// Copyright (c) 2013-2017 The btcsuite developers // Copyright (c) 2015-2016 The Decred developers // Copyright (C) 2015-2017 The Lightning Network Developers package main import ( "bytes" "crypto/rand" "crypto/rsa" "crypto/tls" "crypto/x509" "crypto/x509/pkix" "encoding/pem" "fmt" "io/ioutil" "math/big" "net" "net/http" _ "net/http/pprof" "os" "runtime" "runtime/pprof" "sync" "time" "gopkg.in/macaroon-bakery.v1/bakery" "golang.org/x/net/context" "google.golang.org/grpc" "google.golang.org/grpc/credentials" proxy "github.com/grpc-ecosystem/grpc-gateway/runtime" flags "github.com/jessevdk/go-flags" "github.com/lightningnetwork/lnd/autopilot" "github.com/lightningnetwork/lnd/channeldb" "github.com/lightningnetwork/lnd/lnrpc" "github.com/lightningnetwork/lnd/lnwallet" "github.com/lightningnetwork/lnd/lnwire" "github.com/lightningnetwork/lnd/macaroons" "github.com/lightningnetwork/lnd/walletunlocker" "github.com/roasbeef/btcd/btcec" "github.com/roasbeef/btcutil" ) const ( // Make certificate valid for 14 months. autogenCertValidity = 14 /*months*/ * 30 /*days*/ * 24 * time.Hour ) var ( cfg *config shutdownChannel = make(chan struct{}) registeredChains = newChainRegistry() macaroonDatabaseDir string // End of ASN.1 time. endOfTime = time.Date(2049, 12, 31, 23, 59, 59, 0, time.UTC) // Max serial number. serialNumberLimit = new(big.Int).Lsh(big.NewInt(1), 128) /* * These cipher suites fit the following criteria: * - Don't use outdated algorithms like SHA-1 and 3DES * - Don't use ECB mode or other insecure symmetric methods * - Included in the TLS v1.2 suite * - Are available in the Go 1.7.6 standard library (more are * available in 1.8.3 and will be added after lnd no longer * supports 1.7, including suites that support CBC mode) * * The cipher suites are ordered from strongest to weakest * primitives, but the client's preference order has more * effect during negotiation. **/ tlsCipherSuites = []uint16{ tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, tls.TLS_RSA_WITH_AES_256_GCM_SHA384, tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, tls.TLS_RSA_WITH_AES_128_CBC_SHA256, tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, tls.TLS_RSA_WITH_AES_128_GCM_SHA256, tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305, tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305, } ) // lndMain is the true entry point for lnd. This function is required since // defers created in the top-level scope of a main method aren't executed if // os.Exit() is called. func lndMain() error { // Load the configuration, and parse any command line options. This // function will also set up logging properly. loadedConfig, err := loadConfig() if err != nil { return err } cfg = loadedConfig defer func() { if logRotator != nil { logRotator.Close() } }() // Show version at startup. ltndLog.Infof("Version %s", version()) // Enable http profiling server if requested. if cfg.Profile != "" { go func() { listenAddr := net.JoinHostPort("", cfg.Profile) profileRedirect := http.RedirectHandler("/debug/pprof", http.StatusSeeOther) http.Handle("/", profileRedirect) fmt.Println(http.ListenAndServe(listenAddr, nil)) }() } // Write cpu profile if requested. if cfg.CPUProfile != "" { f, err := os.Create(cfg.CPUProfile) if err != nil { ltndLog.Errorf("Unable to create cpu profile: %v", err) return err } pprof.StartCPUProfile(f) defer f.Close() defer pprof.StopCPUProfile() } // Open the channeldb, which is dedicated to storing channel, and // network related metadata. chanDB, err := channeldb.Open(cfg.DataDir) if err != nil { ltndLog.Errorf("unable to open channeldb: %v", err) return err } defer chanDB.Close() // Only process macaroons if --no-macaroons isn't set. var macaroonService *bakery.Service if !cfg.NoMacaroons { // Create the macaroon authentication/authorization service. macaroonService, err = macaroons.NewService(macaroonDatabaseDir) if err != nil { srvrLog.Errorf("unable to create macaroon service: %v", err) return err } // Create macaroon files for lncli to use if they don't exist. if !fileExists(cfg.AdminMacPath) && !fileExists(cfg.ReadMacPath) { err = genMacaroons(macaroonService, cfg.AdminMacPath, cfg.ReadMacPath) if err != nil { ltndLog.Errorf("unable to create macaroon "+ "files: %v", err) return err } } } // Ensure we create TLS key and certificate if they don't exist if !fileExists(cfg.TLSCertPath) && !fileExists(cfg.TLSKeyPath) { if err := genCertPair(cfg.TLSCertPath, cfg.TLSKeyPath); err != nil { return err } } cert, err := tls.LoadX509KeyPair(cfg.TLSCertPath, cfg.TLSKeyPath) if err != nil { return err } tlsConf := &tls.Config{ Certificates: []tls.Certificate{cert}, CipherSuites: tlsCipherSuites, MinVersion: tls.VersionTLS12, } sCreds := credentials.NewTLS(tlsConf) serverOpts := []grpc.ServerOption{grpc.Creds(sCreds)} cCreds, err := credentials.NewClientTLSFromFile(cfg.TLSCertPath, "") if err != nil { return err } proxyOpts := []grpc.DialOption{grpc.WithTransportCredentials(cCreds)} // We wait until the user provides a password over RPC. In case lnd is // started with the --noencryptwallet flag, we use the default password // "hello" for wallet encryption. privateWalletPw := []byte("hello") publicWalletPw := []byte("public") if !cfg.NoEncryptWallet { privateWalletPw, publicWalletPw, err = waitForWalletPassword( cfg.RPCListeners, cfg.RESTListeners, serverOpts, proxyOpts, tlsConf, macaroonService, ) if err != nil { return err } } // With the information parsed from the configuration, create valid // instances of the pertinent interfaces required to operate the // Lightning Network Daemon. activeChainControl, chainCleanUp, err := newChainControlFromConfig(cfg, chanDB, privateWalletPw, publicWalletPw) if err != nil { fmt.Printf("unable to create chain control: %v\n", err) return err } if chainCleanUp != nil { defer chainCleanUp() } // Finally before we start the server, we'll register the "holy // trinity" of interface for our current "home chain" with the active // chainRegistry interface. primaryChain := registeredChains.PrimaryChain() registeredChains.RegisterChain(primaryChain, activeChainControl) idPrivKey, err := activeChainControl.wallet.GetIdentitykey() if err != nil { return err } idPrivKey.Curve = btcec.S256() // Set up the core server which will listen for incoming peer // connections. server, err := newServer(cfg.Listeners, chanDB, activeChainControl, idPrivKey) if err != nil { srvrLog.Errorf("unable to create server: %v\n", err) return err } // Next, we'll initialize the funding manager itself so it can answer // queries while the wallet+chain are still syncing. nodeSigner := newNodeSigner(idPrivKey) var chanIDSeed [32]byte if _, err := rand.Read(chanIDSeed[:]); err != nil { return err } fundingMgr, err := newFundingManager(fundingConfig{ IDKey: idPrivKey.PubKey(), Wallet: activeChainControl.wallet, Notifier: activeChainControl.chainNotifier, FeeEstimator: activeChainControl.feeEstimator, SignMessage: func(pubKey *btcec.PublicKey, msg []byte) (*btcec.Signature, error) { if pubKey.IsEqual(idPrivKey.PubKey()) { return nodeSigner.SignMessage(pubKey, msg) } return activeChainControl.msgSigner.SignMessage( pubKey, msg, ) }, CurrentNodeAnnouncement: func() (lnwire.NodeAnnouncement, error) { return server.genNodeAnnouncement(true) }, SendAnnouncement: func(msg lnwire.Message) error { errChan := server.authGossiper.ProcessLocalAnnouncement(msg, idPrivKey.PubKey()) return <-errChan }, ArbiterChan: server.breachArbiter.newContracts, SendToPeer: server.SendToPeer, NotifyWhenOnline: server.NotifyWhenOnline, FindPeer: server.FindPeer, TempChanIDSeed: chanIDSeed, FindChannel: func(chanID lnwire.ChannelID) (*lnwallet.LightningChannel, error) { dbChannels, err := chanDB.FetchAllChannels() if err != nil { return nil, err } for _, channel := range dbChannels { if chanID.IsChanPoint(&channel.FundingOutpoint) { // TODO(rosbeef): populate baecon return lnwallet.NewLightningChannel( activeChainControl.signer, server.witnessBeacon, channel) } } return nil, fmt.Errorf("unable to find channel") }, DefaultRoutingPolicy: activeChainControl.routingPolicy, NumRequiredConfs: func(chanAmt btcutil.Amount, pushAmt lnwire.MilliSatoshi) uint16 { // For large channels we increase the number // of confirmations we require for the // channel to be considered open. As it is // always the responder that gets to choose // value, the pushAmt is value being pushed // to us. This means we have more to lose // in the case this gets re-orged out, and // we will require more confirmations before // we consider it open. // TODO(halseth): Use Litecoin params in case // of LTC channels. // In case the user has explicitly specified // a default value for the number of // confirmations, we use it. defaultConf := uint16(cfg.Bitcoin.DefaultNumChanConfs) if defaultConf != 0 { return defaultConf } // If not we return a value scaled linearly // between 3 and 6, depending on channel size. // TODO(halseth): Use 1 as minimum? minConf := uint64(3) maxConf := uint64(6) maxChannelSize := uint64( lnwire.NewMSatFromSatoshis(maxFundingAmount)) stake := lnwire.NewMSatFromSatoshis(chanAmt) + pushAmt conf := maxConf * uint64(stake) / maxChannelSize if conf < minConf { conf = minConf } if conf > maxConf { conf = maxConf } return uint16(conf) }, RequiredRemoteDelay: func(chanAmt btcutil.Amount) uint16 { // We scale the remote CSV delay (the time the // remote have to claim funds in case of a unilateral // close) linearly from minRemoteDelay blocks // for small channels, to maxRemoteDelay blocks // for channels of size maxFundingAmount. // TODO(halseth): Litecoin parameter for LTC. // In case the user has explicitly specified // a default value for the remote delay, we // use it. defaultDelay := uint16(cfg.Bitcoin.DefaultRemoteDelay) if defaultDelay > 0 { return defaultDelay } // If not we scale according to channel size. delay := uint16(maxRemoteDelay * chanAmt / maxFundingAmount) if delay < minRemoteDelay { delay = minRemoteDelay } if delay > maxRemoteDelay { delay = maxRemoteDelay } return delay }, WatchNewChannel: server.chainArb.WatchNewChannel, }) if err != nil { return err } if err := fundingMgr.Start(); err != nil { return err } server.fundingMgr = fundingMgr // Initialize, and register our implementation of the gRPC interface // exported by the rpcServer. rpcServer := newRPCServer(server, macaroonService) if err := rpcServer.Start(); err != nil { return err } grpcServer := grpc.NewServer(serverOpts...) lnrpc.RegisterLightningServer(grpcServer, rpcServer) // Next, Start the gRPC server listening for HTTP/2 connections. for _, listener := range cfg.RPCListeners { lis, err := net.Listen("tcp", listener) if err != nil { ltndLog.Errorf("RPC server unable to listen on %s", listener) return err } defer lis.Close() go func() { rpcsLog.Infof("RPC server listening on %s", lis.Addr()) grpcServer.Serve(lis) }() } // Finally, start the REST proxy for our gRPC server above. ctx := context.Background() ctx, cancel := context.WithCancel(ctx) defer cancel() mux := proxy.NewServeMux() err = lnrpc.RegisterLightningHandlerFromEndpoint(ctx, mux, cfg.RPCListeners[0], proxyOpts) if err != nil { return err } for _, restEndpoint := range cfg.RESTListeners { listener, err := tls.Listen("tcp", restEndpoint, tlsConf) if err != nil { ltndLog.Errorf("gRPC proxy unable to listen on %s", restEndpoint) return err } defer listener.Close() go func() { rpcsLog.Infof("gRPC proxy started at %s", listener.Addr()) http.Serve(listener, mux) }() } // If we're not in simnet mode, We'll wait until we're fully synced to // continue the start up of the remainder of the daemon. This ensures // that we don't accept any possibly invalid state transitions, or // accept channels with spent funds. if !(cfg.Bitcoin.SimNet || cfg.Litecoin.SimNet) { _, bestHeight, err := activeChainControl.chainIO.GetBestBlock() if err != nil { return err } ltndLog.Infof("Waiting for chain backend to finish sync, "+ "start_height=%v", bestHeight) for { synced, err := activeChainControl.wallet.IsSynced() if err != nil { return err } if synced { break } time.Sleep(time.Second * 1) } _, bestHeight, err = activeChainControl.chainIO.GetBestBlock() if err != nil { return err } ltndLog.Infof("Chain backend is fully synced (end_height=%v)!", bestHeight) } // With all the relevant chains initialized, we can finally start the // server itself. if err := server.Start(); err != nil { srvrLog.Errorf("unable to start server: %v\n", err) return err } // Now that the server has started, if the autopilot mode is currently // active, then we'll initialize a fresh instance of it and start it. var pilot *autopilot.Agent if cfg.Autopilot.Active { pilot, err := initAutoPilot(server, cfg.Autopilot) if err != nil { ltndLog.Errorf("unable to create autopilot agent: %v", err) return err } if err := pilot.Start(); err != nil { ltndLog.Errorf("unable to start autopilot agent: %v", err) return err } } addInterruptHandler(func() { ltndLog.Infof("Gracefully shutting down the server...") rpcServer.Stop() fundingMgr.Stop() server.Stop() if pilot != nil { pilot.Stop() } server.WaitForShutdown() }) // Wait for shutdown signal from either a graceful server stop or from // the interrupt handler. <-shutdownChannel ltndLog.Info("Shutdown complete") return nil } func main() { // Use all processor cores. // TODO(roasbeef): remove this if required version # is > 1.6? runtime.GOMAXPROCS(runtime.NumCPU()) // Call the "real" main in a nested manner so the defers will properly // be executed in the case of a graceful shutdown. if err := lndMain(); err != nil { if e, ok := err.(*flags.Error); ok && e.Type == flags.ErrHelp { } else { fmt.Fprintln(os.Stderr, err) } os.Exit(1) } } // fileExists reports whether the named file or directory exists. // This function is taken from https://github.com/btcsuite/btcd func fileExists(name string) bool { if _, err := os.Stat(name); err != nil { if os.IsNotExist(err) { return false } } return true } // genCertPair generates a key/cert pair to the paths provided. The // auto-generated certificates should *not* be used in production for public // access as they're self-signed and don't necessarily contain all of the // desired hostnames for the service. For production/public use, consider a // real PKI. // // This function is adapted from https://github.com/btcsuite/btcd and // https://github.com/btcsuite/btcutil func genCertPair(certFile, keyFile string) error { rpcsLog.Infof("Generating TLS certificates...") org := "lnd autogenerated cert" now := time.Now() validUntil := now.Add(autogenCertValidity) // Check that the certificate validity isn't past the ASN.1 end of time. if validUntil.After(endOfTime) { validUntil = endOfTime } // Generate a serial number that's below the serialNumberLimit. serialNumber, err := rand.Int(rand.Reader, serialNumberLimit) if err != nil { return fmt.Errorf("failed to generate serial number: %s", err) } // Collect the host's IP addresses, including loopback, in a slice. ipAddresses := []net.IP{net.ParseIP("127.0.0.1"), net.ParseIP("::1")} // addIP appends an IP address only if it isn't already in the slice. addIP := func(ipAddr net.IP) { for _, ip := range ipAddresses { if bytes.Equal(ip, ipAddr) { return } } ipAddresses = append(ipAddresses, ipAddr) } // Add all the interface IPs that aren't already in the slice. addrs, err := net.InterfaceAddrs() if err != nil { return err } for _, a := range addrs { ipAddr, _, err := net.ParseCIDR(a.String()) if err == nil { addIP(ipAddr) } } // Collect the host's names into a slice. host, err := os.Hostname() if err != nil { return err } dnsNames := []string{host} if host != "localhost" { dnsNames = append(dnsNames, "localhost") } // Generate a private key for the certificate. priv, err := rsa.GenerateKey(rand.Reader, 4096) if err != nil { return err } // Construct the certificate template. template := x509.Certificate{ SerialNumber: serialNumber, Subject: pkix.Name{ Organization: []string{org}, CommonName: host, }, NotBefore: now.Add(-time.Hour * 24), NotAfter: validUntil, KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign, IsCA: true, // so can sign self. BasicConstraintsValid: true, DNSNames: dnsNames, IPAddresses: ipAddresses, // This signature algorithm is most likely to be compatible // with clients using less-common TLS libraries like BoringSSL. SignatureAlgorithm: x509.SHA256WithRSA, } derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, &priv.PublicKey, priv) if err != nil { return fmt.Errorf("failed to create certificate: %v", err) } certBuf := &bytes.Buffer{} err = pem.Encode(certBuf, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes}) if err != nil { return fmt.Errorf("failed to encode certificate: %v", err) } keybytes := x509.MarshalPKCS1PrivateKey(priv) keyBuf := &bytes.Buffer{} err = pem.Encode(keyBuf, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: keybytes}) if err != nil { return fmt.Errorf("failed to encode private key: %v", err) } // Write cert and key files. if err = ioutil.WriteFile(certFile, certBuf.Bytes(), 0644); err != nil { return err } if err = ioutil.WriteFile(keyFile, keyBuf.Bytes(), 0600); err != nil { os.Remove(certFile) return err } rpcsLog.Infof("Done generating TLS certificates") return nil } // genMacaroons generates a pair of macaroon files; one admin-level and one // read-only. These can also be used to generate more granular macaroons. func genMacaroons(svc *bakery.Service, admFile, roFile string) error { // Generate the admin macaroon and write it to a file. admMacaroon, err := svc.NewMacaroon("", nil, nil) if err != nil { return err } admBytes, err := admMacaroon.MarshalBinary() if err != nil { return err } if err = ioutil.WriteFile(admFile, admBytes, 0600); err != nil { return err } // Generate the read-only macaroon and write it to a file. roMacaroon, err := macaroons.AddConstraints(admMacaroon, macaroons.AllowConstraint(roPermissions...)) if err != nil { return err } roBytes, err := roMacaroon.MarshalBinary() if err != nil { return err } if err = ioutil.WriteFile(roFile, roBytes, 0644); err != nil { os.Remove(admFile) return err } return nil } // waitForWalletPassword will spin up gRPC and REST endpoints for the // WalletUnlocker server, and block until a password is provided by // the user to this RPC server. func waitForWalletPassword(grpcEndpoints, restEndpoints []string, serverOpts []grpc.ServerOption, proxyOpts []grpc.DialOption, tlsConf *tls.Config, macaroonService *bakery.Service) ([]byte, []byte, error) { // Set up a new PasswordService, which will listen // for passwords provided over RPC. grpcServer := grpc.NewServer(serverOpts...) chainConfig := cfg.Bitcoin if registeredChains.PrimaryChain() == litecoinChain { chainConfig = cfg.Litecoin } pwService := walletunlocker.New(macaroonService, chainConfig.ChainDir, activeNetParams.Params) lnrpc.RegisterWalletUnlockerServer(grpcServer, pwService) // Use a WaitGroup so we can be sure the instructions on how to input the // password is the last thing to be printed to the console. var wg sync.WaitGroup for _, grpcEndpoint := range grpcEndpoints { // Start a gRPC server listening for HTTP/2 connections, solely // used for getting the encryption password from the client. lis, err := net.Listen("tcp", grpcEndpoint) if err != nil { ltndLog.Errorf("password RPC server unable to listen on %s", grpcEndpoint) return nil, nil, err } defer lis.Close() wg.Add(1) go func() { rpcsLog.Infof("password RPC server listening on %s", lis.Addr()) wg.Done() grpcServer.Serve(lis) }() } // Start a REST proxy for our gRPC server above. ctx := context.Background() ctx, cancel := context.WithCancel(ctx) defer cancel() mux := proxy.NewServeMux() err := lnrpc.RegisterWalletUnlockerHandlerFromEndpoint(ctx, mux, grpcEndpoints[0], proxyOpts) if err != nil { return nil, nil, err } srv := &http.Server{Handler: mux} defer func() { // We must shut down this server, since we'll let // the regular rpcServer listen on the same address. if err := srv.Shutdown(ctx); err != nil { rpcsLog.Errorf("unable to shutdown password gRPC proxy: %v", err) } }() for _, restEndpoint := range restEndpoints { lis, err := tls.Listen("tcp", restEndpoint, tlsConf) if err != nil { ltndLog.Errorf("password gRPC proxy unable to listen on %s", restEndpoint) return nil, nil, err } defer lis.Close() wg.Add(1) go func() { rpcsLog.Infof("password gRPC proxy started at %s", lis.Addr()) wg.Done() srv.Serve(lis) }() } // Wait for gRPC and REST servers to be up running. wg.Wait() // Wait for user to provide the password. ltndLog.Infof("Waiting for wallet encryption password. " + "Use `lncli create` to create wallet, or " + "`lncli unlock` to unlock already created wallet.") // We currently don't distinguish between getting a password to // be used for creation or unlocking, as a new wallet db will be // created if none exists when creating the chain control. select { case walletPw := <-pwService.CreatePasswords: return walletPw, walletPw, nil case walletPw := <-pwService.UnlockPasswords: return walletPw, walletPw, nil case <-shutdownChannel: return nil, nil, fmt.Errorf("shutting down") } }