public Transaction Build()
{
ulong toLocalSatoshi = _channel.LocalCommitmentTxParameters.ToLocalMsat.MSatToSatoshi().CheckedSubtract(_channel.IsFunder ? FeeSatoshi : 0);
ulong toRemoteSatoshi = _channel.LocalCommitmentTxParameters.ToRemoteMsat.MSatToSatoshi().CheckedSubtract(_channel.IsFunder ? 0 : FeeSatoshi);
List <TxOut> outputs = new List <TxOut>();
var dustLimitSatoshis = Math.Max(_channel.LocalChannelParameters.DustLimitSatoshis, _channel.RemoteChannelParameters.DustLimitSatoshis);
if (toLocalSatoshi >= dustLimitSatoshis)
{
outputs.Add(BuildToLocalOutput(_channel, toLocalSatoshi));
}
if (toRemoteSatoshi >= dustLimitSatoshis)
{
outputs.Add(BuildToRemoteOutput(_channel, toRemoteSatoshi));
}
Transaction tx = Transaction.Create(_networkParameters.Network);
TxIn txIn = new TxIn(new OutPoint(uint256.Parse(_channel.FundingTransactionId), _channel.FundingOutputIndex));
txIn.Sequence = 0xFFFFFFFF;
txIn.ScriptSig = MultiSignaturePubKey.GenerateMultisigPubKey(_channel.LocalCommitmentTxParameters.FundingKey,
_channel.RemoteCommitmentTxParameters.FundingKey).WitHash.ScriptPubKey;
tx.Inputs.Add(txIn);
tx.Outputs.AddRange(outputs);
tx.Outputs.Sort(new Bip69OutputOrdering());
tx.Version = 2;
tx.LockTime = 0;
return(tx);
}
public Transaction Build()
{
var trimmedOfferedHtlcs = GetTrimmedOfferedHtlcs();
var trimmedReceivedHtlcs = GetTrimmedReceivedHtlcs();
ulong feeSatoshi = CalculateFee(trimmedOfferedHtlcs, trimmedReceivedHtlcs);
ulong toLocalSatoshi = CommitmentTxParams.ToLocalMsat.MSatToSatoshi().CheckedSubtract(IsFunder ? feeSatoshi : 0);
ulong toRemoteSatoshi = CommitmentTxParams.ToRemoteMsat.MSatToSatoshi().CheckedSubtract(IsFunder ? 0 : feeSatoshi);
List <(Htlc, TxOut)> htlcTxOutMap = new List <(Htlc, TxOut)>();
List <TxOut> outputs = new List <TxOut>();
if (toRemoteSatoshi >= ChannelParameters.DustLimitSatoshis)
{
outputs.Add(BuildToRemoteOutput(toRemoteSatoshi));
}
if (toLocalSatoshi >= ChannelParameters.DustLimitSatoshis)
{
outputs.Add(BuildToLocalDelayedOutput(toLocalSatoshi));
}
outputs.AddRange(trimmedOfferedHtlcs.Select(htlc =>
{
var txOut = BuildOfferedHtlcOutput(htlc);
htlcTxOutMap.Add((htlc, txOut));
return(txOut);
}));
outputs.AddRange(trimmedReceivedHtlcs.Select(htlc =>
{
var txOut = BuildReceivedHtlcOutput(htlc);
htlcTxOutMap.Add((htlc, txOut));
return(txOut);
}));
ulong obscuredTxNumber = IsFunder
? TransactionNumber.CalculateObscured(CommitmentTxParams.TransactionNumber, CommitmentTxParams.PaymentBasepoint, RemotePaymentBasePoint)
: TransactionNumber.CalculateObscured(CommitmentTxParams.TransactionNumber, RemotePaymentBasePoint, CommitmentTxParams.PaymentBasepoint);
ulong sequence = TransactionNumber.CalculateSequence(obscuredTxNumber);
ulong lockTime = TransactionNumber.CalculateLockTime(obscuredTxNumber);
Transaction tx = Transaction.Create(Network);
TxIn txIn = new TxIn(new OutPoint(uint256.Parse(FundingTransactionHash), FundingTransactionOutputIndex));
txIn.Sequence = new Sequence((uint)sequence);
txIn.ScriptSig = MultiSignaturePubKey.GenerateMultisigPubKey(CommitmentTxParams.FundingKey, RemoteFundingPubKey).WitHash.ScriptPubKey;
tx.Inputs.Add(txIn);
tx.Outputs.AddRange(outputs);
tx.LockTime = new LockTime((uint)lockTime);
tx.Version = 2;
tx.Outputs.Sort(new Bip69OutputOrdering());
_htlcOutputIndexMap = htlcTxOutMap.ToDictionary(k => k.Item1, v => tx.Outputs.FindIndex(o => o == v.Item2));
return(_commitmentTransaction = tx);
}
public void GenerateScriptPubKeyTest()
{
ECKeyPair pubKey1 = new ECKeyPair("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb", false);
ECKeyPair pubKey2 = new ECKeyPair("030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c1", false);
var result = MultiSignaturePubKey.GenerateMultisigPubKey(pubKey1, pubKey2);
Assert.Equal("5221023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb21030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c152ae",
result.ToBytes().ToHex());
}
public TransactionSignature SignCommitmentTransaction(Key fundingPrivateKey, Transaction unsignedCommitmentTransaction = null)
{
var unsigned = unsignedCommitmentTransaction ?? Build();
var redeemScript = MultiSignaturePubKey.GenerateMultisigPubKey(CommitmentTxParams.FundingKey, RemoteFundingPubKey);
var input = unsigned.Inputs[0];
var inputCoin = new Coin(input.PrevOut, new TxOut(Money.Satoshis(FundingAmount), input.ScriptSig));
var scriptCoin = inputCoin.ToScriptCoin(redeemScript);
TransactionBuilder builder2 = new TransactionBuilder();
builder2.AddCoins(scriptCoin);
builder2.AddKeys(fundingPrivateKey);
return(unsigned.SignInput(fundingPrivateKey, scriptCoin));
}
public TransactionSignature SignClosingTransaction(Transaction unsignedClosingTx)
{
var redeemScript = MultiSignaturePubKey.GenerateMultisigPubKey(_channel.LocalCommitmentTxParameters.FundingKey,
_channel.RemoteCommitmentTxParameters.FundingKey);
var input = unsignedClosingTx.Inputs[0];
var amount = _channel.FundingSatoshis;
var inputCoin = new Coin(input.PrevOut, new TxOut(Money.Satoshis(amount), input.ScriptSig));
var scriptCoin = inputCoin.ToScriptCoin(redeemScript);
var fundingPrivateKey = new Key(_channel.LocalCommitmentTxParameters.FundingKey.PrivateKeyData);
TransactionBuilder builder2 = new TransactionBuilder();
builder2.AddCoins(scriptCoin);
builder2.AddKeys(fundingPrivateKey);
return(unsignedClosingTx.SignInput(fundingPrivateKey, scriptCoin));
}
public FundingTransaction CreateFundingTransaction(ulong amount, ulong feeRate, ECKeyPair pubKey1, ECKeyPair pubKey2)
{
var script = MultiSignaturePubKey.GenerateMultisigPubKey(pubKey1, pubKey2);
var redeemScript = script.WitHash.ScriptPubKey;
var unspent = _blockchainClientService.ListUtxo(1, Int32.MaxValue, _walletService.PubKeyAddress);
_logger.LogInformation("Transaction Funding: found " + unspent.Count + " UTXO to fund the funding transaction");
var totalAmount = (ulong)unspent.Select(u => u.AmountSatoshi).Sum();
var fee = TransactionFee.CalculateFee(feeRate, 1000);
var neededAmount = fee + amount;
if (neededAmount > totalAmount)
{
throw new FundingException($"Not enough funds. Needed at least {neededAmount} Satoshi, but only {totalAmount} Satoshi are available.");
}
(Transaction fundingTransaction, List <Coin> inputCoins) = CreateFundingTransactionFromUtxo(amount, unspent, script, feeRate);
ushort fundingOutputIndex = (ushort)fundingTransaction.Outputs.FindIndex(o => o.ScriptPubKey == redeemScript);
return(new FundingTransaction(fundingTransaction, fundingOutputIndex, inputCoins, _walletService.PubKeyAddress.ScriptPubKey.ToBytes()));
}
