From 65e710395448beeaa41ed5398906841d0799e4e8 Mon Sep 17 00:00:00 2001
From: janko33bd <janko33bd@gmail.com>
Date: Tue, 16 Jan 2018 21:58:20 +0100
Subject: [PATCH] Add normalized transaction hash

---
 src/primitives/transaction.cpp |  6 ++++++
 src/primitives/transaction.h   |  2 ++
 src/rpc/rawtransaction.cpp     | 16 ++++++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/src/primitives/transaction.cpp b/src/primitives/transaction.cpp
index c3577dad4..faf4ca511 100644
--- a/src/primitives/transaction.cpp
+++ b/src/primitives/transaction.cpp
@@ -8,6 +8,7 @@
 #include "hash.h"
 #include "tinyformat.h"
 #include "utilstrencodings.h"
+#include "script/interpreter.h"
 
 std::string COutPoint::ToString() const
 {
@@ -68,6 +69,11 @@ uint256 CMutableTransaction::GetHash() const
     return SerializeHash(*this);
 }
 
+uint256 CMutableTransaction::GetNormalizedHash() const
+{
+    return SignatureHash(CScript(), *this, 0, SIGHASH_ALL);
+}
+
 void CTransaction::UpdateHash() const
 {
     *const_cast<uint256*>(&hash) = SerializeHash(*this);
diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
index 50fdc0d6f..7735f0335 100644
--- a/src/primitives/transaction.h
+++ b/src/primitives/transaction.h
@@ -338,6 +338,8 @@ struct CMutableTransaction
      * fly, as opposed to GetHash() in CTransaction, which uses a cached result.
      */
     uint256 GetHash() const;
+
+    uint256 GetNormalizedHash() const;
 };
 
 #endif // BITCOIN_PRIMITIVES_TRANSACTION_H
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index 063beca3c..83ce44a96 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -676,6 +676,21 @@ static void TxInErrorToJSON(const CTxIn& txin, UniValue& vErrorsRet, const std::
     vErrorsRet.push_back(entry);
 }
 
+UniValue getnormalizedtxid(const UniValue& params, bool fHelp)
+{
+	if (fHelp || params.size() != 1)
+	        throw runtime_error(
+	        		            "getnormalizedtxid <hex string>\n"
+	        		            "Return the normalized transaction ID.");
+	// parse hex string from parameter
+	CTransaction tx;
+	if (!DecodeHexTx(tx, params[0].get_str()))
+		throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
+
+	uint256 hashNormalized = CMutableTransaction(tx).GetNormalizedHash();
+	return hashNormalized.GetHex();
+}
+
 UniValue signrawtransaction(const UniValue& params, bool fHelp)
 {
     if (fHelp || params.size() < 1 || params.size() > 4)
@@ -1003,6 +1018,7 @@ static const CRPCCommand commands[] =
     { "rawtransactions",    "decodescript",           &decodescript,           true  },
     { "rawtransactions",    "sendrawtransaction",     &sendrawtransaction,     false },
     { "rawtransactions",    "signrawtransaction",     &signrawtransaction,     false }, /* uses wallet if enabled */
+	{ "rawtransactions",    "getnormalizedtxid",      &getnormalizedtxid,      true },
 
     { "blockchain",         "gettxoutproof",          &gettxoutproof,          true  },
     { "blockchain",         "verifytxoutproof",       &verifytxoutproof,       true  },