PoS improvements

src/primitives/nonce.h

@@ -0,0 +1,66 @@
+// Copyright (c) 2018 Michael Toutonghi
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_PRIMITIVES_NONCE_H
+#define BITCOIN_PRIMITIVES_NONCE_H
+
+#include "serialize.h"
+#include "uint256.h"
+#include "arith_uint256.h"
+
+
+/** For POS blocks, the nNonce of a block header holds the entropy source for the POS contest
+ * in the latest VerusHash protocol, implemented at block below
+ * 
+ * */
+class CPOSNonce : public uint256
+{
+public:
+    static bool NewPOSActive(int32_t height);
+    static bool NewNonceActive(int32_t height);
+
+    CPOSNonce() {}
+    CPOSNonce(const base_blob<256> &b) : uint256(b) {}
+    CPOSNonce(const std::vector<unsigned char> &vch) : uint256(vch) {}
+
+    int32_t GetPOSTarget() const
+    {
+        uint32_t nBits = 0;
+
+        for (const unsigned char *p = begin() + 3; p >= begin(); p--)
+        {
+            nBits <<= 8;
+            nBits += *p;
+        }
+        return nBits;
+    }
+
+    bool IsPOSNonce() const
+    {
+        arith_uint256 arNonce = UintToArith256(*this);
+        arith_uint256 tmpNonce = ((arNonce << 128) >> 128);
+        CVerusHashWriter hashWriter = CVerusHashWriter(SER_GETHASH, PROTOCOL_VERSION);
+        hashWriter << ArithToUint256(tmpNonce);
+        return (*this == ArithToUint256(UintToArith256(hashWriter.GetHash()) << 128 | tmpNonce));
+    }
+
+    void SetPOSTarget(int32_t nBits)
+    {
+        CVerusHashWriter hashWriter = CVerusHashWriter(SER_GETHASH, PROTOCOL_VERSION);
+        arith_uint256 tmpNonce;
+
+        arith_uint256 arNonce = UintToArith256(*this);
+        arNonce = ((arNonce >> 32) << 32) | nBits;
+
+        tmpNonce = ((arNonce << 128) >> 128);
+        hashWriter << ArithToUint256(tmpNonce);
+
+        (uint256 &)(*this) = ArithToUint256(UintToArith256(hashWriter.GetHash()) << 128 | tmpNonce);
+    }
+
+    void SetPOSEntropy(const uint256 &pastHash, uint256 txid, int32_t voutNum);
+    bool CheckPOSEntropy(const uint256 &pastHash, uint256 txid, int32_t voutNum);
+};
+
+#endif // BITCOIN_PRIMITIVES_NONCE_H