Copy&paste typo fix
[NovacoinLibrary.git] / Novacoin / CBlock.cs
index 82a8b88..6ff2da3 100644 (file)
@@ -1,13 +1,50 @@
-\feffusing System;
+\feff/**
+ *  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 <http://www.gnu.org/licenses/>.
+ */
+
+using System;
 using System.Text;
 using System.Collections.Generic;
+using System.Diagnostics.Contracts;
 
 namespace Novacoin
 {
-       /// <summary>
-       /// Represents the block. Block consists of header, transaction array and header signature.
-       /// </summary>
-       public class CBlock
+    [Serializable]
+    public class BlockConstructorException : Exception
+    {
+        public BlockConstructorException()
+        {
+        }
+
+        public BlockConstructorException(string message)
+                : base(message)
+        {
+        }
+
+        public BlockConstructorException(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>
                /// Block header.
@@ -19,14 +56,19 @@ namespace Novacoin
                /// </summary>
                public CTransaction[] vtx;
 
-               /// <summary>
-               /// Block header signature.
-               /// </summary>
-               public byte[] signature;
+        /// <summary>
+        /// Block header signature.
+        /// </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++)
             {
@@ -39,19 +81,26 @@ namespace Novacoin
         /// <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
+            {
+                ByteQueue wBytes = new ByteQueue(blockBytes);
 
-            // Fill the block header fields
-            header = new CBlockHeader(wBytes.Get(80));
+                // Fill the block header fields
+                header = new CBlockHeader(wBytes.Get(80));
 
-            // Parse transactions list
-            vtx = CTransaction.ReadTransactionsList(ref wBytes);
+                // Parse transactions list
+                vtx = CTransaction.ReadTransactionsList(ref wBytes);
 
-            // Read block signature
-            signature = wBytes.Get((int)wBytes.GetVarInt());
+                // Read block signature
+                signature = wBytes.Get((int)wBytes.GetVarInt());
+            }
+            catch (Exception e)
+            {
+                throw new BlockConstructorException("Deserialization failed", e);
+            }
                }
 
         public CBlock()
@@ -63,44 +112,177 @@ namespace Novacoin
         }
 
         /// <summary>
-        /// Convert current instance into sequence of bytes
+        /// Is this a Proof-of-Stake block?
+        /// </summary>
+        public bool IsProofOfStake
+        {
+            get
+            {
+                return (vtx.Length > 1 && vtx[1].IsCoinStake);
+            }
+        }
+
+        /// <summary>
+        /// Was this signed correctly?
+        /// </summary>
+        public bool SignatureOK
+        {
+            get
+            {
+                if (IsProofOfStake)
+                {
+                    if (signature.Length == 0)
+                    {
+                        return false; // No signature
+                    }
+
+                    txnouttype whichType;
+                    IList<byte[]> 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;
+            }
+        }
+
+        /// <summary>
+        /// Get instance as sequence of bytes
         /// </summary>
         /// <returns>Byte sequence</returns>
-        public IList<byte> Bytes 
+        public static implicit operator byte[] (CBlock b)
+        {
+            var r = new List<byte>();
+
+            r.AddRange((byte[])b.header);
+            r.AddRange(VarInt.EncodeVarInt(b.vtx.LongLength)); // transactions count
+
+            foreach (var tx in b.vtx)
+            {
+                r.AddRange((byte[])tx);
+            }
+
+            r.AddRange(VarInt.EncodeVarInt(b.signature.LongLength));
+            r.AddRange(b.signature);
+
+            return r.ToArray();
+        }
+
+        /// <summary>
+        /// Serialized size
+        /// </summary>
+        public int Size
         {
             get
             {
-                List<byte> r = new List<byte>();
+                int nSize = 80 + VarInt.GetEncodedSize(vtx.Length); // CBlockHeader + NumTx
+
+                foreach (var tx in vtx)
+                {
+                    nSize += tx.Size;
+                }
+
+                nSize += VarInt.GetEncodedSize(signature.Length) + signature.Length;
+
+                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 int GetTxOffset(int nTx)
+        {
+            Contract.Requires<ArgumentException>(nTx >= 0 && nTx < vtx.Length, "Transaction index you've specified is incorrect.");
+
+            int nOffset = 80 + VarInt.GetEncodedSize(vtx.Length); // CBlockHeader + NumTx
+
+            for (int i = 0; i < nTx; i++)
+            {
+                nOffset += vtx[i].Size;
+            }
+
+            return nOffset;
+        }
 
-                r.AddRange(header.Bytes);
-                r.AddRange(VarInt.EncodeVarInt(vtx.LongLength)); // transactions count
+        /// <summary>
+        /// Merkle root
+        /// </summary>
+        public Hash256 hashMerkleRoot
+        {
+            get {
+                
+                var merkleTree = new List<byte>();
 
-                foreach (CTransaction tx in vtx)
+                foreach (var tx in vtx)
                 {
-                    r.AddRange(tx.Bytes);
+                    merkleTree.AddRange(Hash256.ComputeRaw256(tx));
                 }
 
-                r.AddRange(VarInt.EncodeVarInt(signature.LongLength));
-                r.AddRange(signature);
+                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();
 
-                return r;
+                        merkleTree.AddRange(Hash256.ComputeRaw256(ref left, ref right));
+                    }
+                    levelOffset += nLevelSize;
+                }
+
+                return (merkleTree.Count == 0) ? new Hash256() : new Hash256(merkleTree.GetRange(merkleTree.Count-32, 32).ToArray());
             }
         }
 
         public override string ToString()
         {
-            StringBuilder sb = new StringBuilder();
+            var sb = new StringBuilder();
 
             sb.AppendFormat("CBlock(\n header={0},\n", header.ToString());
 
-            foreach(CTransaction tx in vtx)
+            foreach(var tx in vtx)
+            {
+                sb.AppendFormat("{0}", tx.ToString());
+            }
+
+            if (IsProofOfStake)
             {
-                sb.AppendFormat("{0},\n", tx.ToString());
+                sb.AppendFormat(", signature={0}, signatureOK={1}\n", Interop.ToHex(signature), SignatureOK);
             }
 
-            sb.AppendFormat("signature={0})\n", Interop.ToHex(signature));
+            sb.Append(")");
             
-            // TODO
             return sb.ToString();
         }
        }