private static PSBT Sign(Party party, DerivationStrategyBase derivationStrategy, PSBT psbt)
{
psbt = psbt.Clone();
// NBXplorer does not have knowledge of the account key path, KeyPath are private information of each peer
// NBXplorer only derive 0/* and 1/* on top of provided account xpubs,
// This mean that the input keypaths in the PSBT are in the form 0/* (as if the account key was the root)
// RebaseKeyPaths modifies the PSBT by adding the AccountKeyPath in prefix of all the keypaths of the PSBT
// Note that this is not necessary to do this if the account key is the same as root key.
// Note that also that you don't have to do this, if you do not pass the account key path in the later SignAll call.
// however, this is best practice to rebase the PSBT before signing.
// If you sign with an offline device (hw wallet), the wallet would need the rebased PSBT.
psbt.RebaseKeyPaths(party.AccountExtPubKey, party.AccountKeyPath);
Console.WriteLine("A PSBT is a data structure with all information for a wallet to sign.");
var spend = psbt.GetBalance(derivationStrategy, party.AccountExtPubKey, party.AccountKeyPath);
Console.WriteLine($"{party.PartyName}, Do you agree to sign this transaction spending {spend}?");
// Ok I sign
psbt.SignAll(derivationStrategy, // What addresses to derive?
party.RootExtKey.Derive(party.AccountKeyPath), // With which account private keys?
party.AccountKeyPath); // What is the keypath of the account private key. If you did not rebased the keypath like before, you can remove this parameter
return(psbt);
}
private PSBT SignPSBT(PSBT psbt, NRustLightningNetwork network)
{
if (BaseXPrivs.TryGetValue(network, out var xpriv))
{
psbt.SignAll(ScriptPubKeyType.Segwit, xpriv);
}
return(psbt);
}
public async Task <PSBT> Sign(PSBT psbt)
{
var btcPayWallet = parent.PayTester.GetService <BTCPayWalletProvider>()
.GetWallet(psbt.Network.NetworkSet.CryptoCode);
var explorerClient = parent.PayTester.GetService <ExplorerClientProvider>()
.GetExplorerClient(psbt.Network.NetworkSet.CryptoCode);
psbt = (await explorerClient.UpdatePSBTAsync(new UpdatePSBTRequest()
{
DerivationScheme = DerivationScheme, PSBT = psbt
})).PSBT;
return(psbt.SignAll(this.DerivationScheme, GenerateWalletResponseV.AccountHDKey,
GenerateWalletResponseV.AccountKeyPath));
}
private async Task <PSBT> SignPSBT(PSBT psbt, NRustLightningNetwork network)
{
var repo = _repositoryProvider.GetRepository(network);
var outpoints = psbt.Inputs.Select(txIn => txIn.PrevOut);
var signingKeys = new List <Key>();
await foreach (var(desc, i) in repo.GetSpendableOutputDescriptors(outpoints).Select((x, i) => (x, i)))
{
if (desc is null)
{
// We don't have any information in repo. This probably means the UTXO is not LN-origin
// (i.e. those are the funds user provided by on-chain)
continue;
}
switch (desc)
{
case SpendableOutputDescriptor.StaticOutput _:
// signature for this input will be generated by Destination key (see below).
// so no need for any operation.
break;
case SpendableOutputDescriptor.DynamicOutputP2WSH p2wshOutput:
{
var(param1, param2) = p2wshOutput.Item.KeyDerivationParams.ToValueTuple();
var amountSat = (ulong)p2wshOutput.Item.Output.Value.Satoshi;
var channelKeys = _keysRepository.DeriveChannelKeys(amountSat, param1, param2);
var delayedPaymentKey = Generators.derivePrivKey(_secp256k1Ctx,
channelKeys.DelayedPaymentBaseKey, p2wshOutput.Item.PerCommitmentPoint.PubKey);
var toSelfDelay = p2wshOutput.Item.ToSelfDelay;
var revokeableRedeemScript =
_keysRepository.GetRevokeableRedeemScript(p2wshOutput.Item.RemoteRevocationPubKey,
toSelfDelay, delayedPaymentKey.PubKey);
Debug.Assert(
p2wshOutput.Item.Output.ScriptPubKey.Equals(revokeableRedeemScript.WitHash.ScriptPubKey));
psbt.AddScripts(revokeableRedeemScript);
psbt.Inputs[i].SetSequence(toSelfDelay);
signingKeys.Add(delayedPaymentKey);
break;
}
case SpendableOutputDescriptor.StaticOutputRemotePayment remoteOutput:
{
var(p1, p2) = remoteOutput.Item.KeyDerivationParams.ToValueTuple();
var amountSat = (ulong)remoteOutput.Item.Output.Value;
var keys = _keysRepository.DeriveChannelKeys(amountSat, p1, p2);
Debug.Assert(
keys.PaymentKey.PubKey.WitHash.ScriptPubKey.Equals(remoteOutput.Item.Output.ScriptPubKey));
signingKeys.Add(keys.PaymentKey);
break;
}
default:
throw new Exception($"Unreachable! Unknown output descriptor type {desc}");
}
}
// sign for user provided on-chain funds utxos.
if (BaseXPrivs.TryGetValue(network, out var xpriv))
{
psbt.SignAll(ScriptPubKeyType.Segwit, xpriv);
}
// sign for static-outputs. Which RL gave us as a result of off-chain balance handling.
var destinationKey = _keysRepository.GetDestinationKey();
psbt.SignWithKeys(destinationKey);
// sign with other keys which we have saved in repo.
foreach (var sk in signingKeys)
{
psbt.SignWithKeys(sk);
}
return(psbt);
}
public void SignPSBT(PSBT psbt)
{
psbt.SignAll(key.AsHDScriptPubKey(scriptPubKeyType), key);
}
