muun-recovery/sweeper.go

82 lines
2.0 KiB
Go

package main
import (
"bytes"
"encoding/hex"
"fmt"
"github.com/muun/recovery/electrum"
"github.com/muun/recovery/scanner"
"github.com/btcsuite/btcd/chaincfg"
"github.com/btcsuite/btcd/wire"
"github.com/btcsuite/btcutil"
"github.com/muun/libwallet"
)
var (
chainParams = chaincfg.MainNetParams
)
type Sweeper struct {
UserKey *libwallet.HDPrivateKey
MuunKey *libwallet.HDPrivateKey
Birthday int
SweepAddress btcutil.Address
}
func (s *Sweeper) GetSweepTxAmountAndWeightInBytes(utxos []*scanner.Utxo) (outputAmount int64, weightInBytes int64, err error) {
// we build a sweep tx with 0 fee with the only purpose of checking its signed size
zeroFeeSweepTx, err := s.BuildSweepTx(utxos, 0)
if err != nil {
return 0, 0, err
}
outputAmount = zeroFeeSweepTx.TxOut[0].Value
weightInBytes = int64(zeroFeeSweepTx.SerializeSize())
return outputAmount, weightInBytes, nil
}
func (s *Sweeper) BuildSweepTx(utxos []*scanner.Utxo, fee int64) (*wire.MsgTx, error) {
derivedMuunKey, err := s.MuunKey.DeriveTo("m/1'/1'")
if err != nil {
return nil, err
}
sweepTx, err := buildSweepTx(utxos, s.SweepAddress, fee)
if err != nil {
return nil, err
}
return buildSignedTx(utxos, sweepTx, s.UserKey, derivedMuunKey)
}
func (s *Sweeper) BroadcastTx(tx *wire.MsgTx) error {
// Connect to an Electurm server using a fresh client and provider pair:
sp := electrum.NewServerProvider(electrum.PublicServers) // TODO create servers module, for provider and pool
client := electrum.NewClient(true)
for !client.IsConnected() {
client.Connect(sp.NextServer())
}
// Encode the transaction for broadcast:
txBytes := new(bytes.Buffer)
err := tx.BtcEncode(txBytes, wire.ProtocolVersion, wire.WitnessEncoding)
if err != nil {
return fmt.Errorf("error while encoding tx: %w", err)
}
txHex := hex.EncodeToString(txBytes.Bytes())
// Do the thing!
_, err = client.Broadcast(txHex)
if err != nil {
return fmt.Errorf("error while broadcasting: %w", err)
}
return nil
}