Generate address of 'private key' from user input

Question

I want to take a private key as input from the user and convert it to a wallet address using C#.

I have seen this in a tutorial to generate a random key:

Key privateKey = new Key();
PubKey publicKey = privateKey.PubKey;
Console.WriteLine(publicKey.GetAddress(ScriptPubKeyType.Legacy, Network.Main));

How do I convert a private key string from the user to a wallet address for main net?

Answer 1

Assuming the private key string in this example is pk

Console.WriteLine("Enter private key:");
string pk = Console.ReadLine();
var bitcoinPrivateKey = new BitcoinSecret(pk, Network.Main);

var legacy_address = bitcoinPrivateKey.GetAddress(ScriptPubKeyType.Legacy);

Console.WriteLine("Legacy Address :" + legacy_address);

And if you want to get p2sh-segwit and bech32 address, add below lines:

var p2shsegwit_address = bitcoinPrivateKey.GetAddress(ScriptPubKeyType.SegwitP2SH);
var nativesegwit_address = bitcoinPrivateKey.GetAddress(ScriptPubKeyType.Segwit);

Console.WriteLine("P2SH-Segwit Address :" + p2shsegwit_address);
Console.WriteLine("Bech32 Address :" + nativesegwit_address);

Answer 2

I have implemented it by javascript, maybe it can help you.

//usage:
//$ yarn add bip32 bip39
// node --version is 16.1.0

const bs58check = require('bs58check');
const bip39 = require("bip39");
const bip32 = require("bip32");
const createHash = require('create-hash');


function addr(node) {
    var hash = node.identifier; // hash160 of the publicKey

    const payload = Buffer.allocUnsafe(21);

    var version = 0x0;
    payload.writeUInt8(version, 0);

    hash.copy(payload, 1);

    var address = bs58check.encode(payload);
    return address;
}

var puzzle = "some puzzle you inputting";

var entropy = createHash("sha256").update(puzzle).digest().toString("hex");
console.log("entropy: " + entropy);

var mnemonic = bip39.entropyToMnemonic(entropy);
console.log("mnemonic: " + mnemonic);

var passphrase = "";

var seed = bip39.mnemonicToSeedSync(mnemonic, passphrase);
var master = bip32.fromSeed(seed); // m

// generate 10 btc addresses...
for (var i = 0; i < 3; i++) {
    var node = master.derivePath("m/44'/0'/0'/1/" + i);
    var address = addr(node);
    console.log("BTC #" + i + ": " + address);
}

Answer 3

You can find information how to calculate Public key from Private here https://bitcoin-math.000webhostapp.com Also, you can find Doubling, Addition and Scalar multiply functions on C# without NBitcoin class Key, BigInteger is used only.