lnd.xprv/lnd.go
2020-11-12 09:12:32 +02:00

1588 lines
48 KiB
Go

// 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"
_ "net/http/pprof" // Blank import to set up profiling HTTP handlers.
"os"
"path/filepath"
"runtime/pprof"
"strconv"
"strings"
"sync"
"time"
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcutil"
"github.com/btcsuite/btcwallet/wallet"
"github.com/btcsuite/btcwallet/walletdb"
proxy "github.com/grpc-ecosystem/grpc-gateway/runtime"
"github.com/lightninglabs/neutrino"
"github.com/lightninglabs/neutrino/headerfs"
"golang.org/x/crypto/acme/autocert"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials"
"gopkg.in/macaroon-bakery.v2/bakery"
"gopkg.in/macaroon.v2"
"github.com/lightningnetwork/lnd/autopilot"
"github.com/lightningnetwork/lnd/build"
"github.com/lightningnetwork/lnd/cert"
"github.com/lightningnetwork/lnd/chainreg"
"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/tor"
"github.com/lightningnetwork/lnd/walletunlocker"
"github.com/lightningnetwork/lnd/watchtower"
"github.com/lightningnetwork/lnd/watchtower/wtdb"
)
// 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(cfg *Config) ([]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(cfg *Config) ([]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
}
// GrpcRegistrar is an interface that must be satisfied by an external subserver
// that wants to be able to register its own gRPC server onto lnd's main
// grpc.Server instance.
type GrpcRegistrar interface {
// RegisterGrpcSubserver is called for each net.Listener on which lnd
// creates a grpc.Server instance. External subservers implementing this
// method can then register their own gRPC server structs to the main
// server instance.
RegisterGrpcSubserver(*grpc.Server) error
}
// RestRegistrar is an interface that must be satisfied by an external subserver
// that wants to be able to register its own REST mux onto lnd's main
// proxy.ServeMux instance.
type RestRegistrar interface {
// RegisterRestSubserver is called after lnd creates the main
// proxy.ServeMux instance. External subservers implementing this method
// can then register their own REST proxy stubs to the main server
// instance.
RegisterRestSubserver(context.Context, *proxy.ServeMux, string,
[]grpc.DialOption) error
}
// RPCSubserverConfig is a struct that can be used to register an external
// subserver with the custom permissions that map to the gRPC server that is
// going to be registered with the GrpcRegistrar.
type RPCSubserverConfig struct {
// Registrar is a callback that is invoked for each net.Listener on
// which lnd creates a grpc.Server instance.
Registrar GrpcRegistrar
// Permissions is the permissions required for the external subserver.
// It is a map between the full HTTP URI of each RPC and its required
// macaroon permissions. If multiple action/entity tuples are specified
// per URI, they are all required. See rpcserver.go for a list of valid
// action and entity values.
Permissions map[string][]bakery.Op
// MacaroonValidator is a custom macaroon validator that should be used
// instead of the default lnd validator. If specified, the custom
// validator is used for all URIs specified in the above Permissions
// map.
MacaroonValidator macaroons.MacaroonValidator
}
// ListenerWithSignal is a net.Listener 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{}
// ExternalRPCSubserverCfg is optional and specifies the registration
// callback and permissions to register external gRPC subservers.
ExternalRPCSubserverCfg *RPCSubserverConfig
// ExternalRestRegistrar is optional and specifies the registration
// callback to register external REST subservers.
ExternalRestRegistrar RestRegistrar
}
// 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. It accepts a fully populated and
// validated main configuration struct and an optional listener config struct.
// This function starts all main system components then blocks until a signal
// is received on the shutdownChan at which point everything is shut down again.
func Main(cfg *Config, lisCfg ListenerCfg, shutdownChan <-chan struct{}) error {
defer func() {
ltndLog.Info("Shutdown complete")
err := cfg.LogWriter.Close()
if err != nil {
ltndLog.Errorf("Could not close log rotator: %v", err)
}
}()
// Show version at startup.
ltndLog.Infof("Version: %s commit=%s, build=%s, logging=%s, debuglevel=%s",
build.Version(), build.Commit, build.Deployment,
build.LoggingType, cfg.DebugLevel)
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(cfg.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()
}
ctx := context.Background()
ctx, cancel := context.WithCancel(ctx)
defer cancel()
localChanDB, remoteChanDB, cleanUp, err := initializeDatabases(ctx, cfg)
switch {
case err == channeldb.ErrDryRunMigrationOK:
ltndLog.Infof("%v, exiting", err)
return nil
case err != nil:
return fmt.Errorf("unable to open databases: %v", err)
}
defer cleanUp()
// Only process macaroons if --no-macaroons isn't set.
serverOpts, restDialOpts, restListen, cleanUp, err := getTLSConfig(cfg)
if err != nil {
err := fmt.Errorf("unable to load TLS credentials: %v", err)
ltndLog.Error(err)
return err
}
defer cleanUp()
// We use the first RPC listener as the destination for our REST proxy.
// If the listener is set to listen on all interfaces, we replace it
// with localhost, as we cannot dial it directly.
restProxyDest := cfg.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,
)
}
// 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 cfg.registeredChains.PrimaryChain() == chainreg.LitecoinChain {
mainChain = cfg.Litecoin
}
var neutrinoCS *neutrino.ChainService
if mainChain.Node == "neutrino" {
neutrinoBackend, neutrinoCleanUp, err := initNeutrinoBackend(
cfg, 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
shutdownUnlocker = func() {}
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, shutdown, err := waitForWalletPassword(
cfg, cfg.RESTListeners, serverOpts, restDialOpts,
restProxyDest, restListen, walletUnlockerListeners,
)
if err != nil {
err := fmt.Errorf("unable to set up wallet password "+
"listeners: %v", err)
ltndLog.Error(err)
return err
}
walletInitParams = *params
shutdownUnlocker = shutdown
privateWalletPw = walletInitParams.Password
publicWalletPw = walletInitParams.Password
defer func() {
if err := walletInitParams.UnloadWallet(); err != nil {
ltndLog.Errorf("Could not unload wallet: %v", err)
}
}()
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(
cfg.networkDir, "lnd", walletInitParams.StatelessInit,
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.
// Ignore ErrAlreadyUnlocked since it could be unlocked by the
// wallet unlocker.
err = macaroonService.CreateUnlock(&privateWalletPw)
if err != nil && err != macaroons.ErrAlreadyUnlocked {
err := fmt.Errorf("unable to unlock macaroons: %v", err)
ltndLog.Error(err)
return err
}
// In case we actually needed to unlock the wallet, we now need
// to create an instance of the admin macaroon and send it to
// the unlocker so it can forward it to the user. In no seed
// backup mode, there's nobody listening on the channel and we'd
// block here forever.
if !cfg.NoSeedBackup {
adminMacBytes, err := bakeMacaroon(
ctx, macaroonService, adminPermissions(),
)
if err != nil {
return err
}
// The channel is buffered by one element so writing
// should not block here.
walletInitParams.MacResponseChan <- adminMacBytes
}
// If the user requested a stateless initialization, no macaroon
// files should be created.
if !walletInitParams.StatelessInit &&
!fileExists(cfg.AdminMacPath) &&
!fileExists(cfg.ReadMacPath) &&
!fileExists(cfg.InvoiceMacPath) {
// Create macaroon files for lncli to use if they don't
// exist.
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
}
}
// As a security service to the user, if they requested
// stateless initialization and there are macaroon files on disk
// we log a warning.
if walletInitParams.StatelessInit {
msg := "Found %s macaroon on disk (%s) even though " +
"--stateless_init was requested. Unencrypted " +
"state is accessible by the host system. You " +
"should change the password and use " +
"--new_mac_root_key with --stateless_init to " +
"clean up and invalidate old macaroons."
if fileExists(cfg.AdminMacPath) {
ltndLog.Warnf(msg, "admin", cfg.AdminMacPath)
}
if fileExists(cfg.ReadMacPath) {
ltndLog.Warnf(msg, "readonly", cfg.ReadMacPath)
}
if fileExists(cfg.InvoiceMacPath) {
ltndLog.Warnf(msg, "invoice", cfg.InvoiceMacPath)
}
}
}
// Now we're definitely done with the unlocker, shut it down so we can
// start the main RPC service later.
shutdownUnlocker()
// With the information parsed from the configuration, create valid
// instances of the pertinent interfaces required to operate the
// Lightning Network Daemon.
//
// When we create the chain control, we need storage for the height
// hints and also the wallet itself, for these two we want them to be
// replicated, so we'll pass in the remote channel DB instance.
chainControlCfg := &chainreg.Config{
Bitcoin: cfg.Bitcoin,
Litecoin: cfg.Litecoin,
PrimaryChain: cfg.registeredChains.PrimaryChain,
HeightHintCacheQueryDisable: cfg.HeightHintCacheQueryDisable,
NeutrinoMode: cfg.NeutrinoMode,
BitcoindMode: cfg.BitcoindMode,
LitecoindMode: cfg.LitecoindMode,
BtcdMode: cfg.BtcdMode,
LtcdMode: cfg.LtcdMode,
LocalChanDB: localChanDB,
RemoteChanDB: remoteChanDB,
PrivateWalletPw: privateWalletPw,
PublicWalletPw: publicWalletPw,
Birthday: walletInitParams.Birthday,
RecoveryWindow: walletInitParams.RecoveryWindow,
Wallet: walletInitParams.Wallet,
NeutrinoCS: neutrinoCS,
ActiveNetParams: cfg.ActiveNetParams,
FeeURL: cfg.FeeURL,
}
activeChainControl, err := chainreg.NewChainControl(chainControlCfg)
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 := cfg.registeredChains.PrimaryChain()
cfg.registeredChains.RegisterChain(primaryChain, activeChainControl)
// TODO(roasbeef): add rotation
idKeyDesc, err := activeChainControl.KeyRing.DeriveKey(
keychain.KeyLocator{
Family: keychain.KeyFamilyNodeKey,
Index: 0,
},
)
if err != nil {
err := fmt.Errorf("error deriving node key: %v", err)
ltndLog.Error(err)
return err
}
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(cfg.localDatabaseDir())
if err != nil {
err := fmt.Errorf("unable to open watchtower client "+
"database: %v", err)
ltndLog.Error(err)
return err
}
defer towerClientDB.Close()
}
// If tor is active and either v2 or v3 onion services have been specified,
// make a tor controller and pass it into both the watchtower server and
// the regular lnd server.
var torController *tor.Controller
if cfg.Tor.Active && (cfg.Tor.V2 || cfg.Tor.V3) {
torController = tor.NewController(
cfg.Tor.Control, cfg.Tor.TargetIPAddress, cfg.Tor.Password,
)
// Start the tor controller before giving it to any other subsystems.
if err := torController.Start(); err != nil {
err := fmt.Errorf("unable to initialize tor controller: %v", err)
ltndLog.Error(err)
return err
}
defer func() {
if err := torController.Stop(); err != nil {
ltndLog.Errorf("error stopping tor controller: %v", err)
}
}()
}
var tower *watchtower.Standalone
if cfg.Watchtower.Active {
// Segment the watchtower directory by chain and network.
towerDBDir := filepath.Join(
cfg.Watchtower.TowerDir,
cfg.registeredChains.PrimaryChain().String(),
lncfg.NormalizeNetwork(cfg.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()
towerKeyDesc, err := activeChainControl.KeyRing.DeriveKey(
keychain.KeyLocator{
Family: keychain.KeyFamilyTowerID,
Index: 0,
},
)
if err != nil {
err := fmt.Errorf("error deriving tower key: %v", err)
ltndLog.Error(err)
return err
}
wtCfg := &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,
)
},
NodeKeyECDH: keychain.NewPubKeyECDH(
towerKeyDesc, activeChainControl.KeyRing,
),
PublishTx: activeChainControl.Wallet.PublishTransaction,
ChainHash: *cfg.ActiveNetParams.GenesisHash,
}
// If there is a tor controller (user wants auto hidden services), then
// store a pointer in the watchtower config.
if torController != nil {
wtCfg.TorController = torController
wtCfg.WatchtowerKeyPath = cfg.Tor.WatchtowerKeyPath
switch {
case cfg.Tor.V2:
wtCfg.Type = tor.V2
case cfg.Tor.V3:
wtCfg.Type = tor.V3
}
}
wtConfig, err := cfg.Watchtower.Apply(wtCfg, 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, cfg.Listeners, localChanDB, remoteChanDB, towerClientDB,
activeChainControl, &idKeyDesc, walletInitParams.ChansToRestore,
chainedAcceptor, torController,
)
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, cfg.ActiveNetParams)
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(
cfg, server, macaroonService, cfg.SubRPCServers, serverOpts,
restDialOpts, restProxyDest, atplManager, server.invoices,
tower, restListen, 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.
<-shutdownChan
return nil
}
// getTLSConfig returns a TLS configuration for the gRPC server and credentials
// and a proxy destination for the REST reverse proxy.
func getTLSConfig(cfg *Config) ([]grpc.ServerOption, []grpc.DialOption,
func(net.Addr) (net.Listener, error), func(), error) {
// Ensure we create TLS key and certificate if they don't exist.
if !fileExists(cfg.TLSCertPath) && !fileExists(cfg.TLSKeyPath) {
rpcsLog.Infof("Generating TLS certificates...")
err := cert.GenCertPair(
"lnd autogenerated cert", cfg.TLSCertPath,
cfg.TLSKeyPath, cfg.TLSExtraIPs, cfg.TLSExtraDomains,
cfg.TLSDisableAutofill, cert.DefaultAutogenValidity,
)
if err != nil {
return nil, nil, nil, nil, err
}
rpcsLog.Infof("Done generating TLS certificates")
}
certData, parsedCert, err := cert.LoadCert(
cfg.TLSCertPath, cfg.TLSKeyPath,
)
if err != nil {
return nil, nil, 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, cfg.TLSExtraIPs,
cfg.TLSExtraDomains, cfg.TLSDisableAutofill,
)
if err != nil {
return nil, nil, 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(cfg.TLSCertPath)
if err != nil {
return nil, nil, nil, nil, err
}
err = os.Remove(cfg.TLSKeyPath)
if err != nil {
return nil, nil, nil, nil, err
}
rpcsLog.Infof("Renewing TLS certificates...")
err = cert.GenCertPair(
"lnd autogenerated cert", cfg.TLSCertPath,
cfg.TLSKeyPath, cfg.TLSExtraIPs, cfg.TLSExtraDomains,
cfg.TLSDisableAutofill, cert.DefaultAutogenValidity,
)
if err != nil {
return nil, nil, nil, nil, err
}
rpcsLog.Infof("Done renewing TLS certificates")
// Reload the certificate data.
certData, _, err = cert.LoadCert(
cfg.TLSCertPath, cfg.TLSKeyPath,
)
if err != nil {
return nil, nil, nil, nil, err
}
}
tlsCfg := cert.TLSConfFromCert(certData)
restCreds, err := credentials.NewClientTLSFromFile(cfg.TLSCertPath, "")
if err != nil {
return nil, nil, nil, nil, err
}
// If Let's Encrypt is enabled, instantiate autocert to request/renew
// the certificates.
cleanUp := func() {}
if cfg.LetsEncryptDomain != "" {
ltndLog.Infof("Using Let's Encrypt certificate for domain %v",
cfg.LetsEncryptDomain)
manager := autocert.Manager{
Cache: autocert.DirCache(cfg.LetsEncryptDir),
Prompt: autocert.AcceptTOS,
HostPolicy: autocert.HostWhitelist(cfg.LetsEncryptDomain),
}
srv := &http.Server{
Addr: cfg.LetsEncryptListen,
Handler: manager.HTTPHandler(nil),
}
shutdownCompleted := make(chan struct{})
cleanUp = func() {
err := srv.Shutdown(context.Background())
if err != nil {
ltndLog.Errorf("Autocert listener shutdown "+
" error: %v", err)
return
}
<-shutdownCompleted
ltndLog.Infof("Autocert challenge listener stopped")
}
go func() {
ltndLog.Infof("Autocert challenge listener started "+
"at %v", cfg.LetsEncryptListen)
err := srv.ListenAndServe()
if err != http.ErrServerClosed {
ltndLog.Errorf("autocert http: %v", err)
}
close(shutdownCompleted)
}()
getCertificate := func(h *tls.ClientHelloInfo) (
*tls.Certificate, error) {
lecert, err := manager.GetCertificate(h)
if err != nil {
ltndLog.Errorf("GetCertificate: %v", err)
return &certData, nil
}
return lecert, err
}
// The self-signed tls.cert remains available as fallback.
tlsCfg.GetCertificate = getCertificate
}
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),
),
}
// Return a function closure that can be used to listen on a given
// address with the current TLS config.
restListen := func(addr net.Addr) (net.Listener, error) {
// For restListen we will call ListenOnAddress if TLS is
// disabled.
if cfg.DisableRestTLS {
return lncfg.ListenOnAddress(addr)
}
return lncfg.TLSListenOnAddress(addr, tlsCfg)
}
return serverOpts, restDialOpts, restListen, cleanUp, 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
}
// bakeMacaroon creates a new macaroon with newest version and the given
// permissions then returns it binary serialized.
func bakeMacaroon(ctx context.Context, svc *macaroons.Service,
permissions []bakery.Op) ([]byte, error) {
mac, err := svc.NewMacaroon(
ctx, macaroons.DefaultRootKeyID, permissions...,
)
if err != nil {
return nil, err
}
return mac.M().MarshalBinary()
}
// 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.
invoiceMacBytes, err := bakeMacaroon(ctx, svc, invoicePermissions)
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.
roBytes, err := bakeMacaroon(ctx, svc, readPermissions)
if err != nil {
return err
}
if err = ioutil.WriteFile(roFile, roBytes, 0644); err != nil {
_ = os.Remove(roFile)
return err
}
// Generate the admin macaroon and write it to a file.
admBytes, err := bakeMacaroon(ctx, svc, adminPermissions())
if err != nil {
return err
}
if err = ioutil.WriteFile(admFile, admBytes, 0600); err != nil {
_ = os.Remove(admFile)
return err
}
return nil
}
// adminPermissions returns a list of all permissions in a safe way that doesn't
// modify any of the source lists.
func adminPermissions() []bakery.Op {
admin := make([]bakery.Op, len(readPermissions)+len(writePermissions))
copy(admin[:len(readPermissions)], readPermissions)
copy(admin[len(readPermissions):], writePermissions)
return admin
}
// 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
// UnloadWallet is a function for unloading the wallet, which should
// be called on shutdown.
UnloadWallet func() error
// StatelessInit signals that the user requested the daemon to be
// initialized stateless, which means no unencrypted macaroons should be
// written to disk.
StatelessInit bool
// MacResponseChan is the channel for sending back the admin macaroon to
// the WalletUnlocker service.
MacResponseChan chan []byte
}
// 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(cfg *Config, restEndpoints []net.Addr,
serverOpts []grpc.ServerOption, restDialOpts []grpc.DialOption,
restProxyDest string, restListen func(net.Addr) (net.Listener, error),
getListeners rpcListeners) (*WalletUnlockParams, func(), error) {
chainConfig := cfg.Bitcoin
if cfg.registeredChains.PrimaryChain() == chainreg.LitecoinChain {
chainConfig = cfg.Litecoin
}
// The macaroonFiles are passed to the wallet unlocker so they can be
// deleted and recreated in case the root macaroon key is also changed
// during the change password operation.
macaroonFiles := []string{
cfg.AdminMacPath, cfg.ReadMacPath, cfg.InvoiceMacPath,
}
pwService := walletunlocker.New(
chainConfig.ChainDir, cfg.ActiveNetParams.Params,
!cfg.SyncFreelist, macaroonFiles,
)
// Set up a new PasswordService, which will listen for passwords
// provided over RPC.
grpcServer := grpc.NewServer(serverOpts...)
lnrpc.RegisterWalletUnlockerServer(grpcServer, pwService)
var shutdownFuncs []func()
shutdown := func() {
// Make sure nothing blocks on reading on the macaroon channel,
// otherwise the GracefulStop below will never return.
close(pwService.MacResponseChan)
for _, shutdownFn := range shutdownFuncs {
shutdownFn()
}
}
shutdownFuncs = append(shutdownFuncs, grpcServer.GracefulStop)
// 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, shutdown, err
}
shutdownFuncs = append(shutdownFuncs, cleanup)
// 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)
shutdownFuncs = append(shutdownFuncs, cancel)
mux := proxy.NewServeMux()
err = lnrpc.RegisterWalletUnlockerHandlerFromEndpoint(
ctx, mux, restProxyDest, restDialOpts,
)
if err != nil {
return nil, shutdown, err
}
srv := &http.Server{Handler: allowCORS(mux, cfg.RestCORS)}
for _, restEndpoint := range restEndpoints {
lis, err := restListen(restEndpoint)
if err != nil {
ltndLog.Errorf("Password gRPC proxy unable to listen "+
"on %s", restEndpoint)
return nil, shutdown, err
}
shutdownFuncs = append(shutdownFuncs, func() {
err := lis.Close()
if err != nil {
rpcsLog.Errorf("Error closing listener: %v",
err)
}
})
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, shutdown, fmt.Errorf("invalid internal "+
"seed version %v, current version is %v",
cipherSeed.InternalVersion,
keychain.KeyDerivationVersion)
}
netDir := btcwallet.NetworkDir(
chainConfig.ChainDir, cfg.ActiveNetParams.Params,
)
loader := wallet.NewLoader(
cfg.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, shutdown, err
}
// For new wallets, the ResetWalletTransactions flag is a no-op.
if cfg.ResetWalletTransactions {
ltndLog.Warnf("Ignoring reset-wallet-transactions " +
"flag for new wallet as it has no effect")
}
return &WalletUnlockParams{
Password: password,
Birthday: birthday,
RecoveryWindow: recoveryWindow,
Wallet: newWallet,
ChansToRestore: initMsg.ChanBackups,
UnloadWallet: loader.UnloadWallet,
StatelessInit: initMsg.StatelessInit,
MacResponseChan: pwService.MacResponseChan,
}, shutdown, 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:
// Resetting the transactions is something the user likely only
// wants to do once so we add a prominent warning to the log to
// remind the user to turn off the setting again after
// successful completion.
if cfg.ResetWalletTransactions {
ltndLog.Warnf("Dropping all transaction history from " +
"on-chain wallet. Remember to disable " +
"reset-wallet-transactions flag for next " +
"start of lnd")
err := wallet.DropTransactionHistory(
unlockMsg.Wallet.Database(), true,
)
if err != nil {
if err := unlockMsg.UnloadWallet(); err != nil {
ltndLog.Errorf("Could not unload "+
"wallet: %v", err)
}
return nil, shutdown, err
}
}
return &WalletUnlockParams{
Password: unlockMsg.Passphrase,
RecoveryWindow: unlockMsg.RecoveryWindow,
Wallet: unlockMsg.Wallet,
ChansToRestore: unlockMsg.ChanBackups,
UnloadWallet: unlockMsg.UnloadWallet,
StatelessInit: unlockMsg.StatelessInit,
MacResponseChan: pwService.MacResponseChan,
}, shutdown, nil
case <-signal.ShutdownChannel():
return nil, shutdown, fmt.Errorf("shutting down")
}
}
// initializeDatabases extracts the current databases that we'll use for normal
// operation in the daemon. Two databases are returned: one remote and one
// local. However, only if the replicated database is active will the remote
// database point to a unique database. Otherwise, the local and remote DB will
// both point to the same local database. A function closure that closes all
// opened databases is also returned.
func initializeDatabases(ctx context.Context,
cfg *Config) (*channeldb.DB, *channeldb.DB, func(), error) {
ltndLog.Infof("Opening the main database, this might take a few " +
"minutes...")
if cfg.DB.Backend == lncfg.BoltBackend {
ltndLog.Infof("Opening bbolt database, sync_freelist=%v",
cfg.DB.Bolt.SyncFreelist)
}
startOpenTime := time.Now()
databaseBackends, err := cfg.DB.GetBackends(
ctx, cfg.localDatabaseDir(), cfg.networkName(),
)
if err != nil {
return nil, nil, nil, fmt.Errorf("unable to obtain database "+
"backends: %v", err)
}
// If the remoteDB is nil, then we'll just open a local DB as normal,
// having the remote and local pointer be the exact same instance.
var (
localChanDB, remoteChanDB *channeldb.DB
closeFuncs []func()
)
if databaseBackends.RemoteDB == nil {
// Open the channeldb, which is dedicated to storing channel,
// and network related metadata.
localChanDB, err = channeldb.CreateWithBackend(
databaseBackends.LocalDB,
channeldb.OptionSetRejectCacheSize(cfg.Caches.RejectCacheSize),
channeldb.OptionSetChannelCacheSize(cfg.Caches.ChannelCacheSize),
channeldb.OptionDryRunMigration(cfg.DryRunMigration),
)
switch {
case err == channeldb.ErrDryRunMigrationOK:
return nil, nil, nil, err
case err != nil:
err := fmt.Errorf("unable to open local channeldb: %v", err)
ltndLog.Error(err)
return nil, nil, nil, err
}
closeFuncs = append(closeFuncs, func() {
localChanDB.Close()
})
remoteChanDB = localChanDB
} else {
ltndLog.Infof("Database replication is available! Creating " +
"local and remote channeldb instances")
// Otherwise, we'll open two instances, one for the state we
// only need locally, and the other for things we want to
// ensure are replicated.
localChanDB, err = channeldb.CreateWithBackend(
databaseBackends.LocalDB,
channeldb.OptionSetRejectCacheSize(cfg.Caches.RejectCacheSize),
channeldb.OptionSetChannelCacheSize(cfg.Caches.ChannelCacheSize),
channeldb.OptionDryRunMigration(cfg.DryRunMigration),
)
switch {
// As we want to allow both versions to get thru the dry run
// migration, we'll only exit the second time here once the
// remote instance has had a time to migrate as well.
case err == channeldb.ErrDryRunMigrationOK:
ltndLog.Infof("Local DB dry run migration successful")
case err != nil:
err := fmt.Errorf("unable to open local channeldb: %v", err)
ltndLog.Error(err)
return nil, nil, nil, err
}
closeFuncs = append(closeFuncs, func() {
localChanDB.Close()
})
ltndLog.Infof("Opening replicated database instance...")
remoteChanDB, err = channeldb.CreateWithBackend(
databaseBackends.RemoteDB,
channeldb.OptionDryRunMigration(cfg.DryRunMigration),
)
switch {
case err == channeldb.ErrDryRunMigrationOK:
return nil, nil, nil, err
case err != nil:
localChanDB.Close()
err := fmt.Errorf("unable to open remote channeldb: %v", err)
ltndLog.Error(err)
return nil, nil, nil, err
}
closeFuncs = append(closeFuncs, func() {
remoteChanDB.Close()
})
}
openTime := time.Since(startOpenTime)
ltndLog.Infof("Database now open (time_to_open=%v)!", openTime)
cleanUp := func() {
for _, closeFunc := range closeFuncs {
closeFunc()
}
}
return localChanDB, remoteChanDB, cleanUp, nil
}
// initNeutrinoBackend inits a new instance of the neutrino light client
// backend given a target chain directory to store the chain state.
func initNeutrinoBackend(cfg *Config, chainDir string) (*neutrino.ChainService,
func(), error) {
// First we'll open the database file for neutrino, creating the
// database if needed. We append the normalized network name here to
// match the behavior of btcwallet.
dbPath := filepath.Join(
chainDir, lncfg.NormalizeNetwork(cfg.ActiveNetParams.Name),
)
// Ensure that the neutrino db path exists.
if err := os.MkdirAll(dbPath, 0700); err != nil {
return nil, nil, err
}
dbName := filepath.Join(dbPath, "neutrino.db")
db, err := walletdb.Create("bdb", dbName, !cfg.SyncFreelist)
if err != nil {
return nil, nil, fmt.Errorf("unable to create neutrino "+
"database: %v", err)
}
headerStateAssertion, err := parseHeaderStateAssertion(
cfg.NeutrinoMode.AssertFilterHeader,
)
if err != nil {
db.Close()
return nil, nil, err
}
// With the database open, we can now create an instance of the
// neutrino light client. We pass in relevant configuration parameters
// required.
config := neutrino.Config{
DataDir: dbPath,
Database: db,
ChainParams: *cfg.ActiveNetParams.Params,
AddPeers: cfg.NeutrinoMode.AddPeers,
ConnectPeers: cfg.NeutrinoMode.ConnectPeers,
Dialer: func(addr net.Addr) (net.Conn, error) {
return cfg.net.Dial(
addr.Network(), addr.String(),
cfg.ConnectionTimeout,
)
},
NameResolver: func(host string) ([]net.IP, error) {
addrs, err := cfg.net.LookupHost(host)
if err != nil {
return nil, err
}
ips := make([]net.IP, 0, len(addrs))
for _, strIP := range addrs {
ip := net.ParseIP(strIP)
if ip == nil {
continue
}
ips = append(ips, ip)
}
return ips, nil
},
AssertFilterHeader: headerStateAssertion,
}
neutrino.MaxPeers = 8
neutrino.BanDuration = time.Hour * 48
neutrino.UserAgentName = cfg.NeutrinoMode.UserAgentName
neutrino.UserAgentVersion = cfg.NeutrinoMode.UserAgentVersion
neutrinoCS, err := neutrino.NewChainService(config)
if err != nil {
db.Close()
return nil, nil, fmt.Errorf("unable to create neutrino light "+
"client: %v", err)
}
if err := neutrinoCS.Start(); err != nil {
db.Close()
return nil, nil, err
}
cleanUp := func() {
if err := neutrinoCS.Stop(); err != nil {
ltndLog.Infof("Unable to stop neutrino light client: %v", err)
}
db.Close()
}
return neutrinoCS, cleanUp, nil
}
// parseHeaderStateAssertion parses the user-specified neutrino header state
// into a headerfs.FilterHeader.
func parseHeaderStateAssertion(state string) (*headerfs.FilterHeader, error) {
if len(state) == 0 {
return nil, nil
}
split := strings.Split(state, ":")
if len(split) != 2 {
return nil, fmt.Errorf("header state assertion %v in "+
"unexpected format, expected format height:hash", state)
}
height, err := strconv.ParseUint(split[0], 10, 32)
if err != nil {
return nil, fmt.Errorf("invalid filter header height: %v", err)
}
hash, err := chainhash.NewHashFromStr(split[1])
if err != nil {
return nil, fmt.Errorf("invalid filter header hash: %v", err)
}
return &headerfs.FilterHeader{
Height: uint32(height),
FilterHash: *hash,
}, nil
}