add dumphtlcsummary command.

Author: ziggie1984

cmd/chantools/root.go

@@ -119,6 +119,7 @@ func main() {
 		newVanityGenCommand(),
 		newWalletInfoCommand(),
 		newZombieRecoveryCommand(),
+		dumphtlcsummary(),
 	)
 
 	if err := rootCmd.Execute(); err != nil {

cmd/chantools/summaryhtlc.go

@@ -0,0 +1,166 @@
+package main
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/btcsuite/btcd/btcutil"
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/wire"
+	"github.com/lightninglabs/chantools/lnd"
+	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/input"
+	"github.com/lightningnetwork/lnd/lnrpc"
+	"github.com/lightningnetwork/lnd/lnwallet"
+	"github.com/spf13/cobra"
+)
+
+type summaryHTLC struct {
+	ChannelDB    string
+	ChannelPoint string
+
+	rootKey *rootKey
+	cmd     *cobra.Command
+}
+
+var errBadChanPoint = errors.New("expecting chan_point to be in format of: " +
+	"txid:index")
+
+func parseChanPoint(s string) (*lnrpc.ChannelPoint, error) {
+	split := strings.Split(s, ":")
+	if len(split) != 2 || len(split[0]) == 0 || len(split[1]) == 0 {
+		return nil, errBadChanPoint
+	}
+
+	index, err := strconv.ParseInt(split[1], 10, 64)
+	if err != nil {
+		return nil, fmt.Errorf("unable to decode output index: %v", err)
+	}
+
+	txid, err := chainhash.NewHashFromStr(split[0])
+	if err != nil {
+		return nil, fmt.Errorf("unable to parse hex string: %v", err)
+	}
+
+	return &lnrpc.ChannelPoint{
+		FundingTxid: &lnrpc.ChannelPoint_FundingTxidBytes{
+			FundingTxidBytes: txid[:],
+		},
+		OutputIndex: uint32(index),
+	}, nil
+}
+
+func dumphtlcsummary() *cobra.Command {
+	cc := &summaryHTLC{}
+	cc.cmd = &cobra.Command{
+		Use: "dumphtlcsummary",
+		Short: "dump all the necessary htlc information which are " +
+			"needed for the peer to recover his funds",
+		Long: `...`,
+		Example: `chantools dumphtlcsummary \
+	--channeldb ~/.lnd/data/graph/mainnet/channel.db`,
+		RunE: cc.Execute,
+	}
+	cc.cmd.Flags().StringVar(
+		&cc.ChannelDB, "channeldb", "", "lnd channel.db file to dump "+
+			"channels from",
+	)
+	cc.cmd.Flags().StringVar(
+		&cc.ChannelPoint, "ChannelPoint", "", "",
+	)
+
+	cc.rootKey = newRootKey(cc.cmd, "deriving keys")
+
+	return cc.cmd
+}
+
+func (c *summaryHTLC) Execute(_ *cobra.Command, _ []string) error {
+	// Check that we have a channel DB.
+	if c.ChannelDB == "" {
+		return fmt.Errorf("channel DB is required")
+	}
+	db, err := lnd.OpenDB(c.ChannelDB, true)
+	if err != nil {
+		return fmt.Errorf("error opening rescue DB: %w", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	return dumpHtlcInfos(db.ChannelStateDB(), c.ChannelPoint)
+}
+
+type hltcInfo struct {
+	HtlcAddress   string
+	WitnessScript string
+	CommitPoint   string
+}
+
+func dumpHtlcInfos(chanDb *channeldb.ChannelStateDB, channel string) error {
+
+	var htlcs []hltcInfo
+
+	chanPoint, err := parseChanPoint(channel)
+	if err != nil {
+		return err
+	}
+
+	//Open the Historical Bucket
+	fundingHash, err := chainhash.NewHash(chanPoint.GetFundingTxidBytes())
+
+	if err != nil {
+		return err
+	}
+	outPoint := wire.NewOutPoint(fundingHash, chanPoint.OutputIndex)
+
+	dbChannel, err := chanDb.FetchHistoricalChannel(outPoint)
+	if err != nil {
+		return err
+	}
+
+	for _, htlc := range dbChannel.LocalCommitment.Htlcs {
+		// Only Incoming HTLCs for now.
+		if !htlc.Incoming {
+			continue
+		}
+
+		revocationPreimage, err := dbChannel.RevocationProducer.AtIndex(
+			dbChannel.LocalCommitment.CommitHeight,
+		)
+		if err != nil {
+			return err
+		}
+		localCommitPoint := input.ComputeCommitmentPoint(revocationPreimage[:])
+
+		keyRing := lnwallet.DeriveCommitmentKeys(
+			localCommitPoint, true, dbChannel.ChanType,
+			&dbChannel.LocalChanCfg,
+			&dbChannel.RemoteChanCfg,
+		)
+
+		witnessScript, err := input.ReceiverHTLCScript(
+			htlc.RefundTimeout, keyRing.RemoteHtlcKey, keyRing.LocalHtlcKey,
+			keyRing.RevocationKey, htlc.RHash[:], dbChannel.ChanType.HasAnchors(),
+		)
+		witnessScriptHash := sha256.Sum256(witnessScript)
+		htlcAddr, err := btcutil.NewAddressWitnessScriptHash(
+			witnessScriptHash[:], chainParams,
+		)
+
+		htlcs = append(htlcs, hltcInfo{
+			HtlcAddress:   htlcAddr.String(),
+			WitnessScript: hex.EncodeToString(witnessScript),
+			CommitPoint:   hex.EncodeToString(localCommitPoint.SerializeCompressed()),
+		})
+	}
+
+	data, err := json.MarshalIndent(htlcs, "", "  ")
+
+	fmt.Printf("%v", string(data))
+
+	return nil
+
+}