From 154dc1af6698dbcd95460949ded26a1bbe8858f2 Mon Sep 17 00:00:00 2001
From: Oliver Gugger <gugger@gmail.com>
Date: Mon, 7 Sep 2020 18:02:42 +0200
Subject: [PATCH] lncli: allow final transaction as raw hex in PSBT funding
 flow

---
 cmd/lncli/cmd_open_channel.go | 68 ++++++++++++++++++++++++++---------
 1 file changed, 51 insertions(+), 17 deletions(-)

diff --git a/cmd/lncli/cmd_open_channel.go b/cmd/lncli/cmd_open_channel.go
index 412306ba..d6547de9 100644
--- a/cmd/lncli/cmd_open_channel.go
+++ b/cmd/lncli/cmd_open_channel.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bytes"
 	"context"
 	"crypto/rand"
 	"encoding/base64"
@@ -11,6 +12,7 @@ import (
 	"strings"
 
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/wire"
 	"github.com/btcsuite/btcutil"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnwallet/chanfunding"
@@ -43,9 +45,9 @@ Base64 encoded PSBT: `
 	userMsgSign = `
 PSBT verified by lnd, please continue the funding flow by signing the PSBT by 
 all required parties/devices. Once the transaction is fully signed, paste it
-again here.
+again here either in base64 PSBT or hex encoded raw wire TX format.
 
-Base64 encoded signed PSBT: `
+Signed base64 encoded PSBT or hex encoded raw wire TX: `
 )
 
 // TODO(roasbeef): change default number of confirmations
@@ -505,7 +507,7 @@ func openChannelPsbt(ctx *cli.Context, client lnrpc.LightningClient,
 				return fmt.Errorf("reading from console "+
 					"failed: %v", err)
 			}
-			psbt, err := base64.StdEncoding.DecodeString(
+			fundedPsbt, err := base64.StdEncoding.DecodeString(
 				strings.TrimSpace(psbtBase64),
 			)
 			if err != nil {
@@ -515,7 +517,7 @@ func openChannelPsbt(ctx *cli.Context, client lnrpc.LightningClient,
 			verifyMsg := &lnrpc.FundingTransitionMsg{
 				Trigger: &lnrpc.FundingTransitionMsg_PsbtVerify{
 					PsbtVerify: &lnrpc.FundingPsbtVerify{
-						FundedPsbt:    psbt,
+						FundedPsbt:    fundedPsbt,
 						PendingChanId: pendingChanID[:],
 					},
 				},
@@ -531,7 +533,7 @@ func openChannelPsbt(ctx *cli.Context, client lnrpc.LightningClient,
 			fmt.Print(userMsgSign)
 
 			// Read the signed PSBT and send it to lnd.
-			psbtBase64, err = readLine(quit)
+			finalTxStr, err := readLine(quit)
 			if err == io.EOF {
 				return nil
 			}
@@ -539,22 +541,16 @@ func openChannelPsbt(ctx *cli.Context, client lnrpc.LightningClient,
 				return fmt.Errorf("reading from console "+
 					"failed: %v", err)
 			}
-			psbt, err = base64.StdEncoding.DecodeString(
-				strings.TrimSpace(psbtBase64),
+			finalizeMsg, err := finalizeMsgFromString(
+				finalTxStr, pendingChanID[:],
 			)
 			if err != nil {
-				return fmt.Errorf("base64 decode failed: %v",
-					err)
+				return err
 			}
-			finalizeMsg := &lnrpc.FundingTransitionMsg{
-				Trigger: &lnrpc.FundingTransitionMsg_PsbtFinalize{
-					PsbtFinalize: &lnrpc.FundingPsbtFinalize{
-						SignedPsbt:    psbt,
-						PendingChanId: pendingChanID[:],
-					},
-				},
+			transitionMsg := &lnrpc.FundingTransitionMsg{
+				Trigger: finalizeMsg,
 			}
-			err = sendFundingState(ctxc, ctx, finalizeMsg)
+			err = sendFundingState(ctxc, ctx, transitionMsg)
 			if err != nil {
 				return fmt.Errorf("finalizing PSBT funding "+
 					"flow failed: %v", err)
@@ -686,3 +682,41 @@ func sendFundingState(cancelCtx context.Context, cliCtx *cli.Context,
 	_, err := client.FundingStateStep(cancelCtx, msg)
 	return err
 }
+
+// finalizeMsgFromString creates the final message for the PsbtFinalize step
+// from either a hex encoded raw wire transaction or a base64 encoded PSBT
+// packet.
+func finalizeMsgFromString(tx string,
+	pendingChanID []byte) (*lnrpc.FundingTransitionMsg_PsbtFinalize, error) {
+
+	rawTx, err := hex.DecodeString(strings.TrimSpace(tx))
+	if err == nil {
+		// Hex decoding succeeded so we assume we have a raw wire format
+		// transaction. Let's submit that instead of a PSBT packet.
+		tx := &wire.MsgTx{}
+		err := tx.Deserialize(bytes.NewReader(rawTx))
+		if err != nil {
+			return nil, fmt.Errorf("deserializing as raw wire "+
+				"transaction failed: %v", err)
+		}
+		return &lnrpc.FundingTransitionMsg_PsbtFinalize{
+			PsbtFinalize: &lnrpc.FundingPsbtFinalize{
+				FinalRawTx:    rawTx,
+				PendingChanId: pendingChanID,
+			},
+		}, nil
+	}
+
+	// If the string isn't a hex encoded transaction, we assume it must be
+	// a base64 encoded PSBT packet.
+	psbtBytes, err := base64.StdEncoding.DecodeString(strings.TrimSpace(tx))
+	if err != nil {
+		return nil, fmt.Errorf("base64 decode failed: %v", err)
+	}
+	return &lnrpc.FundingTransitionMsg_PsbtFinalize{
+		PsbtFinalize: &lnrpc.FundingPsbtFinalize{
+			SignedPsbt:    psbtBytes,
+			PendingChanId: pendingChanID,
+		},
+	}, nil
+}