private string GetAddressFromScript(string script)
{
if (string.IsNullOrEmpty(script))
{
return(string.Empty);
}
string firstOP = script.Substring(0, 2);
string remove = string.Empty;
if (firstOP == NumberConversions.IntToHex((int)OPCodes.opcodetype.OP_DUP, 1))
{
remove =
NumberConversions.IntToHex((int)OPCodes.opcodetype.OP_DUP, 1) +
NumberConversions.IntToHex((int)OPCodes.opcodetype.OP_HASH160, 1) +
NumberConversions.IntToHex(40 / 2, 1);
}
else if (firstOP == NumberConversions.IntToHex(0x01, 1))
{
remove =
NumberConversions.IntToHex(0x01, 1) +
NumberConversions.IntToHex((int)OPCodes.opcodetype.OP_INVALIDOPCODE, 1) +
NumberConversions.IntToHex(0x16, 1) +
NumberConversions.IntToHex((int)OPCodes.opcodetype.OP_PUBKEYHASH, 1) +
NumberConversions.IntToHex((int)OPCodes.opcodetype.OP_0, 1);
}
string addressHash = script.Substring(remove.Length, 40);
return(BitcoinConversions.Hash160ToBase58(addressHash));
}
public override async Task <Response <List <UTXO> > > GetUTXO(List <SendingAddress> addrList)
{
Response <List <UTXO> > resp = new Response <List <UTXO> >();
string addresses = string.Join("|", addrList.Select(b => b.Address).ToArray());
string url = "https://blockchain.info/unspent?active=" + addresses;
Response <JObject> apiResp = await SendApiRequestAsync(url);
if (apiResp.Errors.Any())
{
resp.Errors.AddRange(apiResp.Errors);
return(resp);
}
resp.Result = new List <UTXO>();
foreach (var item in apiResp.Result["unspent_outputs"])
{
UTXO u = new UTXO();
string script = item["script"].ToString();
u.AddressHash160 = script.Substring("76a914".Length, script.Length - "76a91488ac".Length);
u.Address = BitcoinConversions.Hash160ToBase58(u.AddressHash160);
u.TxHash = item["tx_hash_big_endian"].ToString();
u.Amount = (ulong)item["value"];
u.Confirmation = (int)item["confirmations"];
u.OutIndex = (uint)item["tx_output_n"];
resp.Result.Add(u);
}
return(resp);
}
private static string BuildScriptPub(string addr)
{
string hash160 = BitcoinConversions.Base58ToHash160(addr);
return(ByteArray.ConcatArrays(
new byte[] { (byte)OPCodes.OP_DUP, (byte)OPCodes.OP_HASH160 },
new byte[] { (byte)(hash160.Length / 2) },
Base16.ToByteArray(hash160),
new byte[] { (byte)OPCodes.OP_EQUALVERIFY, (byte)OPCodes.OP_CHECKSIG }).ToBase16());
}
private void MakeTx()
{
List <UTXO> uList = new List <UTXO>();
foreach (var item in TxInList)
{
UTXO u = new UTXO();
u.TxHash = item.TxId;
u.OutIndex = item.OutIndex;
if (BTx.Status == BitcoinTransaction.TxStatus.Signed)
{
int pubKeyLength = 65;
string pubKey = item.ScriptSig.Substring((item.ScriptSigLength * 2) - (pubKeyLength + 1));
u.Address = BitcoinConversions.PubKeyToBase58(pubKey);
u.AddressHash160 = BitcoinConversions.ByteArrayToHex(BitcoinConversions.PubKeyToHash160(pubKey));
}
else
{
var addr = GetAddressFromScript(item.ScriptSig);
if (string.IsNullOrEmpty(addr))
{
u.Address = string.Empty;
u.AddressHash160 = string.Empty;
}
else
{
u.Address = addr;
u.AddressHash160 = BitcoinConversions.Base58ToHash160(addr);
}
}
uList.Add(u);
}
try
{
UInt32 lockTime = 0;
RawTx = Transaction.CreateRawTx(uList, ReceiveList.ToList(), lockTime, SelectedWalletType);
}
catch (Exception ex)
{
RawTx = string.Empty;
MessageBox.Show(ex.Message);
}
}
/// <summary>
/// Makes ScriptSig based on wallet type.
/// <para/> INCOMPLETE!
/// </summary>
/// <param name="addr">Hes string to put inside of ScriptSig.</param>
/// <param name="type">Type of wallet that is supposed to sign this transaction.</param>
/// <returns>ScriptSig</returns>
public static string BuildScriptSig(string addr, WalletType type)
{
string hash160 = BitcoinConversions.Base58ToHash160(addr);
switch (type)
{
case WalletType.Electrum:
//01 ff 16 fd 00
return(ByteArray.ConcatArrays(
new byte[] { 1, (byte)OPCodes.OP_INVALIDOPCODE, 16, (byte)OPCodes.OP_PUBKEYHASH, 0 },
Base16.ToByteArray(hash160)
).ToBase16());
case WalletType.Normal:
case WalletType.Core:
default:
return(BuildScriptPub(addr));
}
}
public async Task <List <UTXO> > GetUTXO(List <SendingAddress> addrList)
{
using (var client = new HttpClient())
{
// Make sure all balances are 0
foreach (var ad in addrList)
{
ad.BalanceSatoshi = 0;
}
var addresses = string.Join("|", addrList.Select(b => b.Address).ToArray());
string url = "https://blockchain.info/unspent?active=" + addresses;
string result = await client.GetStringAsync(url);
JObject jResult = JObject.Parse(result);
List <UTXO> utxList = new List <UTXO>();
foreach (var item in jResult["unspent_outputs"])
{
UTXO u = new UTXO();
string script = item["script"].ToString();
u.AddressHash160 = script.Substring("76a914".Length, script.Length - "76a91488ac".Length);
u.Address = BitcoinConversions.Hash160ToBase58(u.AddressHash160);
u.TxHash = item["tx_hash_big_endian"].ToString();
u.Amount = (int)item["value"];
u.Confirmation = (int)item["confirmations"];
u.OutIndex = (UInt32)item["tx_output_n"];
utxList.Add(u);
// Update address balance
foreach (var ad in addrList)
{
if (ad.Address == u.Address)
{
ad.BalanceSatoshi += u.Amount;
}
}
}
return(utxList);
}
}
/// <summary>
/// Creates a Raw Unsigned bitcoin transaction Transaction.
/// <para/> Sources:
/// <para/> 1. https://bitcoin.stackexchange.com/questions/32628/redeeming-a-raw-transaction-step-by-step-example-required
/// <para/> 2. https://bitcoin.org/en/developer-reference#raw-transaction-format
/// <para/> 3. https://bitcoin.org/en/developer-examples#simple-raw-transaction
/// </summary>
/// <param name="txToSpend">List of UTXOs to spend.</param>
/// <param name="receiveAddr">List of receiving addresses and the amount to be paid to each.</param>
/// <param name="wallet">Type of the wallet (Electrum does not recognize normal type of scriptSig placeholder).</param>
/// <returns>Rat unsigned transaction string.</returns>
public static string CreateRawTx(List <UTXO> txToSpend, List <ReceivingAddress> receiveAddr, UInt32 lockTime, WalletType wallet)
{
StringBuilder rawTx = new StringBuilder();
// 1) 4 byte - version
UInt32 version = 1;
rawTx.Append(NumberConversions.IntToHex(version, 4));
// 2) ? byte - tx_in count (compactSize uint)
int txInCount = txToSpend.Count;
rawTx.Append(NumberConversions.MakeCompactSize((UInt64)txInCount));
for (int i = 0; i < txInCount; i++)
{
// 3) 32 byte - TX hash (reverse)
string txToSend = txToSpend[i].TxHash;
rawTx.Append(ReverseTx(txToSend));
// 4) 4 byte - output Index
UInt32 outputIndex = txToSpend[i].OutIndex;
rawTx.Append(NumberConversions.IntToHex(outputIndex, 4));
// 5) ? byte - scriptSig length (compactSize uint) (Maximum value is 10,000 bytes)
// Can be from 0 and up. Will be replaced by actual scriptSig with another length.
// Format can be different based on the client which will be used for signing.
if (string.IsNullOrEmpty(txToSpend[i].AddressHash160) && wallet != WalletType.Core)
{
throw new Exception(string.Format("No address was found. Set wallet type to Core."));
}
string scriptSig = BuildScript(txToSpend[i].AddressHash160, wallet);
rawTx.Append(NumberConversions.IntToHex((UInt64)(scriptSig.Length / 2), 1));
// 6) ? byte - scriptSig which is filled with scriptPubkey temporarily (20 is half the length of address hash160)
rawTx.Append(scriptSig);
//7) 4 byte - sequence - max is 0xffffffff - can change for RBF transactions
// Ref:
// https://bitcoin.stackexchange.com/questions/2025/what-is-txins-sequence
UInt32 sequence = UInt32.MaxValue;
rawTx.Append(NumberConversions.IntToHex(sequence, 4));
}
//8) ? byte - tx_out count (compactSize uint)
int txOutCount = receiveAddr.Count;
rawTx.Append(NumberConversions.MakeCompactSize((UInt64)txOutCount));
foreach (var item in receiveAddr)
{
//9) 8 byte - amout to transfer
UInt64 amount = item.PaymentSatoshi;
rawTx.Append(NumberConversions.IntToHex(amount, 8));
//10) ? byte - pk_script length (compactSize uint)
string itemHash = BitcoinConversions.Base58ToHash160(item.Address);
string outputScript = BuildScript(itemHash, WalletType.Normal);
rawTx.Append(NumberConversions.MakeCompactSize((UInt64)outputScript.Length / 2));
//11) ? byte - pk_script
rawTx.Append(outputScript);
}
//12) 4 byte - lock time
// * If less than 500 million, locktime is parsed as a block height. The transaction can be added to any block which has this height or higher.
// * If greater than or equal to 500 million, locktime is parsed using the Unix epoch time format (the number of seconds elapsed since 1970-01-01T00:00 UTC—currently over 1.395 billion). The transaction can be added to any block whose block time is greater than the locktime.
rawTx.Append(NumberConversions.IntToHex(lockTime, 4));
return(rawTx.ToString());
}
/// <summary>
/// Deserialize the transaction hex string.
/// </summary>
/// <param name="tx">Transaction hex string</param>
/// <returns>Bitcoin Transaction</returns>
public static BitcoinTransaction DecodeRawTx(string tx)
{
BitcoinTransaction btx = new BitcoinTransaction();
int index = 0;
// 1) 4 byte - version
string version = tx.Substring(index, 8);
btx.Version = (UInt32)NumberConversions.HexToUInt(version);
index += 8;
// 2) ? byte - tx_in count (CompactSize uint)
btx.TxInCount = NumberConversions.ReadCompactSize(tx, ref index);
bool isSigned = true;
bool isRbf = false;
// Initialize the array
btx.TxInList = new TxIn[btx.TxInCount];
for (UInt64 i = 0; i < btx.TxInCount; i++)
{
TxIn temp = new TxIn();
// 3) 32 byte - TX hash (reverse)
temp.TxId = tx.Substring(index, 64);
temp.TxId = ReverseTx(temp.TxId);
index += 64;
// 4) 4 byte - output Index
string outIndex = tx.Substring(index, 8);
temp.OutIndex = (UInt32)NumberConversions.HexToUInt(outIndex);
index += 8;
// 5) ? byte - scriptSig length (CompactSize uint) (Maximum value is 10,000 bytes)
string scriptSigLength = tx.Substring(index, 2);
temp.ScriptSigLength = (int)NumberConversions.ReadCompactSize(tx, ref index);
// 6) ? byte - scriptSig or a placeholder for unsigned (can be empty too)
temp.ScriptSig = tx.Substring(index, temp.ScriptSigLength * 2);
index += temp.ScriptSigLength * 2;
//7) 4 byte - sequence - max is 0xffffffff - can change for RBF transactions
string sequence = tx.Substring(index, 8);
temp.Sequence = (UInt32)NumberConversions.HexToUInt(sequence);
index += 8;
btx.TxInList[i] = temp;
// Check to see if all the inputs are signed
if (temp.ScriptSigLength <= 25)
{
isSigned = false;
}
// Check for opt-in Replace By Fee
if (temp.Sequence != UInt32.MaxValue)
{
isRbf = true;
}
}
// Set transaction sign and RBF status.
btx.Status = (isSigned) ? BitcoinTransaction.TxStatus.Signed : BitcoinTransaction.TxStatus.Unsigned;
btx.IsRbf = isRbf;
//8) ? byte - tx_out count (compactSize uint)
btx.TxOutCount = NumberConversions.ReadCompactSize(tx, ref index);
// Initialize the array
btx.TxOutList = new TxOut[btx.TxOutCount];
for (UInt64 i = 0; i < btx.TxOutCount; i++)
{
TxOut temp = new TxOut();
//9) 8 byte - amout to transfer
string amount = tx.Substring(index, 16);
temp.Amount = NumberConversions.HexToUInt(amount);
index += 16;
//10) ? byte - pk_script length (compactSize uint)
string pkScriptLength = tx.Substring(index, 2);
temp.PkScriptLength = (Int32)NumberConversions.HexToUInt(pkScriptLength);
index += 2;
//11) ? byte - pk_script
temp.PkScript = tx.Substring(index, temp.PkScriptLength * 2);
index += temp.PkScriptLength * 2;
btx.TxOutList[i] = temp;
}
//12) 4 byte - lock time
string lockTime = tx.Substring(index, 8);
btx.LockTime = (UInt32)NumberConversions.HexToUInt(lockTime);
index += 8;
// If the transaction is signed, then it has a TxId
if (isSigned)
{
btx.TxId = BitcoinConversions.GetTxId(tx);
}
return(btx);
}
