From 61b5152d445508f12155b477d77fa0940ae7fba7 Mon Sep 17 00:00:00 2001
From: sanket1729 <sanket1729@gmail.com>
Date: Wed, 25 Aug 2021 08:43:33 +0000
Subject: [PATCH] Expose transaction data via BaseSignatureChecker

---
 src/script/interpreter.cpp | 44 ++++++++++++++++++++++++++++++++++++++
 src/script/interpreter.h   | 43 +++++++++++++++++++++++++++++++++++++
 2 files changed, 87 insertions(+)

diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
index 03cbca8954..dd9bcdb0e2 100644
--- a/src/script/interpreter.cpp
+++ b/src/script/interpreter.cpp
@@ -5,6 +5,7 @@
 
 #include <script/interpreter.h>
 
+#include <consensus/consensus.h>
 #include <crypto/ripemd160.h>
 #include <crypto/sha1.h>
 #include <crypto/sha256.h>
@@ -2398,6 +2399,49 @@ bool GenericTransactionSignatureChecker<T>::CheckSequence(const CScriptNum& nSeq
     return true;
 }
 
+template <class T>
+uint32_t GenericTransactionSignatureChecker<T>::GetLockTime() const
+{
+    return txTo->nLockTime;
+}
+
+template <class T>
+int32_t GenericTransactionSignatureChecker<T>::GetTxVersion() const
+{
+    return txTo->nVersion;
+}
+
+template <class T>
+const std::vector<CTxIn>* GenericTransactionSignatureChecker<T>::GetTxvIn() const
+{
+    return &(txTo->vin);
+}
+
+template <class T>
+const std::vector<CTxOut>* GenericTransactionSignatureChecker<T>::GetTxvOut() const
+{
+    return &(txTo->vout);
+}
+
+template <class T>
+uint64_t GenericTransactionSignatureChecker<T>::GetTxWeight() const
+{
+    // line copied from GetTransactionWeight() in src/consensus/validation.h
+    return ::GetSerializeSize(*txTo, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) * (WITNESS_SCALE_FACTOR - 1) + ::GetSerializeSize(*txTo, PROTOCOL_VERSION);
+}
+
+template <class T>
+const PrecomputedTransactionData* GenericTransactionSignatureChecker<T>::GetPrecomputedTransactionData() const
+{
+    return txdata;
+}
+
+template <class T>
+uint32_t GenericTransactionSignatureChecker<T>::GetnIn() const
+{
+    return nIn;
+}
+
 // explicit instantiation
 template class GenericTransactionSignatureChecker<CTransaction>;
 template class GenericTransactionSignatureChecker<CMutableTransaction>;
diff --git a/src/script/interpreter.h b/src/script/interpreter.h
index 2837c932d0..c452c5dc29 100644
--- a/src/script/interpreter.h
+++ b/src/script/interpreter.h
@@ -269,6 +269,41 @@ public:
          return false;
     }
 
+    virtual const std::vector<CTxIn>* GetTxvIn() const
+    {
+        return nullptr;
+    }
+
+    virtual const std::vector<CTxOut>* GetTxvOut() const
+    {
+        return nullptr;
+    }
+
+    virtual uint32_t GetLockTime() const
+    {
+        return 0;
+    }
+
+    virtual int32_t GetTxVersion() const
+    {
+        return 0;
+    }
+
+    virtual uint64_t GetTxWeight() const
+    {
+        return 0;
+    }
+
+    virtual const PrecomputedTransactionData* GetPrecomputedTransactionData() const
+    {
+        return nullptr;
+    }
+
+    virtual uint32_t GetnIn() const
+    {
+        return std::numeric_limits<uint32_t>::max();
+    }
+
     virtual ~BaseSignatureChecker() {}
 };
 
@@ -292,6 +327,14 @@ public:
     bool CheckSchnorrSignature(Span<const unsigned char> sig, Span<const unsigned char> pubkey, SigVersion sigversion, const ScriptExecutionData& execdata, ScriptError* serror = nullptr) const override;
     bool CheckLockTime(const CScriptNum& nLockTime) const override;
     bool CheckSequence(const CScriptNum& nSequence) const override;
+    const std::vector<CTxIn>* GetTxvIn() const override;
+    const std::vector<CTxOut>* GetTxvOut() const override;
+    uint32_t GetLockTime() const override;
+    int32_t GetTxVersion() const override;
+    uint64_t GetTxWeight() const override;
+
+    const PrecomputedTransactionData* GetPrecomputedTransactionData() const override;
+    uint32_t GetnIn() const override;
 };
 
 using TransactionSignatureChecker = GenericTransactionSignatureChecker<CTransaction>;