*/
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 = new CTransaction[b.vtx.Length];
for (int i = 0; i < b.vtx.Length; i++)
{
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>
- public CBlock (IList<byte> blockBytes)
+ /// <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<uint256>(); // 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 > NetInfo.FutureDrift(NetInfo.GetAdjustedTime()))
+ {
+ return false;
+ }
+
+ // Check coinbase timestamp
+ if (header.nTime < NetInfo.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(uint256 hash, uint nBits)
+ {
+ uint256 nTarget = new uint256();
+ nTarget.Compact = nBits;
+
+ // Check range
+ if (nTarget > NetInfo.nProofOfWorkLimit)
+ {
+ // nBits below minimum work
+ return false;
+ }
+
+ // Check proof of work matches claimed amount
+ if (hash > nTarget)
+ {
+ // hash doesn't match nBits
+ return false;
+ }
+
+ return true;
+ }
+
/// <summary>
/// Is this a Proof-of-Stake block?
/// </summary>
}
/// <summary>
- /// Get current instance as sequence of bytes
+ /// Get instance as sequence of bytes
/// </summary>
/// <returns>Byte sequence</returns>
- public IList<byte> Bytes
+ public static implicit operator byte[] (CBlock b)
{
- get
+ var stream = new MemoryStream();
+ var writer = new BinaryWriter(stream);
+
+ writer.Write(b.header);
+ writer.Write(VarInt.EncodeVarInt(b.vtx.LongLength));
+
+ foreach (var tx in b.vtx)
{
- var r = new List<byte>();
+ writer.Write(tx);
+ }
+
+ writer.Write(VarInt.EncodeVarInt(b.signature.LongLength));
+ writer.Write(b.signature);
+
+ var resultBytes = stream.ToArray();
+
+ writer.Close();
- r.AddRange(header.Bytes);
- r.AddRange(VarInt.EncodeVarInt(vtx.LongLength)); // transactions count
+ return resultBytes;
+ }
+
+ /// <summary>
+ /// Serialized size
+ /// </summary>
+ public uint Size
+ {
+ get
+ {
+ uint nSize = 80 + VarInt.GetEncodedSize(vtx.Length); // CBlockHeader + NumTx
foreach (var tx in vtx)
{
- r.AddRange(tx.Bytes);
+ nSize += tx.Size;
}
- r.AddRange(VarInt.EncodeVarInt(signature.LongLength));
- r.AddRange(signature);
+ nSize += VarInt.GetEncodedSize(signature.Length) + (uint)signature.Length;
- return r;
+ return nSize;
}
}
/// <summary>
+ /// Get transaction offset inside block.
+ /// </summary>
+ /// <param name="nTx">Transaction index.</param>
+ /// <returns>Offset in bytes from the beginning of block header.</returns>
+ public uint GetTxOffset(int nTx)
+ {
+ Contract.Requires<ArgumentException>(nTx >= 0 && nTx < vtx.Length, "Transaction index you've specified is incorrect.");
+
+ uint nOffset = 80 + VarInt.GetEncodedSize(vtx.Length); // CBlockHeader + NumTx
+
+ for (int i = 0; i < nTx; i++)
+ {
+ nOffset += vtx[i].Size;
+ }
+
+ return nOffset;
+ }
+
+ /// <summary>
/// Merkle root
/// </summary>
- public Hash256 hashMerkleRoot
+ public uint256 hashMerkleRoot
{
get {
foreach (var tx in vtx)
{
- merkleTree.AddRange(Hash256.ComputeRaw256(tx.Bytes));
+ merkleTree.AddRange(CryptoUtils.ComputeHash256(tx));
}
int levelOffset = 0;
var left = merkleTree.GetRange((levelOffset + nLeft) * 32, 32).ToArray();
var right = merkleTree.GetRange((levelOffset + nRight) * 32, 32).ToArray();
- merkleTree.AddRange(Hash256.ComputeRaw256(ref left, ref right));
+ merkleTree.AddRange(CryptoUtils.ComputeHash256(ref left, ref right));
}
levelOffset += nLevelSize;
}
- return (merkleTree.Count == 0) ? new Hash256() : new Hash256(merkleTree.GetRange(merkleTree.Count-32, 32).ToArray());
+ return (merkleTree.Count == 0) ? 0 : (uint256)merkleTree.GetRange(merkleTree.Count-32, 32).ToArray();
}
}
return sb.ToString();
}
- }
+
+ /// <summary>
+ /// Calculate proof-of-work reward.
+ /// </summary>
+ /// <param name="nBits">Packed difficulty representation.</param>
+ /// <param name="nFees">Amount of fees.</param>
+ /// <returns>Reward value.</returns>
+ public static ulong GetProofOfWorkReward(uint nBits, ulong nFees)
+ {
+ // NovaCoin: subsidy is cut in half every 64x multiply of PoW difficulty
+ // A reasonably continuous curve is used to avoid shock to market
+ // (nSubsidyLimit / nSubsidy) ** 6 == bnProofOfWorkLimit / bnTarget
+ //
+ // Human readable form:
+ //
+ // nSubsidy = 100 / (diff ^ 1/6)
+ //
+ // Please note that we're using bisection to find an approximate solutuion
+
+
+ uint256 nTarget = 0;
+ nTarget.Compact = nBits;
+
+ BigNum bnTarget = nTarget;
+ BigNum bnTargetLimit = NetInfo.nProofOfWorkLimit;
+
+ BigNum bnSubsidyLimit = NetInfo.nMaxMintProofOfWork;
+ BigNum bnLowerBound = CTransaction.nCent;
+ BigNum bnUpperBound = bnSubsidyLimit;
+
+ while (bnLowerBound + CTransaction.nCent <= bnUpperBound)
+ {
+ BigNum bnMidValue = (bnLowerBound + bnUpperBound) / 2;
+ if (bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnTargetLimit > bnSubsidyLimit * bnSubsidyLimit * bnSubsidyLimit * bnSubsidyLimit * bnSubsidyLimit * bnSubsidyLimit * bnTarget)
+ bnUpperBound = bnMidValue;
+ else
+ bnLowerBound = bnMidValue;
+ }
+
+ ulong nSubsidy = bnUpperBound;
+ nSubsidy = (nSubsidy / CTransaction.nCent) * CTransaction.nCent;
+
+ return Math.Min(nSubsidy, NetInfo.nMaxMintProofOfWork) + nFees;
+ }
+
+ public static ulong GetProofOfStakeReward(ulong nCoinAge, uint nBits, uint nTime)
+ {
+ ulong nRewardCoinYear, nSubsidy, nSubsidyLimit = 10 * CTransaction.nCoin;
+
+ if (nTime > NetInfo.nDynamicStakeRewardTime)
+ {
+ // Stage 2 of emission process is PoS-based. It will be active on mainNet since 20 Jun 2013.
+
+ BigNum bnRewardCoinYearLimit = NetInfo.nMaxMintProofOfStake; // Base stake mint rate, 100% year interest
+
+ uint256 nTarget = 0;
+ nTarget.Compact = nBits;
+
+ BigNum bnTarget = nTarget;
+ BigNum bnTargetLimit = NetInfo.GetProofOfStakeLimit(0, nTime);
+
+ // NovaCoin: A reasonably continuous curve is used to avoid shock to market
+
+ BigNum bnLowerBound = CTransaction.nCent, // Lower interest bound is 1% per year
+ bnUpperBound = bnRewardCoinYearLimit, // Upper interest bound is 100% per year
+ bnMidPart, bnRewardPart;
+
+ while (bnLowerBound + CTransaction.nCent <= bnUpperBound)
+ {
+ BigNum bnMidValue = (bnLowerBound + bnUpperBound) / 2;
+ if (nTime < NetInfo.nStakeCurveSwitchTime)
+ {
+ //
+ // Until 20 Oct 2013: reward for coin-year is cut in half every 64x multiply of PoS difficulty
+ //
+ // (nRewardCoinYearLimit / nRewardCoinYear) ** 6 == bnProofOfStakeLimit / bnTarget
+ //
+ // Human readable form: nRewardCoinYear = 1 / (posdiff ^ 1/6)
+ //
+
+ bnMidPart = bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnMidValue;
+ bnRewardPart = bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnRewardCoinYearLimit;
+ }
+ else
+ {
+ //
+ // Since 20 Oct 2013: reward for coin-year is cut in half every 8x multiply of PoS difficulty
+ //
+ // (nRewardCoinYearLimit / nRewardCoinYear) ** 3 == bnProofOfStakeLimit / bnTarget
+ //
+ // Human readable form: nRewardCoinYear = 1 / (posdiff ^ 1/3)
+ //
+
+ bnMidPart = bnMidValue * bnMidValue * bnMidValue;
+ bnRewardPart = bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnRewardCoinYearLimit;
+ }
+
+ if (bnMidPart * bnTargetLimit > bnRewardPart * bnTarget)
+ bnUpperBound = bnMidValue;
+ else
+ bnLowerBound = bnMidValue;
+ }
+
+ nRewardCoinYear = bnUpperBound;
+ nRewardCoinYear = Math.Min((nRewardCoinYear / CTransaction.nCent) * CTransaction.nCent, NetInfo.nMaxMintProofOfStake);
+ }
+ else
+ {
+ // Old creation amount per coin-year, 5% fixed stake mint rate
+ nRewardCoinYear = 5 * CTransaction.nCent;
+ }
+
+ nSubsidy = nCoinAge * nRewardCoinYear * 33 / (365 * 33 + 8);
+
+ // Set reasonable reward limit for large inputs since 20 Oct 2013
+ //
+ // This will stimulate large holders to use smaller inputs, that's good for the network protection
+ if (NetInfo.nStakeCurveSwitchTime < nTime)
+ {
+ nSubsidy = Math.Min(nSubsidy, nSubsidyLimit);
+ }
+
+ return nSubsidy;
+ }
+ }
}
git://git.novaco.in / NovacoinLibrary.git / blobdiff