//public CTemporaryBlock(CBlock Block, CPeer Sender) : base(Block.Header.BlockNumber, Block.Header.Hash, Block.Header.PreviousBlockHash, Block.Transiction, Block.Nonce, Block.Timestamp, Block.Difficulty)
public CTemporaryBlock(CBlock Block, CPeer Sender) : base(Block.Header.BlockNumber, Block.Header.Hash, Block.Header.PreviousBlockHash, Block.TxLimit, Block.Nonce, Block.Timestamp, Block.Difficulty, Block.Transactions)
{
this.Nonce = Block.Nonce;
this.Timestamp = Block.Timestamp;
mSender = Sender;
{ }
}
/// <summary>
/// Aggiunge il proof of work(l'hash) al blocco.
/// </summary>
/// <param name="Block">Blocco su cui calcolare il proof of work.</param>
public static void AddProof(CBlock Block) //TODO: implementare evento per l'uscita in caso sia stato trovato un blocco parallelo. Implementare multithreading
{
string hash = "";
bool found = false;
while (!found)
{
Block.Timestamp = DateTime.Now;
Block.Nonce++; //incremento della nonce per cambiare hash
hash = HashBlock(Block); //calcola l'hash secondo il template di scrypt usato da litecoin
found = true;
for (int i = 0; i < Block.Difficulty && found; i++)
{
if (hash[i] != '0')
{
found = false;
}
}
}
if (Program.DEBUG)
{
CIO.DebugOut("Found hash for block " + Block.Header.BlockNumber + ": " + hash);
}
Block.Header.Hash = hash;
}
/// <summary>
/// Aggiunge i blocchi presenti nel vettore e ritorna l'indice dell'ultimo blocco aggiunto.
/// </summary>
/// <param name="Blocks"></param>
/// <returns></returns>
public ulong Add(CTemporaryBlock[] Blocks)
{
ulong counter = 0;
string filepath = PATH + "\\" + FILENAME;
//(!) e se scarico tutta la blockchain e da un certo punto in poi sbagliata?
foreach (CTemporaryBlock b in Blocks)
{
if (b == null)
{
break;
}
if (CValidator.ValidateBlock(b, true))
{
if (b.Header.BlockNumber == LastValidBlock.Header.BlockNumber)
{
break;
}
mLastValidBlock = b as CBlock;
counter++;
lock (Instance)
{
MemPool.Instance.RemoveBlock(b);
UTXOManager.Instance.ApplyBlock(b);
File.AppendAllText(filepath, (b as CBlock).Serialize() + '\n');
}
}
else
{
break;
}
}
return(counter);
}
/// <summary>
/// Carica l'ultimo blocco della blockchain.
/// </summary>
private void Load()
{
string filepath = PATH + "\\" + FILENAME;
string block = "";
mLastValidBlock = new CGenesisBlock();
if (File.Exists(filepath))
{
StreamReader streamReader = new StreamReader(filepath);
while ((block = streamReader.ReadLine()) != null)
{
CBlock b = JsonConvert.DeserializeObject <CBlock>(block);
if (b.Header.BlockNumber > mLastValidBlock.Header.BlockNumber)
{
mLastValidBlock = b;
}
}
streamReader.Close();
}
else
{
File.WriteAllText(filepath, new CGenesisBlock().Serialize() + '\n');
mLastValidBlock = new CGenesisBlock();
}
}
public CBlock RetriveBlock(ulong index, bool searchInSidechain = false)
{
string filepath = PATH + "\\" + FILENAME;
string blockJson = "";
lock (Instance)
{
StreamReader streamReader = new StreamReader(filepath);
while ((blockJson = streamReader.ReadLine()) != null)
{
CBlock block = JsonConvert.DeserializeObject <CBlock>(blockJson);
if (block.Header.BlockNumber == index)
{
streamReader.Close();
return(block);
}
}
streamReader.Close();
}
if (searchInSidechain)
{
lock (mSideChain)
if (LastBlock.Header.BlockNumber >= index)
{
return(mSideChain.RetriveBlock(index));
}
}
return(null);
}
private CHeaderChain[] FindParallelChains(CBlock startBlock)
{
CHeader tmp1, tmp2;
Stack <CHeaderChain> res = new Stack <CHeaderChain>();
int ID = 0;
for (int i = 0; i < Peers.Length; i++)
{
if (Peers[i] != null)
{
ID = Peers[i].SendRequest(new CMessage(EMessageType.Request, ERequestType.GetLastHeader));
tmp1 = Peers[i].ReceiveHeader(ID, 5000);
res.Push(new CHeaderChain());
res.Peek().AddPeer(Peers[i]);
res.Peek().FinalIndex = tmp1.BlockNumber;
Peers[i] = null;
for (int j = i + 1; j < Peers.Length; j++)
{
ID = Peers[j].SendRequest(new CMessage(EMessageType.Request, ERequestType.GetLastHeader));
tmp2 = Peers[j].ReceiveHeader(ID, 5000);
if (tmp1.Hash == tmp2.Hash)
{
res.Peek().AddPeer(Peers[j]);
Peers[j] = null;
}
}
}
}
return(res.ToArray());
}
private static CBlock GenerateNextBlock(int txLimit)
{
short newBlockDifficulty = Miner.CalculateDifficulty();
CBlock res = new CBlock(CBlockChain.Instance.LastBlock.Header.BlockNumber + 1, CBlockChain.Instance.LastBlock.Header.Hash, (ushort)newBlockDifficulty, 10);
Console.WriteLine("Address: {0}", Utilities.Base64SHA2Hash(RSA.ExportPubKey(CServer.rsaKeyPair)));
return(res);
}
/// <summary>
/// Esegue una richiesta ai peer collegati.
/// </summary>
/// <param name="rqs">Richiesta da effettuare.</param>
/// <param name="arg">Parametro usato per passare un valore e/o ritornare un risultato quando necessario.</param>
/// <returns></returns>
public object DoRequest(ERequest rqs, object arg = null) //(!) rivedere i metodi di input/output del metodo
{
switch (rqs)
{
case ERequest.UpdatePeers:
{
UpdatePeers();
break;
}
case ERequest.LastValidBlock:
{
return(RequestLastValidBlock());
}
case ERequest.DownloadMissingBlock:
{
object[] args = arg as object[];
ulong startingIndex = Convert.ToUInt64(args[0]);
ulong finalIndex = Convert.ToUInt64(args[1]);
return(DistribuiteDownloadBlocks(startingIndex, finalIndex));
}
case ERequest.BroadcastMinedBlock:
{
CBlock b = arg as CBlock;
foreach (CPeer p in Peers)
{
p.SendRequest(new CMessage(EMessageType.Request, ERequestType.NewBlockMined, EDataType.Block, b.Serialize()));
}
break;
}
case ERequest.LastCommonValidBlock:
{
return(FindLastCommonBlocks());
}
case ERequest.FindParallelChain:
{
return(FindParallelChains(arg as CBlock));
}
case ERequest.BroadcastNewTransaction:
{
foreach (CPeer p in Peers)
{
p.SendRequest(new CMessage(EMessageType.Request, ERequestType.NewTransaction, EDataType.Transaction, JsonConvert.SerializeObject(arg as Transaction))); //TODO : implementa richiesta di invio transazione
}
break;
}
default:
throw new ArgumentException("Invalid request: " + rqs);
}
return(null);
}
public static string HashBlock(CBlock block)
{
string toHash = block.Header.PreviousBlockHash + block.Nonce + block.Timestamp + block.MerkleRoot; //si concatenano vari parametri del blocco TODO: usare i parmetri giusti, quelli usati qua sono solo per dimostrazione e placeholder
return(Utilities.ByteArrayToHexString(
SCrypt.ComputeDerivedKey(
Encoding.ASCII.GetBytes(toHash), Encoding.ASCII.GetBytes(toHash), 1024, 1, 1, 1, 32)
)); //calcola l'hash secondo il template di scrypt usato da litecoin
}
/// <summary>
/// Inserisce le transazioni di un dato blocco nella mempool
/// </summary>
/// <param name="block">Il blocco da inserire</param>
public void DumpBlock(CBlock block)
{
foreach (Transaction tx in block.Transactions)
{
if (!(tx.inputs.Count == 0))
{
this.AddUTX(tx);
}
}
}
/// <summary>
/// Rimuove dalla mempool tutte le transazioni contenute in un blocco dato
/// </summary>
/// <param name="block"></param>
public void RemoveBlock(CBlock block)
{
foreach (Transaction tx in block.Transactions)
{
if (this.CheckDouble(tx))
{
this.RemoveUTX(tx.Hash);
}
}
}
/// <summary>
/// Calcola l'hash di un blocco e lo confronta al proof of work fornito per verificarne la validità
/// </summary>
/// <param name="block">Il blocco da confermare</param>
/// <returns></returns>
public static bool Verify(CBlock block)
{
if (block.Header.PreviousBlockHash == CBlockChain.Instance.RetriveBlock(block.Header.BlockNumber - 1).Header.Hash)
{
string toHash = block.Header.PreviousBlockHash + block.Nonce + block.Timestamp + block.MerkleRoot;
if (block.Header.Hash == Utilities.ByteArrayToHexString(SCrypt.ComputeDerivedKey(Encoding.ASCII.GetBytes(toHash), Encoding.ASCII.GetBytes(toHash), 1024, 1, 1, 1, 32)))
{
return(true);
}
}
return(false);
}
public CBlock[] RetriveBlocks(ulong initialIndex, ulong finalIndex)
{
CBlock[] ris = new CBlock[finalIndex - initialIndex];
int c = 0;
while (initialIndex < finalIndex)
{
ris[c++] = RetriveBlock(initialIndex);
initialIndex++;
}
return(ris);
}
public ulong AverageBlockTime(CBlock start, CBlock final)
{
TimeSpan timespan = final.Timestamp.Subtract(start.Timestamp);
ulong seconds = (ulong)timespan.TotalSeconds;
ulong nblock = final.Header.BlockNumber - start.Header.BlockNumber;
try
{
return(seconds / nblock);
}
catch
{
return(60);
}
}
///<summary>
///Dato un blocco, rimuove tutti gli UTXO dal disco in base agli input contenuti, poi crea nuovi UTXO in base agli output
///</summary>
public void ApplyBlock(CBlock block)
{
foreach (Transaction tx in block.Transactions)
{
if (tx.inputs != null)
{
foreach (Input input in tx.inputs)
{
if (input.OutputIndex != -1)
{
this.RemoveUTXO(Utilities.Base64SHA2Hash(tx.PubKey), input.TxHash, input.OutputIndex);
}
}
}
this.AddUTXO(new UTXO(tx.Hash, tx.outputs));
}
}
public static bool ValidateBlock(CBlock block, bool CheckPreviusHash = false)
{
int coinbaseTx = 0;
//TODO IMPORTANTE: aggiungere verifica timestamp
if (block.Header.Hash != Miner.HashBlock(block))
{
return(false);
}
if (CheckPreviusHash)
{
if (CBlockChain.Instance.RetriveBlock(block.Header.BlockNumber - 1)?.Header.Hash != block.Header.PreviousBlockHash)
{
return(false);
}
}
/*
* if (block.Difficulty < Miner.CalculateDifficulty() - 1 || block.Difficulty > Miner.CalculateDifficulty() + 1)
* {
* return false;
*
* }
*/
if (block.MerkleRoot != block.GenerateMerkleRoot())
{
return(false);
}
foreach (Transaction tx in block.Transactions)
{
if (!tx.Verify())
{
if (coinbaseTx == 0 && tx.inputs.Count == 1 && tx.inputs.First().TxHash == "0" && tx.inputs.First().OutputIndex == -1)
{
coinbaseTx++;
}
else
{
return(false);
}
}
}
return(true);
}
private static bool ValidateRequest(CMessage Msg)
{
switch (Msg.RqsType)
{
case ERequestType.UpdPeers:
{
if (Msg.DataType == EDataType.NULL && Msg.Data == null)
{
return(true);
}
else
{
return(false);
}
}
case ERequestType.NewBlockMined:
{
if (Msg.DataType == EDataType.Block && Msg.Data != null)
{
try
{
CBlock.Deserialize(Msg.Data);
return(true);
}
catch
{
return(false);
}
}
else
{
return(false);
}
}
case ERequestType.ChainLength:
{
if (Msg.DataType == EDataType.NULL && Msg.Data == null)
{
return(true);
}
else
{
return(false);
}
}
case ERequestType.GetHeader:
{
if (Msg.DataType == EDataType.ULong)
{
try { Convert.ToInt64(Msg.Data); }
catch { return(false); }
return(true);
}
else
{
return(false);
}
}
case ERequestType.GetLastHeader:
{
{
if (Msg.DataType == EDataType.NULL && Msg.Data == null)
{
return(true);
}
else
{
return(false);
}
}
}
case ERequestType.GetLastValid:
{
{
if (Msg.DataType == EDataType.NULL && Msg.Data == null)
{
return(true);
}
else
{
return(false);
}
}
}
case ERequestType.DownloadBlock:
{
if (Msg.DataType == EDataType.ULong && Msg.Data != null)
{
try
{
Convert.ToUInt64(Msg.Data);
return(true);
}
catch { return(false); }
}
return(false);
}
case ERequestType.DownloadBlocks:
{
if (Msg.DataType == EDataType.ULongList && Msg.Data != null)
{
try
{
string[] stringToConvert = Msg.Data.Split(';');
if (stringToConvert.Length != 2)
{
return(false);
}
foreach (string s in stringToConvert)
{
Convert.ToUInt64(s);
}
return(true);
}
catch { return(false); }
}
return(false);
}
case ERequestType.DownloadHeaders:
{
if (Msg.DataType == EDataType.ULongList && Msg.Data != null)
{
try
{
string[] stringToConvert = Msg.Data.Split(';');
if (stringToConvert.Length != 2)
{
return(false);
}
foreach (string s in stringToConvert)
{
Convert.ToUInt64(s);
}
return(true);
}
catch { return(false); }
}
return(false);
}
case ERequestType.NewTransaction:
{
if (Msg.DataType == EDataType.Transaction && Msg.Data != null)
{
try
{
Transaction t = JsonConvert.DeserializeObject <Transaction>(Msg.Data);
if (MemPool.Instance.CheckDouble(t))
{
return(false);
}
if (MemPool.Instance.CheckDoubleSpending(t))
{
return(false);
}
if (CBlockChain.Instance.SideChain.CheckDouble(t))
{
return(false);
}
MemPool.Instance.AddUTX(t);
return(true);
}
catch { return(false); }
}
return(false);
}
default:
return(false);
}
}
private void ExecuteRequest()
{
CMessage rqs;
while (mIsConnected)
{
Thread.Sleep(100);
if (RequestQueue.Count > 0)
{
rqs = RequestQueue.Dequeue();
switch (rqs.RqsType)
{
case ERequestType.UpdPeers:
{
if (Program.DEBUG)
{
CIO.DebugOut("UpdPeers received by " + mIp);
}
//(!) è meglio farsi ritornare la lista e poi usare json?
SendRequest(new CMessage(EMessageType.Data, ERequestType.NULL, EDataType.PeersList,
CPeers.Instance.PeersList(), rqs.ID));
break;
}
case ERequestType.NewBlockMined:
{
if (CPeers.Instance.CanReceiveBlock)
{
if (Program.DEBUG)
{
CIO.DebugOut("NewBlockMined received by " + mIp);
}
CTemporaryBlock newBlock = new CTemporaryBlock(CBlock.Deserialize(rqs.Data), this);
if (!CValidator.ValidateBlock(newBlock) && newBlock.Header.BlockNumber < CBlockChain.Instance.LastValidBlock.Header.BlockNumber)
{
Disconnect();
break;
}
//TODO scaricare i blocchi mancanti se ne mancano(sono al blocco 10 e mi arriva il blocco 50)
if (!CBlockChain.Instance.AddNewMinedBlock(newBlock))
{
Stack <CTemporaryBlock> blocks = new Stack <CTemporaryBlock>();
int ID = 0;
blocks.Push(newBlock);
for (ulong i = newBlock.Header.BlockNumber - 1; i > CBlockChain.Instance.LastValidBlock.Header.BlockNumber; i--)
{
ID = SendRequest(new CMessage(EMessageType.Request, ERequestType.DownloadBlock, EDataType.ULong, Convert.ToString(i)));
blocks.Push(new CTemporaryBlock(JsonConvert.DeserializeObject <CBlock>(ReceiveData(ID, 5000).Data), this));
if (!CValidator.ValidateBlock(blocks.Peek()) && blocks.Peek().Header.BlockNumber < CBlockChain.Instance.LastValidBlock.Header.BlockNumber)
{
Disconnect();
break;
}
if (CBlockChain.Instance.AddNewMinedBlock(blocks.Peek()))
{
blocks.Pop();
for (int j = blocks.Count; j > 0; j--)
{
CBlockChain.Instance.AddNewMinedBlock(blocks.Pop());
}
}
}
}
}
break;
}
case ERequestType.GetLastHeader:
{
if (Program.DEBUG)
{
CIO.DebugOut("GetLastHeader received by " + mIp);
}
SendRequest(new CMessage(EMessageType.Data, ERequestType.NULL, EDataType.Header,
JsonConvert.SerializeObject(CBlockChain.Instance.LastValidBlock.Header), rqs.ID));
break;
}
case ERequestType.ChainLength:
{
if (Program.DEBUG)
{
CIO.DebugOut("ChainLength received by " + mIp);
}
SendRequest(new CMessage(EMessageType.Data, ERequestType.NULL, EDataType.ULong,
Convert.ToString(CBlockChain.Instance.LastValidBlock.Header.BlockNumber), rqs.ID));
break;
}
case ERequestType.GetLastValid:
{
if (Program.DEBUG)
{
CIO.DebugOut("GetLastValid received by " + mIp);
}
SendRequest(new CMessage(EMessageType.Data, ERequestType.NULL, EDataType.Block,
CBlockChain.Instance.LastValidBlock.Serialize(), rqs.ID));
break;
}
case ERequestType.DownloadBlock:
{
if (Program.DEBUG)
{
CIO.DebugOut("DownloadBlock received by " + mIp);
}
SendRequest(new CMessage(EMessageType.Data, ERequestType.NULL, EDataType.Block,
JsonConvert.SerializeObject(CBlockChain.Instance.RetriveBlock(Convert.ToUInt64(rqs.Data), true)), rqs.ID));
break;
}
case ERequestType.DownloadBlocks:
{
if (Program.DEBUG)
{
CIO.DebugOut("DownloadBlocks received by " + mIp);
}
SendRequest(new CMessage(EMessageType.Data, ERequestType.NULL, EDataType.BlockList,
JsonConvert.SerializeObject(CBlockChain.Instance.RetriveBlocks(Convert.ToUInt64(rqs.Data.Split(';')[0]), Convert.ToUInt64(rqs.Data.Split(';')[1]))), rqs.ID));
break;
}
case ERequestType.DownloadHeaders:
{
if (Program.DEBUG)
{
CIO.DebugOut("DownloadBlocks received by " + mIp);
}
SendRequest(new CMessage(EMessageType.Data, ERequestType.NULL, EDataType.HeaderList,
JsonConvert.SerializeObject(CBlockChain.Instance.RetriveHeaders(Convert.ToUInt64(rqs.Data.Split(';')[0]), Convert.ToUInt64(rqs.Data.Split(';')[1]))), rqs.ID));
break;
}
case ERequestType.GetHeader:
{
if (Program.DEBUG)
{
CIO.DebugOut("GetLastHeader received by " + mIp);
}
SendRequest(new CMessage(EMessageType.Data, ERequestType.NULL, EDataType.Header,
JsonConvert.SerializeObject(CBlockChain.Instance.RetriveBlock(Convert.ToUInt64(rqs.Data)).Header), rqs.ID));
break;
}
case ERequestType.NewTransaction:
{
Transaction t = JsonConvert.DeserializeObject <Transaction>(rqs.Data);
if (t.Verify())
{
MemPool.Instance.AddUTX(t);
}
break;
}
default:
if (Program.DEBUG)
{
CIO.DebugOut("Ricevuto comando sconosciuto: " + rqs.RqsType + " da " + IP);
}
break;
}
}
}
}
private static bool ValidateData(CMessage Msg)
{
if (Msg.RqsType != ERequestType.NULL)
{
return(false);
}
switch (Msg.DataType)
{
case EDataType.PeersList:
try
{
string[] peers = Msg.Data.Split(';');
foreach (string rp in peers)
{
CPeer.Deserialize(rp);
}
return(true);
}
catch
{
return(false);
}
case EDataType.Block:
try
{
CBlock.Deserialize(Msg.Data);
return(true);
}
catch
{
return(false);
}
case EDataType.ULong:
try
{
Convert.ToUInt64(Msg.Data);
return(true);
}
catch
{
return(false);
}
case EDataType.ULongList:
try
{
JsonConvert.DeserializeObject <ulong[]>(Msg.Data);
return(true);
}
catch
{
return(false);
}
case EDataType.Header:
try
{
JsonConvert.DeserializeObject <CHeader>(Msg.Data);
return(true);
}
catch
{
return(false);
}
case EDataType.BlockList:
try
{
JsonConvert.DeserializeObject <CBlock[]>(Msg.Data);
return(true);
}
catch
{
return(false);
}
case EDataType.HeaderList:
try
{
JsonConvert.DeserializeObject <CHeader[]>(Msg.Data);
return(true);
}
catch
{
return(false);
}
default:
return(false);
}
}
public static short CalculateDifficulty()
{
int numberOfBlocks = 300;
CBlock lastBlock = CBlockChain.Instance.LastBlock;
CBlock previousBlock;
short newBlockDifficulty = 0;
ulong highAverangeTimeLimit = 70, lowAverangeTimeLimit = 30;
ulong averangeBlockTime = 0;
if (lastBlock.Header.BlockNumber > (ulong)numberOfBlocks)
{
previousBlock = CBlockChain.Instance.RetriveBlock(lastBlock.Header.BlockNumber - (ulong)numberOfBlocks, true);
}
else
{
previousBlock = CBlockChain.Instance.RetriveBlock(1, true);
}
if (previousBlock != null)
{
averangeBlockTime = CBlockChain.Instance.AverageBlockTime(previousBlock, lastBlock); //in secondi
}
else
{
averangeBlockTime = 60;
}
if (averangeBlockTime > highAverangeTimeLimit)
{
newBlockDifficulty = (short)(lastBlock.Difficulty - 1);
if (newBlockDifficulty <= 0)
{
newBlockDifficulty = 1;
}
if (Program.DEBUG)
{
CIO.DebugOut("La nuova difficoltà è: " + newBlockDifficulty);
//Thread.Sleep(1000);
}
}
else if (averangeBlockTime < lowAverangeTimeLimit)
{
newBlockDifficulty = (short)(lastBlock.Difficulty + 1);
if (newBlockDifficulty >= 4)
{
newBlockDifficulty = 4;
}
if (Program.DEBUG)
{
CIO.DebugOut("La nuova difficoltà è: " + newBlockDifficulty);
//Thread.Sleep(1000);
}
}
else
{
newBlockDifficulty = (short)lastBlock.Difficulty;
if (Program.DEBUG)
{
CIO.DebugOut("La nuova difficoltà è: " + newBlockDifficulty);
//Thread.Sleep(1000);
}
}
return(3);
}
private CBlock FindLastCommonBlocks()
{
ulong minLength = ulong.MaxValue, tmp = 0;
int rqsID = 0;
bool found = false;
Stack <CHeader> headers = new Stack <CHeader>();
CBlock res = null;
foreach (CPeer p in Peers)
{
try
{
rqsID = p.SendRequest(new CMessage(EMessageType.Request, ERequestType.ChainLength));
tmp = p.ReceiveULong(rqsID, 5000);
if (tmp < minLength)
{
minLength = tmp;
}
}
catch (SocketException)
{ }
p.Socket.ReceiveTimeout = 0;
}
CRange r = new CRange(CBlockChain.Instance.LastValidBlock.Header.BlockNumber, minLength);
if (r.End != ulong.MaxValue && r.Start < r.End)
{
//trova l'ultimo blocco uguale tra i peer e salva l'indice di quel blocco in r.start
int ID = 0;
while (r.Start < r.End)
{
found = true;
tmp = (r.Start + r.End) / 2;
if (r.End - r.Start == 1)
{
tmp++;
}
foreach (CPeer p in Peers)
{
ID = p.SendRequest(new CMessage(EMessageType.Request, ERequestType.GetHeader, EDataType.ULong, Convert.ToString(tmp)));
headers.Push(p.ReceiveHeader(ID, 5000));
}
while (headers.Count > 1 && found)
{
if (!(headers?.Pop().Hash == headers?.Peek().Hash))
{
found = false;
}
}
if (headers.Count == 1)
{
headers.Pop();
}
//se tutti i blocchi sono uguali allora found=true, mentre se ce n'è qualcuno di diverso found=false
if (found)
{
r.Start = tmp;
}
else if (!(r.End - r.Start == 1))
{
r.End = tmp;
}
else
{
r.End--;
}
}
//controlla se l'ultimo blocco è valido?
foreach (CPeer p in Peers)
{
ID = p.SendRequest(new CMessage(EMessageType.Request, ERequestType.DownloadBlock, EDataType.ULong, Convert.ToString(r.Start)));
res = p.ReceiveBlock(ID, 5000);
if (res != null && CValidator.ValidateBlock(res))
{
break;
}
else
{
p.Disconnect();
}
p.Socket.ReceiveTimeout = 0;
}
return(res);
}
else
{
return(CBlockChain.Instance.LastValidBlock);
}
}