public static Transaction CreateFakeTx(NetworkParameters @params, ulong nanocoins, Address to)
{
var t = new Transaction(@params);
var o1 = new TransactionOutput(@params, t, nanocoins, to);
t.AddOutput(o1);
// Make a previous tx simply to send us sufficient coins. This prev tx is not really valid but it doesn't
// matter for our purposes.
var prevTx = new Transaction(@params);
var prevOut = new TransactionOutput(@params, prevTx, nanocoins, to);
prevTx.AddOutput(prevOut);
// Connect it.
t.AddInput(prevOut);
return t;
}
public void Transactions()
{
// This test covers a _bug in which Transaction.getValueSentFromMe was calculating incorrectly.
var tx = TestUtils.CreateFakeTx(Params, Utils.ToNanoCoins(1, 0), _myAddress);
// Now add another output (ie, change) that goes to some other address.
var someOtherGuy = new EcKey().ToAddress(Params);
var output = new TransactionOutput(Params, tx, Utils.ToNanoCoins(0, 5), someOtherGuy);
tx.AddOutput(output);
// Note that tx is no longer valid: it spends more than it imports. However checking transactions balance
// correctly isn't possible in SPV mode because value is a property of outputs not inputs. Without all
// transactions you can't check they add up.
_defaultWallet.Receive(tx, null, BlockChain.NewBlockType.BestChain);
// Now the other guy creates a transaction which spends that change.
var tx2 = new Transaction(Params);
tx2.AddInput(output);
tx2.AddOutput(new TransactionOutput(Params, tx2, Utils.ToNanoCoins(0, 5), _myAddress));
// tx2 doesn't send any coins from us, even though the output is in the wallet.
Assert.AreEqual(Utils.ToNanoCoins(0, 0), tx2.GetValueSentFromMe(_defaultWallet));
}
public void Bounce()
{
// This test covers _bug 64 (False double spends). Check that if we create a spend and it's immediately sent
// back to us, this isn't considered as a double spend.
var coin1 = Utils.ToNanoCoins(1, 0);
var coinHalf = Utils.ToNanoCoins(0, 50);
// Start by giving us 1 coin.
var inbound1 = TestUtils.CreateFakeTx(Params, coin1, _myAddress);
_defaultWallet.Receive(inbound1, null, BlockChain.NewBlockType.BestChain);
// Send half to some other guy. Sending only half then waiting for a confirm is important to ensure the tx is
// in the unspent pool, not pending or spent.
Assert.AreEqual(1, _defaultWallet.GetPoolSize(WalletPool.Unspent));
Assert.AreEqual(1, _defaultWallet.GetPoolSize(WalletPool.All));
var someOtherGuy = new EcKey().ToAddress(Params);
var outbound1 = _defaultWallet.CreateSend(someOtherGuy, coinHalf);
_defaultWallet.ConfirmSend(outbound1);
_defaultWallet.Receive(outbound1, null, BlockChain.NewBlockType.BestChain);
// That other guy gives us the coins right back.
var inbound2 = new Transaction(Params);
inbound2.AddOutput(new TransactionOutput(Params, inbound2, coinHalf, _myAddress));
inbound2.AddInput(outbound1.TransactionOutputs[0]);
_defaultWallet.Receive(inbound2, null, BlockChain.NewBlockType.BestChain);
Assert.AreEqual(coin1, _defaultWallet.GetBalance());
}
private static Block CreateGenesis(NetworkParameters networkParameters)
{
var genesisBlock = new Block(networkParameters);
var transaction = new Transaction(networkParameters);
// A script containing the difficulty bits and the following message:
// "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks"
var bytes = Hex.Decode("04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73");
transaction.AddInput(new TransactionInput(networkParameters, transaction, bytes));
using (var scriptPubKeyBytes = new MemoryStream())
{
Script.WriteBytes(scriptPubKeyBytes,Hex.Decode("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f"));
scriptPubKeyBytes.Write(Script.OpCheckSig);
transaction.AddOutput(new TransactionOutput(networkParameters, transaction, scriptPubKeyBytes.ToArray()));
}
genesisBlock.AddTransaction(transaction);
return genesisBlock;
}
/// <summary>
/// Returns a solved block that builds on top of this one. This exists for unit tests.
/// </summary>
internal Block CreateNextBlock(Address toAddress, uint time)
{
var block = new Block(NetworkParameters) {TargetDifficulty = _targetDifficulty};
block.AddCoinbaseTransaction(EmptyBytes);
// Add a transaction paying 50 coins to the "to" address.
var transaction = new Transaction(NetworkParameters);
transaction.AddOutput(new TransactionOutput(NetworkParameters, transaction, Utils.ToNanoCoins(50, 0),
toAddress));
// The input does not really need to be a valid signature, as long as it has the right general form.
var input = new TransactionInput(NetworkParameters, transaction,
Script.CreateInputScript(EmptyBytes, EmptyBytes));
// Importantly the outpoint hash cannot be zero as that's how we detect a coinbase transaction in isolation
// but it must be unique to avoid 'different' transactions looking the same.
var counter = new byte[32];
counter[0] = (byte) _transactionCounter++;
input.Outpoint.Hash = new Sha256Hash(counter);
transaction.AddInput(input);
block.AddTransaction(transaction);
block.PreviousBlockHash = Hash;
block.TimeSeconds = time;
block.Solve();
block.VerifyHeader();
return block;
}
/// <summary>
/// Adds a coinbase transaction to the block. This exists for unit tests.
/// </summary>
internal void AddCoinbaseTransaction(byte[] pubKeyTo)
{
Transactions = new List<Transaction>();
var coinbase = new Transaction(NetworkParameters);
// A real coinbase transaction has some stuff in the scriptSig like the extraNonce and difficulty. The
// transactions are distinguished by every TX output going to a different key.
//
// Here we will do things a bit differently so a new address isn't needed every time. We'll put a simple
// counter in the scriptSig so every transaction has a different hash.
coinbase.AddInput(new TransactionInput(NetworkParameters, coinbase, new[] {(byte) _transactionCounter++}));
coinbase.AddOutput(new TransactionOutput(NetworkParameters, coinbase, Script.CreateOutputScript(pubKeyTo)));
Transactions.Add(coinbase);
}
/// <summary>
/// Creates a transaction that sends $coins.$cents BTC to the given address.
/// </summary>
/// <remarks>
/// IMPORTANT: This method does NOT update the wallet. If you call createSend again you may get two transactions
/// that spend the same coins. You have to call confirmSend on the created transaction to prevent this,
/// but that should only occur once the transaction has been accepted by the network. This implies you cannot have
/// more than one outstanding sending tx at once.
/// </remarks>
/// <param name="address">The BitCoin address to send the money to.</param>
/// <param name="nanocoins">How much currency to send, in nanocoins.</param>
/// <param name="changeAddress">
/// Which address to send the change to, in case we can't make exactly the right value from
/// our coins. This should be an address we own (is in the keychain).
/// </param>
/// <returns>
/// A new <see cref="BitcoinSharp.Core.Messages.Transaction"/> or null if we cannot afford this send.
/// </returns>
public Transaction CreateSend(Address address, ulong nanocoins, Address changeAddress)
{
lock (this)
{
Log.Info("Creating send tx to " + address + " for " +
Utils.BitcoinValueToFriendlyString(nanocoins));
// To send money to somebody else, we need to do gather up transactions with unspent outputs until we have
// sufficient value. Many coin selection algorithms are possible, we use a simple but suboptimal one.
// TODO: Sort coins so we use the smallest first, to combat wallet fragmentation and reduce fees.
var valueGathered = 0UL;
var gathered = new LinkedList<TransactionOutput>();
foreach (var transaction in Unspent.Values)
{
foreach (var transactionOutput in transaction.TransactionOutputs)
{
if (!transactionOutput.IsAvailableForSpending) continue;
if (!transactionOutput.IsMine(this)) continue;
gathered.AddLast(transactionOutput);
valueGathered += transactionOutput.Value;
}
if (valueGathered >= nanocoins) break;
}
// Can we afford this?
if (valueGathered < nanocoins)
{
Log.Info("Insufficient value in wallet for send, missing " +
Utils.BitcoinValueToFriendlyString(nanocoins - valueGathered));
// TODO: Should throw an exception here.
return null;
}
Debug.Assert(gathered.Count > 0);
var sendTransaction = new Transaction(_networkParameters);
sendTransaction.AddOutput(new TransactionOutput(_networkParameters, sendTransaction, nanocoins, address));
var change = (long) (valueGathered - nanocoins);
if (change > 0)
{
// The value of the inputs is greater than what we want to send. Just like in real life then,
// we need to take back some coins ... this is called "change". Add another output that sends the change
// back to us.
Log.Info(" with " + Utils.BitcoinValueToFriendlyString((ulong) change) + " coins change");
sendTransaction.AddOutput(new TransactionOutput(_networkParameters, sendTransaction, (ulong) change,
changeAddress));
}
foreach (var output in gathered)
{
sendTransaction.AddInput(output);
}
// Now sign the inputs, thus proving that we are entitled to redeem the connected outputs.
sendTransaction.SignInputs(Transaction.SigHash.All, this);
Log.InfoFormat(" created {0}", sendTransaction.HashAsString);
return sendTransaction;
}
}