X-Git-Url: https://git.novaco.in/?a=blobdiff_plain;f=Novacoin%2FCBlock.cs;h=e8f220799ab111a28ca5a76f5137046dc0cb9a92;hb=624ac1021490395614a0cbee619c79860c22061a;hp=d3b402225f69b0c2dbc3d3623951cb94de380608;hpb=892af99303ad6d6ece3e57bebd36b521102df838;p=NovacoinLibrary.git
diff --git a/Novacoin/CBlock.cs b/Novacoin/CBlock.cs
index d3b4022..e8f2207 100644
--- a/Novacoin/CBlock.cs
+++ b/Novacoin/CBlock.cs
@@ -17,19 +17,47 @@
*/
using System;
-using System.Linq;
using System.Text;
using System.Collections.Generic;
-using System.Security.Cryptography;
using System.Diagnostics.Contracts;
+using System.IO;
+using System.Numerics;
namespace Novacoin
{
- ///
- /// Represents the block. Block consists of header, transaction array and header signature.
- ///
- 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)
+ {
+ }
+ }
+
+ ///
+ /// Represents the block. Block consists of header, transaction array and header signature.
+ ///
+ public class CBlock
{
+ ///
+ /// Maximum block size is 1Mb.
+ ///
+ public const uint nMaxBlockSize = 1000000;
+
+ ///
+ /// Sanity threshold for amount of sigops.
+ ///
+ public const uint nMaxSigOps = 20000;
+
///
/// Block header.
///
@@ -45,6 +73,10 @@ namespace Novacoin
///
public byte[] signature = new byte[0];
+ ///
+ /// Copy constructor.
+ ///
+ /// CBlock instance.
public CBlock(CBlock b)
{
header = new CBlockHeader(b.header);
@@ -55,25 +87,36 @@ namespace Novacoin
vtx[i] = new CTransaction(b.vtx[i]);
}
+ signature = new byte[b.signature.Length];
b.signature.CopyTo(signature, 0);
}
///
/// Parse byte sequence and initialize new block instance
///
- ///
+ /// Bytes sequence.
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(wBytes.Get(80));
+ // Fill the block header fields
+ header = new CBlockHeader(ref reader);
- // Parse transactions list
- vtx = CTransaction.ReadTransactionsList(ref wBytes);
+ // Parse transactions list
+ vtx = CTransaction.ReadTransactionsList(ref reader);
- // Read block signature
- signature = wBytes.Get((int)wBytes.GetVarInt());
+ // Read block signature
+ signature = reader.ReadBytes((int)VarInt.ReadVarInt(ref reader));
+
+ reader.Close();
+ }
+ catch (Exception e)
+ {
+ throw new BlockException("Deserialization failed", e);
+ }
}
public CBlock()
@@ -84,6 +127,171 @@ namespace Novacoin
vtx = new CTransaction[0];
}
+ public bool CheckBlock(bool fCheckPOW = true, bool fCheckMerkleRoot = true, bool fCheckSig = true)
+ {
+ var uniqueTX = new List(); // 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;
+ }
+
///
/// Is this a Proof-of-Stake block?
///
@@ -150,20 +358,25 @@ namespace Novacoin
/// Byte sequence
public static implicit operator byte[] (CBlock b)
{
- var r = new List();
+ 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();
- return r.ToArray();
+ writer.Close();
+
+ return resultBytes;
}
///
@@ -199,7 +412,7 @@ namespace Novacoin
for (int i = 0; i < nTx; i++)
{
- nOffset += vtx[nTx].Size;
+ nOffset += vtx[i].Size;
}
return nOffset;
@@ -208,7 +421,7 @@ namespace Novacoin
///
/// Merkle root
///
- public Hash256 hashMerkleRoot
+ public uint256 hashMerkleRoot
{
get {
@@ -216,7 +429,7 @@ namespace Novacoin
foreach (var tx in vtx)
{
- merkleTree.AddRange(Hash256.ComputeRaw256(tx));
+ merkleTree.AddRange(CryptoUtils.ComputeHash256(tx));
}
int levelOffset = 0;
@@ -229,12 +442,12 @@ namespace Novacoin
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();
}
}
@@ -258,6 +471,51 @@ namespace Novacoin
return sb.ToString();
}
- }
+
+ ///
+ /// Calculate proof-of-work reward.
+ ///
+ /// Packed difficulty representation.
+ /// Amount of fees.
+ /// Reward value.
+ 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
+
+ BigInteger bnSubsidyLimit = NetInfo.nMaxMintProofOfWork;
+
+ uint256 nTarget = 0;
+ nTarget.Compact = nBits;
+
+ BigInteger bnTarget = new BigInteger(nTarget);
+ BigInteger bnTargetLimit = new BigInteger(NetInfo.nProofOfWorkLimit);
+
+ BigInteger bnLowerBound = CTransaction.nCent;
+ BigInteger bnUpperBound = bnSubsidyLimit;
+
+ while (bnLowerBound + CTransaction.nCent <= bnUpperBound)
+ {
+ BigInteger 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 = (ulong)bnUpperBound;
+ nSubsidy = (nSubsidy / CTransaction.nCent) * CTransaction.nCent;
+
+
+ return Math.Min(nSubsidy, NetInfo.nMaxMintProofOfWork) + nFees;
+ }
+ }
}