From c97bffcc13b9a7a24ddfd74d5dcf16b13c1daee5 Mon Sep 17 00:00:00 2001
From: UdjinM6 <UdjinM6@users.noreply.github.com>
Date: Wed, 31 May 2023 01:16:05 +0300
Subject: [PATCH] feat: use m_protxHash instead of masternodeOutpoint for
 hashing dsq and dstx after v19 activation

---
 src/coinjoin/coinjoin.cpp | 25 ++++++++++++++-----------
 src/coinjoin/coinjoin.h   |  8 ++++----
 2 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/src/coinjoin/coinjoin.cpp b/src/coinjoin/coinjoin.cpp
index 237dfaeb2459..b6a9f92323ec 100644
--- a/src/coinjoin/coinjoin.cpp
+++ b/src/coinjoin/coinjoin.cpp
@@ -41,22 +41,22 @@ bool CCoinJoinEntry::AddScriptSig(const CTxIn& txin)
     return false;
 }
 
-uint256 CCoinJoinQueue::GetSignatureHash() const
+uint256 CCoinJoinQueue::GetSignatureHash(bool legacy) const
 {
-    return SerializeHash(*this);
+    int version = legacy ? COINJOIN_PROTX_HASH_PROTO_VERSION - 1 : PROTOCOL_VERSION;
+    return SerializeHash(*this, SER_GETHASH, version);
 }
 
 bool CCoinJoinQueue::Sign()
 {
     if (!fMasternodeMode) return false;
 
-
-    uint256 hash = GetSignatureHash();
+    bool legacy_bls_scheme = !llmq::utils::IsV19Active(::ChainActive().Tip());
+    uint256 hash = GetSignatureHash(legacy_bls_scheme);
     CBLSSignature sig = WITH_LOCK(activeMasternodeInfoCs, return activeMasternodeInfo.blsKeyOperator->Sign(hash));
     if (!sig.IsValid()) {
         return false;
     }
-    bool legacy_bls_scheme = !llmq::utils::IsV19Active(::ChainActive().Tip());
     vchSig = sig.ToByteVector(legacy_bls_scheme);
 
     return true;
@@ -64,7 +64,8 @@ bool CCoinJoinQueue::Sign()
 
 bool CCoinJoinQueue::CheckSignature(const CBLSPublicKey& blsPubKey) const
 {
-    if (!CBLSSignature(vchSig).VerifyInsecure(blsPubKey, GetSignatureHash())) {
+    bool legacy_bls_scheme = !llmq::utils::IsV19Active(::ChainActive().Tip());
+    if (!CBLSSignature(vchSig).VerifyInsecure(blsPubKey, GetSignatureHash(legacy_bls_scheme))) {
         LogPrint(BCLog::COINJOIN, "CCoinJoinQueue::CheckSignature -- VerifyInsecure() failed\n");
         return false;
     }
@@ -89,21 +90,22 @@ bool CCoinJoinQueue::IsTimeOutOfBounds(int64_t current_time) const
            nTime - current_time > COINJOIN_QUEUE_TIMEOUT;
 }
 
-uint256 CCoinJoinBroadcastTx::GetSignatureHash() const
+uint256 CCoinJoinBroadcastTx::GetSignatureHash(bool legacy) const
 {
-    return SerializeHash(*this);
+    int version = legacy ? COINJOIN_PROTX_HASH_PROTO_VERSION - 1 : PROTOCOL_VERSION;
+    return SerializeHash(*this, SER_GETHASH, version);
 }
 
 bool CCoinJoinBroadcastTx::Sign()
 {
     if (!fMasternodeMode) return false;
 
-    uint256 hash = GetSignatureHash();
+    bool legacy_bls_scheme = !llmq::utils::IsV19Active(::ChainActive().Tip());
+    uint256 hash = GetSignatureHash(legacy_bls_scheme);
     CBLSSignature sig = WITH_LOCK(activeMasternodeInfoCs, return activeMasternodeInfo.blsKeyOperator->Sign(hash));
     if (!sig.IsValid()) {
         return false;
     }
-    bool legacy_bls_scheme = !llmq::utils::IsV19Active(::ChainActive().Tip());
     vchSig = sig.ToByteVector(legacy_bls_scheme);
 
     return true;
@@ -111,7 +113,8 @@ bool CCoinJoinBroadcastTx::Sign()
 
 bool CCoinJoinBroadcastTx::CheckSignature(const CBLSPublicKey& blsPubKey) const
 {
-    if (!CBLSSignature(vchSig).VerifyInsecure(blsPubKey, GetSignatureHash())) {
+    bool legacy_bls_scheme = !llmq::utils::IsV19Active(::ChainActive().Tip());
+    if (!CBLSSignature(vchSig).VerifyInsecure(blsPubKey, GetSignatureHash(legacy_bls_scheme))) {
         LogPrint(BCLog::COINJOIN, "CCoinJoinBroadcastTx::CheckSignature -- VerifyInsecure() failed\n");
         return false;
     }
diff --git a/src/coinjoin/coinjoin.h b/src/coinjoin/coinjoin.h
index 538e7011fab3..2131c32d30d9 100644
--- a/src/coinjoin/coinjoin.h
+++ b/src/coinjoin/coinjoin.h
@@ -219,7 +219,7 @@ class CCoinJoinQueue
     {
         READWRITE(obj.nDenom);
 
-        if (s.GetVersion() < COINJOIN_PROTX_HASH_PROTO_VERSION || (s.GetType() & SER_GETHASH)) {
+        if (s.GetVersion() < COINJOIN_PROTX_HASH_PROTO_VERSION) {
             READWRITE(obj.masternodeOutpoint);
         } else {
             READWRITE(obj.m_protxHash);
@@ -230,7 +230,7 @@ class CCoinJoinQueue
         }
     }
 
-    [[nodiscard]] uint256 GetSignatureHash() const;
+    [[nodiscard]] uint256 GetSignatureHash(bool legacy) const;
     /** Sign this mixing transaction
      *  return true if all conditions are met:
      *     1) we have an active Masternode,
@@ -292,7 +292,7 @@ class CCoinJoinBroadcastTx
     {
         READWRITE(obj.tx);
 
-        if (s.GetVersion() < COINJOIN_PROTX_HASH_PROTO_VERSION || (s.GetType() & SER_GETHASH)) {
+        if (s.GetVersion() < COINJOIN_PROTX_HASH_PROTO_VERSION) {
             READWRITE(obj.masternodeOutpoint);
         } else {
             READWRITE(obj.m_protxHash);
@@ -317,7 +317,7 @@ class CCoinJoinBroadcastTx
         return *this != CCoinJoinBroadcastTx();
     }
 
-    [[nodiscard]] uint256 GetSignatureHash() const;
+    [[nodiscard]] uint256 GetSignatureHash(bool legacy) const;
 
     bool Sign();
     [[nodiscard]] bool CheckSignature(const CBLSPublicKey& blsPubKey) const;