fix: remove incorrect request generation with bad serialization hash

We should not be generating the hash using a CTxIn, only a COutPoint

Author: kwvg

src/instantsend/instantsend.cpp

@@ -44,7 +44,11 @@ Uint256HashSet GetIdsFromLockable(const std::vector<T>& vec)
     if (vec.empty()) return ret;
     ret.reserve(vec.size());
     for (const auto& in : vec) {
-        ret.emplace(instantsend::GenInputLockRequestId(in));
+        if constexpr (std::is_same_v<T, CTxIn>) {
+            ret.emplace(instantsend::GenInputLockRequestId(in.prevout));
+        } else {
+            ret.emplace(instantsend::GenInputLockRequestId(in));
+        }
     }
     return ret;
 }

src/instantsend/lock.cpp

@@ -38,11 +38,8 @@ bool InstantSendLock::TriviallyValid() const
     return inputs_set.size() == inputs.size();
 }
 
-template <typename T>
-uint256 GenInputLockRequestId(const T& val)
+uint256 GenInputLockRequestId(const COutPoint& val)
 {
     return ::SerializeHash(std::make_pair(INPUTLOCK_REQUESTID_PREFIX, val));
 }
-template uint256 GenInputLockRequestId(const COutPoint& val);
-template uint256 GenInputLockRequestId(const CTxIn& val);
 } // namespace instantsend

src/instantsend/lock.h

@@ -40,8 +40,7 @@ struct InstantSendLock {
     bool TriviallyValid() const;
 };
 
-template <typename T>
-uint256 GenInputLockRequestId(const T& val);
+uint256 GenInputLockRequestId(const COutPoint& val);
 
 using InstantSendLockPtr = std::shared_ptr<InstantSendLock>;
 } // namespace instantsend

src/instantsend/signing.cpp

@@ -295,7 +295,7 @@ bool InstantSendSigner::TrySignInputLocks(const CTransaction& tx, bool fRetroact
 
     size_t alreadyVotedCount = 0;
     for (const auto& in : tx.vin) {
-        auto id = GenInputLockRequestId(in);
+        auto id = GenInputLockRequestId(in.prevout);
         ids.emplace_back(id);
 
         uint256 otherTxHash;
@@ -344,7 +344,7 @@ void InstantSendSigner::TrySignInstantSendLock(const CTransaction& tx)
     const auto llmqType = Params().GetConsensus().llmqTypeDIP0024InstantSend;
 
     for (const auto& in : tx.vin) {
-        auto id = GenInputLockRequestId(in);
+        auto id = GenInputLockRequestId(in.prevout);
         if (!m_sigman.HasRecoveredSig(llmqType, id, tx.GetHash())) {
             return;
         }