public static void Execute(BitcoinSecret privateKey)
{
// PRNG (Pseudo-Random-Number-Generator)
// add entropy to the PRNG output that NBitcoin is using
RandomUtils.AddEntropy("Hello");
RandomUtils.AddEntropy(new byte[] { 1, 2, 3 });
Key nsaProofKey = new Key();
// KDF (Key Derivation Function)
byte[] derived = SCrypt.BitcoinComputeDerivedKey("Hello", new byte[] { 1, 2, 3 });
RandomUtils.AddEntropy(derived);
string password = "******";
BitcoinEncryptedSecret encryptedBitcoinPrivateKey = privateKey.Encrypt(password);
BitcoinSecret decryptedBitcoinPrivateKey = encryptedBitcoinPrivateKey.GetSecret(password);
Console.WriteLine("-------------------Key Derivation Function------------------");
Console.WriteLine("BitcoinPrivateKey : " + privateKey);
Console.WriteLine("BitcoinPrivateKey(encrypted) : " + encryptedBitcoinPrivateKey);
Console.WriteLine("BitcoinPrivateKey(decrypted) : " + decryptedBitcoinPrivateKey);
// BIP38 (Part 2)
string mySecret = "Secret Phrase";
BitcoinPassphraseCode passphraseCode = new BitcoinPassphraseCode(mySecret, Network.Main, null);
EncryptedKeyResult encryptedKeyResult = passphraseCode.GenerateEncryptedSecret();
var generatedAddress = encryptedKeyResult.GeneratedAddress;
var encryptedKey = encryptedKeyResult.EncryptedKey;
var confirmationCode = encryptedKeyResult.ConfirmationCode;
var bitcoinPrivateKey = encryptedKey.GetSecret(mySecret);
Console.WriteLine("---------------------BIP38 (Part 2)---------------------");
Console.WriteLine("check generatedAddress: " + confirmationCode.Check(mySecret, generatedAddress)); // True
Console.WriteLine("check generatedAddress: " + (bitcoinPrivateKey.GetAddress() == generatedAddress)); // True
Console.WriteLine("bitcoinPrivateKey: " + bitcoinPrivateKey);
}
public static void BIP38PassphraseCode()
{
// BIP is in reality two ideas in one document.
// The second part of the BIP lets you delegate Key and Address creation to an untrusted peer.
// ---
// You generate a PassphraseCode to the key generator.
// With this PassphraseCode, they will be able to generate encrypted keys on your behalf.
// They don't have to know your password or any private key.
// The PassphraseCode can be given to your key generator in WIF format.
// In NBitcoin, all types prefixed by "Bitcoin" are Base58 (WIF) data.
var passphraseCode = new BitcoinPassphraseCode("my secret", Network.Main, null);
EncryptedKeyResult encryptedKeyResult = passphraseCode.GenerateEncryptedSecret();
var generatedAddress = encryptedKeyResult.GeneratedAddress;
var encryptedKey = encryptedKeyResult.EncryptedKey;
var confirmedCode = encryptedKeyResult.ConfirmationCode;
// The ConfirmationCode lets the third party prove that the generated key and address correspond to your password.
// Now, as the owner...
// Check to make sure the generator didn't cheat.
Console.WriteLine(confirmedCode.Check("my secret", generatedAddress));
var bitcoinPrivateKey = encryptedKey.GetSecret("my secret");
Console.WriteLine(bitcoinPrivateKey.GetAddress() == generatedAddress);
Console.WriteLine(bitcoinPrivateKey);
// BIP 32, or Hierarchical Deterministic Wallets (HD wallets) proposes a solution to prevented outdated backups.
}
static void GenerateKey(Network network, string passphrase)
{
var passphraseCode = new BitcoinPassphraseCode(passphrase, network, null);
EncryptedKeyResult encryptedKeyResult = passphraseCode.GenerateEncryptedSecret();
Console.WriteLine("Addy: " + encryptedKeyResult.GeneratedAddress);
}
public static string createPassPharaseCOde(string password)
{
BitcoinPassphraseCode passphraseCode = new BitcoinPassphraseCode(password, MainActivity.net, null);
EncryptedKeyResult encryptedKey1 = passphraseCode.GenerateEncryptedSecret();
BitcoinSecret privateKey = encryptedKey1.EncryptedKey.GetSecret(password);
return(encryptedKey1.EncryptedKey.ToString());
}
public static string createPassPharaseCOde(string password)
{
BitcoinPassphraseCode passphraseCode = new BitcoinPassphraseCode(password, MainActivity.net, null);
EncryptedKeyResult encryptedKey1 = passphraseCode.GenerateEncryptedSecret();
Console.WriteLine(encryptedKey1.GeneratedAddress);
Console.WriteLine(encryptedKey1.EncryptedKey);
Console.WriteLine(encryptedKey1.ConfirmationCode);
Console.WriteLine(encryptedKey1.ConfirmationCode.Check(password, encryptedKey1.GeneratedAddress));
BitcoinSecret privateKey = encryptedKey1.EncryptedKey.GetSecret(password);
Console.WriteLine(privateKey.GetAddress() == encryptedKey1.GeneratedAddress);
return(encryptedKey1.EncryptedKey.ToString());
}
private void buttonGenerate_Click(object sender, EventArgs e)
{
if (string.IsNullOrEmpty(textBoxPhrase.Text))
{
MessageBox.Show(this, "You need to create or enter a [Passphrase] first.", "knoledge-keychain", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
using (new HourGlass())
{
BitcoinPassphraseCode phrase = new BitcoinPassphraseCode(textBoxPhrase.Text, Network.TestNet);
EncryptedKeyResult encryptedKey = phrase.GenerateEncryptedSecret();
textBoxEncKey.Text = encryptedKey.EncryptedKey.ToWif();
textBoxAddress.Text = encryptedKey.GeneratedAddress.ToWif();
textBoxConfirmation.Text = encryptedKey.ConfirmationCode.ToWif();
}
}
private void Code9()
{
BitcoinPassphraseCode passphraseCode = new BitcoinPassphraseCode("my secret", Network.Main, null);
EncryptedKeyResult encryptedKey1 = passphraseCode.GenerateEncryptedSecret();
Console.WriteLine(encryptedKey1.GeneratedAddress);
Console.WriteLine(encryptedKey1.EncryptedKey);
Console.WriteLine(encryptedKey1.ConfirmationCode);
var confirmationCode = encryptedKey1.ConfirmationCode;
var generatedAddress = encryptedKey1.GeneratedAddress;
var encryptedKey = encryptedKey1.EncryptedKey;
Console.WriteLine(confirmationCode.Check("my secret", generatedAddress));
BitcoinSecret privateKey = encryptedKey.GetSecret("my secret");
Console.WriteLine(privateKey.GetAddress() == generatedAddress);
Console.WriteLine(privateKey);
}
void Start()
{
var passphraseCode = new BitcoinPassphraseCode("my secret", Network.Main, null);
EncryptedKeyResult encryptedKeyResult = passphraseCode.GenerateEncryptedSecret();
var generatedAddress = encryptedKeyResult.GeneratedAddress;
var encryptedKey = encryptedKeyResult.EncryptedKey;
var confirmationCode = encryptedKeyResult.ConfirmationCode;
UnityEngine.Debug.Log(generatedAddress); // 14KZsAVLwafhttaykXxCZt95HqadPXuz73
UnityEngine.Debug.Log(encryptedKey); // 6PnWtBokjVKMjuSQit1h1Ph6rLMSFz2n4u3bjPJH1JMcp1WHqVSfr5ebNS
UnityEngine.Debug.Log(confirmationCode); // cfrm38VUcrdt2zf1dCgf4e8gPNJJxnhJSdxYg6STRAEs7QuAuLJmT5W7uNqj88hzh9bBnU9GFkN
UnityEngine.Debug.Log(confirmationCode.Check("my secret", generatedAddress)); // True
var bitcoinPrivateKey = encryptedKey.GetSecret("my secret");
UnityEngine.Debug.Log(bitcoinPrivateKey.GetAddress() == generatedAddress); // True
UnityEngine.Debug.Log(bitcoinPrivateKey); // KzzHhrkr39a7upeqHzYNNeJuaf1SVDBpxdFDuMvFKbFhcBytDF1R
}
public void EncryptedSecretECmultiplyNoLotSimple()
{
var compressedValues = new[] { false, true };
foreach (bool compressed in compressedValues)
{
var code = new BitcoinPassphraseCode("test", Network.Main, null);
Assert.Null(code.LotSequence);
EncryptedKeyResult result = code.GenerateEncryptedSecret(compressed);
Assert.True(result.ConfirmationCode.Check("test", result.GeneratedAddress));
Assert.False(result.ConfirmationCode.Check("toto", result.GeneratedAddress));
Assert.False(result.ConfirmationCode.Check("test", new Key().PubKey.GetAddress(Network.Main)));
Key decryptedKey = result.EncryptedKey.GetKey("test");
Assert.Equal(result.GeneratedAddress.ToString(), decryptedKey.PubKey.GetAddress(Network.Main).ToString());
Assert.Throws <SecurityException>(() => result.EncryptedKey.GetKey("wrong"));
//Can regenerate same result with same seed
EncryptedKeyResult result2 = code.GenerateEncryptedSecret(compressed, seedb: result.Seed);
Key decryptedKey2 = result.EncryptedKey.GetKey("test");
AssertEx.CollectionEquals(decryptedKey2.ToBytes(), decryptedKey.ToBytes());
}
}
private static void KeyGenerationAndEncryption()
{
// 02.01. Key Generation
RandomUtils.AddEntropy("hello");
RandomUtils.AddEntropy(new byte[] { 1, 2, 3 });
var nsaProofKey = new Key();
Console.WriteLine("Key with entropy " + nsaProofKey.GetBitcoinSecret(Network.TestNet));
var derived = SCrypt.BitcoinComputeDerivedKey("hello", new byte[] { 1, 2, 3 });
RandomUtils.AddEntropy(derived);
var privateKey = new Key();
var privateKeyBitcoinSecret = privateKey.GetWif(Network.TestNet);
Console.WriteLine(privateKeyBitcoinSecret); // L1tZPQt7HHj5V49YtYAMSbAmwN9zRjajgXQt9gGtXhNZbcwbZk2r
BitcoinEncryptedSecret bitcoinEncryptedSecret = privateKeyBitcoinSecret.Encrypt("password");
Console.WriteLine(bitcoinEncryptedSecret); // 6PYKYQQgx947Be41aHGypBhK6TA5Xhi9TdPBkatV3fHbbKrdDoBoXFCyLK
var decryptedBitcoinPrivateKey = bitcoinEncryptedSecret.GetSecret("password");
Console.WriteLine(decryptedBitcoinPrivateKey); // L1tZPQt7HHj5V49YtYAMSbAmwN9zRjajgXQt9gGtXhNZbcwbZk2r
//02.02 BIP38 and HD (Hierarchical Deterministic) Wallet
var passphraseCode = new BitcoinPassphraseCode("my secret", Network.TestNet, null);
// we give this passphraseCode to 3rd party
EncryptedKeyResult encryptedKeyResult = passphraseCode.GenerateEncryptedSecret();
var generatedAddress = encryptedKeyResult.GeneratedAddress;
var encryptedKeySecretEc = encryptedKeyResult.EncryptedKey;
var confirmationCode = encryptedKeyResult.ConfirmationCode;
Console.WriteLine(confirmationCode.Check("my secret", generatedAddress)); // True
var privateKeyBitcoinSecret1 = encryptedKeySecretEc.GetSecret("my secret");
Console.WriteLine(privateKeyBitcoinSecret1.GetAddress() == generatedAddress); // True
Console.WriteLine(privateKeyBitcoinSecret1); // KzzHhrkr39a7upeqHzYNNeJuaf1SVDBpxdFDuMvFKbFhcBytDF1R
ExtKey masterKey = new ExtKey();
Console.WriteLine("Master key : " + masterKey.ToString(Network.TestNet));
for (int i = 0; i < 5; i++)
{
ExtKey extKey1 = masterKey.Derive((uint)i);
Console.WriteLine("Key " + i + " : " + extKey1.ToString(Network.TestNet));
}
ExtKey extKey = new ExtKey();
byte[] chainCode = extKey.ChainCode;
Key key = extKey.PrivateKey;
ExtKey newExtKey = new ExtKey(key, chainCode);
ExtPubKey masterPubKey = masterKey.Neuter();
for (int i = 0; i < 5; i++)
{
ExtPubKey pubkey = masterPubKey.Derive((uint)i);
Console.WriteLine("PubKey " + i + " : " + pubkey.ToString(Network.TestNet));
}
ExtKey key1 = masterKey.Derive(4);
//Check it is legit
var generatedAddr = masterPubKey.Derive(4).PubKey.GetAddress(Network.TestNet);
var expectedAddr = key1.PrivateKey.PubKey.GetAddress(Network.TestNet);
Console.WriteLine("Generated address : " + generatedAddr);
Console.WriteLine("Expected address : " + expectedAddr);
ExtKey parent = new ExtKey();
ExtKey child11 = parent.Derive(1).Derive(1);
ExtKey sameChild11 = parent.Derive(new KeyPath("1/1"));
Console.WriteLine("child11 : " + child11.PrivateKey.PubKey.GetAddress(Network.TestNet));
Console.WriteLine("child11.PrivateKey == sameChild11.PrivateKey : " +
(child11.PrivateKey == sameChild11.PrivateKey));
ExtKey ceoKey = new ExtKey();
Console.WriteLine("CEO: " + ceoKey.ToString(Network.TestNet));
ExtKey notHardenedAccountingKey = ceoKey.Derive(0, hardened: false);
ExtPubKey ceoPubkey = ceoKey.Neuter();
//Recover ceo key with accounting private key and ceo public key
ExtKey ceoKeyRecovered = notHardenedAccountingKey.GetParentExtKey(ceoPubkey);
Console.WriteLine("CEO recovered: " + ceoKeyRecovered.ToString(Network.TestNet));
ExtKey hardenedAccountingKey = ceoKey.Derive(0, hardened: true);
// ExtKey ceoKeyRecovered2 = hardenedAccountingKey.GetParentExtKey(ceoPubkey); => //throws exception
Mnemonic mnemo = new Mnemonic(Wordlist.English, WordCount.Twelve); // generate random 12 words list
ExtKey hdRoot = mnemo.DeriveExtKey("my password");
mnemo = new Mnemonic("minute put grant neglect anxiety case globe win famous correct turn link",
Wordlist.English);
hdRoot = mnemo.DeriveExtKey("my password");
Console.WriteLine(mnemo);
Console.WriteLine(hdRoot.ToString(Network.TestNet));
var scanKey = new Key();
var spendKey = new Key();
BitcoinStealthAddress stealthAddress
= new BitcoinStealthAddress
(
scanKey: scanKey.PubKey,
pubKeys: new[] { spendKey.PubKey },
signatureCount: 1,
bitfield: null,
network: Network.TestNet);
Transaction transaction = new Transaction();
stealthAddress.SendTo(transaction, Money.Coins(1.0m));
Console.WriteLine(transaction);
// personal tests Mycelium
mnemo = new Mnemonic("artist tiger always access sport major donkey coil scale carry laptop ticket", Wordlist.English);
hdRoot = mnemo.DeriveExtKey();//leave the password null as sample
Console.WriteLine(hdRoot.ToString(Network.Main));
var hardened2 = new KeyPath("44'/0'/0'/0/1");
ExtKey paymentKey2 = hdRoot.Derive(hardened2);
Console.WriteLine(hardened2 + ": " + paymentKey2.ScriptPubKey.GetDestinationAddress(Network.Main));
Console.WriteLine(hardened2 + ": private " + paymentKey2.ToString(Network.Main));
var hardened1 = new KeyPath("44'/0'/0'/0/0");
ExtKey paymentKey1 = hdRoot.Derive(hardened1);
Console.WriteLine(hardened1 + ": " + paymentKey1.ScriptPubKey.GetDestinationAddress(Network.Main));
Console.WriteLine(hardened1 + ": private " + paymentKey1.ToString(Network.Main));
}
private void buttonOk_Click(object sender, EventArgs e)
{
if (string.IsNullOrEmpty(textBoxKey.Text))
{
MessageBox.Show(this, "Enter a key.", "Knoledge-keychain", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
return;
}
using (new HourGlass())
{
Result = Util.InterpretKey(textBoxKey.Text);
}
if (Result == null)
{
MessageBox.Show(this, "Unrecognized or invalid key.", "Knoledge-keychain", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
}
else
{
using (new HourGlass())
{
Type type = Result.GetType();
switch (type.ToString())
{
case "NBitcoin.BitcoinEncryptedSecretEC":
if (string.IsNullOrEmpty(textBoxPassword.Text))
{
MessageBox.Show(this, "This is an encrypted BitcoinSecret, please provide the password.", "Knoledge-keychain", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
return;
}
else
{
try
{
BitcoinEncryptedSecretEC encEC = Result as BitcoinEncryptedSecretEC;
Result = encEC.GetKey(textBoxPassword.Text).GetBitcoinSecret(Network.TestNet);
DialogResult = System.Windows.Forms.DialogResult.OK;
}
catch
{
MessageBox.Show(this, "The pasword you entered is incorrect.", "Knoledge-keychain", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
break;
case "NBitcoin.BitcoinEncryptedSecretNoEC":
if (string.IsNullOrEmpty(textBoxPassword.Text))
{
MessageBox.Show(this, "This is an encrypted BitcoinSecret, please provide the password.", "Knoledge-keychain", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
return;
}
else
{
try
{
BitcoinEncryptedSecretNoEC encEC = Result as BitcoinEncryptedSecretNoEC;
Result = encEC.GetKey(textBoxPassword.Text).GetBitcoinSecret(Network.TestNet);
DialogResult = System.Windows.Forms.DialogResult.OK;
}
catch
{
MessageBox.Show(this, "The pasword you entered is incorrect.", "Knoledge-keychain", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
break;
case "NBitcoin.BitcoinPassphraseCode":
if (string.IsNullOrEmpty(textBoxPassword.Text))
{
MessageBox.Show(this, "This is a PassphraseCode, please provide the password.", "Knoledge-keychain", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
return;
}
else
{
try
{
BitcoinPassphraseCode phrase = Result as BitcoinPassphraseCode;
EncryptedKeyResult key = phrase.GenerateEncryptedSecret();
if (key.ConfirmationCode.Check(textBoxPassword.Text, key.GeneratedAddress))
{
BitcoinSecret secret = key.EncryptedKey.GetSecret(textBoxPassword.Text);
if (secret.GetAddress() == key.GeneratedAddress)
{
Result = secret;
DialogResult = System.Windows.Forms.DialogResult.OK;
}
else
{
MessageBox.Show(this, "The Generated Addresses do not match.", "Knoledge-keychain", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
else
{
MessageBox.Show(this, "The Confirmation Code check failed.", "Knoledge-keychain", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
catch
{
MessageBox.Show(this, "The password you entered is incorrect.", "Knoledge-keychain", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
break;
default:
DialogResult = System.Windows.Forms.DialogResult.OK;
break;
}
}
}
}
private static void Main(string[] args)
{
// add entropy before creating key
RandomUtils.AddEntropy("hello");
RandomUtils.AddEntropy(new byte[] { 1, 2, 3 });
// key created with added entropy
var nsaProofKey = new Key();
// What NBitcoin does when you call AddEntropy(data) is:
// additionalEntropy = SHA(SHA(data) ^ additionalEntropy)
// Then when you generate a new number:
// result = SHA(PRNG() ^ additionalEntropy)
// Key Derivation Function is a way to have a stronger key, even if your entropy is low
// KDF is a hash function that wastes computing resources on purpose.
var derived = SCrypt.BitcoinComputeDerivedKey("hello", new byte[] { 1, 2, 3 });
RandomUtils.AddEntropy(derived);
// even if attacker knows that your source of entropy contains 5 letters,
// they will need to run Scrypt to check each possibility
// standard for encrypting private key with a password using kdf is BIP38
var privateKey = new Key();
var bitcoinPrivateKey = privateKey.GetWif(Network.Main);
Console.WriteLine(bitcoinPrivateKey);
BitcoinEncryptedSecret encryptedBitcoinPrivateKey = bitcoinPrivateKey.Encrypt("password");
Console.WriteLine(encryptedBitcoinPrivateKey);
var decryptedBitcoinPrivateKey = encryptedBitcoinPrivateKey.GetKey("password");
Console.WriteLine(decryptedBitcoinPrivateKey);
Key keyFromIncorrectPassword = null;
Exception error = null;
try
{
keyFromIncorrectPassword = encryptedBitcoinPrivateKey.GetKey("lahsdlahsdlakhslkdash");
}
catch (Exception e)
{
error = e;
}
var result = keyFromIncorrectPassword != null
? keyFromIncorrectPassword.ToString()
: $"{error?.GetType().Name ?? "Error"}: icorrect password";
Console.WriteLine(result);
// BIP 38
// how to delegate Key and Address creation to an untrusted peer
// create pass phrase code
BitcoinPassphraseCode passphraseCode = new BitcoinPassphraseCode("my secret", Network.Main, null);
Console.WriteLine(passphraseCode);
// then give passPhraseCode to 3rd party key generator
// third party can generate encrypted keys on your behalf
// without knowing your password and private key.
EncryptedKeyResult encryptedKeyResult = passphraseCode.GenerateEncryptedSecret();
var generatedAddress = encryptedKeyResult.GeneratedAddress;
var encryptedKey = encryptedKeyResult.EncryptedKey;
// used by 3rd party to confirm generated key and address correspond to password
var confirmationCode = encryptedKeyResult.ConfirmationCode;
// check
var isValid = confirmationCode.Check("my secret", generatedAddress);
Console.WriteLine(isValid);
var bitcoinPrivateKeyFromPassphraseCode = encryptedKey.GetSecret("my secret");
Console.WriteLine(bitcoinPrivateKeyFromPassphraseCode.GetAddress() == generatedAddress);
Console.WriteLine(bitcoinPrivateKey);
// BIP 32
// hierarchical deterministic wallets
// prevent outdated backups
var masterKey = new ExtKey();
Console.WriteLine($"Master Key: {masterKey.ToString(Network.Main)}");
for (uint i = 0; i < 5; i++)
{
ExtKey nextKey = masterKey.Derive(i);
Console.WriteLine($"Key {i} : {nextKey.ToString(Network.Main)}");
}
// go back from a Key to ExtKey by supplying the Key and the ChainCode to the ExtKey constructor.
var extKey = new ExtKey();
byte[] chainCode = extKey.ChainCode;
Key key = extKey.PrivateKey;
var newExtKey = new ExtKey(key, chainCode);
// the base58 type equivalent of ExtKey is BitcoinExtKey
// "neuter" master key so 3rd party can generate public keys without knowing private key
ExtPubKey masterPubKey = masterKey.Neuter();
for (uint i = 0; i < 5; i++)
{
ExtPubKey pubKey = masterPubKey.Derive(i);
Console.WriteLine($"PubKey {i} : {pubKey.ToString(Network.Main)}");
}
// get corresponding private key with master key
masterKey = new ExtKey();
masterPubKey = masterKey.Neuter();
// 3rd party generates pubkey1
ExtPubKey pubKey1 = masterPubKey.Derive(1);
// get privatekey of pubKey1
ExtKey key1 = masterKey.Derive(1);
Console.WriteLine($"Generated address: {pubKey1.PubKey.GetAddress(Network.Main)}");
Console.WriteLine($"Expected address: {key1.PrivateKey.PubKey.GetAddress(Network.Main)}");
// deterministic keys
// derive the 1st child of the 1st child
ExtKey parent = new ExtKey();
// method 1:
ExtKey child11 = parent.Derive(1).Derive(1);
// method 2:
child11 = parent.Derive(new KeyPath("1/1"));
// why use HD wallets ?
// easier control, easier to classify keys for multiple accounts
// but child keys can recover parent key (non-hardened)
ExtKey ceoExtKey = new ExtKey();
Console.WriteLine($"CEO: {ceoExtKey.ToString(Network.Main)}");
ExtKey accountingKey = ceoExtKey.Derive(0, hardened: false);
ExtPubKey ceoPubKey = ceoExtKey.Neuter();
// recover ceo key with accounting private key and ceo public key
ExtKey ceoKeyRecovered = accountingKey.GetParentExtKey(ceoPubKey);
Console.WriteLine($"CEO recovered: {ceoKeyRecovered.ToString(Network.Main)}");
// create a hardened key
var privateCeoExtKey = new ExtKey();
Console.WriteLine($"Private CEO: {privateCeoExtKey.ToString(Network.Main)}");
var assitantExtKey = privateCeoExtKey.Derive(1, hardened: true);
ExtPubKey privateCeoPubKey = privateCeoExtKey.Neuter();
ExtKey privateCeoKeyRecovered = null;
try
{
privateCeoKeyRecovered = assitantExtKey.GetParentExtKey(privateCeoPubKey);
}
catch (Exception e)
{
Console.WriteLine($"{e.Message}");
}
// creating hardened keys via keypath
var isNonHardened = new KeyPath("1/2/3").IsHardened;
Console.WriteLine(isNonHardened);
var isHardened = new KeyPath("1/2/3'").IsHardened;
Console.WriteLine(isHardened);
// imagine that the Accounting Department generates 1 parent key for each customer, and a child for each of the customer’s payments.
// As the CEO, you want to spend the money on one of these addresses.
var accountingCeoKey = new ExtKey();
string accounting = "1'"; // hardened with apostrophe
int customerId = 5;
int paymentId = 50;
KeyPath path = new KeyPath($"{accounting}/{customerId}/{paymentId}");
// path: 1/5/50
ExtKey paymentKey = accountingCeoKey.Derive(path);
Console.WriteLine(paymentKey);
// mnemonic code for HD keys BIP 39
// used for easy to write keys
Mnemonic mnemo = new Mnemonic(Wordlist.English, WordCount.Twelve);
ExtKey hdRoot = mnemo.DeriveExtKey("my password");
Console.WriteLine(mnemo);
// recover hdRoot with mnemonic and password
mnemo = new Mnemonic(mnemo.ToString(), Wordlist.English);
ExtKey recoverdHdRoot = mnemo.DeriveExtKey("my password");
Console.WriteLine(hdRoot.PrivateKey == recoverdHdRoot.PrivateKey);
// dark wallet
// Prevent outdated backups
// Delegate key / address generation to an untrusted peer
// bonus feature: only share one address (StealthAddress)
var scanKey = new Key();
var spendKey = new Key();
var stealthAddress = new BitcoinStealthAddress(
scanKey: scanKey.PubKey,
pubKeys: new[] { spendKey.PubKey },
signatureCount: 1,
bitfield: null,
network: Network.Main
);
// payer will take StealthAddress and generate temp key called Ephem Key, and generate a Stealth Pub Key
// then they package the Ephem PubKey in Stealth Metadata obj embedded in OP_RETURN
// they will also add the output to the generated bitcoin address (Stealth pub key)
//The creation of the EphemKey is an implementation detail
// it can be omitted as NBitcoin will generate one automatically:
var ephemKey = new Key();
var transaction = new Transaction();
stealthAddress.SendTo(transaction, Money.Coins(1.0m), ephemKey);
Console.WriteLine(transaction);
// the Scanner knows the StealthAddress
// and recovers the Stealth PubKey and Bitcoin Address with the Scan Key
// scanner then checks if if one of the tx corresponds to the address
// if true, Scanner notifies the Receiver about tx
// the receiver can get the private key of the address with their spend key
// note: a StealthAddress can have mulitple spend pubkeys 9multi sig)
// limit: use of OP_RETURN makes embedding data in tx difficult
// OP_RETURN limit is 40 bytes
Console.ReadLine();
}
static void Main()
{
RandomUtils.Random = new UnsecureRandom();
//====================================================================================
//Section. BIP38(Part 2)
//We already looked at using BIP38 to encrypt a key. However this BIP is in reality two ideas in one document.
//The second part of the BIP shows how you can delegate Key and Address creation to an untrusted peer. It will fix one of our concerns.
//The idea is to generate a PassphraseCode to the key generator. With this PassphraseCode, they will be able to generate encrypted keys on your behalf, without knowing your password, nor any private key.
//This PassphraseCode can be given to your key generator in WIF format.
//Tip: In NBitcoin, all types prefixed by “Bitcoin” are Base58 (WIF) data.
//So, as a user that wants to delegate key creation, first you will create the PassphraseCode.
//Illustration:
//Password + Network => PassphraseCode
var passphraseCode = new BitcoinPassphraseCode("my secret", Network.Main, null);
//You then give this PassphraseCode to a third party key generator. And then, the third party key generator will generate new encrypted keys for me.
//Illustration:
//PassphraseCode => EncryptedKey1, EncryptedKey2
EncryptedKeyResult encryptedKeyResult = passphraseCode.GenerateEncryptedSecret();
//This EncryptedKeyResult class has lots of information:
//Illustration:
//First is the generated Bitcoin address.
var generatedAddress = encryptedKeyResult.GeneratedAddress;
//Output:
//14KZsAVLwafhttaykXxCZt95HqadPXuz73
//Second is the encryptedKey itself as we have seen in the previous, Key Encryption lesson.
var encryptedKey = encryptedKeyResult.EncryptedKey;
//And last but not least, the ConfirmationCode, so that the third party can prove that the generated key and address correspond to my password.
var confirmationCode = encryptedKeyResult.ConfirmationCode;
//Output:
//cfrm38VUcrdt2zf1dCgf4e8gPNJJxnhJSdxYg6STRAEs7QuAuLJmT5W7uNqj88hzh9bBnU9GFkN
Console.WriteLine(generatedAddress);
//Output:
//14KZsAVLwafhttaykXxCZt95HqadPXuz73
Console.WriteLine(encryptedKey);
//Output:
//6PnWtBokjVKMjuSQit1h1Ph6rLMSFz2n4u3bjPJH1JMcp1WHqVSfr5ebNS
Console.WriteLine(confirmationCode);
//Output:
//cfrm38VUcrdt2zf1dCgf4e8gPNJJxnhJSdxYg6STRAEs7QuAuLJmT5W7uNqj88hzh9bBnU9GFkN
//As the owner, once you receive this information, you need to check that the key generator did not cheat by using ConfirmationCode.Check, then get your private key with your password:
Console.WriteLine(confirmationCode.Check("my secret", generatedAddress));
//Output:
//True
//Get bitcoinPrivateKey by a password.
var bitcoinPrivateKey = encryptedKey.GetSecret("my secret");
Console.WriteLine(bitcoinPrivateKey.GetAddress() == generatedAddress);
//Output:
//True
Console.WriteLine(bitcoinPrivateKey);
//Output:
//KzzHhrkr39a7upeqHzYNNeJuaf1SVDBpxdFDuMvFKbFhcBytDF1R
//So, we have just seen how the third party can generate encrypted keys on your behalf, without them knowing your password and private key.
//In other words, you've delegated a Key and Address creation to an untrusted peer, the third party.
//Illustration:
//However, one problem remains:
//All backups of your wallet that you have will become outdated when you generate a new key.
//BIP 32, or Hierarchical Deterministic Wallets (HD wallets), proposes another solution which is more widely supported.
}
