forceclose: extract close tx from backups

Author: starius

cmd/chantools/forceclose.go

@@ -7,13 +7,15 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"os"
 	"time"
 
 	"github.com/btcsuite/btcd/btcutil/hdkeychain"
 	"github.com/btcsuite/btcd/txscript"
 	"github.com/lightninglabs/chantools/btc"
 	"github.com/lightninglabs/chantools/dataformat"
 	"github.com/lightninglabs/chantools/lnd"
+	"github.com/lightningnetwork/lnd/chanbackup"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/spf13/cobra"
@@ -24,18 +26,18 @@ type forceCloseCommand struct {
 	ChannelDB string
 	Publish   bool
 
+	// channel.backup.
+	SingleBackup string
+	SingleFile   string
+	MultiBackup  string
+	MultiFile    string
+
 	rootKey *rootKey
 	inputs  *inputFlags
 	cmd     *cobra.Command
 }
 
-func newForceCloseCommand() *cobra.Command {
-	cc := &forceCloseCommand{}
-	cc.cmd = &cobra.Command{
-		Use: "forceclose",
-		Short: "Force-close the last state that is in the channel.db " +
-			"provided",
-		Long: `If you are certain that a node is offline for good (AFTER
+const forceCloseWarning = `If you are certain that a node is offline for good (AFTER
 you've tried SCB!) and a channel is still open, you can use this method to
 force-close your latest state that you have in your channel.db.
 
@@ -46,7 +48,15 @@ the remote node *could* punish you by taking the whole channel amount *if* they
 come online before you can sweep the funds from the time locked (144 - 2000
 blocks) transaction *or* they have a watch tower looking out for them.
 
-**This should absolutely be the last resort and you have been warned!**`,
+**This should absolutely be the last resort and you have been warned!**`
+
+func newForceCloseCommand() *cobra.Command {
+	cc := &forceCloseCommand{}
+	cc.cmd = &cobra.Command{
+		Use: "forceclose",
+		Short: "Force-close the last state that is in the channel.db " +
+			"provided",
+		Long: forceCloseWarning,
 		Example: `chantools forceclose \
 	--fromsummary results/summary-xxxx-yyyy.json
 	--channeldb ~/.lnd/data/graph/mainnet/channel.db \
@@ -61,6 +71,24 @@ blocks) transaction *or* they have a watch tower looking out for them.
 		&cc.ChannelDB, "channeldb", "", "lnd channel.db file to use "+
 			"for force-closing channels",
 	)
+
+	cc.cmd.Flags().StringVar(
+		&cc.SingleBackup, "single_backup", "", "a hex encoded single channel "+
+			"backup obtained from exportchanbackup for force-closing channels",
+	)
+	cc.cmd.Flags().StringVar(
+		&cc.MultiBackup, "multi_backup", "", "a hex encoded multi-channel "+
+			"backup obtained from exportchanbackup for force-closing channels",
+	)
+	cc.cmd.Flags().StringVar(
+		&cc.SingleFile, "single_file", "", "the path to a single-channel "+
+			"backup file",
+	)
+	cc.cmd.Flags().StringVar(
+		&cc.MultiFile, "multi_file", "", "the path to a single-channel "+
+			"backup file (channel.backup)",
+	)
+
 	cc.cmd.Flags().BoolVar(
 		&cc.Publish, "publish", false, "publish force-closing TX to "+
 			"the chain API instead of just printing the TX",
@@ -78,6 +106,10 @@ func (c *forceCloseCommand) Execute(_ *cobra.Command, _ []string) error {
 		return fmt.Errorf("error reading root key: %w", err)
 	}
 
+	if c.SingleBackup != "" || c.MultiBackup != "" || c.SingleFile != "" || c.MultiFile != "" {
+		return useChanBackup(extendedKey, c.SingleBackup, c.MultiBackup, c.SingleFile, c.MultiFile)
+	}
+
 	// Check that we have a channel DB.
 	if c.ChannelDB == "" {
 		return fmt.Errorf("rescue DB is required")
@@ -232,3 +264,67 @@ func forceCloseChannels(apiURL string, extendedKey *hdkeychain.ExtendedKey,
 	log.Infof("Writing result to %s", fileName)
 	return ioutil.WriteFile(fileName, summaryBytes, 0644)
 }
+
+func useChanBackup(extendedKey *hdkeychain.ExtendedKey, singleBackup, multiBackup, singleFile, multiFile string) error {
+	keyRing := &lnd.HDKeyRing{
+		ExtendedKey: extendedKey,
+		ChainParams: chainParams,
+	}
+	var backups []chanbackup.Single
+	var err error
+	if singleBackup != "" || singleFile != "" {
+		if singleBackup != "" && singleFile != "" {
+			return fmt.Errorf("must not pass --single_backup and --single_file together")
+		}
+		var singleBackupBytes []byte
+		if singleBackup != "" {
+			singleBackupBytes, err = hex.DecodeString(singleBackup)
+		} else if singleFile != "" {
+			singleBackupBytes, err = os.ReadFile(singleFile)
+		}
+		if err != nil {
+			return fmt.Errorf("failed to get single backup: %w", err)
+		}
+		var s chanbackup.Single
+		if err := s.UnpackFromReader(bytes.NewReader(singleBackupBytes), keyRing); err != nil {
+			return fmt.Errorf("failed to unpack single backup: %w", err)
+		}
+		backups = append(backups, s)
+	}
+	if multiBackup != "" || multiFile != "" {
+		if len(backups) != 0 {
+			return fmt.Errorf("must not pass single and multi backups together")
+		}
+		if multiBackup != "" && multiFile != "" {
+			return fmt.Errorf("must not pass --multi_backup and --multi_file together")
+		}
+		var multiBackupBytes []byte
+		if multiBackup != "" {
+			multiBackupBytes, err = hex.DecodeString(multiBackup)
+		} else if multiFile != "" {
+			multiBackupBytes, err = os.ReadFile(multiFile)
+		}
+		if err != nil {
+			return fmt.Errorf("failed to get multi backup: %w", err)
+		}
+		var m chanbackup.Multi
+		if err := m.UnpackFromReader(bytes.NewReader(multiBackupBytes), keyRing); err != nil {
+			return fmt.Errorf("failed to unpack multi backup: %w", err)
+		}
+		backups = append(backups, m.StaticBackups...)
+	}
+
+	fmt.Println()
+	fmt.Println("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@")
+	fmt.Println(forceCloseWarning)
+	fmt.Println("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@")
+	fmt.Println()
+
+	for _, s := range backups {
+		fmt.Println(s.FundingOutpoint)
+		fmt.Println(hex.EncodeToString(s.CloseTx))
+		fmt.Println()
+	}
+
+	return nil
+}