public void CheckSolutions(Transaction fulfillTx)
{
if (fulfillTx == null)
{
throw new ArgumentNullException(nameof(fulfillTx));
}
AssertState(SolverClientStates.WaitingPuzzleSolutions);
foreach (var input in fulfillTx.Inputs)
{
var solutions = SolverScriptBuilder.ExtractSolutions(input.ScriptSig, Parameters.RealPuzzleCount);
if (solutions == null)
{
continue;
}
try
{
CheckSolutions(solutions);
return;
}
catch (PuzzleException)
{
}
}
throw new PuzzleException("Impossible to find solution to the puzzle");
}
public TrustedBroadcastRequest FulfillOffer(
TransactionSignature clientSignature,
Script cashout,
FeeRate feeRate)
{
if (clientSignature == null)
{
throw new ArgumentNullException(nameof(clientSignature));
}
if (feeRate == null)
{
throw new ArgumentNullException(nameof(feeRate));
}
AssertState(SolverServerStates.WaitingFulfillment);
Script offerScript = GetOfferScript();
var offer = GetUnsignedOfferTransaction();
PubKey clientKey = AssertValidSignature(clientSignature, offer);
TransactionBuilder builder = new TransactionBuilder();
builder.StandardTransactionPolicy.CheckFee = false;
builder.Extensions.Add(new EscrowBuilderExtension());
builder.AddCoins(InternalState.EscrowedCoin);
builder.AddKeys(InternalState.EscrowKey);
builder.AddKnownSignature(clientKey, clientSignature);
builder.SignTransactionInPlace(offer);
if (!builder.Verify(offer))
{
throw new PuzzleException("invalid-tumbler-signature");
}
var offerCoin = offer.Outputs.AsCoins().First().ToScriptCoin(offerScript);
var solutions = InternalState.SolvedPuzzles.Select(s => s.SolutionKey).ToArray();
Transaction fulfill = new Transaction();
fulfill.Inputs.Add(new TxIn(offerCoin.Outpoint));
fulfill.Outputs.Add(new TxOut(offerCoin.Amount, cashout));
var fulfillScript = SolverScriptBuilder.CreateFulfillScript(NBitcoin.BuilderExtensions.BuilderExtension.DummySignature, solutions);
fulfill.Inputs[0].ScriptSig = fulfillScript + Op.GetPushOp(offerCoin.Redeem.ToBytes());
fulfill.Outputs[0].Value -= feeRate.GetFee(fulfill.GetVirtualSize());
var signature = fulfill.Inputs.AsIndexedInputs().First().Sign(InternalState.FulfillKey, offerCoin, SigHash.All);
fulfillScript = SolverScriptBuilder.CreateFulfillScript(signature, solutions);
fulfill.Inputs[0].ScriptSig = fulfillScript + Op.GetPushOp(offerCoin.Redeem.ToBytes());
InternalState.OfferClientSignature = clientSignature;
InternalState.Status = SolverServerStates.WaitingEscape;
return(new TrustedBroadcastRequest
{
Key = InternalState.FulfillKey,
PreviousScriptPubKey = offerCoin.ScriptPubKey,
Transaction = fulfill
});
}
public TrustedBroadcastRequest FulfillOffer(
TransactionSignature clientSignature,
Script cashout,
FeeRate feeRate)
{
if (clientSignature == null)
{
throw new ArgumentNullException(nameof(clientSignature));
}
if (feeRate == null)
{
throw new ArgumentNullException(nameof(feeRate));
}
AssertState(SolverServerStates.WaitingFulfillment);
var offer = GetUnsignedOfferTransaction();
PubKey clientKey = AssertValidSignature(clientSignature, offer);
offer.Inputs[0].ScriptSig = new Script(
Op.GetPushOp(clientSignature.ToBytes()),
Op.GetPushOp(CreateOfferSignature().ToBytes()),
Op.GetPushOp(InternalState.EscrowedCoin.Redeem.ToBytes())
);
offer.Inputs[0].Witnessify();
if (!offer.Inputs.AsIndexedInputs().First().VerifyScript(_Network, InternalState.EscrowedCoin))
{
throw new PuzzleException("invalid-tumbler-signature");
}
var solutions = InternalState.SolvedPuzzles.Select(s => s.SolutionKey).ToArray();
Transaction fulfill = new Transaction();
fulfill.Inputs.Add(new TxIn());
fulfill.Outputs.Add(new TxOut(InternalState.OfferCoin.Amount, cashout));
var fulfillScript = SolverScriptBuilder.CreateFulfillScript(null, solutions);
fulfill.Inputs[0].ScriptSig = fulfillScript + Op.GetPushOp(InternalState.OfferCoin.Redeem.ToBytes());
fulfill.Inputs[0].Witnessify();
var virtualSize = fulfill.HasWitness ? fulfill.GetVirtualSize(_Network.Consensus.Options.WitnessScaleFactor) : fulfill.GetSerializedSize();
fulfill.Outputs[0].Value -= feeRate.GetFee(virtualSize);
InternalState.OfferClientSignature = clientSignature;
InternalState.Status = SolverServerStates.WaitingEscape;
return(new TrustedBroadcastRequest
{
Key = InternalState.FulfillKey,
PreviousScriptPubKey = InternalState.OfferCoin.ScriptPubKey,
Transaction = fulfill
});
}
private Script GetOfferScript()
{
var escrow = EscrowScriptBuilder.ExtractEscrowScriptPubKeyParameters(InternalState.EscrowedCoin.Redeem);
return(SolverScriptBuilder.CreateOfferScript(new OfferScriptPubKeyParameters
{
Hashes = InternalState.SolvedPuzzles.Select(p => p.SolutionKey.GetHash()).ToArray(),
FulfillKey = InternalState.FulfillKey.PubKey,
RedeemKey = escrow.RedeemKey,
Expiration = escrow.LockTime
}));
}
public override Script GenerateScriptSig(Script scriptPubKey, IKeyRepository keyRepo, ISigner signer)
{
var offer = SolverScriptBuilder.ExtractOfferScriptParameters(scriptPubKey);
var key = keyRepo.FindKey(offer.FulfillKey.ScriptPubKey) ?? keyRepo.FindKey(offer.RedeemKey.ScriptPubKey);
if (key == null)
{
return(null);
}
var sig = signer.Sign(key);
return(new Script(Op.GetPushOp(sig.ToBytes())));
}
public void CheckSolutions(Script scriptSig)
{
if (scriptSig == null)
{
throw new ArgumentNullException(nameof(scriptSig));
}
AssertState(SolverClientStates.WaitingPuzzleSolutions);
var solutions = SolverScriptBuilder.ExtractSolutions(scriptSig, Parameters.RealPuzzleCount);
if (solutions == null)
{
throw new PuzzleException("Impossible to find solution to the puzzle");
}
CheckSolutions(solutions);
}
private Script CreateOfferScript()
{
return(SolverScriptBuilder.CreateOfferScript(CreateOfferScriptParameters()));
}
public override int EstimateScriptSigSize(Script scriptPubKey)
{
var offer = SolverScriptBuilder.ExtractOfferScriptParameters(scriptPubKey);
return(DummySignature.ToBytes().Length + offer.Hashes.Length * (int)SolutionKey.KeySize);
}
public override bool CanGenerateScriptSig(Script scriptPubKey)
{
return(SolverScriptBuilder.ExtractOfferScriptParameters(scriptPubKey) != null);
}