public async Task <uint160.MutableUint160> BeginOpenChannel(
[ModelBinder(BinderType = typeof(TumblerParametersModelBinder))]
ClassicTumblerParameters tumblerId,
[FromBody] OpenChannelRequest request)
{
if (tumblerId == null)
{
throw new ArgumentNullException("tumblerId");
}
var height = Services.BlockExplorerService.GetCurrentHeight();
if (Repository.IsUsed(request.CycleStart, request.Nonce))
{
throw new ActionResultException(BadRequest("duplicate-query"));
}
var cycle = GetCycle(request.CycleStart);
if (!cycle.IsInPhase(CyclePhase.TumblerChannelEstablishment, height))
{
throw new ActionResultException(BadRequest("invalid-phase"));
}
var fee = await Services.FeeService.GetFeeRateAsync();
try
{
if (!Parameters.VoucherKey.PublicKey.Verify(request.Signature, NBitcoin.Utils.ToBytes((uint)request.CycleStart, true), request.Nonce))
{
throw new ActionResultException(BadRequest("incorrect-voucher"));
}
if (!Repository.MarkUsedNonce(request.CycleStart, request.Nonce))
{
throw new ActionResultException(BadRequest("duplicate-query"));
}
var escrowKey = new Key();
var escrow = new EscrowScriptPubKeyParameters();
escrow.LockTime = cycle.GetTumblerLockTime();
escrow.Receiver = request.EscrowKey;
escrow.Initiator = escrowKey.PubKey;
var channelId = new uint160(RandomUtils.GetBytes(20));
Logs.Tumbler.LogInformation($"Cycle {cycle.Start} Asked to open channel");
var txOut = new TxOut(Parameters.Denomination, escrow.ToScript().WitHash.ScriptPubKey.Hash);
var unused = Services.WalletService.FundTransactionAsync(txOut, fee)
.ContinueWith(async(Task <Transaction> task) =>
{
try
{
var tx = await task.ConfigureAwait(false);
var correlation = new CorrelationId(channelId);
Tracker.TransactionCreated(cycle.Start, TransactionType.TumblerEscrow, tx.GetHash(), correlation);
//Logging/Broadcast per funding TX one time
if (Repository.MarkUsedNonce(cycle.Start, new uint160(tx.GetHash().ToBytes().Take(20).ToArray())))
{
var bobCount = Parameters.CountEscrows(tx, Client.Identity.Bob);
Logs.Tumbler.LogInformation($"Cycle {cycle.Start} channel created {tx.GetHash()} with {bobCount} users");
await Services.BroadcastService.BroadcastAsync(tx).ConfigureAwait(false);
}
await Services.BlockExplorerService.TrackAsync(txOut.ScriptPubKey).ConfigureAwait(false);
Tracker.AddressCreated(cycle.Start, TransactionType.TumblerEscrow, txOut.ScriptPubKey, correlation);
var coin = tx.Outputs.AsCoins().First(o => o.ScriptPubKey == txOut.ScriptPubKey && o.TxOut.Value == txOut.Value);
var session = new PromiseServerSession(Parameters.CreatePromiseParamaters());
var redeem = await Services.WalletService.GenerateAddressAsync().ConfigureAwait(false);
session.ConfigureEscrowedCoin(channelId, coin.ToScriptCoin(escrow.ToScript()), escrowKey, redeem.ScriptPubKey);
var redeemTx = session.CreateRedeemTransaction(fee);
Services.TrustedBroadcastService.Broadcast(cycle.Start, TransactionType.TumblerRedeem, correlation, redeemTx);
Repository.Save(cycle.Start, session);
Tracker.AddressCreated(cycle.Start, TransactionType.TumblerRedeem, redeem.ScriptPubKey, correlation);
}
catch (Exception ex)
{
Logs.Tumbler.LogCritical(new EventId(), ex, "Error during escrow transaction callback");
}
});
return(channelId.AsBitcoinSerializable());
}
catch (NotEnoughFundsException ex)
{
Logs.Tumbler.LogInformation(ex.Message);
throw new ActionResultException(BadRequest("tumbler-insufficient-funds"));
}
}
