public byte[] ExtractSecret()
{
if (BitcoinBasedSwapTemplate.IsP2PkhSwapRedeem(_input.ScriptSig))
{
return(BitcoinBasedSwapTemplate.ExtractSecretFromP2PkhSwapRedeem(_input.ScriptSig));
}
// todo: segwit p2pkh swap redeem
throw new NotSupportedException("Can't extract secret from scriptsig. Unknown script type.");
}
public static bool TryVerifyPartyPaymentTx(
IBitcoinBasedTransaction tx,
ClientSwap swap,
byte[] secretHash,
long refundLockTime,
out Error error)
{
if (tx == null)
{
throw new ArgumentNullException(nameof(tx));
}
if (swap == null)
{
throw new ArgumentNullException(nameof(swap));
}
// check swap output
if (!tx.SwapOutputs().Any())
{
error = new Error(
code: Errors.InvalidSwapPaymentTx,
description: $"No swap outputs in tx @{tx.Id}",
swap: swap);
return(false);
}
var targetAddressHash = new BitcoinPubKeyAddress(swap.ToAddress)
.Hash
.ToBytes();
var hasSwapOutput = false;
foreach (var txOutput in tx.SwapOutputs())
{
try
{
var output = (BitcoinBasedTxOutput)txOutput;
// check address
var outputTargetAddressHash = BitcoinBasedSwapTemplate.ExtractTargetPkhFromHtlcP2PkhSwapPayment(
script: output.Coin.TxOut.ScriptPubKey);
if (!outputTargetAddressHash.SequenceEqual(targetAddressHash))
{
continue;
}
var outputSecretHash = BitcoinBasedSwapTemplate.ExtractSecretHashFromHtlcP2PkhSwapPayment(
script: output.Coin.TxOut.ScriptPubKey);
if (!outputSecretHash.SequenceEqual(secretHash))
{
continue;
}
hasSwapOutput = true;
// check swap output refund lock time
var outputLockTime = BitcoinBasedSwapTemplate.ExtractLockTimeFromHtlcP2PkhSwapPayment(
script: output.Coin.TxOut.ScriptPubKey);
var swapTimeUnix = (long)swap.TimeStamp.ToUniversalTime().ToUnixTime();
if (outputLockTime - swapTimeUnix < refundLockTime)
{
error = new Error(
code: Errors.InvalidRefundLockTime,
description: "Invalid refund time",
swap: swap);
return(false);
}
// check swap amount
var currency = (BitcoinBasedCurrency)swap.PurchasedCurrency;
var side = swap.Symbol
.OrderSideForBuyCurrency(currency)
.Opposite();
var requiredAmount = AmountHelper.QtyToAmount(side, swap.Qty, swap.Price);
var requiredAmountInSatoshi = currency.CoinToSatoshi(requiredAmount);
if (output.Value < requiredAmountInSatoshi)
{
error = new Error(
code: Errors.InvalidSwapPaymentTxAmount,
description: "Invalid payment tx amount",
swap: swap);
return(false);
}
}
catch (Exception e)
{
Log.Error(e, "Transaction verification error");
error = new Error(
code: Errors.TransactionVerificationError,
description: e.Message,
swap: swap);
return(false);
}
}
if (!hasSwapOutput)
{
error = new Error(
code: Errors.TransactionVerificationError,
description: $"No swap outputs in tx @{tx.Id} for address {swap.ToAddress}",
swap: swap);
return(false);
}
// todo: check fee
// todo: try to verify
error = null;
return(true);
}
