*/
using System;
-using System.Linq;
using System.Text;
using System.Collections.Generic;
-using System.Security.Cryptography;
using System.Diagnostics.Contracts;
+using System.IO;
namespace Novacoin
{
- /// <summary>
- /// Represents the block. Block consists of header, transaction array and header signature.
- /// </summary>
- public class CBlock
+ [Serializable]
+ public class BlockException : Exception
+ {
+ public BlockException()
+ {
+ }
+
+ public BlockException(string message)
+ : base(message)
+ {
+ }
+
+ public BlockException(string message, Exception inner)
+ : base(message, inner)
+ {
+ }
+ }
+
+ /// <summary>
+ /// Represents the block. Block consists of header, transaction array and header signature.
+ /// </summary>
+ public class CBlock
{
+ /// <summary>
+ /// Maximum block size is 1Mb.
+ /// </summary>
+ public const uint nMaxBlockSize = 1000000;
+
+ /// <summary>
+ /// Sanity threshold for amount of sigops.
+ /// </summary>
+ public const uint nMaxSigOps = 20000;
+
/// <summary>
/// Block header.
/// </summary>
/// </summary>
public byte[] signature = new byte[0];
+ /// <summary>
+ /// Copy constructor.
+ /// </summary>
+ /// <param name="b">CBlock instance.</param>
public CBlock(CBlock b)
{
header = new CBlockHeader(b.header);
vtx[i] = new CTransaction(b.vtx[i]);
}
+ signature = new byte[b.signature.Length];
b.signature.CopyTo(signature, 0);
}
/// <summary>
/// Parse byte sequence and initialize new block instance
/// </summary>
- /// <param name="blockBytes"></param>
+ /// <param name="blockBytes">Bytes sequence.</param>
public CBlock (byte[] blockBytes)
{
- ByteQueue wBytes = new ByteQueue(blockBytes);
+ try
+ {
+ var stream = new MemoryStream(blockBytes);
+ var reader = new BinaryReader(stream);
+
+ // Fill the block header fields
+ header = new CBlockHeader(ref reader);
- // Fill the block header fields
- header = new CBlockHeader(wBytes.Get(80));
+ // Parse transactions list
+ vtx = CTransaction.ReadTransactionsList(ref reader);
- // Parse transactions list
- vtx = CTransaction.ReadTransactionsList(ref wBytes);
+ // Read block signature
+ signature = reader.ReadBytes((int)VarInt.ReadVarInt(ref reader));
- // Read block signature
- signature = wBytes.Get((int)wBytes.GetVarInt());
+ reader.Close();
+ }
+ catch (Exception e)
+ {
+ throw new BlockException("Deserialization failed", e);
+ }
}
public CBlock()
vtx = new CTransaction[0];
}
+ public bool CheckBlock(bool fCheckPOW = true, bool fCheckMerkleRoot = true, bool fCheckSig = true)
+ {
+ var uniqueTX = new List<Hash256>(); // tx hashes
+ uint nSigOps = 0; // total sigops
+
+ // Basic sanity checkings
+ if (vtx.Length == 0 || Size > nMaxBlockSize)
+ {
+ return false;
+ }
+
+ bool fProofOfStake = IsProofOfStake;
+
+ // First transaction must be coinbase, the rest must not be
+ if (!vtx[0].IsCoinBase)
+ {
+ return false;
+ }
+
+ if (!vtx[0].CheckTransaction())
+ {
+ return false;
+ }
+
+ uniqueTX.Add(vtx[0].Hash);
+ nSigOps += vtx[0].LegacySigOpCount;
+
+ if (fProofOfStake)
+ {
+ // Proof-of-STake related checkings. Note that we know here that 1st transactions is coinstake. We don't need
+ // check the type of 1st transaction because it's performed earlier by IsProofOfStake()
+
+ // nNonce must be zero for proof-of-stake blocks
+ if (header.nNonce != 0)
+ {
+ return false;
+ }
+
+ // Coinbase output should be empty if proof-of-stake block
+ if (vtx[0].vout.Length != 1 || !vtx[0].vout[0].IsEmpty)
+ {
+ return false;
+ }
+
+ // Check coinstake timestamp
+ if (header.nTime != vtx[1].nTime)
+ {
+ return false;
+ }
+
+ // Check proof-of-stake block signature
+ if (fCheckSig && !SignatureOK)
+ {
+ return false;
+ }
+
+ if (!vtx[1].CheckTransaction())
+ {
+ return false;
+ }
+
+ uniqueTX.Add(vtx[1].Hash);
+ nSigOps += vtx[1].LegacySigOpCount;
+ }
+ else
+ {
+ // Check proof of work matches claimed amount
+ if (fCheckPOW && !CheckProofOfWork(header.Hash, header.nBits))
+ {
+ return false;
+ }
+
+ // Check timestamp
+ if (header.nTime > NetUtils.FutureDrift(NetUtils.GetAdjustedTime()))
+ {
+ return false;
+ }
+
+ // Check coinbase timestamp
+ if (header.nTime < NetUtils.PastDrift(vtx[0].nTime))
+ {
+ return false;
+ }
+ }
+
+ // Iterate all transactions starting from second for proof-of-stake block
+ // or first for proof-of-work block
+ for (int i = fProofOfStake ? 2 : 1; i < vtx.Length; i++)
+ {
+ var tx = vtx[i];
+
+ // Reject coinbase transactions at non-zero index
+ if (tx.IsCoinBase)
+ {
+ return false;
+ }
+
+ // Reject coinstake transactions at index != 1
+ if (tx.IsCoinStake)
+ {
+ return false;
+ }
+
+ // Check transaction timestamp
+ if (header.nTime < tx.nTime)
+ {
+ return false;
+ }
+
+ // Check transaction consistency
+ if (!tx.CheckTransaction())
+ {
+ return false;
+ }
+
+ // Add transaction hash into list of unique transaction IDs
+ uniqueTX.Add(tx.Hash);
+
+ // Calculate sigops count
+ nSigOps += tx.LegacySigOpCount;
+ }
+
+ // Check for duplicate txids.
+ if (uniqueTX.Count != vtx.Length)
+ {
+ return false;
+ }
+
+ // Reject block if validation would consume too much resources.
+ if (nSigOps > nMaxSigOps)
+ {
+ return false;
+ }
+
+ // Check merkle root
+ if (fCheckMerkleRoot && hashMerkleRoot != header.merkleRoot)
+ {
+ return false;
+ }
+
+ return true;
+ }
+
+ private bool CheckProofOfWork(ScryptHash256 hash, uint nBits)
+ {
+ // TODO: stub!
+
+ return true;
+ }
+
/// <summary>
/// Is this a Proof-of-Stake block?
/// </summary>
/// <returns>Byte sequence</returns>
public static implicit operator byte[] (CBlock b)
{
- var r = new List<byte>();
+ var stream = new MemoryStream();
+ var writer = new BinaryWriter(stream);
- r.AddRange((byte[])b.header);
- r.AddRange(VarInt.EncodeVarInt(b.vtx.LongLength)); // transactions count
+ writer.Write(b.header);
+ writer.Write(VarInt.EncodeVarInt(b.vtx.LongLength));
foreach (var tx in b.vtx)
{
- r.AddRange((byte[])tx);
+ writer.Write(tx);
}
- r.AddRange(VarInt.EncodeVarInt(b.signature.LongLength));
- r.AddRange(b.signature);
+ writer.Write(VarInt.EncodeVarInt(b.signature.LongLength));
+ writer.Write(b.signature);
+
+ var resultBytes = stream.ToArray();
+
+ writer.Close();
- return r.ToArray();
+ return resultBytes;
}
/// <summary>
git://git.novaco.in / NovacoinLibrary.git / blobdiff