X-Git-Url: https://git.novaco.in/?a=blobdiff_plain;f=Novacoin%2FCBlock.cs;h=69c8a28e1d389e8d0c200edf1ee79d7214b128dd;hb=6b0501a53995f78928332cfcd7ce1cae4b07486f;hp=4eb3a335b88f29b5cbfe099a95b3f8e0a0f70264;hpb=8b06904374c83d9e4216bcd202913c5e5ce10442;p=NovacoinLibrary.git
diff --git a/Novacoin/CBlock.cs b/Novacoin/CBlock.cs
index 4eb3a33..69c8a28 100644
--- a/Novacoin/CBlock.cs
+++ b/Novacoin/CBlock.cs
@@ -1,12 +1,62 @@
-using System;
+/**
+ * Novacoin classes library
+ * Copyright (C) 2015 Alex D. (balthazar.ad@gmail.com)
+
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see .
+ */
+
+using System;
+using System.Text;
+using System.Collections.Generic;
+using System.Diagnostics.Contracts;
+using System.IO;
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.
///
@@ -15,16 +65,515 @@ namespace Novacoin
///
/// Transactions array.
///
- public CTransaction[] tx;
+ public CTransaction[] vtx;
- ///
- /// Block header signature.
- ///
- public byte[] signature = {};
+ ///
+ /// Block header signature.
+ ///
+ public byte[] signature = new byte[0];
+
+ ///
+ /// Copy constructor.
+ ///
+ /// CBlock instance.
+ 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);
+ }
- public CBlock ()
+ ///
+ /// Parse byte sequence and initialize new block instance
+ ///
+ /// Bytes sequence.
+ public CBlock (byte[] blockBytes)
{
+ try
+ {
+ var stream = new MemoryStream(blockBytes);
+ var reader = new BinaryReader(stream);
+
+ // Fill the block header fields
+ header = new CBlockHeader(ref reader);
+
+ // Parse transactions list
+ vtx = CTransaction.ReadTransactionsList(ref reader);
+
+ // Read block signature
+ signature = reader.ReadBytes((int)VarInt.ReadVarInt(ref reader));
+
+ reader.Close();
+ }
+ catch (Exception e)
+ {
+ throw new BlockException("Deserialization failed", e);
+ }
}
- }
+
+ public CBlock()
+ {
+ // Initialize empty array of transactions. Please note that such
+ // configuration is not valid real block since it has to provide
+ // at least one transaction.
+ 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 must 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; // Proof-of-Stake signature checking failure.
+ }
+
+ 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 static 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?
+ ///
+ public bool IsProofOfStake
+ {
+ get
+ {
+ return (vtx.Length > 1 && vtx[1].IsCoinStake);
+ }
+ }
+
+ ///
+ /// Was this signed correctly?
+ ///
+ public bool SignatureOK
+ {
+ get
+ {
+ if (IsProofOfStake)
+ {
+ if (signature.Length == 0)
+ {
+ return false; // No signature
+ }
+
+ txnouttype whichType;
+ IList solutions;
+
+ if (!ScriptCode.Solver(vtx[1].vout[1].scriptPubKey, out whichType, out solutions))
+ {
+ return false; // No solutions found
+ }
+
+ if (whichType == txnouttype.TX_PUBKEY)
+ {
+ CPubKey pubkey;
+
+ try
+ {
+ pubkey = new CPubKey(solutions[0]);
+ }
+ catch (Exception)
+ {
+ return false; // Error while loading public key
+ }
+
+ return pubkey.VerifySignature(header.Hash, signature);
+ }
+ }
+ else
+ {
+ // Proof-of-Work blocks have no signature
+
+ return true;
+ }
+
+ return false;
+ }
+ }
+
+ ///
+ /// Get instance as sequence of bytes
+ ///
+ /// Byte sequence
+ public static implicit operator byte[] (CBlock b)
+ {
+ 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)
+ {
+ writer.Write(tx);
+ }
+
+ writer.Write(VarInt.EncodeVarInt(b.signature.LongLength));
+ writer.Write(b.signature);
+
+ var resultBytes = stream.ToArray();
+
+ writer.Close();
+
+ return resultBytes;
+ }
+
+ ///
+ /// Serialized size
+ ///
+ public uint Size
+ {
+ get
+ {
+ uint nSize = 80 + VarInt.GetEncodedSize(vtx.Length); // CBlockHeader + NumTx
+
+ foreach (var tx in vtx)
+ {
+ nSize += tx.Size;
+ }
+
+ nSize += VarInt.GetEncodedSize(signature.Length) + (uint)signature.Length;
+
+ return nSize;
+ }
+ }
+
+ ///
+ /// Get transaction offset inside block.
+ ///
+ /// Transaction index.
+ /// Offset in bytes from the beginning of block header.
+ public uint GetTxOffset(int nTx)
+ {
+ Contract.Requires(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;
+ }
+
+ ///
+ /// Merkle root
+ ///
+ public uint256 hashMerkleRoot
+ {
+ get {
+
+ var merkleTree = new List();
+
+ foreach (var tx in vtx)
+ {
+ merkleTree.AddRange(CryptoUtils.ComputeHash256(tx));
+ }
+
+ int levelOffset = 0;
+ for (int nLevelSize = vtx.Length; nLevelSize > 1; nLevelSize = (nLevelSize + 1) / 2)
+ {
+ for (int nLeft = 0; nLeft < nLevelSize; nLeft += 2)
+ {
+ int nRight = Math.Min(nLeft + 1, nLevelSize - 1);
+
+ var left = merkleTree.GetRange((levelOffset + nLeft) * 32, 32).ToArray();
+ var right = merkleTree.GetRange((levelOffset + nRight) * 32, 32).ToArray();
+
+ merkleTree.AddRange(CryptoUtils.ComputeHash256(ref left, ref right));
+ }
+ levelOffset += nLevelSize;
+ }
+
+ return (merkleTree.Count == 0) ? 0 : (uint256)merkleTree.GetRange(merkleTree.Count-32, 32).ToArray();
+ }
+ }
+
+ public override string ToString()
+ {
+ var sb = new StringBuilder();
+
+ sb.AppendFormat("CBlock(\n header={0},\n", header.ToString());
+
+ foreach(var tx in vtx)
+ {
+ sb.AppendFormat("{0}", tx.ToString());
+ }
+
+ if (IsProofOfStake)
+ {
+ sb.AppendFormat(", signature={0}, signatureOK={1}\n", Interop.ToHex(signature), SignatureOK);
+ }
+
+ sb.Append(")");
+
+ return sb.ToString();
+ }
+
+ ///
+ /// Calculate proof-of-work reward.
+ ///
+ /// Packed difficulty representation.
+ /// Amount of fees.
+ /// Reward value.
+ public static long GetProofOfWorkReward(uint nBits, long 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;
+ }
+
+ long nSubsidy = bnUpperBound;
+ nSubsidy = (nSubsidy / CTransaction.nCent) * CTransaction.nCent;
+
+ return Math.Min(nSubsidy, NetInfo.nMaxMintProofOfWork) + nFees;
+ }
+
+ public static long GetProofOfStakeReward(long nCoinAge, uint nBits, uint nTime)
+ {
+ // Second stage of emission process is mostly PoS-based.
+
+ long nRewardCoinYear, nSubsidy, nSubsidyLimit = 10 * CTransaction.nCoin;
+ // Base stake mint rate, 100% year interest
+ BigNum bnRewardCoinYearLimit = NetInfo.nMaxMintProofOfStake;
+
+ uint256 nTarget = 0;
+ nTarget.Compact = nBits;
+
+ BigNum bnTarget = nTarget;
+ BigNum bnTargetLimit = NetInfo.GetProofOfStakeLimit(0, nTime);
+
+ // 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;
+
+ // 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);
+
+ nSubsidy = nCoinAge * nRewardCoinYear * 33 / (365 * 33 + 8);
+
+ // Set reasonable reward limit for large inputs
+ // This will stimulate large holders to use smaller inputs, that's good
+ // for the network protection
+ return Math.Min(nSubsidy, nSubsidyLimit);
+ }
+
+ public Tuple ProofOfStake
+ {
+ get { return IsProofOfStake ? new Tuple(vtx[1].vin[0].prevout, vtx[1].nTime) : new Tuple(new COutPoint(), 0); }
+ }
+
+}
}