public static Transaction CreateSpendTransaction(Transaction prevTx, int prevInputIndex, byte hashType, UInt64 value, ECPrivateKeyParameters fromPrivateKey, ECPublicKeyParameters fromPublicKey, ECPublicKeyParameters toPublicKey)
{
var tx = new Transaction
(
version: 1,
inputs: ImmutableArray.Create
(
new TxInput
(
previousTxOutputKey: new TxOutputKey
(
txHash: prevTx.Hash,
txOutputIndex: (UInt32)prevInputIndex
),
scriptSignature: ImmutableArray.Create<byte>(),
sequence: 0
)
),
outputs: ImmutableArray.Create
(
new TxOutput
(
value: value,
scriptPublicKey: ImmutableArray.Create(CreatePublicKeyScript(toPublicKey))
)
),
lockTime: 0
);
// sign the transaction
var scriptSignature = ImmutableArray.Create(CreatePrivateKeyScript(tx, 0, hashType, fromPrivateKey, fromPublicKey));
// add the signature script to the transaction
tx = tx.With(Inputs: ImmutableArray.Create(tx.Inputs[0].With(scriptSignature: scriptSignature)));
return tx;
}
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();
}
}