public static StealthPayment[] GetPayments(Transaction transaction, PubKey[] spendKeys, BitField bitField, Key scan)
{
List<StealthPayment> result = new List<StealthPayment>();
for(int i = 0 ; i < transaction.Outputs.Count ; i++)
{
var metadata = StealthMetadata.TryParse(transaction.Outputs[i].ScriptPubKey);
if(metadata != null && bitField.Match(metadata.BitField))
{
var payment = new StealthPayment(transaction.Outputs[i + 1].ScriptPubKey, metadata);
if(scan != null && spendKeys != null)
{
if(payment.StealthKeys.Length != spendKeys.Length)
continue;
var expectedStealth = spendKeys.Select(s => s.UncoverReceiver(scan, metadata.EphemKey)).ToList();
foreach(var stealth in payment.StealthKeys)
{
var match = expectedStealth.FirstOrDefault(expected => expected.ID == stealth.ID);
if(match != null)
expectedStealth.Remove(match);
}
if(expectedStealth.Count != 0)
continue;
}
result.Add(payment);
}
}
return result.ToArray();
}
public static StealthMetadata CreateMetadata(Key ephemKey, BitField bitField = null)
{
for(uint nonce = 0 ; nonce < uint.MaxValue ; nonce++)
{
var metadata = new StealthMetadata(ephemKey, nonce);
if(bitField == null || bitField.Match(metadata.BitField))
return metadata;
}
throw new ArgumentException("No nonce can satisfy the given bitfield, use another ephemKey");
}
public BitcoinStealthAddress(PubKey scanKey, PubKey[] pubKeys, int signatureCount, BitField bitfield, Network network)
: base(GenerateBytes(scanKey, pubKeys, bitfield, signatureCount), network)
{
}
private static byte[] GenerateBytes(PubKey scanKey, PubKey[] pubKeys, BitField bitField, int signatureCount)
{
MemoryStream ms = new MemoryStream();
ms.WriteByte(0); //Options
ms.Write(scanKey.Compress().ToBytes(), 0, 33);
ms.WriteByte((byte)pubKeys.Length);
foreach(var key in pubKeys)
{
ms.Write(key.Compress().ToBytes(), 0, 33);
}
ms.WriteByte((byte)signatureCount);
if(bitField == null)
ms.Write(new byte[] { 0 }, 0, 1);
else
{
ms.WriteByte((byte)bitField.BitCount);
var raw = bitField.GetRawForm();
ms.Write(raw, 0, raw.Length);
}
return ms.ToArray();
}
public BitcoinStealthAddress(PubKey scanKey, PubKey[] pubKeys, int signatureCount, BitField bitfield, Network network)
: base(GenerateBytes(scanKey, pubKeys, bitfield, signatureCount), network)
{
}
