// Copyright (c) 2013-2017 The btcsuite developers // Copyright (c) 2015-2016 The Decred developers // Copyright (C) 2015-2017 The Lightning Network Developers package lnd import ( "context" "crypto/tls" "fmt" "io/ioutil" "net" "net/http" "os" "path/filepath" "runtime/pprof" "strings" "sync" "time" // Blank import to set up profiling HTTP handlers. _ "net/http/pprof" "gopkg.in/macaroon-bakery.v2/bakery" "gopkg.in/macaroon.v2" "google.golang.org/grpc" "google.golang.org/grpc/credentials" "github.com/btcsuite/btcd/btcec" "github.com/btcsuite/btcutil" "github.com/btcsuite/btcwallet/wallet" proxy "github.com/grpc-ecosystem/grpc-gateway/runtime" "github.com/lightninglabs/neutrino" "github.com/lightningnetwork/lnd/autopilot" "github.com/lightningnetwork/lnd/build" "github.com/lightningnetwork/lnd/cert" "github.com/lightningnetwork/lnd/chanacceptor" "github.com/lightningnetwork/lnd/channeldb" "github.com/lightningnetwork/lnd/keychain" "github.com/lightningnetwork/lnd/lncfg" "github.com/lightningnetwork/lnd/lnrpc" "github.com/lightningnetwork/lnd/lnwallet" "github.com/lightningnetwork/lnd/lnwallet/btcwallet" "github.com/lightningnetwork/lnd/macaroons" "github.com/lightningnetwork/lnd/signal" "github.com/lightningnetwork/lnd/walletunlocker" "github.com/lightningnetwork/lnd/watchtower" "github.com/lightningnetwork/lnd/watchtower/wtdb" ) var ( cfg *config registeredChains = newChainRegistry() // networkDir is the path to the directory of the currently active // network. This path will hold the files related to each different // network. networkDir string ) // WalletUnlockerAuthOptions returns a list of DialOptions that can be used to // authenticate with the wallet unlocker service. // // NOTE: This should only be called after the WalletUnlocker listener has // signaled it is ready. func WalletUnlockerAuthOptions() ([]grpc.DialOption, error) { creds, err := credentials.NewClientTLSFromFile(cfg.TLSCertPath, "") if err != nil { return nil, fmt.Errorf("unable to read TLS cert: %v", err) } // Create a dial options array with the TLS credentials. opts := []grpc.DialOption{ grpc.WithTransportCredentials(creds), } return opts, nil } // AdminAuthOptions returns a list of DialOptions that can be used to // authenticate with the RPC server with admin capabilities. // // NOTE: This should only be called after the RPCListener has signaled it is // ready. func AdminAuthOptions() ([]grpc.DialOption, error) { creds, err := credentials.NewClientTLSFromFile(cfg.TLSCertPath, "") if err != nil { return nil, fmt.Errorf("unable to read TLS cert: %v", err) } // Create a dial options array. opts := []grpc.DialOption{ grpc.WithTransportCredentials(creds), } // Get the admin macaroon if macaroons are active. if !cfg.NoMacaroons { // Load the adming macaroon file. macBytes, err := ioutil.ReadFile(cfg.AdminMacPath) if err != nil { return nil, fmt.Errorf("unable to read macaroon "+ "path (check the network setting!): %v", err) } mac := &macaroon.Macaroon{} if err = mac.UnmarshalBinary(macBytes); err != nil { return nil, fmt.Errorf("unable to decode macaroon: %v", err) } // Now we append the macaroon credentials to the dial options. cred := macaroons.NewMacaroonCredential(mac) opts = append(opts, grpc.WithPerRPCCredentials(cred)) } return opts, nil } // ListnerWithSignal is a net.Listner that has an additional Ready channel that // will be closed when a server starts listening. type ListenerWithSignal struct { net.Listener // Ready will be closed by the server listening on Listener. Ready chan struct{} } // ListenerCfg is a wrapper around custom listeners that can be passed to lnd // when calling its main method. type ListenerCfg struct { // WalletUnlocker can be set to the listener to use for the wallet // unlocker. If nil a regular network listener will be created. WalletUnlocker *ListenerWithSignal // RPCListener can be set to the listener to use for the RPC server. If // nil a regular network listener will be created. RPCListener *ListenerWithSignal } // rpcListeners is a function type used for closures that fetches a set of RPC // listeners for the current configuration. If no custom listeners are present, // this should return normal listeners from the RPC endpoints defined in the // config. The second return value us a closure that will close the fetched // listeners. type rpcListeners func() ([]*ListenerWithSignal, func(), error) // Main 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 Main(lisCfg ListenerCfg) error { // Hook interceptor for os signals. signal.Intercept() // 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() { ltndLog.Info("Shutdown complete") err := logWriter.Close() if err != nil { ltndLog.Errorf("Could not close log rotator: %v", err) } }() // Show version at startup. ltndLog.Infof("Version: %s, build=%s, logging=%s", build.Version(), build.Deployment, build.LoggingType) var network string switch { case cfg.Bitcoin.TestNet3 || cfg.Litecoin.TestNet3: network = "testnet" case cfg.Bitcoin.MainNet || cfg.Litecoin.MainNet: network = "mainnet" case cfg.Bitcoin.SimNet || cfg.Litecoin.SimNet: network = "simnet" case cfg.Bitcoin.RegTest || cfg.Litecoin.RegTest: network = "regtest" } ltndLog.Infof("Active chain: %v (network=%v)", strings.Title(registeredChains.PrimaryChain().String()), network, ) // 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 { err := fmt.Errorf("Unable to create CPU profile: %v", err) ltndLog.Error(err) return err } pprof.StartCPUProfile(f) defer f.Close() defer pprof.StopCPUProfile() } // Create the network-segmented directory for the channel database. graphDir := filepath.Join(cfg.DataDir, defaultGraphSubDirname, normalizeNetwork(activeNetParams.Name)) ltndLog.Infof("Opening the main database, this might take a few " + "minutes...") // Open the channeldb, which is dedicated to storing channel, and // network related metadata. startOpenTime := time.Now() chanDB, err := channeldb.Open( graphDir, channeldb.OptionSetRejectCacheSize(cfg.Caches.RejectCacheSize), channeldb.OptionSetChannelCacheSize(cfg.Caches.ChannelCacheSize), channeldb.OptionSetSyncFreelist(cfg.SyncFreelist), ) if err != nil { err := fmt.Errorf("Unable to open channeldb: %v", err) ltndLog.Error(err) return err } defer chanDB.Close() openTime := time.Since(startOpenTime) ltndLog.Infof("Database now open (time_to_open=%v)!", openTime) // Only process macaroons if --no-macaroons isn't set. ctx := context.Background() ctx, cancel := context.WithCancel(ctx) defer cancel() tlsCfg, restCreds, restProxyDest, err := getTLSConfig( cfg.TLSCertPath, cfg.TLSKeyPath, cfg.TLSExtraIPs, cfg.TLSExtraDomains, cfg.RPCListeners, ) if err != nil { err := fmt.Errorf("Unable to load TLS credentials: %v", err) ltndLog.Error(err) return err } serverCreds := credentials.NewTLS(tlsCfg) serverOpts := []grpc.ServerOption{grpc.Creds(serverCreds)} // For our REST dial options, we'll still use TLS, but also increase // the max message size that we'll decode to allow clients to hit // endpoints which return more data such as the DescribeGraph call. // We set this to 200MiB atm. Should be the same value as maxMsgRecvSize // in cmd/lncli/main.go. restDialOpts := []grpc.DialOption{ grpc.WithTransportCredentials(*restCreds), grpc.WithDefaultCallOptions( grpc.MaxCallRecvMsgSize(1 * 1024 * 1024 * 200), ), } // Before starting the wallet, we'll create and start our Neutrino // light client instance, if enabled, in order to allow it to sync // while the rest of the daemon continues startup. mainChain := cfg.Bitcoin if registeredChains.PrimaryChain() == litecoinChain { mainChain = cfg.Litecoin } var neutrinoCS *neutrino.ChainService if mainChain.Node == "neutrino" { neutrinoBackend, neutrinoCleanUp, err := initNeutrinoBackend( mainChain.ChainDir, ) if err != nil { err := fmt.Errorf("Unable to initialize neutrino "+ "backend: %v", err) ltndLog.Error(err) return err } defer neutrinoCleanUp() neutrinoCS = neutrinoBackend } var ( walletInitParams WalletUnlockParams privateWalletPw = lnwallet.DefaultPrivatePassphrase publicWalletPw = lnwallet.DefaultPublicPassphrase ) // If the user didn't request a seed, then we'll manually assume a // wallet birthday of now, as otherwise the seed would've specified // this information. walletInitParams.Birthday = time.Now() // getListeners is a closure that creates listeners from the // RPCListeners defined in the config. It also returns a cleanup // closure and the server options to use for the GRPC server. getListeners := func() ([]*ListenerWithSignal, func(), error) { var grpcListeners []*ListenerWithSignal for _, grpcEndpoint := range cfg.RPCListeners { // Start a gRPC server listening for HTTP/2 // connections. lis, err := lncfg.ListenOnAddress(grpcEndpoint) if err != nil { ltndLog.Errorf("unable to listen on %s", grpcEndpoint) return nil, nil, err } grpcListeners = append( grpcListeners, &ListenerWithSignal{ Listener: lis, Ready: make(chan struct{}), }) } cleanup := func() { for _, lis := range grpcListeners { lis.Close() } } return grpcListeners, cleanup, nil } // walletUnlockerListeners is a closure we'll hand to the wallet // unlocker, that will be called when it needs listeners for its GPRC // server. walletUnlockerListeners := func() ([]*ListenerWithSignal, func(), error) { // If we have chosen to start with a dedicated listener for the // wallet unlocker, we return it directly. if lisCfg.WalletUnlocker != nil { return []*ListenerWithSignal{lisCfg.WalletUnlocker}, func() {}, nil } // Otherwise we'll return the regular listeners. return getListeners() } // We wait until the user provides a password over RPC. In case lnd is // started with the --noseedbackup flag, we use the default password // for wallet encryption. if !cfg.NoSeedBackup { params, err := waitForWalletPassword( cfg.RESTListeners, serverOpts, restDialOpts, restProxyDest, tlsCfg, walletUnlockerListeners, ) if err != nil { err := fmt.Errorf("Unable to set up wallet password "+ "listeners: %v", err) ltndLog.Error(err) return err } walletInitParams = *params privateWalletPw = walletInitParams.Password publicWalletPw = walletInitParams.Password if walletInitParams.RecoveryWindow > 0 { ltndLog.Infof("Wallet recovery mode enabled with "+ "address lookahead of %d addresses", walletInitParams.RecoveryWindow) } } var macaroonService *macaroons.Service if !cfg.NoMacaroons { // Create the macaroon authentication/authorization service. macaroonService, err = macaroons.NewService( networkDir, macaroons.IPLockChecker, ) if err != nil { err := fmt.Errorf("Unable to set up macaroon "+ "authentication: %v", err) ltndLog.Error(err) return err } defer macaroonService.Close() // Try to unlock the macaroon store with the private password. err = macaroonService.CreateUnlock(&privateWalletPw) if err != nil { err := fmt.Errorf("Unable to unlock macaroons: %v", err) ltndLog.Error(err) return err } // Create macaroon files for lncli to use if they don't exist. if !fileExists(cfg.AdminMacPath) && !fileExists(cfg.ReadMacPath) && !fileExists(cfg.InvoiceMacPath) { err = genMacaroons( ctx, macaroonService, cfg.AdminMacPath, cfg.ReadMacPath, cfg.InvoiceMacPath, ) if err != nil { err := fmt.Errorf("Unable to create macaroons "+ "%v", err) ltndLog.Error(err) return err } } } // With the information parsed from the configuration, create valid // instances of the pertinent interfaces required to operate the // Lightning Network Daemon. activeChainControl, err := newChainControlFromConfig( cfg, chanDB, privateWalletPw, publicWalletPw, walletInitParams.Birthday, walletInitParams.RecoveryWindow, walletInitParams.Wallet, neutrinoCS, ) if err != nil { err := fmt.Errorf("Unable to create chain control: %v", err) ltndLog.Error(err) return err } // 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) // TODO(roasbeef): add rotation idPrivKey, err := activeChainControl.wallet.DerivePrivKey(keychain.KeyDescriptor{ KeyLocator: keychain.KeyLocator{ Family: keychain.KeyFamilyNodeKey, Index: 0, }, }) if err != nil { err := fmt.Errorf("Unable to derive node private key: %v", err) ltndLog.Error(err) return err } idPrivKey.Curve = btcec.S256() if cfg.Tor.Active { srvrLog.Infof("Proxying all network traffic via Tor "+ "(stream_isolation=%v)! NOTE: Ensure the backend node "+ "is proxying over Tor as well", cfg.Tor.StreamIsolation) } // If the watchtower client should be active, open the client database. // This is done here so that Close always executes when lndMain returns. var towerClientDB *wtdb.ClientDB if cfg.WtClient.Active { var err error towerClientDB, err = wtdb.OpenClientDB(graphDir) if err != nil { err := fmt.Errorf("Unable to open watchtower client "+ "database: %v", err) ltndLog.Error(err) return err } defer towerClientDB.Close() } var tower *watchtower.Standalone if cfg.Watchtower.Active { // Segment the watchtower directory by chain and network. towerDBDir := filepath.Join( cfg.Watchtower.TowerDir, registeredChains.PrimaryChain().String(), normalizeNetwork(activeNetParams.Name), ) towerDB, err := wtdb.OpenTowerDB(towerDBDir) if err != nil { err := fmt.Errorf("Unable to open watchtower "+ "database: %v", err) ltndLog.Error(err) return err } defer towerDB.Close() towerPrivKey, err := activeChainControl.wallet.DerivePrivKey( keychain.KeyDescriptor{ KeyLocator: keychain.KeyLocator{ Family: keychain.KeyFamilyTowerID, Index: 0, }, }, ) if err != nil { err := fmt.Errorf("Unable to derive watchtower "+ "private key: %v", err) ltndLog.Error(err) return err } wtConfig, err := cfg.Watchtower.Apply(&watchtower.Config{ BlockFetcher: activeChainControl.chainIO, DB: towerDB, EpochRegistrar: activeChainControl.chainNotifier, Net: cfg.net, NewAddress: func() (btcutil.Address, error) { return activeChainControl.wallet.NewAddress( lnwallet.WitnessPubKey, false, ) }, NodePrivKey: towerPrivKey, PublishTx: activeChainControl.wallet.PublishTransaction, ChainHash: *activeNetParams.GenesisHash, }, lncfg.NormalizeAddresses) if err != nil { err := fmt.Errorf("Unable to configure watchtower: %v", err) ltndLog.Error(err) return err } tower, err = watchtower.New(wtConfig) if err != nil { err := fmt.Errorf("Unable to create watchtower: %v", err) ltndLog.Error(err) return err } } // Initialize the ChainedAcceptor. chainedAcceptor := chanacceptor.NewChainedAcceptor() // Set up the core server which will listen for incoming peer // connections. server, err := newServer( cfg.Listeners, chanDB, towerClientDB, activeChainControl, idPrivKey, walletInitParams.ChansToRestore, chainedAcceptor, ) if err != nil { err := fmt.Errorf("Unable to create server: %v", err) ltndLog.Error(err) return err } // Set up an autopilot manager from the current config. This will be // used to manage the underlying autopilot agent, starting and stopping // it at will. atplCfg, err := initAutoPilot(server, cfg.Autopilot, mainChain) if err != nil { err := fmt.Errorf("Unable to initialize autopilot: %v", err) ltndLog.Error(err) return err } atplManager, err := autopilot.NewManager(atplCfg) if err != nil { err := fmt.Errorf("Unable to create autopilot manager: %v", err) ltndLog.Error(err) return err } if err := atplManager.Start(); err != nil { err := fmt.Errorf("Unable to start autopilot manager: %v", err) ltndLog.Error(err) return err } defer atplManager.Stop() // rpcListeners is a closure we'll hand to the rpc server, that will be // called when it needs listeners for its GPRC server. rpcListeners := func() ([]*ListenerWithSignal, func(), error) { // If we have chosen to start with a dedicated listener for the // rpc server, we return it directly. if lisCfg.RPCListener != nil { return []*ListenerWithSignal{lisCfg.RPCListener}, func() {}, nil } // Otherwise we'll return the regular listeners. return getListeners() } // Initialize, and register our implementation of the gRPC interface // exported by the rpcServer. rpcServer, err := newRPCServer( server, macaroonService, cfg.SubRPCServers, serverOpts, restDialOpts, restProxyDest, atplManager, server.invoices, tower, tlsCfg, rpcListeners, chainedAcceptor, ) if err != nil { err := fmt.Errorf("Unable to create RPC server: %v", err) ltndLog.Error(err) return err } if err := rpcServer.Start(); err != nil { err := fmt.Errorf("Unable to start RPC server: %v", err) ltndLog.Error(err) return err } defer rpcServer.Stop() // If we're not in regtest or 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.RegTest || cfg.Bitcoin.SimNet || cfg.Litecoin.RegTest || cfg.Litecoin.SimNet) { _, bestHeight, err := activeChainControl.chainIO.GetBestBlock() if err != nil { err := fmt.Errorf("Unable to determine chain tip: %v", err) ltndLog.Error(err) return err } ltndLog.Infof("Waiting for chain backend to finish sync, "+ "start_height=%v", bestHeight) for { if !signal.Alive() { return nil } synced, _, err := activeChainControl.wallet.IsSynced() if err != nil { err := fmt.Errorf("Unable to determine if "+ "wallet is synced: %v", err) ltndLog.Error(err) return err } if synced { break } time.Sleep(time.Second * 1) } _, bestHeight, err = activeChainControl.chainIO.GetBestBlock() if err != nil { err := fmt.Errorf("Unable to determine chain tip: %v", err) ltndLog.Error(err) 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 { err := fmt.Errorf("Unable to start server: %v", err) ltndLog.Error(err) return err } defer server.Stop() // Now that the server has started, if the autopilot mode is currently // active, then we'll start the autopilot agent immediately. It will be // stopped together with the autopilot service. if cfg.Autopilot.Active { if err := atplManager.StartAgent(); err != nil { err := fmt.Errorf("Unable to start autopilot agent: %v", err) ltndLog.Error(err) return err } } if cfg.Watchtower.Active { if err := tower.Start(); err != nil { err := fmt.Errorf("Unable to start watchtower: %v", err) ltndLog.Error(err) return err } defer tower.Stop() } // Wait for shutdown signal from either a graceful server stop or from // the interrupt handler. <-signal.ShutdownChannel() return nil } // getTLSConfig returns a TLS configuration for the gRPC server and credentials // and a proxy destination for the REST reverse proxy. func getTLSConfig(tlsCertPath string, tlsKeyPath string, tlsExtraIPs, tlsExtraDomains []string, rpcListeners []net.Addr) (*tls.Config, *credentials.TransportCredentials, string, error) { // Ensure we create TLS key and certificate if they don't exist. if !fileExists(tlsCertPath) && !fileExists(tlsKeyPath) { rpcsLog.Infof("Generating TLS certificates...") err := cert.GenCertPair( "lnd autogenerated cert", tlsCertPath, tlsKeyPath, tlsExtraIPs, tlsExtraDomains, cert.DefaultAutogenValidity, ) if err != nil { return nil, nil, "", err } rpcsLog.Infof("Done generating TLS certificates") } certData, parsedCert, err := cert.LoadCert(tlsCertPath, tlsKeyPath) if err != nil { return nil, nil, "", err } // We check whether the certifcate we have on disk match the IPs and // domains specified by the config. If the extra IPs or domains have // changed from when the certificate was created, we will refresh the // certificate if auto refresh is active. refresh := false if cfg.TLSAutoRefresh { refresh, err = cert.IsOutdated( parsedCert, tlsExtraIPs, tlsExtraDomains, ) if err != nil { return nil, nil, "", err } } // If the certificate expired or it was outdated, delete it and the TLS // key and generate a new pair. if time.Now().After(parsedCert.NotAfter) || refresh { ltndLog.Info("TLS certificate is expired or outdated, " + "generating a new one") err := os.Remove(tlsCertPath) if err != nil { return nil, nil, "", err } err = os.Remove(tlsKeyPath) if err != nil { return nil, nil, "", err } rpcsLog.Infof("Renewing TLS certificates...") err = cert.GenCertPair( "lnd autogenerated cert", tlsCertPath, tlsKeyPath, tlsExtraIPs, tlsExtraDomains, cert.DefaultAutogenValidity, ) if err != nil { return nil, nil, "", err } rpcsLog.Infof("Done renewing TLS certificates") // Reload the certificate data. certData, _, err = cert.LoadCert(tlsCertPath, tlsKeyPath) if err != nil { return nil, nil, "", err } } tlsCfg := cert.TLSConfFromCert(certData) restCreds, err := credentials.NewClientTLSFromFile(tlsCertPath, "") if err != nil { return nil, nil, "", err } restProxyDest := rpcListeners[0].String() switch { case strings.Contains(restProxyDest, "0.0.0.0"): restProxyDest = strings.Replace( restProxyDest, "0.0.0.0", "127.0.0.1", 1, ) case strings.Contains(restProxyDest, "[::]"): restProxyDest = strings.Replace( restProxyDest, "[::]", "[::1]", 1, ) } return tlsCfg, &restCreds, restProxyDest, nil } // 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 } // genMacaroons generates three macaroon files; one admin-level, one for // invoice access and one read-only. These can also be used to generate more // granular macaroons. func genMacaroons(ctx context.Context, svc *macaroons.Service, admFile, roFile, invoiceFile string) error { // First, we'll generate a macaroon that only allows the caller to // access invoice related calls. This is useful for merchants and other // services to allow an isolated instance that can only query and // modify invoices. invoiceMac, err := svc.Oven.NewMacaroon( ctx, bakery.LatestVersion, nil, invoicePermissions..., ) if err != nil { return err } invoiceMacBytes, err := invoiceMac.M().MarshalBinary() if err != nil { return err } err = ioutil.WriteFile(invoiceFile, invoiceMacBytes, 0644) if err != nil { os.Remove(invoiceFile) return err } // Generate the read-only macaroon and write it to a file. roMacaroon, err := svc.Oven.NewMacaroon( ctx, bakery.LatestVersion, nil, readPermissions..., ) if err != nil { return err } roBytes, err := roMacaroon.M().MarshalBinary() if err != nil { return err } if err = ioutil.WriteFile(roFile, roBytes, 0644); err != nil { os.Remove(admFile) return err } // Generate the admin macaroon and write it to a file. adminPermissions := append(readPermissions, writePermissions...) admMacaroon, err := svc.Oven.NewMacaroon( ctx, bakery.LatestVersion, nil, adminPermissions..., ) if err != nil { return err } admBytes, err := admMacaroon.M().MarshalBinary() if err != nil { return err } if err = ioutil.WriteFile(admFile, admBytes, 0600); err != nil { return err } return nil } // WalletUnlockParams holds the variables used to parameterize the unlocking of // lnd's wallet after it has already been created. type WalletUnlockParams struct { // Password is the public and private wallet passphrase. Password []byte // Birthday specifies the approximate time that this wallet was created. // This is used to bound any rescans on startup. Birthday time.Time // RecoveryWindow specifies the address lookahead when entering recovery // mode. A recovery will be attempted if this value is non-zero. RecoveryWindow uint32 // Wallet is the loaded and unlocked Wallet. This is returned // from the unlocker service to avoid it being unlocked twice (once in // the unlocker service to check if the password is correct and again // later when lnd actually uses it). Because unlocking involves scrypt // which is resource intensive, we want to avoid doing it twice. Wallet *wallet.Wallet // ChansToRestore a set of static channel backups that should be // restored before the main server instance starts up. ChansToRestore walletunlocker.ChannelsToRecover } // 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(restEndpoints []net.Addr, serverOpts []grpc.ServerOption, restDialOpts []grpc.DialOption, restProxyDest string, tlsConf *tls.Config, getListeners rpcListeners) (*WalletUnlockParams, error) { // Start a gRPC server listening for HTTP/2 connections, solely used // for getting the encryption password from the client. listeners, cleanup, err := getListeners() if err != nil { return nil, err } defer cleanup() // Set up a new PasswordService, which will listen for passwords // provided over RPC. grpcServer := grpc.NewServer(serverOpts...) defer grpcServer.GracefulStop() chainConfig := cfg.Bitcoin if registeredChains.PrimaryChain() == litecoinChain { chainConfig = cfg.Litecoin } // The macaroon files are passed to the wallet unlocker since they are // also encrypted with the wallet's password. These files will be // deleted within it and recreated when successfully changing the // wallet's password. macaroonFiles := []string{ filepath.Join(networkDir, macaroons.DBFilename), cfg.AdminMacPath, cfg.ReadMacPath, cfg.InvoiceMacPath, } pwService := walletunlocker.New( chainConfig.ChainDir, activeNetParams.Params, !cfg.SyncFreelist, macaroonFiles, ) 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 _, lis := range listeners { wg.Add(1) go func(lis *ListenerWithSignal) { rpcsLog.Infof("password RPC server listening on %s", lis.Addr()) // Close the ready chan to indicate we are listening. close(lis.Ready) wg.Done() grpcServer.Serve(lis) }(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, restProxyDest, restDialOpts, ) if err != nil { return nil, err } srv := &http.Server{Handler: mux} for _, restEndpoint := range restEndpoints { lis, err := lncfg.TLSListenOnAddress(restEndpoint, tlsConf) if err != nil { ltndLog.Errorf( "password gRPC proxy unable to listen on %s", restEndpoint, ) return 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 a wallet, `lncli unlock` to unlock an " + "existing wallet, or `lncli changepassword` to change the " + "password of an existing wallet and unlock it.") // 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 { // The wallet is being created for the first time, we'll check to see // if the user provided any entropy for seed creation. If so, then // we'll create the wallet early to load the seed. case initMsg := <-pwService.InitMsgs: password := initMsg.Passphrase cipherSeed := initMsg.WalletSeed recoveryWindow := initMsg.RecoveryWindow // Before we proceed, we'll check the internal version of the // seed. If it's greater than the current key derivation // version, then we'll return an error as we don't understand // this. if cipherSeed.InternalVersion != keychain.KeyDerivationVersion { return nil, fmt.Errorf("invalid internal seed version "+ "%v, current version is %v", cipherSeed.InternalVersion, keychain.KeyDerivationVersion) } netDir := btcwallet.NetworkDir( chainConfig.ChainDir, activeNetParams.Params, ) loader := wallet.NewLoader( activeNetParams.Params, netDir, !cfg.SyncFreelist, recoveryWindow, ) // With the seed, we can now use the wallet loader to create // the wallet, then pass it back to avoid unlocking it again. birthday := cipherSeed.BirthdayTime() newWallet, err := loader.CreateNewWallet( password, password, cipherSeed.Entropy[:], birthday, ) if err != nil { // Don't leave the file open in case the new wallet // could not be created for whatever reason. if err := loader.UnloadWallet(); err != nil { ltndLog.Errorf("Could not unload new "+ "wallet: %v", err) } return nil, err } return &WalletUnlockParams{ Password: password, Birthday: birthday, RecoveryWindow: recoveryWindow, Wallet: newWallet, ChansToRestore: initMsg.ChanBackups, }, nil // The wallet has already been created in the past, and is simply being // unlocked. So we'll just return these passphrases. case unlockMsg := <-pwService.UnlockMsgs: return &WalletUnlockParams{ Password: unlockMsg.Passphrase, RecoveryWindow: unlockMsg.RecoveryWindow, Wallet: unlockMsg.Wallet, ChansToRestore: unlockMsg.ChanBackups, }, nil case <-signal.ShutdownChannel(): return nil, fmt.Errorf("shutting down") } }