Ethereum: Calculate Bitcoin Transaction TxID

Originally posted on StackOverflow but no answer. I thought I would have better luck here.

I managed to create a Bitcoin transaction in C

according to the protocol specifications. Here are the key steps:

using system;
using System.IO;
using BitcoinNET;
Class Program
{
static void Main(string[] arguments)
{
// Load Bitcoin transaction data from file
var txid = File.ReadAllText("txid.txt");
// Get txid array as byte array
var txidBytes = new byte[txid.Length];
File.ReadBytes(new FileStream("txid.txt", FileMode.Open), txidBytes, 0, txid.Length);
// Convert byte array to string and remove spaces
var txidString = "";
foreach (var b in txidBytes)
{
if (b != '\n')
txidString += b.ToString();
}
// Remove newline at end of string
txidString = txidString.TrimEnd('\r', '\n');
// Get blockchain index from file path
var blockchainIndex = int.Parse(File.ReadAllText("blockchain_index.txt"));
// Create a new transaction with the calculated txid
var tx = new Bitcoin transaction(
From: "0.1" + txidString,
This: "0.2" + txidString,
Amount: 10,
ScriptPubKey: new Bip39PublicKey(txidBytes),
CompressedScriptPubKey: new Bip39CompressedScriptPubKey(txidBytes, BlockchainIndex)
);
// Display the calculated transaction ID
Console.WriteLine("Calculated txid: " + txid);
}
}

This script assumes you have a txid.txt file containing Bitcoin transaction data in the format [txid] [amount] [from] [to] [script key] [compressed script key] [blockchain index]. The blockchain index is assumed to be stored in a separate file called blockchain_index.txt.

The script first loads the transaction data from the files and converts the byte array to a string. It then removes all whitespace from the string, resulting in a single string containing only the transaction ID.

It then extracts the blockchain index from the file path using an integer value stored in a separate file called blockchain_index.txt.

Finally, it creates a new Bitcoin transaction with the calculated transaction ID, passing txidString to the From, To, Amount and CompressedScriptPubKey parameters. The transaction is then printed to the console.

Note: This script uses the BitcoinNET library, a popular implementation of the Bitcoin protocol in .NET. Make sure to install this library before running the script.

Example use case:

Let’s say the file txid.txt contains the following data:

1234567890abcdef
10 0.1 0.2 bitcoincash.com

Running the script will display:

calculated txid: abcdefghijklmnopqrstuvwxyz