public Block MineNextBlock(string minerAddress, int difficulty)
{
// Prepare the next block for mining
var oldDifficulty = this.CurrentDifficulty;
this.CurrentDifficulty = difficulty;
var nextBlock = this.GetMiningJob(minerAddress);
this.CurrentDifficulty = oldDifficulty;
// Mine the next block
nextBlock.DateCreated = GeneralUtils.NowInISO8601();
nextBlock.Nonce = 0;
do
{
nextBlock.Nonce++;
nextBlock.BlockHash = nextBlock.CalculateBlockHash();
} while (!ValidationUtils.IsValidDifficulty(CryptoUtils.BytesToHex(nextBlock.BlockHash), difficulty));
// Submit the mined block
var newBlock = this.SubmitMinedBlock(nextBlock.BlockDataHash, // ?? thing if I have to recalculate that
nextBlock.DateCreated, nextBlock.Nonce, nextBlock.BlockHash);
return(newBlock);
}
public Block ExtendChain(Block newBlock)
{
if (newBlock.Index != this.Blocks.Count)
{
throw new ArgumentException("The submitted block was already mined by someone else");
}
var prevBlock = this.Blocks[this.Blocks.Count - 1];
if (CryptoUtils.BytesToHex(prevBlock.BlockHash) != CryptoUtils.BytesToHex(newBlock.PrevBlockHash))
{
throw new ArgumentException("Incorrect prevBlockHash");
}
// The block is correct --> accept it
this.Blocks.Add(newBlock);
this.MiningJobs = new Dictionary <string, Block>(); // Invalidate all mining jobs
this.RemovePendingTransactions(newBlock.Transactions);
this.AdjustDifficulty();
return(newBlock);
}
public Transaction FindTransactionByDataHash(string transactionDataHash)
{
var allTransactions = this.GetAllTransactions();
var matchingTransaction = allTransactions.FirstOrDefault(
t => CryptoUtils.BytesToHex(t.TransactionDataHash) == transactionDataHash);
return(matchingTransaction);
}
private Node(string serverHost, string serverPort, Blockchain blockchain)
{
this.NodeId = Guid.NewGuid().ToString();
this.Host = serverHost;
this.Port = serverPort;
this.SelfUrl = string.Format("http://{0}:{1}", serverHost, serverPort);
this.Peers = new Dictionary <string, string>();
this.Chain = blockchain;
this.ChainId = CryptoUtils.BytesToHex(blockchain.Blocks[0].BlockHash);
}
public void Test_CryptoUtils_HexToBytesAndViseVersa()
{
var expResult = "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08";
var bytes = CryptoUtils.HexToBytes(expResult);
Assert.True(bytes.Length == 32);
var resultString = CryptoUtils.BytesToHex(bytes);
Assert.True(expResult == resultString);
Assert.True(expResult.Length == 64);
}
public void RemovePendingTransactions(IEnumerable <Transaction> transactionsToRemove)
{
var tranHashesToRemove = new HashSet <string>();
foreach (var item in transactionsToRemove)
{
tranHashesToRemove.Add(CryptoUtils.BytesToHex(item.TransactionDataHash));
}
foreach (var dataHash in tranHashesToRemove)
{
this.PendingTransactions.RemoveAll(s => CryptoUtils.BytesToHex(s.TransactionDataHash) == dataHash);
}
}
public IActionResult GetMiningJob(string address)
{
var blockCandidate = this.GetNodeSingleton().Chain.GetMiningJob(address);
//retun candidate block
return(Ok(new
{
index = blockCandidate.Index,
transactionsIncluded = blockCandidate.Transactions.Count,
difficulty = blockCandidate.Difficulty,
expectedReward = blockCandidate.Transactions[0].Value,
rewardAddress = blockCandidate.Transactions[0].To,
blockDataHash = CryptoUtils.BytesToHex(blockCandidate.BlockDataHash)
}));
}
} // the unique chain ID (hash of the genesis block)
public void BroadcastTransactionToAllPeers(Transaction tran)
{
foreach (var nodeId in this.Peers)
{
var peerUrl = this.Peers[nodeId.Key];
Console.WriteLine("Broadcasting a transaction {0} to peer {1}"
, CryptoUtils.BytesToHex(tran.TransactionDataHash), peerUrl);
try
{
var result = WebRequester
.Post(peerUrl + "/api/Node/transactions/send", tran);
}
catch (Exception ex)
{
Console
.WriteLine("Broadcasting a transaction to {0} failed, due to {1}"
, peerUrl, ex.Message);
}
}
}
public Block SubmitMinedBlock(byte[] blockDataHash, string dateCreated, ulong nonce, byte[] blockHash)
{
// Find the block candidate by its data hash
var newBlock = this.MiningJobs[CryptoUtils.BytesToHex(blockDataHash)];
if (newBlock == null)
{
throw new ArgumentException("Block not found or already mined");
}
// Build the new block
newBlock.DateCreated = dateCreated;
newBlock.Nonce = nonce;
newBlock.BlockHash = newBlock.CalculateBlockHash();
// We can not compare block hash because the one we have in newBlock is not ok
// Validate the block hash + the proof of work
//if (CryptoUtils.BytesToHex(newBlock.BlockHash) != CryptoUtils.BytesToHex(blockHash))
// throw new ArgumentException("Block hash is incorrectly calculated");
if (!ValidationUtils.IsValidDifficulty(
CryptoUtils.BytesToHex(newBlock.BlockHash), newBlock.Difficulty))
{
throw new ArgumentException("The calculated block hash does not match the block difficulty");
}
newBlock = this.ExtendChain(newBlock);
//if (!newBlock.errorMsg)
// logger.debug("Mined a new block: " + JSON.stringify(newBlock));
return(newBlock);
}
public byte[] CalculateBlockHash()
{
var data = string.Format("{0}|{1}|{2}", CryptoUtils.BytesToHex(this.BlockDataHash), this.DateCreated, this.Nonce);
return(CryptoUtils.CalcSHA256(data));
}
public Block GetMiningJob(string minerAddress)
{
var nextBlockIndex = this.Blocks.Count;
// Deep clone all pending transactions & sort them by fee
var clonedTransactions = (SerializeUtils.CloneList <Transaction>(this.PendingTransactions))
.OrderByDescending(s => s.Fee).ToList(); // sort descending by fee
var dateCreated = GeneralUtils.NowInISO8601();
var key = nextBlockIndex + "_" + minerAddress;
if (MinerAddressBlockIndexDateTimeMap.ContainsKey(key))
{
dateCreated = MinerAddressBlockIndexDateTimeMap[key];
}
else
{
MinerAddressBlockIndexDateTimeMap[key] = dateCreated;
}
// Prepare the coinbase transaction -> it will collect all tx fees
var coinbaseTransaction = new Transaction(
Config.NullAddress, // from (address)
minerAddress, // to (address)
Config.BlockReward, // value (of transfer)
0, // fee (for mining)
dateCreated, // dateCreated
"coinbase tx", // data (payload / comments)
Config.NullPubKey, // senderPubKey
null, // transactionDataHash
Config.GetNullSignatureHex(), // senderSignature
nextBlockIndex, // minedInBlockIndex
true
);
// Execute all pending transactions (after paying their fees)
// Transfer the requested values if the balance is sufficient
var balances = this.CalcAllConfirmedBalances();
foreach (var tran in clonedTransactions)
{
if (!balances.ContainsKey(tran.From))
{
balances[tran.From] = 0;
}
if (!balances.ContainsKey(tran.To))
{
balances[tran.To] = 0;
}
if (balances[tran.From] >= tran.Fee)
{
tran.MinedInBlockIndex = nextBlockIndex;
// The transaction sender pays the processing fee
balances[tran.From] -= tran.Fee;
coinbaseTransaction.Value += tran.Fee;
// Transfer the requested value: sender -> recipient
if (balances[tran.From] >= tran.Value)
{
balances[tran.From] -= tran.Value;
balances[tran.To] += tran.Value;
tran.TransferSuccessful = true;
}
else
{
tran.TransferSuccessful = false;
}
}
else
{
// The transaction cannot be mined due to insufficient
// balance to pay the transaction fee -> drop it
this.RemovePendingTransactions(new List <Transaction>()
{
tran
});
clonedTransactions.Remove(tran);
}
}
// Insert the coinbase transaction, holding the block reward + tx fees
coinbaseTransaction.CalculateDataHash();
clonedTransactions.Insert(0, coinbaseTransaction);
// Prepare the next block candidate (block template)
var previousBlock = this.Blocks[this.Blocks.Count - 1];
//TODO: test that with Date null??
var nextBlockCandidate = new Block(
nextBlockIndex,
clonedTransactions.ToList(),
this.CurrentDifficulty,
previousBlock.BlockHash,
previousBlock.Index,
minerAddress
);
this.MiningJobs[CryptoUtils.BytesToHex(nextBlockCandidate.BlockDataHash)] = nextBlockCandidate;
return(nextBlockCandidate);
}
public Transaction AddNewTransaction(Transaction tranData)
{
// Validate the transaction & add it to the pending transactions
if (!ValidationUtils.IsValidAddress(tranData.From))
{
throw new ArgumentException("Invalid sender address:" + tranData.From);
}
if (!ValidationUtils.IsValidAddress(tranData.To))
{
throw new ArgumentException("Invalid recipient address:" + tranData.To);
}
if (!ValidationUtils.IsValidPublicKey(tranData.SenderPubKey))
{
throw new ArgumentException("Invalid public key:" + tranData.SenderPubKey);
}
var senderAddr = CryptoUtils.GetAddressFromPublicKey(tranData.SenderPubKey);
if (senderAddr != tranData.From)
{
throw new ArgumentException("The public key should match the sender address:" + tranData.SenderPubKey);
}
if (!ValidationUtils.IsValidTransferValue(tranData.Value))
{
throw new ArgumentException("Invalid transfer value: " + tranData.Value);
}
if (!ValidationUtils.IsValidFee(tranData.Fee))
{
throw new ArgumentException("Invalid transaction fee: " + tranData.Fee);
}
if (!ValidationUtils.IsValidDate(tranData.DateCreated))
{
throw new ArgumentException("Invalid date: " + tranData.DateCreated);
}
if (!ValidationUtils.IsValidSignatureFormat(CryptoUtils.SignatureByHex(tranData.SenderSignature)))
{
throw new ArgumentException("Invalid or missing signature. Expected signature format: BigInteger[2] " + tranData.SenderSignature);
}
var tran = new Transaction(
tranData.From,
tranData.To,
tranData.Value,
tranData.Fee,
tranData.DateCreated,
tranData.Data,
tranData.SenderPubKey,
null, // the transactionDataHash is auto-calculated
tranData.SenderSignature
);
//tran.IsSignatureValid = tranData.IsSignatureValid;
// Check for duplicated transactions (to avoid "replay attack")
var tranDataHex = CryptoUtils.BytesToHex(tran.TransactionDataHash);
if (this.FindTransactionByDataHash(tranDataHex) != null)
{
throw new ArgumentException("Duplicated transaction: " + tranDataHex);
}
if (!CryptoUtils.VerifySignature(CryptoUtils.SignatureByHex(tran.SenderSignature), tran.TransactionDataHash))
{
throw new ArgumentException("Invalid signature: " + tranData.SenderSignature);
}
var balances = this.GetAccountBalance(tran.From);
if (balances.ConfirmedBalance < tran.Fee)
{
throw new ArgumentException("Unsufficient sender balance at address: " + tran.From);
}
//if (this.PendingTransactions.Any(s => CryptoUtils.BytesToHex(s.TransactionDataHash) == CryptoUtils.BytesToHex(tran.TransactionDataHash)))
// throw new ArgumentException("Trying to add duplicate transaction: " + CryptoUtils.BytesToHex(tran.TransactionDataHash));
this.PendingTransactions.Add(tran);
Console.WriteLine("Added pending transaction: " + JsonConvert.SerializeObject(tran));
return(tran);
}
