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 StealthPayment(int sigCount, PubKey[] spendPubKeys, Key privateKey, PubKey publicKey, StealthMetadata metadata)
{
Metadata = metadata;
if(sigCount == 1 && spendPubKeys.Length == 1)
{
var template = new PayToPubkeyHashTemplate();
SpendableScript = template.GenerateScriptPubKey(spendPubKeys[0].Uncover(privateKey, publicKey).ID);
}
else
{
var template = new PayToMultiSigTemplate();
SpendableScript = template.GenerateScriptPubKey(sigCount, spendPubKeys.Select(p => p.Uncover(privateKey, publicKey)).ToArray());
}
ParseSpendable();
}
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 - 1; 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 TryParse(Script metadata)
{
StealthMetadata result = new StealthMetadata();
try
{
if(!Fill(result, metadata))
return null;
}
catch(Exception)
{
return null;
}
return result;
}
private static bool Fill(StealthMetadata output, Script metadata)
{
var ops = metadata.ToOps().ToArray();
if(ops.Length != 2 || ops[0].Code != OpcodeType.OP_RETURN)
return false;
var data = ops[1].PushData;
if(data == null || data.Length != 1 + 4 + 33)
return false;
MemoryStream ms = new MemoryStream(data);
output.Version = ms.ReadByte();
if(output.Version != 6)
return false;
output.Nonce = ms.ReadBytes(4);
output.EphemKey = new PubKey(ms.ReadBytes(33));
output.Script = metadata;
output.Hash = Hashes.Hash256(data);
var msprefix = new MemoryStream(output.Hash.ToBytes(false));
output.BitField = Utils.ToUInt32(msprefix.ReadBytes(4), true);
return true;
}
public StealthPayment(Script spendable, StealthMetadata metadata)
{
Metadata = metadata;
SpendableScript = spendable;
ParseSpendable();
}
public StealthPayment(int sigCount, PubKey[] spendPubKeys, Key privateKey, PubKey publicKey, StealthMetadata metadata)
{
Metadata = metadata;
if (sigCount == 1 && spendPubKeys.Length == 1)
{
var template = new PayToPubkeyHashTemplate();
SpendableScript = template.GenerateScriptPubKey(spendPubKeys[0].Uncover(privateKey, publicKey).ID);
}
else
{
var template = new PayToMultiSigTemplate();
SpendableScript = template.GenerateScriptPubKey(sigCount, spendPubKeys.Select(p => p.Uncover(privateKey, publicKey)).ToArray());
}
ParseSpendable();
}
public bool Match(StealthMetadata metadata)
{
return Match(metadata.BitField);
}
public StealthPayment(Script spendable, StealthMetadata metadata)
{
Metadata = metadata;
SpendableScript = spendable;
ParseSpendable();
}
public bool Match(StealthMetadata metadata)
{
return(Match(metadata.BitField));
}
