public BlindingFactor Blind_sum(BlindSum blindSum)
{
var posKeys = blindSum.PositiveKeyIds.Select(Derived_key).ToList();
var negKeys = blindSum.NegativeKeyIds.Select(Derived_key).ToList();
posKeys.AddRange(blindSum.PositiveBlindingFactors.Select(pbf => pbf.Key));
negKeys.AddRange(blindSum.NegativeBlindingFactors.Select(nbf => nbf.Key));
var blinding = Secp.blind_sum(posKeys.ToArray(), negKeys.ToArray());
return(BlindingFactor.New(blinding));
}
/// Builds a PartialTx from data sent by a sender (not yet completed by the receiver).
public static PartialTx build_partial_tx(
ulong receiveAmount,
BlindingFactor blindSum,
Transaction transaction
)
{
return(new PartialTx
{
Amount = receiveAmount,
BlindSum = HexUtil.to_hex(blindSum.Key.Value),
Tx = HexUtil.to_hex(Ser.Ser_vec(transaction))
});
}
/// Reads a partial transaction into the amount, sum of blinding
/// factors and the transaction itself.
public static (ulong amount, BlindingFactor blinding, Transaction tx) read_partial_tx(
Keychain keychain,
PartialTx partialTx
)
{
var blindBin = HexUtil.from_hex(partialTx.BlindSum);
var blinding = BlindingFactor.from_slice(keychain.Secp, blindBin);
var txBin = HexUtil.from_hex(partialTx.Tx);
Transaction transaction;
using (var ms = new MemoryStream(txBin))
{
transaction = Ser.Deserialize(ms, Transaction.Empty());
;
}
return(partialTx.Amount, blinding, transaction);
}
public Signiture Sign_with_blinding(Message msg, BlindingFactor blinding)
{
var sig = Secp.Sign(msg, blinding.Key);
return(sig);
}
/// Sets a known excess value on the transaction being built. Usually used in
/// combination with the initial_tx function when a new transaction is built
/// by adding to a pre-existing one.
public static Append with_excess(this Context build, BlindingFactor excess)
{
return(new Append(build.Tx, build.Sum.add_blinding_factor(excess.Clone())));
}
