public async Task <IActionResult> PostSignaturesAsync([FromQuery] string uniqueId, [FromQuery] long roundId, [FromBody] IDictionary <int, string> signatures)
{
if (roundId <= 0 ||
signatures == null ||
signatures.Count() <= 0 ||
signatures.Any(x => x.Key < 0 || string.IsNullOrWhiteSpace(x.Value)) ||
!ModelState.IsValid)
{
return(BadRequest());
}
Guid uniqueIdGuid = CheckUniqueId(uniqueId, out IActionResult returnFailureResponse);
if (returnFailureResponse != null)
{
return(returnFailureResponse);
}
CcjRound round = Coordinator.TryGetRound(roundId);
if (round == null)
{
return(NotFound("Round not found."));
}
Alice alice = round.TryGetAliceBy(uniqueIdGuid);
if (alice == null)
{
return(NotFound("Alice not found."));
}
// Check if Alice provided signature to all her inputs.
if (signatures.Count != alice.Inputs.Count())
{
return(BadRequest("Alice did not provide enough witnesses."));
}
if (round.Status != CcjRoundStatus.Running)
{
return(Gone("Round is not running."));
}
CcjRoundPhase phase = round.Phase;
switch (phase)
{
case CcjRoundPhase.Signing:
{
using (await SigningLock.LockAsync())
{
foreach (var signaturePair in signatures)
{
int index = signaturePair.Key;
WitScript witness = null;
try
{
witness = new WitScript(signaturePair.Value);
}
catch (Exception ex)
{
return(BadRequest($"Malformed witness is provided. Details: {ex.Message}"));
}
int maxIndex = round.UnsignedCoinJoin.Inputs.Count - 1;
if (maxIndex < index)
{
return(BadRequest($"Index out of range. Maximum value: {maxIndex}. Provided value: {index}"));
}
// Check duplicates.
if (!string.IsNullOrWhiteSpace(round.SignedCoinJoin.Inputs[index].WitScript?.ToString())) // Not sure why WitScript?.ToString() is needed, there was something wrong in previous HiddenWallet version if I didn't do this.
{
return(BadRequest($"Input is already signed."));
}
// Verify witness.
var cjCopy = new Transaction(round.UnsignedCoinJoin.ToHex());
cjCopy.Inputs[index].WitScript = witness;
TxOut output = alice.Inputs.Single(x => x.OutPoint == cjCopy.Inputs[index].PrevOut).Output;
if (!Script.VerifyScript(output.ScriptPubKey, cjCopy, index, output.Value, ScriptVerify.Standard, SigHash.All))
{
return(BadRequest($"Invalid witness is provided."));
}
// Finally add it to our CJ.
round.SignedCoinJoin.Inputs[index].WitScript = witness;
}
alice.State = AliceState.SignedCoinJoin;
await round.BroadcastCoinJoinIfFullySignedAsync();
}
return(NoContent());
}
default:
{
return(Conflict($"CoinJoin can only be requested from Signing phase. Current phase: {phase}."));
}
}
}
