public static Script CreateOfferScript(OfferScriptPubKeyParameters parameters)
{
if (parameters == null)
{
throw new ArgumentNullException(nameof(parameters));
}
List <Op> ops = new List <Op>();
ops.Add(OpcodeType.OP_DEPTH);
ops.Add(Op.GetPushOp(parameters.Hashes.Length + 1));
ops.Add(OpcodeType.OP_EQUAL);
ops.Add(OpcodeType.OP_IF);
foreach (var hash in parameters.Hashes)
{
ops.Add(OpcodeType.OP_RIPEMD160);
ops.Add(Op.GetPushOp(hash.ToBytes()));
ops.Add(OpcodeType.OP_EQUALVERIFY);
}
ops.Add(Op.GetPushOp(parameters.FulfillKey.ToBytes()));
ops.Add(OpcodeType.OP_ELSE);
ops.Add(Op.GetPushOp(parameters.Expiration));
ops.Add(OpcodeType.OP_CHECKLOCKTIMEVERIFY);
ops.Add(OpcodeType.OP_DROP);
ops.Add(Op.GetPushOp(parameters.RedeemKey.ToBytes()));
ops.Add(OpcodeType.OP_ENDIF);
ops.Add(OpcodeType.OP_CHECKSIG);
return(new Script(ops.ToArray()));
}
public TransactionSignature SignOffer(OfferInformation offerInformation)
{
if (offerInformation == null)
{
throw new ArgumentNullException(nameof(offerInformation));
}
AssertState(SolverClientStates.WaitingOffer);
var offerScript = new OfferScriptPubKeyParameters
{
Hashes = _PuzzleElements.OfType <RealPuzzle>().Select(p => p.Commitment.KeyHash).ToArray(),
FulfillKey = offerInformation.FulfillKey,
Expiration = EscrowScriptPubKeyParameters.GetFromCoin(InternalState.EscrowedCoin).LockTime,
RedeemKey = InternalState.EscrowKey.PubKey
}.ToScript();
var escrowCoin = InternalState.EscrowedCoin;
var txOut = new TxOut(escrowCoin.Amount - offerInformation.Fee, offerScript.WitHash.ScriptPubKey.Hash);
var offerCoin = new Coin(escrowCoin.Outpoint, txOut).ToScriptCoin(offerScript);
Transaction tx = new Transaction();
tx.Inputs.Add(new TxIn(escrowCoin.Outpoint));
tx.Outputs.Add(offerCoin.TxOut);
var escrow = EscrowScriptPubKeyParameters.GetFromCoin(escrowCoin);
escrowCoin = escrowCoin.Clone();
escrowCoin.OverrideScriptCode(escrow.GetInitiatorScriptCode());
var signature = tx.Inputs.AsIndexedInputs().First().Sign(InternalState.EscrowKey, escrowCoin, SigHash.All);
InternalState.OfferCoin = offerCoin;
InternalState.Status = SolverClientStates.WaitingPuzzleSolutions;
return(signature);
}
public OfferInformation CheckBlindedFactors(BlindFactor[] blindFactors, FeeRate feeRate)
{
if (blindFactors == null)
{
throw new ArgumentNullException(nameof(blindFactors));
}
if (blindFactors.Length != Parameters.RealPuzzleCount)
{
throw new ArgumentException("Expecting " + Parameters.RealPuzzleCount + " blind factors");
}
AssertState(SolverServerStates.WaitingBlindFactor);
Puzzle unblindedPuzzle = null;
int y = 0;
for (int i = 0; i < Parameters.RealPuzzleCount; i++)
{
var solvedPuzzle = InternalState.SolvedPuzzles[i];
var unblinded = new Puzzle(Parameters.ServerKey, solvedPuzzle.Puzzle).Unblind(blindFactors[i]);
if (unblindedPuzzle == null)
{
unblindedPuzzle = unblinded;
}
else if (unblinded != unblindedPuzzle)
{
throw new PuzzleException("Invalid blind factor");
}
y++;
}
InternalState.FulfillKey = new Key();
Transaction dummy = new Transaction();
dummy.AddInput(new TxIn(InternalState.EscrowedCoin.Outpoint));
dummy.Inputs[0].ScriptSig = new Script(
Op.GetPushOp(TrustedBroadcastRequest.PlaceholderSignature),
Op.GetPushOp(TrustedBroadcastRequest.PlaceholderSignature),
Op.GetPushOp(InternalState.EscrowedCoin.Redeem.ToBytes())
);
dummy.Inputs[0].Witnessify();
dummy.AddOutput(new TxOut(InternalState.EscrowedCoin.Amount, new Key().ScriptPubKey.Hash));
var offerTransactionFee = feeRate.GetFee(dummy.GetVirtualSize());
var escrow = InternalState.EscrowedCoin;
var escrowInformation = EscrowScriptPubKeyParameters.GetFromCoin(InternalState.EscrowedCoin);
var redeem = new OfferScriptPubKeyParameters
{
Hashes = InternalState.SolvedPuzzles.Select(p => p.SolutionKey.GetHash()).ToArray(),
FulfillKey = InternalState.FulfillKey.PubKey,
Expiration = escrowInformation.LockTime,
RedeemKey = escrowInformation.Initiator
}.ToScript();
var txOut = new TxOut(escrow.Amount - offerTransactionFee, redeem.WitHash.ScriptPubKey.Hash);
InternalState.OfferCoin = new Coin(escrow.Outpoint, txOut).ToScriptCoin(redeem);
InternalState.Status = SolverServerStates.WaitingFulfillment;
return(new OfferInformation
{
FulfillKey = InternalState.FulfillKey.PubKey,
Fee = offerTransactionFee
});
}
public static OfferScriptPubKeyParameters ExtractOfferScriptParameters(Script scriptPubKey)
{
if (scriptPubKey == null)
{
throw new ArgumentNullException(nameof(scriptPubKey));
}
try
{
var result = new OfferScriptPubKeyParameters();
var ops = scriptPubKey.ToOps().ToArray();
int i = 0;
if (ops[i++].Code != OpcodeType.OP_DEPTH)
{
return(null);
}
var pushCount = ops[i++].GetInt();
if (pushCount == null || pushCount > 500)
{
return(null);
}
result.Hashes = new uint160[pushCount.Value - 1];
CheckMinimal(ops[i - 1], pushCount.Value);
if (ops[i++].Code != OpcodeType.OP_EQUAL)
{
return(null);
}
if (ops[i++].Code != OpcodeType.OP_IF)
{
return(null);
}
for (int y = 0; y < result.Hashes.Length; y++)
{
if (ops[i++].Code != OpcodeType.OP_RIPEMD160)
{
return(null);
}
result.Hashes[y] = new uint160(ops[i++].PushData);
if (ops[i++].Code != OpcodeType.OP_EQUALVERIFY)
{
return(null);
}
}
result.FulfillKey = new PubKey(ops[i++].PushData);
if (ops[i++].Code != OpcodeType.OP_ELSE)
{
return(null);
}
result.Expiration = new LockTime(checked ((uint)ops[i++].GetLong()));
CheckMinimal(ops[i - 1], (uint)result.Expiration);
if (ops[i++].Code != OpcodeType.OP_CHECKLOCKTIMEVERIFY)
{
return(null);
}
if (ops[i++].Code != OpcodeType.OP_DROP)
{
return(null);
}
result.RedeemKey = new PubKey(ops[i++].PushData);
if (ops[i++].Code != OpcodeType.OP_ENDIF)
{
return(null);
}
if (ops[i++].Code != OpcodeType.OP_CHECKSIG)
{
return(null);
}
if (i != ops.Length)
{
return(null);
}
return(result);
}
catch { return(null); }
}