTLV: timeLock, } } return runningAmt, totalTimelock, hops } type paymentResponse struct { rhash chainhash.Hash err chan error } func (r *paymentResponse) Wait(d time.Duration) (chainhash.Hash, error) { select { case err := <-r.err: close(r.err) return r.rhash, err case <-time.After(d): return r.rhash, errors.New("htlc was no settled in time") } } // makePayment takes the destination node and amount as input, sends the // payment and returns the error channel to wait for error to be received and // invoice in order to check its status after the payment finished. // // With this function you can send payments: // * from Alice to Bob // * from Alice to Carol through the Bob // * from Alice to some another peer through the Bob func (n *threeHopNetwork) makePayment(sendingPeer, receivingPeer Peer, firstHopPub [33]byte, hops []ForwardingInfo, invoiceAmt, htlcAmt lnwire.MilliSatoshi, timelock uint32) *paymentResponse { paymentErr := make(chan error, 1) var rhash chainhash.Hash sender := sendingPeer.(*mockServer) receiver := receivingPeer.(*mockServer) // Generate route convert it to blob, and return next destination for // htlc add request. blob, err := generateRoute(hops...) if err != nil { paymentErr <- err return &paymentResponse{ rhash: rhash, err: paymentErr, } } // Generate payment: invoice and htlc. invoice, htlc, err := generatePayment(invoiceAmt, htlcAmt, timelock, blob) if err != nil { paymentErr <- err return &paymentResponse{ rhash: rhash, err: paymentErr, } } rhash = fastsha256.Sum256(invoice.Terms.PaymentPreimage[:]) // Check who is last in the route and add invoice to server registry. if err := receiver.registry.AddInvoice(*invoice); err != nil { paymentErr <- err return &paymentResponse{ rhash: rhash, err: paymentErr, } } // Send payment and expose err channel. go func() { _, err := sender.htlcSwitch.SendHTLC(firstHopPub, htlc, newMockDeobfuscator()) paymentErr <- err }() return &paymentResponse{ rhash: rhash, err: paymentErr, } } // start starts the three hop network alice,bob,carol servers. func (n *threeHopNetwork) start() error { if err := n.aliceServer.Start(); err != nil { return err } if err := n.bobServer.Start(); err != nil { return err } if err := n.carolServer.Start(); err != nil { return err } return nil } // stop stops nodes and cleanup its databases. func (n *threeHopNetwork) stop() { done := make(chan struct{}) go func() { n.aliceServer.Stop() done <- struct{}{} }() go func() { n.bobServer.Stop() done <- struct{}{} }() go func() { n.carolServer.Stop() done <- struct{}{} }() for i := 0; i < 3; i++ { <-done } } type clusterChannels struct { aliceToBob *lnwallet.LightningChannel bobToAlice *lnwallet.LightningChannel bobToCarol *lnwallet.LightningChannel carolToBob *lnwallet.LightningChannel } // createClusterChannels creates lightning channels which are needed for // network cluster to be initialized. func createClusterChannels(aliceToBob, bobToCarol btcutil.Amount) ( *clusterChannels, func(), func() (*clusterChannels, error), error) { firstChanID := lnwire.NewShortChanIDFromInt(4) secondChanID := lnwire.NewShortChanIDFromInt(5) // Create lightning channels between Alice<->Bob and Bob<->Carol aliceChannel, firstBobChannel, cleanAliceBob, restoreAliceBob, err := createTestChannel( alicePrivKey, bobPrivKey, aliceToBob, aliceToBob, firstChanID) if err != nil { return nil, nil, nil, errors.Errorf("unable to create "+ "alice<->bob channel: %v", err) } secondBobChannel, carolChannel, cleanBobCarol, restoreBobCarol, err := createTestChannel( bobPrivKey, carolPrivKey, bobToCarol, bobToCarol, secondChanID) if err != nil { cleanAliceBob() return nil, nil, nil, errors.Errorf("unable to create "+ "bob<->carol channel: %v", err) } cleanUp := func() { cleanAliceBob() cleanBobCarol() } restoreFromDb := func() (*clusterChannels, error) { a2b, b2a, err := restoreAliceBob() if err != nil { return nil, err } b2c, c2b, err := restoreBobCarol() if err != nil { return nil, err } return &clusterChannels{ aliceToBob: a2b, bobToAlice: b2a, bobToCarol: b2c, carolToBob: c2b, }, nil } return &clusterChannels{ aliceToBob: aliceChannel, bobToAlice: firstBobChannel, bobToCarol: secondBobChannel, carolToBob: carolChannel, }, cleanUp, restoreFromDb, nil } // newThreeHopNetwork function creates the following topology and returns the // control object to manage this cluster: // // alice bob carol // server - <-connection-> - server - - <-connection-> - - - server // | | | // alice htlc bob htlc carol htlc // switch switch \ switch // | | \ | // | | \ | // alice first bob second bob carol // channel link channel link channel link channel link // func newThreeHopNetwork(t testing.TB, aliceChannel, firstBobChannel, secondBobChannel, carolChannel *lnwallet.LightningChannel, startingHeight uint32) *threeHopNetwork { // Create three peers/servers. aliceServer := newMockServer(t, "alice") bobServer := newMockServer(t, "bob") carolServer := newMockServer(t, "carol") // Create mock decoder instead of sphinx one in order to mock the // route which htlc should follow. decoder := &mockIteratorDecoder{} globalEpoch := &chainntnfs.BlockEpochEvent{ Epochs: make(chan *chainntnfs.BlockEpoch), Cancel: func() { }, } globalPolicy := ForwardingPolicy{ MinHTLC: lnwire.NewMSatFromSatoshis(5), BaseFee: lnwire.NewMSatFromSatoshis(1), TimeLockDelta: 6, } obfuscator := newMockObfuscator() aliceChannelLink := NewChannelLink( ChannelLinkConfig{ FwrdingPolicy: globalPolicy, Peer: bobServer, Switch: aliceServer.htlcSwitch, DecodeHopIterator: decoder.DecodeHopIterator, DecodeOnionObfuscator: func(io.Reader) (ErrorEncrypter, lnwire.FailCode) { return obfuscator, lnwire.CodeNone }, GetLastChannelUpdate: mockGetChanUpdateMessage, Registry: aliceServer.registry, BlockEpochs: globalEpoch, SyncStates: true, }, aliceChannel, startingHeight, ) if err := aliceServer.htlcSwitch.addLink(aliceChannelLink); err != nil { t.Fatalf("unable to add alice channel link: %v", err) } firstBobChannelLink := NewChannelLink( ChannelLinkConfig{ FwrdingPolicy: globalPolicy, Peer: aliceServer, Switch: bobServer.htlcSwitch, DecodeHopIterator: decoder.DecodeHopIterator, DecodeOnionObfuscator: func(io.Reader) (ErrorEncrypter, lnwire.FailCode) { return obfuscator, lnwire.CodeNone }, GetLastChannelUpdate: mockGetChanUpdateMessage, Registry: bobServer.registry, BlockEpochs: globalEpoch, SyncStates: true, }, firstBobChannel, startingHeight, ) if err := bobServer.htlcSwitch.addLink(firstBobChannelLink); err != nil { t.Fatalf("unable to add first bob channel link: %v", err) } secondBobChannelLink := NewChannelLink( ChannelLinkConfig{ FwrdingPolicy: globalPolicy, Peer: carolServer, Switch: bobServer.htlcSwitch, DecodeHopIterator: decoder.DecodeHopIterator, DecodeOnionObfuscator: func(io.Reader) (ErrorEncrypter, lnwire.FailCode) { return obfuscator, lnwire.CodeNone }, GetLastChannelUpdate: mockGetChanUpdateMessage, Registry: bobServer.registry, BlockEpochs: globalEpoch, SyncStates: true, }, secondBobChannel, startingHeight, ) if err := bobServer.htlcSwitch.addLink(secondBobChannelLink); err != nil { t.Fatalf("unable to add second bob channel link: %v", err) } carolChannelLink := NewChannelLink( ChannelLinkConfig{ FwrdingPolicy: globalPolicy, Peer: bobServer, Switch: carolServer.htlcSwitch, DecodeHopIterator: decoder.DecodeHopIterator, DecodeOnionObfuscator: func(io.Reader) (ErrorEncrypter, lnwire.FailCode) { return obfuscator, lnwire.CodeNone }, GetLastChannelUpdate: mockGetChanUpdateMessage, Registry: carolServer.registry, BlockEpochs: globalEpoch, SyncStates: true, }, carolChannel, startingHeight, ) if err := carolServer.htlcSwitch.addLink(carolChannelLink); err != nil { t.Fatalf("unable to add carol channel link: %v", err) } return &threeHopNetwork{ aliceServer: aliceServer, aliceChannelLink: aliceChannelLink.(*channelLink), firstBobChannelLink: firstBobChannelLink.(*channelLink), bobServer: bobServer, secondBobChannelLink: secondBobChannelLink.(*channelLink), carolChannelLink: carolChannelLink.(*channelLink), carolServer: carolServer, globalPolicy: globalPolicy, } }