private string CalculateMinedBlockHash(Block blockCandidate, MinedBlockPostModel minedBlock)
{
string blockData = blockCandidate.Index.ToString() +
blockCandidate.Transactions.Count.ToString() +
blockCandidate.BlockDataHash;
var nonceStr = minedBlock.Nonce.ToString();
var data = blockData + minedBlock.DateCreated + nonceStr;
var blockHash = this.cryptographyHelpers.CalcSHA256(data);
string requiredLeadingZeroes = new String('0', blockCandidate.Difficulty);
if (blockHash.StartsWith(requiredLeadingZeroes))
{
return(blockHash);
}
throw new Exception(
$"Can not calculate valid block {blockCandidate.Index} hash: hash {blockHash}, nonce {nonceStr}, difficulty {blockCandidate.Difficulty.ToString()}"
);
}
public IActionResult SubmitBlock([FromBody] MinedBlockPostModel minedBlock)
{
if (!ModelState.IsValid)
{
return(BadRequest());
}
if (!this.dataService.MiningJobs.ContainsKey(minedBlock.BlockDataHash))
{
return(NotFound());
}
this.nodeService.VerifyMinedJob(minedBlock);
var response = new
{
Status = "accepted",
Message = string.Format("Block accepted, reward paid.")
};
return(Ok(response));
}
public void VerifyMinedJob(MinedBlockPostModel minedBlock)
{
var blockCandidate = this.dataService.MiningJobs[minedBlock.BlockDataHash];
try
{
var blockHash = this.CalculateMinedBlockHash(blockCandidate, minedBlock);
// if next block - add to blockchain and notify peers
if (blockCandidate.Index == (ulong)this.dataService.Blocks.Count + 1)
{
blockCandidate.Nonce = minedBlock.Nonce;
blockCandidate.BlockHash = blockHash;
blockCandidate.DateCreated = DateTime.Parse(minedBlock.DateCreated);
this.AddBlockToBlockchain(blockCandidate);
//remove pending transactions that are already included in the blockchain
blockCandidate.Transactions.ForEach(transaction =>
{
this.dataService.PendingTransactions.Remove(
this.dataService
.PendingTransactions
.Single(t => t.TransactionHash == transaction.TransactionHash)
);
});
this.logger.LogInformation($"Block {blockCandidate.Index} with hash {blockHash} added to blockchain");
}
else
{
this.logger.LogInformation($"Block candidate {blockCandidate.Index} with hash {blockHash} already exists in blockckain");
}
}
catch (Exception e)
{
this.logger.LogInformation(e.Message);
}
}
public static async Task MineAsync(IHttpHelpers httpHelpers, IDateTimeHelpers dateTimeHelpers, Logger log)
{
HttpStatusCode statusCode = HttpStatusCode.RequestTimeout;
Stopwatch sw = new Stopwatch();
TimeSpan maxTaskLength = new TimeSpan(0, 0, 2); // 2 seconds
while (true)
{
sw.Start();
MiningJob miningJob = null;
do
{
try
{
string path = "mining/get-mining-job/{minerAddress}";
var parameter = new Parameter()
{
Name = "minerAddress",
Value = minerAddress,
Type = ParameterType.UrlSegment
};
log.Information($"Trying to get mining job from node: {nodeUrl}");
Response <MiningJob> response = await httpHelpers.DoApiGet <MiningJob>(nodeUrl, path, parameter);
miningJob = response.Data;
statusCode = response.StatusCode;
}
catch (WebException e)
{
Console.WriteLine("WebException raised!");
Console.WriteLine("{0}\n", e.Message);
}
catch (Exception e)
{
Console.WriteLine("Exception raised!");
Console.WriteLine("Source : {0}", e.Source);
Console.WriteLine("Message : {0}\n", e.Message);
}
} while (statusCode != HttpStatusCode.OK);
log.Information($"Successfully received mining job (Block Data Hash: {miningJob.BlockDataHash}) from node!");
Console.WriteLine("Start New Mining Job:");
Console.WriteLine("Block Index: {0}", miningJob.BlockIndex);
Console.WriteLine("Transactions Included: {0}", miningJob.TransactionsIncluded);
Console.WriteLine("Expected Reward: {0}", miningJob.ExpectedReward);
Console.WriteLine("Reward Address: {0}", miningJob.RewardAddress);
Console.WriteLine("Block Data Hash: {0}", miningJob.BlockDataHash);
Console.WriteLine("Difficulty: {0}", miningJob.Difficulty);
bool blockFound = false;
ulong nonce = 0;
string timestamp = dateTimeHelpers.ConvertDateTimeToUniversalTimeISO8601String(DateTime.Now);
string requiredLeadingZeroes = new String('0', miningJob.Difficulty);
string blockData = miningJob.BlockIndex.ToString() +
miningJob.TransactionsIncluded.ToString() +
miningJob.BlockDataHash;
string data;
string blockHash;
while (!blockFound && nonce < uint.MaxValue)
{
data = blockData + timestamp + nonce.ToString();
blockHash = ByteArrayToHexString(Sha256(Encoding.UTF8.GetBytes(data)));
if (blockHash.StartsWith(requiredLeadingZeroes))
{
Console.WriteLine("Block Mined!");
Console.WriteLine($"Block Hash: {blockHash}\n");
var minedBlock = new MinedBlockPostModel()
{
DateCreated = timestamp,
Nonce = nonce,
BlockDataHash = miningJob.BlockDataHash
};
int retries = 0;
do
{
try
{
statusCode = HttpStatusCode.RequestTimeout;
string path = "mining/submit-mined-block";
HttpResponseMessage response = await httpHelpers.DoApiPost(nodeUrl, path, minedBlock);
statusCode = response.StatusCode;
string statusDescription = response.ReasonPhrase;
log.Information($"Sent request to: {nodeUrl} with mined block (hash: {blockHash})!");
Console.WriteLine(statusDescription);
log.Information($"Received response from {nodeUrl} - status code: {statusCode}, description: {statusDescription}");
}
catch (WebException e)
{
Console.WriteLine("WebException raised!");
Console.WriteLine("{0}\n", e.Message);
}
catch (Exception e)
{
Console.WriteLine("Exception raised!");
Console.WriteLine("Source : {0}", e.Source);
Console.WriteLine("Message : {0}\n", e.Message);
}
System.Threading.Thread.Sleep(1000);
} while (statusCode != HttpStatusCode.OK && retries++ < 3);
blockFound = true;
break;
}
// print intermediate data
if (nonce % 1000000 == 0)
{
Console.WriteLine(timestamp);
Console.WriteLine($"Nonce: {nonce}");
Console.WriteLine($"Block Hash: {blockHash}\n");
}
// get new timestamp on every 100000 iterations
if (nonce % 100000 == 0)
{
timestamp = dateTimeHelpers.ConvertDateTimeToUniversalTimeISO8601String(DateTime.Now);
}
nonce++;
if (maxTaskLength < sw.Elapsed)
{
sw.Reset();
break;
}
}
}
}
