Verification of claimed Proof-of-Work.

[NovacoinLibrary.git] / Novacoin / CBlock.cs

diff --git a/Novacoin/CBlock.cs b/Novacoin/CBlock.cs
index d8d7a75..9bf7e36 100644 (file)
--- a/Novacoin/CBlock.cs
+++ b/Novacoin/CBlock.cs
@@ -47,6 +47,16 @@ namespace Novacoin
     /// </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>
@@ -118,11 +128,11 @@ namespace Novacoin
 
         public bool CheckBlock(bool fCheckPOW = true, bool fCheckMerkleRoot = true, bool fCheckSig = true)
         {
-            var uniqueTX = new List<Hash256>(); // tx hashes
+            var uniqueTX = new List<uint256>(); // tx hashes
             uint nSigOps = 0; // total sigops
 
             // Basic sanity checkings
-            if (vtx.Length == 0 || Size > 1000000)
+            if (vtx.Length == 0 || Size > nMaxBlockSize)
             {
                 return false;
             }
@@ -245,7 +255,7 @@ namespace Novacoin
             }
 
             // Reject block if validation would consume too much resources.
-            if (nSigOps > 50000)
+            if (nSigOps > nMaxSigOps)
             {
                 return false;
             }
@@ -259,9 +269,24 @@ namespace Novacoin
             return true;
         }
 
-        private bool CheckProofOfWork(ScryptHash256 hash, uint nBits)
+        private bool CheckProofOfWork(uint256 hash, uint nBits)
         {
-            // TODO: stub!
+            uint256 nTarget = new uint256();
+            nTarget.Compact = nBits;
+
+            // Check range
+            if (nTarget > NetUtils.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;
         }
@@ -395,7 +420,7 @@ namespace Novacoin
         /// <summary>
         /// Merkle root
         /// </summary>
-        public Hash256 hashMerkleRoot
+        public uint256 hashMerkleRoot
         {
             get {
                 
@@ -403,7 +428,7 @@ namespace Novacoin
 
                 foreach (var tx in vtx)
                 {
-                    merkleTree.AddRange(Hash256.ComputeRaw256(tx));
+                    merkleTree.AddRange(CryptoUtils.ComputeHash256(tx));
                 }
 
                 int levelOffset = 0;
@@ -416,12 +441,12 @@ 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();
             }
         }