public async Task BroadcastCoinJoinIfFullySignedAsync()
{
using (await RoundSyncronizerLock.LockAsync())
{
// Check if fully signed.
if (SignedCoinJoin.Inputs.All(x => x.HasWitness()))
{
Logger.LogInfo <CcjRound>($"Round ({RoundId}): Trying to broadcast coinjoin.");
try
{
Coin[] spentCoins = Alices.SelectMany(x => x.Inputs.Select(y => new Coin(y.OutPoint, y.Output))).ToArray();
Money networkFee = SignedCoinJoin.GetFee(spentCoins);
Logger.LogInfo <CcjRound>($"Round ({RoundId}): Network Fee: {networkFee.ToString(false, false)} BTC.");
Logger.LogInfo <CcjRound>($"Round ({RoundId}): Coordinator Fee: {SignedCoinJoin.Outputs.SingleOrDefault(x => x.ScriptPubKey == Constants.GetCoordinatorAddress(RpcClient.Network).ScriptPubKey)?.Value?.ToString(false, false) ?? "0"} BTC.");
FeeRate feeRate = SignedCoinJoin.GetFeeRate(spentCoins);
Logger.LogInfo <CcjRound>($"Round ({RoundId}): Network Fee Rate: {feeRate.FeePerK.ToDecimal(MoneyUnit.Satoshi) / 1000} satoshi/byte.");
Logger.LogInfo <CcjRound>($"Round ({RoundId}): Number of inputs: {SignedCoinJoin.Inputs.Count}.");
Logger.LogInfo <CcjRound>($"Round ({RoundId}): Number of outputs: {SignedCoinJoin.Outputs.Count}.");
Logger.LogInfo <CcjRound>($"Round ({RoundId}): Serialized Size: {SignedCoinJoin.GetSerializedSize() / 1024} KB.");
Logger.LogInfo <CcjRound>($"Round ({RoundId}): VSize: {SignedCoinJoin.GetVirtualSize() / 1024} KB.");
foreach (var o in SignedCoinJoin.GetIndistinguishableOutputs().Where(x => x.count > 1))
{
Logger.LogInfo <CcjRound>($"Round ({RoundId}): There are {o.count} occurences of {o.value.ToString(true, false)} BTC output.");
}
await RpcClient.SendRawTransactionAsync(SignedCoinJoin);
Succeed(syncLock: false);
Logger.LogInfo <CcjRound>($"Round ({RoundId}): Successfully broadcasted the CoinJoin: {SignedCoinJoin.GetHash()}.");
}
catch (Exception ex)
{
Logger.LogError <CcjRound>($"Round ({RoundId}): Failed to broadcast the CoinJoin: {SignedCoinJoin.GetHash()}.");
Logger.LogError <CcjRound>(ex);
Fail(syncLock: false);
}
}
}
}
public async Task ExecuteNextPhaseAsync(CcjRoundPhase expectedPhase)
{
using (await RoundSyncronizerLock.LockAsync())
{
try
{
Logger.LogInfo <CcjRound>($"Round ({RoundId}): Phase change requested: {expectedPhase.ToString()}.");
if (Status == CcjRoundStatus.NotStarted) // So start the input registration phase
{
if (expectedPhase != CcjRoundPhase.InputRegistration)
{
return;
}
// Calculate fees
var inputSizeInBytes = (int)Math.Ceiling(((3 * Constants.P2wpkhInputSizeInBytes) + Constants.P2pkhInputSizeInBytes) / 4m);
var outputSizeInBytes = Constants.OutputSizeInBytes;
try
{
var estimateSmartFeeResponse = await RpcClient.EstimateSmartFeeAsync(ConfirmationTarget, EstimateSmartFeeMode.Conservative, simulateIfRegTest : true);
if (estimateSmartFeeResponse == null)
{
throw new InvalidOperationException("FeeRate is not yet initialized");
}
var feeRate = estimateSmartFeeResponse.FeeRate;
Money feePerBytes = (feeRate.FeePerK / 1000);
// Make sure min relay fee (1000 sat) is hit.
FeePerInputs = Math.Max(feePerBytes * inputSizeInBytes, new Money(500));
FeePerOutputs = Math.Max(feePerBytes * outputSizeInBytes, new Money(250));
}
catch (Exception ex)
{
// If fee hasn't been initialized once, fall back.
if (FeePerInputs == null || FeePerOutputs == null)
{
var feePerBytes = new Money(100); // 100 satoshi per byte
// Make sure min relay fee (1000 sat) is hit.
FeePerInputs = Math.Max(feePerBytes * inputSizeInBytes, new Money(500));
FeePerOutputs = Math.Max(feePerBytes * outputSizeInBytes, new Money(250));
}
Logger.LogError <CcjRound>(ex);
}
Status = CcjRoundStatus.Running;
}
else if (Status != CcjRoundStatus.Running) // Failed or succeeded, swallow
{
return;
}
else if (Phase == CcjRoundPhase.InputRegistration)
{
if (expectedPhase != CcjRoundPhase.ConnectionConfirmation)
{
return;
}
RoundHash = NBitcoinHelpers.HashOutpoints(Alices.SelectMany(x => x.Inputs).Select(y => y.OutPoint));
Phase = CcjRoundPhase.ConnectionConfirmation;
}
else if (Phase == CcjRoundPhase.ConnectionConfirmation)
{
if (expectedPhase != CcjRoundPhase.OutputRegistration)
{
return;
}
Phase = CcjRoundPhase.OutputRegistration;
}
else if (Phase == CcjRoundPhase.OutputRegistration)
{
if (expectedPhase != CcjRoundPhase.Signing)
{
return;
}
// Build CoinJoin
// 1. Set new denomination: minor optimization.
Money newDenomination = Alices.Min(x => x.OutputSumWithoutCoordinatorFeeAndDenomination);
var transaction = RpcClient.Network.Consensus.ConsensusFactory.CreateTransaction();
// 2. Add Bob outputs.
foreach (Bob bob in Bobs)
{
transaction.AddOutput(newDenomination, bob.ActiveOutputAddress.ScriptPubKey);
}
BitcoinWitPubKeyAddress coordinatorAddress = Constants.GetCoordinatorAddress(RpcClient.Network);
// 3. If there are less Bobs than Alices, then add our own address. The malicious Alice, who will refuse to sign.
for (int i = 0; i < Alices.Count - Bobs.Count; i++)
{
transaction.AddOutput(newDenomination, coordinatorAddress);
}
// 4. Start building Coordinator fee.
Money coordinatorFeePerAlice = newDenomination.Percentange(CoordinatorFeePercent);
Money coordinatorFee = Alices.Count * coordinatorFeePerAlice;
// 5. Add the inputs and the changes of Alices.
foreach (Alice alice in Alices)
{
foreach (var input in alice.Inputs)
{
transaction.AddInput(new TxIn(input.OutPoint));
}
Money changeAmount = alice.GetChangeAmount(newDenomination, coordinatorFeePerAlice);
if (changeAmount > Money.Zero) // If the coordinator fee would make change amount to be negative or zero then no need to pay it.
{
Money minimumOutputAmount = Money.Coins(0.0001m); // If the change would be less than about $1 then add it to the coordinator.
Money onePercentOfDenomination = newDenomination.Percentange(1m); // If the change is less than about 1% of the newDenomination then add it to the coordinator fee.
Money minimumChangeAmount = Math.Max(minimumOutputAmount, onePercentOfDenomination);
if (changeAmount < minimumChangeAmount)
{
coordinatorFee += changeAmount;
}
else
{
transaction.AddOutput(changeAmount, alice.ChangeOutputAddress.ScriptPubKey);
}
}
else
{
coordinatorFee -= coordinatorFeePerAlice;
}
}
// 6. Add Coordinator fee only if > about $3, else just let it to be miner fee.
if (coordinatorFee > Money.Coins(0.0003m))
{
transaction.AddOutput(coordinatorFee, coordinatorAddress);
}
// 7. Create the unsigned transaction.
var builder = new TransactionBuilder();
UnsignedCoinJoin = builder
.ContinueToBuild(transaction)
.Shuffle()
.BuildTransaction(false);
SignedCoinJoin = RpcClient.Network.Consensus.ConsensusFactory.CreateTransaction();
SignedCoinJoin.FromHex(UnsignedCoinJoin.ToHex());
Phase = CcjRoundPhase.Signing;
}
else
{
return;
}
Logger.LogInfo <CcjRound>($"Round ({RoundId}): Phase initialized: {expectedPhase.ToString()}.");
}
catch (Exception ex)
{
Logger.LogError <CcjRound>(ex);
Status = CcjRoundStatus.Failed;
throw;
}
}
#pragma warning disable CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
Task.Run(async() =>
{
TimeSpan timeout;
switch (expectedPhase)
{
case CcjRoundPhase.InputRegistration:
timeout = InputRegistrationTimeout;
break;
case CcjRoundPhase.ConnectionConfirmation:
timeout = ConnectionConfirmationTimeout;
break;
case CcjRoundPhase.OutputRegistration:
timeout = OutputRegistrationTimeout;
break;
case CcjRoundPhase.Signing:
timeout = SigningTimeout;
break;
default: throw new InvalidOperationException("This is impossible to happen.");
}
// Delay asyncronously to the requested timeout.
await Task.Delay(timeout);
var executeRunFailure = false;
using (await RoundSyncronizerLock.LockAsync())
{
executeRunFailure = Status == CcjRoundStatus.Running && Phase == expectedPhase;
}
if (executeRunFailure)
{
Logger.LogInfo <CcjRound>($"Round ({RoundId}): {expectedPhase.ToString()} timed out after {timeout.TotalSeconds} seconds. Failure mode is executing.");
// This will happen outside the lock.
Task.Run(async() =>
{
try
{
switch (expectedPhase)
{
case CcjRoundPhase.InputRegistration:
{
// Only fail if less two one Alice is registered.
// Don't ban anyone, it's ok if they lost connection.
await RemoveAlicesIfInputsSpentAsync();
int aliceCountAfterInputRegistrationTimeout = CountAlices();
if (aliceCountAfterInputRegistrationTimeout < 2)
{
Fail();
}
else
{
UpdateAnonymitySet(aliceCountAfterInputRegistrationTimeout);
// Progress to the next phase, which will be ConnectionConfirmation
await ExecuteNextPhaseAsync(CcjRoundPhase.ConnectionConfirmation);
}
}
break;
case CcjRoundPhase.ConnectionConfirmation:
{
// Only fail if less than two one alices are registered.
// What if an attacker registers all the time many alices, then drops out. He'll achieve only 2 alices to participate?
// If he registers many alices at InputRegistration
// AND never confirms in connection confirmation
// THEN connection confirmation will go with 2 alices in every round
// Therefore Alices those didn't confirm, nor requested dsconnection should be banned:
IEnumerable <Alice> alicesToBan1 = GetAlicesBy(AliceState.InputsRegistered);
IEnumerable <Alice> alicesToBan2 = await RemoveAlicesIfInputsSpentAsync(); // So ban only those who confirmed participation, yet spent their inputs.
IEnumerable <OutPoint> inputsToBan = alicesToBan1.SelectMany(x => x.Inputs).Select(y => y.OutPoint).Concat(alicesToBan2.SelectMany(x => x.Inputs).Select(y => y.OutPoint)).Distinct();
if (inputsToBan.Any())
{
await UtxoReferee.BanUtxosAsync(1, DateTimeOffset.UtcNow, inputsToBan.ToArray());
}
RemoveAlicesBy(alicesToBan1.Select(x => x.UniqueId).Concat(alicesToBan2.Select(y => y.UniqueId)).Distinct().ToArray());
int aliceCountAfterConnectionConfirmationTimeout = CountAlices();
if (aliceCountAfterConnectionConfirmationTimeout < 2)
{
Fail();
}
else
{
UpdateAnonymitySet(aliceCountAfterConnectionConfirmationTimeout);
// Progress to the next phase, which will be OutputRegistration
await ExecuteNextPhaseAsync(CcjRoundPhase.OutputRegistration);
}
}
break;
case CcjRoundPhase.OutputRegistration:
{
// Output registration never fails.
// We don't know which Alice to ban.
// Therefore proceed to signing, and whichever Alice doesn't sign ban.
await ExecuteNextPhaseAsync(CcjRoundPhase.Signing);
}
break;
case CcjRoundPhase.Signing:
{
var outpointsToBan = new List <OutPoint>();
using (await RoundSyncronizerLock.LockAsync())
{
foreach (Alice alice in Alices)
{
if (alice.State != AliceState.SignedCoinJoin)
{
outpointsToBan.AddRange(alice.Inputs.Select(x => x.OutPoint));
}
}
}
if (outpointsToBan.Any())
{
await UtxoReferee.BanUtxosAsync(1, DateTimeOffset.UtcNow, outpointsToBan.ToArray());
}
Fail();
}
break;
default: throw new InvalidOperationException("This is impossible to happen.");
}
}
catch (Exception ex)
{
Logger.LogWarning <CcjRound>($"Round ({RoundId}): {expectedPhase.ToString()} timeout failed with exception: {ex}");
}
});
}
});
#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
}