Novacoin/CBlock.cs

   1 \feff/**
   2  *  Novacoin classes library
   3  *  Copyright (C) 2015 Alex D. (balthazar.ad@gmail.com)
   4
   5  *  This program is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU Affero General Public License as
   7  *  published by the Free Software Foundation, either version 3 of the
   8  *  License, or (at your option) any later version.
   9
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU Affero General Public License for more details.
  14
  15  *  You should have received a copy of the GNU Affero General Public License
  16  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 using System;
  20 using System.Linq;
  21 using System.Text;
  22 using System.Collections.Generic;
  23 using System.Security.Cryptography;
  24
  25 namespace Novacoin
  26 {
  27         /// <summary>
  28         /// Represents the block. Block consists of header, transaction array and header signature.
  29         /// </summary>
  30         public class CBlock
  31         {
  32                 /// <summary>
  33                 /// Block header.
  34                 /// </summary>
  35                 public CBlockHeader header;
  36
  37                 /// <summary>
  38                 /// Transactions array.
  39                 /// </summary>
  40                 public CTransaction[] vtx;
  41
  42         /// <summary>
  43         /// Block header signature.
  44         /// </summary>
  45         public byte[] signature = new byte[0];
  46
  47         public CBlock(CBlock b)
  48         {
  49             header = new CBlockHeader(b.header);
  50
  51             for (int i = 0; i < b.vtx.Length; i++)
  52             {
  53                 vtx[i] = new CTransaction(b.vtx[i]);
  54             }
  55
  56             b.signature.CopyTo(signature, 0);
  57         }
  58
  59         /// <summary>
  60         /// Parse byte sequence and initialize new block instance
  61         /// </summary>
  62         /// <param name="blockBytes"></param>
  63                 public CBlock (IList<byte> blockBytes)
  64                 {
  65             ByteQueue wBytes = new ByteQueue(blockBytes);
  66
  67             // Fill the block header fields
  68             header = new CBlockHeader(wBytes.Get(80));
  69
  70             // Parse transactions list
  71             vtx = CTransaction.ReadTransactionsList(ref wBytes);
  72
  73             // Read block signature
  74             signature = wBytes.Get((int)wBytes.GetVarInt());
  75                 }
  76
  77         public CBlock()
  78         {
  79             // Initialize empty array of transactions. Please note that such
  80             // configuration is not valid real block since it has to provide
  81             // at least one transaction.
  82             vtx = new CTransaction[0];
  83         }
  84
  85         /// <summary>
  86         /// Is this a Proof-of-Stake block?
  87         /// </summary>
  88         public bool IsProofOfStake
  89         {
  90             get
  91             {
  92                 return (vtx.Length > 1 && vtx[1].IsCoinStake);
  93             }
  94         }
  95
  96         /// <summary>
  97         /// Was this signed correctly?
  98         /// </summary>
  99         public bool SignatureOK
 100         {
 101             get
 102             {
 103                 if (IsProofOfStake)
 104                 {
 105                     if (signature.Length == 0)
 106                     {
 107                         return false; // No signature
 108                     }
 109
 110                     txnouttype whichType;
 111                     IList<byte[]> solutions;
 112
 113                     if (!ScriptCode.Solver(vtx[1].vout[1].scriptPubKey, out whichType, out solutions))
 114                     {
 115                         return false; // No solutions found
 116                     }
 117
 118                     if (whichType == txnouttype.TX_PUBKEY)
 119                     {
 120                         CPubKey pubkey;
 121
 122                         try
 123                         {
 124                             pubkey = new CPubKey(solutions[0]);
 125                         }
 126                         catch (Exception)
 127                         {
 128                             return false; // Error while loading public key
 129                         }
 130
 131                         return pubkey.VerifySignature(header.Hash, signature);
 132                     }
 133                 }
 134                 else
 135                 {
 136                     // Proof-of-Work blocks have no signature
 137
 138                     return true;
 139                 }
 140
 141                 return false;
 142             }
 143         }
 144
 145         /// <summary>
 146         /// Get current instance as sequence of bytes
 147         /// </summary>
 148         /// <returns>Byte sequence</returns>
 149         public IList<byte> Bytes
 150         {
 151             get
 152             {
 153                 var r = new List<byte>();
 154
 155                 r.AddRange(header.Bytes);
 156                 r.AddRange(VarInt.EncodeVarInt(vtx.LongLength)); // transactions count
 157
 158                 foreach (var tx in vtx)
 159                 {
 160                     r.AddRange(tx.Bytes);
 161                 }
 162
 163                 r.AddRange(VarInt.EncodeVarInt(signature.LongLength));
 164                 r.AddRange(signature);
 165
 166                 return r;
 167             }
 168         }
 169
 170         /// <summary>
 171         /// MErkle root
 172         /// </summary>
 173         public Hash256 hashMerkleRoot
 174         {
 175             get {
 176
 177                 var merkleTree = new List<byte>();
 178
 179                 foreach (var tx in vtx)
 180                 {
 181                     merkleTree.AddRange(tx.Hash.hashBytes);
 182                 }
 183
 184                 var hasher = new SHA256Managed();
 185                 hasher.Initialize();
 186
 187                 int j = 0;
 188                 for (int nSize = vtx.Length; nSize > 1; nSize = (nSize + 1) / 2)
 189                 {
 190                     for (int i = 0; i < nSize; i += 2)
 191                     {
 192                         int i2 = Math.Min(i + 1, nSize - 1);
 193
 194                         var pair = new List<byte>();
 195
 196                         pair.AddRange(merkleTree.GetRange((j + i)*32, 32));
 197                         pair.AddRange(merkleTree.GetRange((j + i2)*32, 32));
 198
 199                         var digest1 = hasher.ComputeHash(pair.ToArray());
 200                         var digest2 = hasher.ComputeHash(digest1);
 201
 202                         merkleTree.AddRange(digest2);
 203                     }
 204                     j += nSize;
 205                 }
 206
 207                 return (merkleTree.Count == 0) ? new Hash256() : new Hash256(merkleTree.GetRange(merkleTree.Count-32, 32));
 208             }
 209         }
 210
 211         public override string ToString()
 212         {
 213             var sb = new StringBuilder();
 214
 215             sb.AppendFormat("CBlock(\n header={0},\n", header.ToString());
 216
 217             foreach(var tx in vtx)
 218             {
 219                 sb.AppendFormat("{0}", tx.ToString());
 220             }
 221
 222             if (IsProofOfStake)
 223             {
 224                 sb.AppendFormat(", signature={0}, signatureOK={1}\n", Interop.ToHex(signature), SignatureOK);
 225             }
 226
 227             sb.Append(")");
 228
 229             return sb.ToString();
 230         }
 231         }
 232 }
 233