private static MsgTx DecodeTransaction(byte[] rawTransaction)
{
var msgTx = new MsgTx();
msgTx.Decode(rawTransaction);
return(msgTx);
}
/// <summary>
///
/// </summary>
/// <param name="transaction">The transaction that the script applies to.</param>
/// <param name="script"></param>
/// <param name="options"></param>
public ScriptEngine(MsgTx transaction, int txIndex, Script script, ScriptOptions options)
{
if (transaction == null)
{
throw new ArgumentNullException(nameof(transaction));
}
if (txIndex < 0 || txIndex >= transaction.TxIn.Length)
{
throw new ArgumentOutOfRangeException(nameof(txIndex));
}
if (script == null)
{
throw new ArgumentNullException(nameof(script));
}
if (options == null)
{
throw new ArgumentNullException(nameof(options));
}
_transaction = transaction;
_txIndex = txIndex;
_script = script;
_opCodeLookup = new Dictionary <OpCode, Action <ParsedOpCode> >();
Options = options;
MainStack = new ScriptStack(Options.AssertScriptIntegerMinimalEncoding);
AltStack = new ScriptStack(Options.AssertScriptIntegerMinimalEncoding);
BranchStack = new BranchStack();
InitializeOpCodeDictionary();
}
public void OpCheckSig(ParsedOpCode op, MsgTx transaction)
{
try
{
var rawPublicKey = MainStack.Pop();
var rawSignature = MainStack.Pop();
if (rawSignature.Length < 1)
{
MainStack.Push(false);
return;
}
var signature = rawSignature.Take(rawSignature.Length - 1).ToArray();
var signatureType = (SignatureHashType)rawSignature.Last();
AssertSignatureHashType(signatureType);
AssertSignatureEncoding(signature);
AssertPublicKeyEncoding(rawPublicKey);
var subScript = _script.GetOpCodesWithoutData(rawSignature);
var hash = CalculateSignatureHash(subScript, signatureType, (MsgTx)transaction.Clone(), _txIndex);
var ecSignature = new ECSignature(signature);
var securityService = new ECPublicSecurityService(rawPublicKey);
var isValidSignature = securityService.VerifySignature(hash, ecSignature);
MainStack.Push(isValidSignature);
}
catch (ScriptException)
{
MainStack.Push(false);
}
}
/// <summary>
/// Broadcasts a signed transaction to the Decred network
/// </summary>
/// <param name="operationId"></param>
/// <param name="hexTransaction"></param>
/// <returns></returns>
/// <exception cref="TransactionBroadcastException"></exception>
public async Task Broadcast(Guid operationId, string hexTransaction)
{
if (operationId == Guid.Empty)
{
throw new BusinessException(ErrorReason.BadRequest, "Operation id is invalid");
}
if (string.IsNullOrWhiteSpace(hexTransaction))
{
throw new BusinessException(ErrorReason.BadRequest, "SignedTransaction is invalid");
}
var txBytes = HexUtil.ToByteArray(hexTransaction);
var msgTx = new MsgTx();
msgTx.Decode(txBytes);
// If the operation exists in the cache, throw exception
var cachedResult = await _broadcastTxRepo.GetAsync(operationId.ToString());
if (cachedResult != null)
{
throw new BusinessException(ErrorReason.DuplicateRecord, "Operation already broadcast");
}
var txHash = HexUtil.FromByteArray(msgTx.GetHash().Reverse().ToArray());
var txWasMined = await _txRepo.GetTxInfoByHash(txHash, long.MaxValue) != null;
if (txWasMined)
{
await SaveBroadcastedTransaction(new BroadcastedTransaction
{
OperationId = operationId,
Hash = txHash,
EncodedTransaction = hexTransaction
});
throw new BusinessException(ErrorReason.DuplicateRecord, "Operation already broadcast");
}
// Submit the transaction to the network via dcrd
var result = await _dcrdClient.SendRawTransactionAsync(hexTransaction);
if (result.Error != null)
{
throw new TransactionBroadcastException($"[{result.Error.Code}] {result.Error.Message}");
}
await SaveBroadcastedTransaction(new BroadcastedTransaction
{
OperationId = operationId,
Hash = txHash,
EncodedTransaction = hexTransaction
});
}
/// <summary>
/// Calculates the hash of a transaction to be signed.
/// </summary>
/// <param name="transaction"></param>
/// <returns></returns>
private byte[] CalculateTxHash(MsgTx transaction)
{
var wbuf = new List <byte>(32 * 2 + 4);
wbuf.AddRange(BitConverter.GetBytes((uint)1));
var prefixHash = transaction.GetHash(TxSerializeType.NoWitness);
var witnessHash = transaction.GetHash(TxSerializeType.WitnessSigning);
wbuf.AddRange(prefixHash);
wbuf.AddRange(witnessHash);
return(HashUtil.Blake256(wbuf.ToArray()));
}
public void GetHash_GivenTestObjectWithKnownHash_ReturnsExpectedHash()
{
var msgTx = new MsgTx
{
Version = 1,
SerializationType = TxSerializeType.Full,
TxIn = new[] { txIn },
TxOut = new[] { txOut }
};
var actualHash = msgTx.GetHash().Reverse().ToArray();
var actualHashString = Hex.ToHexString(actualHash);
Assert.Equal(expectedHash, actualHashString);
}
public void New_GivenSerializedValueWithMultipleTx_DeserializesInputAndReserializes()
{
var tests = new MsgTxTestSubject[]
{
new MultiTxTestSubject(),
new NoTxTests()
};
foreach (var test in tests)
{
var subject = new MsgTx();
subject.Decode(test.EncodedMessage);
var deserialized = subject.Encode();
Assert.True(test.EncodedMessage.SequenceEqual(deserialized));
}
}
/// <summary>
/// Determines the state of a broadcasted transaction
/// </summary>
/// <param name="operationId"></param>
/// <returns></returns>
/// <exception cref="BusinessException"></exception>
public async Task <BroadcastedSingleTransactionResponse> GetBroadcastedTxSingle(Guid operationId)
{
if (operationId == Guid.Empty)
{
throw new BusinessException(ErrorReason.BadRequest, "Operation id is invalid");
}
// Retrieve the broadcasted transaction and deserialize it.
var broadcastedTransaction = await GetBroadcastedTransaction(operationId);
var transaction = new MsgTx();
transaction.Decode(HexUtil.ToByteArray(broadcastedTransaction.EncodedTransaction));
// Calculate the fee and total amount spent from the transaction.
var fee = transaction.TxIn.Sum(t => t.ValueIn) - transaction.TxOut.Sum(t => t.Value);
var amount = transaction.TxOut.Sum(t => t.Value);
// Check to see if the transaction has been included in a block.
var safeBlockHeight = await _dcrdClient.GetMaxConfirmedBlockHeight();
var knownTx = await _txRepo.GetTxInfoByHash(broadcastedTransaction.Hash, safeBlockHeight);
var txState = knownTx == null
? BroadcastedTransactionState.InProgress
: BroadcastedTransactionState.Completed;
// If the tx has been included in a block,
// use the block height + timestamp from the block
var txBlockHeight = knownTx?.BlockHeight ?? safeBlockHeight;
var timestamp = knownTx?.BlockTime.UtcDateTime ?? DateTime.UtcNow;
return(new BroadcastedSingleTransactionResponse
{
Block = txBlockHeight,
State = txState,
Hash = broadcastedTransaction.Hash,
Amount = amount.ToString(),
Fee = fee.ToString(),
Error = "",
ErrorCode = null,
OperationId = operationId,
Timestamp = timestamp
});
}
public MsgTx SpendingTx()
{
var coinbaseTx = new MsgTx
{
TxIn = new[]
{
new TxIn
{
PreviousOutPoint = new OutPoint(new byte[32], 0, TxTree.TxTreeRegular),
SignatureScript = new[] { (byte)OpCode.OP_0, (byte)OpCode.OP_0 }
}
},
TxOut = new[]
{
new TxOut
{
Value = 0,
PkScript = PublicKeyScript.Bytes
}
}
};
var coinbaseTxHash = coinbaseTx.GetHash();
var spendingTx = new MsgTx
{
TxIn = new[]
{
new TxIn
{
PreviousOutPoint = new OutPoint(coinbaseTxHash, 0, TxTree.TxTreeRegular),
SignatureScript = SignatureScript.Bytes
}
},
TxOut = new[]
{
new TxOut()
}
};
return(spendingTx);
}
public void GetRoot_GivenTestnetGenesisTranasction_ReturnsExpectedMerkleRoot()
{
var testnetGenesisTx = new MsgTx
{
SerializationType = TxSerializeType.Full,
Version = 1,
TxIn = new[]
{
new TxIn
{
PreviousOutPoint = new OutPoint
{
Hash = new byte[32],
Index = 0xffffffff,
},
SignatureScript = new byte[]
{
0x04, 0xff, 0xff, 0x00, 0x1d, 0x01, 0x04, 0x45,
0x54, 0x68, 0x65, 0x20, 0x54, 0x69, 0x6d, 0x65,
0x73, 0x20, 0x30, 0x33, 0x2f, 0x4a, 0x61, 0x6e,
0x2f, 0x32, 0x30, 0x30, 0x39, 0x20, 0x43, 0x68,
0x61, 0x6e, 0x63, 0x65, 0x6c, 0x6c, 0x6f, 0x72,
0x20, 0x6f, 0x6e, 0x20, 0x62, 0x72, 0x69, 0x6e,
0x6b, 0x20, 0x6f, 0x66, 0x20, 0x73, 0x65, 0x63,
0x6f, 0x6e, 0x64, 0x20, 0x62, 0x61, 0x69, 0x6c,
0x6f, 0x75, 0x74, 0x20, 0x66, 0x6f, 0x72, 0x20,
0x62, 0x61, 0x6e, 0x6b, 0x73,
},
Sequence = 0xffffffff
},
},
TxOut = new TxOut[]
{
new TxOut()
{
Value = 0x00000000,
PkScript = new byte[]
{
0x41, 0x04, 0x67, 0x8a, 0xfd, 0xb0, 0xfe, 0x55,
0x48, 0x27, 0x19, 0x67, 0xf1, 0xa6, 0x71, 0x30,
0xb7, 0x10, 0x5c, 0xd6, 0xa8, 0x28, 0xe0, 0x39,
0x09, 0xa6, 0x79, 0x62, 0xe0, 0xea, 0x1f, 0x61,
0xde, 0xb6, 0x49, 0xf6, 0xbc, 0x3f, 0x4c, 0xef,
0x38, 0xc4, 0xf3, 0x55, 0x04, 0xe5, 0x1e, 0xc1,
0x12, 0xde, 0x5c, 0x38, 0x4d, 0xf7, 0xba, 0x0b,
0x8d, 0x57, 0x8a, 0x4c, 0x70, 0x2b, 0x6b, 0xf1,
0x1d, 0x5f, 0xac
},
},
},
LockTime = 0,
Expiry = 0,
};
// For some reason, the testnet genesis tx is hashed differently than mainnet to
// get the merkle root.
var hash = testnetGenesisTx.GetHash();
var merkleTree = new MerkleTree();
var merkleRoot = merkleTree.GetRoot(new[] { hash });
// Assert.True();
}
public static byte[] CalculateSignatureHash(ParsedOpCode[] subScript, SignatureHashType hashType, MsgTx transaction, int index)
{
const SignatureHashType mask = (SignatureHashType)0x1f;
if ((hashType & mask) == SignatureHashType.Single && index >= transaction.TxOut.Length)
{
throw new InvalidSignatureException("SignatureHashType.Single index out of range");
}
// Clear out signature scripts for input transactions not at index
// transactionIndex
for (var i = 0; i < transaction.TxIn.Length; i++)
{
transaction.TxIn[i].SignatureScript =
i == index?
subScript.SelectMany(s => s.Serialize()).ToArray()
: new byte[0];
}
switch (hashType & mask)
{
case SignatureHashType.None:
transaction.TxOut = new TxOut[0];
for (var i = 0; i < transaction.TxIn.Length; i++)
{
if (i != index)
{
transaction.TxIn[i].Sequence = 0;
}
}
break;
case SignatureHashType.Single:
transaction.TxOut = new TxOut[index];
for (var i = 0; i < index; i++)
{
transaction.TxOut[i].Value = -1;
transaction.TxOut[i].PkScript = null;
}
for (var i = 0; i < transaction.TxIn.Length; i++)
{
if (i != index)
{
transaction.TxIn[i].Sequence = 0;
}
}
break;
case SignatureHashType.Old:
break;
case SignatureHashType.All:
break;
case SignatureHashType.AllValue:
break;
case SignatureHashType.AnyOneCanPay:
break;
default:
throw new ArgumentOutOfRangeException();
}
if ((hashType & SignatureHashType.AnyOneCanPay) != 0)
{
transaction.TxIn = transaction.TxIn
.Skip(index)
.Take(1)
.ToArray();
}
var wbuf = new List <byte>(32 * 2 + 4);
wbuf.AddRange(BitConverter.GetBytes((uint)hashType));
var prefixHash = transaction.GetHash(TxSerializeType.NoWitness);
var witnessHash = transaction.GetHash(
(hashType & mask) != SignatureHashType.All ?
TxSerializeType.WitnessSigning :
TxSerializeType.WitnessValueSigning
);
wbuf.AddRange(prefixHash);
wbuf.AddRange(witnessHash);
return(HashUtil.Blake256(wbuf.ToArray()));
}
private void OpCheckSigVerify(ParsedOpCode op, MsgTx transaction)
{
OpCheckSig(op, transaction);
OpVerify();
}
