/// <summary>
/// Parses a Bitcoin transaction.
/// </summary>
/// <param name="blockMemoryStreamReader">
/// Provides access to a section of the Bitcoin blockchain file.
/// </param>
/// <returns>
/// The Bitcoin transaction that was parsed.
/// </returns>
private static Transaction ParseTransaction(BlockMemoryStreamReader blockMemoryStreamReader)
{
Transaction transaction = new Transaction();
int positionInBaseStreamAtTransactionStart = (int)blockMemoryStreamReader.BaseStream.Position;
transaction.TransactionVersion = blockMemoryStreamReader.ReadUInt32();
int inputsCount = (int)blockMemoryStreamReader.ReadVariableLengthInteger();
bool isSegWit = false;
if (inputsCount == 0)
{
byte flag = blockMemoryStreamReader.ReadByte();
if (flag != 0x01)
{
throw new InvalidBlockchainContentException(string.Format(CultureInfo.InvariantCulture,
"Unknown transaction serialization. No input transactions, but SegWit flag was {0} instead of 1.", flag));
}
inputsCount = (int)blockMemoryStreamReader.ReadVariableLengthInteger();
isSegWit = true;
}
for (int inputIndex = 0; inputIndex < inputsCount; inputIndex++)
{
TransactionInput transactionInput = BlockchainParser.ParseTransactionInput(blockMemoryStreamReader);
transaction.AddInput(transactionInput);
}
int outputsCount = (int)blockMemoryStreamReader.ReadVariableLengthInteger();
for (int outputIndex = 0; outputIndex < outputsCount; outputIndex++)
{
TransactionOutput transactionOutput = BlockchainParser.ParseTransactionOutput(blockMemoryStreamReader);
transaction.AddOutput(transactionOutput);
}
int positionInBaseStreamAfterTxOuts = (int)blockMemoryStreamReader.BaseStream.Position;
if (isSegWit)
{
for (int inputIndex = 0; inputIndex < inputsCount; inputIndex++)
{
Witness witness = BlockchainParser.ParseWitness(blockMemoryStreamReader);
transaction.AddWitness(witness);
}
}
// TODO: Need to find out more details about the semantic of TransactionLockTime.
transaction.TransactionLockTime = blockMemoryStreamReader.ReadUInt32();
int positionInBaseStreamAfterTransactionEnd = (int)blockMemoryStreamReader.BaseStream.Position;
using (SHA256Managed sha256 = new SHA256Managed())
{
//// We need to calculate the double SHA256 hash of this transaction.
//// We need to access the buffer that contains the transaction that we jut read through.
//// Here we take advantage of the fact that the entire block was loaded as an in-memory buffer.
//// The base stream of blockMemoryStreamReader is that in-memory buffer.
//byte[] baseBuffer = blockMemoryStreamReader.GetBuffer();
//int transactionBufferSize = positionInBaseStreamAfterTransactionEnd - positionInBaseStreamAtTransactionStart;
byte[] baseBuffer = blockMemoryStreamReader.GetBuffer(), hash1 = null;
if (isSegWit)
{
using (SHA256Managed innerSHA256 = new SHA256Managed())
{
//// SegWit transactions are still identified by their txid, which is double SHA256 of the old
//// serialization format (i.e. no marker, flag, or witness). So, we need to calculate the txid by
//// recreating the old format as the input to the hash algorithm.
// First, the version number
innerSHA256.TransformBlock(baseBuffer, positionInBaseStreamAtTransactionStart, 4, baseBuffer, positionInBaseStreamAtTransactionStart);
// Skip the marker and flag (each one byte), then read in txins and txouts (starting with txin count)
int txStart = positionInBaseStreamAtTransactionStart + 6;
int txSize = positionInBaseStreamAfterTxOuts - txStart;
innerSHA256.TransformBlock(baseBuffer, txStart, txSize, baseBuffer, txStart);
///// After the transactions comes the segregated witness data, which is not included in the txid.
///// The only thing left to add to calcualte the txid is nLockTime located in the last 4 bytes
int lockTimeStart = positionInBaseStreamAfterTransactionEnd - 4;
innerSHA256.TransformFinalBlock(baseBuffer, lockTimeStart, 4);
hash1 = innerSHA256.Hash;
}
}
else
{
int transactionBufferSize = positionInBaseStreamAfterTransactionEnd - positionInBaseStreamAtTransactionStart;
hash1 = sha256.ComputeHash(baseBuffer, positionInBaseStreamAtTransactionStart, transactionBufferSize);
}
// byte[] hash1 = sha256.ComputeHash(baseBuffer, positionInBaseStreamAtTransactionStart, transactionBufferSize);
transaction.TransactionHash = new ByteArray(sha256.ComputeHash(hash1).ReverseByteArray());
}
return(transaction);
}
/// <summary>
/// Parses a Bitcoin transaction output.
/// </summary>
/// <param name="blockMemoryStreamReader">
/// Provides access to a section of the Bitcoin blockchain file.
/// </param>
/// <returns>
/// The Bitcoin transaction output that was parsed.
/// </returns>
private static TransactionOutput ParseTransactionOutput(BlockMemoryStreamReader blockMemoryStreamReader)
{
TransactionOutput transactionOutput = new TransactionOutput();
transactionOutput.OutputValueSatoshi = blockMemoryStreamReader.ReadUInt64();
int scriptLength = (int)blockMemoryStreamReader.ReadVariableLengthInteger();
byte[] OutputScriptBytes = blockMemoryStreamReader.ReadBytes(scriptLength);
transactionOutput.OutputScript = new ByteArray(OutputScriptBytes);
//this is new add to parse address, if can't parse the address, set the address = '0'
byte[] outputAddress;
if (scriptLength > 2)
{
using (BlockMemoryStreamReader outputScriptReader = new BlockMemoryStreamReader(OutputScriptBytes))
{
byte first = outputScriptReader.ReadByte();
if (first == 0x6a)//RETURN: can't parse the address
{
outputAddress = System.Text.Encoding.ASCII.GetBytes("0");
}
else if (first == 0x00 && (OutputScriptBytes[1] == 0x14 || OutputScriptBytes[1] == 0x20))//witness addr
{
int hash_len = outputScriptReader.ReadByte();
byte[] addr_hash = outputScriptReader.ReadBytes(hash_len);
outputAddress = Bench32.SegwitAddrEncode("bc", 0, addr_hash, addr_hash.Length);
}
else if (first == 0x76 && OutputScriptBytes[1] == 0xa9)//normal bitcoin addr,base58check encode and prefix = 0
{
outputScriptReader.ReadByte();
int hash_len = outputScriptReader.ReadByte();
byte[] addr_hash = outputScriptReader.ReadBytes(hash_len);
outputAddress = Base58.EncodeBase58Check(addr_hash, addr_hash.Length, 0);
}
else if (first == 0xa9 && (OutputScriptBytes[1] == 0x14 || OutputScriptBytes[1] == 0x20))//base58check encode and prefix = 5
{
int hash_len = outputScriptReader.ReadByte();
byte[] addr_hash = outputScriptReader.ReadBytes(hash_len);
outputAddress = Base58.EncodeBase58Check(addr_hash, addr_hash.Length, 1);
}
else if (first == 0x41)//非压缩公钥
{
byte[] bitcoin_addr = outputScriptReader.ReadBytes(65);
byte[] addr_hash = Hash160.hash160(bitcoin_addr);
outputAddress = Base58.EncodeBase58Check(addr_hash, addr_hash.Length, 0);
}
else
{
/*
* string str = string.Empty;
* foreach (byte item in OutputScriptBytes)
* {
* str += string.Format("{0:x2}", item);
* }
* Console.WriteLine(str);
*/
outputAddress = System.Text.Encoding.ASCII.GetBytes("0");
}
}
}
else
{
/*
* Console.WriteLine(scriptLength);
* string str = string.Empty;
* foreach (byte item in OutputScriptBytes)
* {
* str += string.Format("{0:x2}", item);
* }
* Console.WriteLine(str);
*/
outputAddress = System.Text.Encoding.ASCII.GetBytes("0");
}
transactionOutput.OutputAddress = new ByteArray(outputAddress);
return(transactionOutput);
}