public byte[] TxSignature(ImmutableArray<byte> scriptPubKey, Transaction tx, int inputIndex, byte hashType)
{
///TODO
Debug.Assert(inputIndex < tx.Inputs.Length);
// Blank out other inputs' signatures
var empty = ImmutableArray.Create<byte>();
var newInputs = new TxInput[tx.Inputs.Length];
for (var i = 0; i < tx.Inputs.Length; i++)
{
var oldInput = tx.Inputs[i];
var newInput = oldInput.With(scriptSignature: i == inputIndex ? scriptPubKey : empty);
newInputs[i] = newInput;
}
//// Blank out some of the outputs
//if ((hashType & 0x1F) == (int)ScriptHashType.SIGHASH_NONE)
//{
// //TODO
// Debug.Assert(false);
// // Wildcard payee
// // Let the others update at will
//}
//else if ((hashType & 0x1F) == (int)ScriptHashType.SIGHASH_SINGLE)
//{
// //TODO
// Debug.Assert(false);
// // Only lock-in the txout payee at same index as txin
// // Let the others update at will
//}
//// Blank out other inputs completely, not recommended for open transactions
//if ((hashType & 0x80) == (int)ScriptHashType.SIGHASH_ANYONECANPAY)
//{
// //TODO
// Debug.Assert(false);
//}
// create simplified transaction
var newTx = tx.With(Inputs: newInputs.ToImmutableArray());
// return wire-encoded simplified transaction with the 4-byte hashType tacked onto the end
var stream = new MemoryStream();
using (var writer = new BinaryWriter(stream))
{
writer.WriteBytes(DataCalculator.EncodeTransaction(newTx));
writer.Write4Bytes(hashType);
return stream.ToArray();
}
}
private static ImmutableArray<byte> GetScriptFromInputPrevOutput(TxInput input, TxOutput prevOutput)
{
return input.ScriptSignature.AddRange(prevOutput.ScriptPublicKey);
}
public static byte[] EncodeTxInput(TxInput txInput)
{
var stream = new MemoryStream();
EncodeTxInput(stream, txInput);
return stream.ToArray();
}
public static void EncodeTxInput(Stream stream, TxInput txInput)
{
using (var writer = new BinaryWriter(stream, Encoding.ASCII, leaveOpen: true))
{
writer.Write32Bytes(txInput.PreviousTxOutputKey.TxHash);
writer.Write4Bytes(txInput.PreviousTxOutputKey.TxOutputIndex);
writer.WriteVarBytes(txInput.ScriptSignature.ToArray());
writer.Write4Bytes(txInput.Sequence);
}
}
