Introduce DeferringSignatureChecker and inherit with SignatureExtractor

achow101 · achow101 · commit 7de019bc619b · 2021-04-08T18:18:55.000-04:00
Introduces a DeferringSignatureChecker which simply takes a BaseSignatureChecker and passes through everything. SignatureExtractorChecker now subclasses DeferringSignatureChecker. This allows for all BaseSignatureChecker functions to be implemented for SignatureExtractorChecker, while allowing for future signature checkers which opreate similarly to SignatureExtractorChecker. Github-Pull: #21166 Rebased-From: 6965456
diff --git a/src/script/interpreter.h b/src/script/interpreter.h
@@ -272,6 +272,34 @@ class GenericTransactionSignatureChecker : public BaseSignatureChecker
 using TransactionSignatureChecker = GenericTransactionSignatureChecker<CTransaction>;
 using MutableTransactionSignatureChecker = GenericTransactionSignatureChecker<CMutableTransaction>;
 
+class DeferringSignatureChecker : public BaseSignatureChecker
+{
+protected:
+    BaseSignatureChecker& m_checker;
+
+public:
+    DeferringSignatureChecker(BaseSignatureChecker& checker) : m_checker(checker) {}
+
+    bool CheckECDSASignature(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode, SigVersion sigversion) const override
+    {
+        return m_checker.CheckECDSASignature(scriptSig, vchPubKey, scriptCode, sigversion);
+    }
+
+    bool CheckSchnorrSignature(Span<const unsigned char> sig, Span<const unsigned char> pubkey, SigVersion sigversion, const ScriptExecutionData& execdata, ScriptError* serror = nullptr) const override
+    {
+        return m_checker.CheckSchnorrSignature(sig, pubkey, sigversion, execdata, serror);
+    }
+
+    bool CheckLockTime(const CScriptNum& nLockTime) const override
+    {
+        return m_checker.CheckLockTime(nLockTime);
+    }
+    bool CheckSequence(const CScriptNum& nSequence) const override
+    {
+        return m_checker.CheckSequence(nSequence);
+    }
+};
+
 bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript& script, unsigned int flags, const BaseSignatureChecker& checker, SigVersion sigversion, ScriptExecutionData& execdata, ScriptError* error = nullptr);
 bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript& script, unsigned int flags, const BaseSignatureChecker& checker, SigVersion sigversion, ScriptError* error = nullptr);
 bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, const CScriptWitness* witness, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* serror = nullptr);
diff --git a/src/script/sign.cpp b/src/script/sign.cpp
@@ -253,17 +253,17 @@ bool ProduceSignature(const SigningProvider& provider, const BaseSignatureCreato
 }
 
 namespace {
-class SignatureExtractorChecker final : public BaseSignatureChecker
+class SignatureExtractorChecker final : public DeferringSignatureChecker
 {
 private:
     SignatureData& sigdata;
-    BaseSignatureChecker& checker;
 
 public:
-    SignatureExtractorChecker(SignatureData& sigdata, BaseSignatureChecker& checker) : sigdata(sigdata), checker(checker) {}
+    SignatureExtractorChecker(SignatureData& sigdata, BaseSignatureChecker& checker) : DeferringSignatureChecker(checker), sigdata(sigdata) {}
+
     bool CheckECDSASignature(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode, SigVersion sigversion) const override
     {
-        if (checker.CheckECDSASignature(scriptSig, vchPubKey, scriptCode, sigversion)) {
+        if (m_checker.CheckECDSASignature(scriptSig, vchPubKey, scriptCode, sigversion)) {
             CPubKey pubkey(vchPubKey);
             sigdata.signatures.emplace(pubkey.GetID(), SigPair(pubkey, scriptSig));
             return true;
