Merge #21640: [0.21] Introduce DeferredSignatureChecker and have SignatureExtractorClass subclass it

f79189ca54524881d52b91679eb9035d6718ce01 Test that signrawtx works when a signed CSV and CLTV inputs are present (Andrew Chow)
7de019bc619b0b2433bfb553feba5f6dc58c8db8 Introduce DeferringSignatureChecker and inherit with SignatureExtractor (Andrew Chow)

Pull request description:

  Backport of #21166

ACKs for top commit:
  MarcoFalke:
    checked this is a clean cherry-pick did not review ACK f79189ca54524881d52b91679eb9035d6718ce01 🐖
  instagibbs:
    ACK https://github.com/bitcoin/bitcoin/pull/21640/commits/f79189ca54524881d52b91679eb9035d6718ce01

Tree-SHA512: 51e945c9b353713423d3886c557066c66a6517d2300523832e5a5471ab91a8943385096d9bf5b46910477cb4c47470431690cf3da09b9f6956fe030f13ddff51

3 files changed, 111 insertions, 8 deletions

diff --git a/src/script/interpreter.h b/src/script/interpreter.h
index c0c2b012c6..70789869a0 100644
--- a/src/script/interpreter.h
+++ b/src/script/interpreter.h
@@ -272,6 +272,34 @@ public:
 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
index 0e6864d547..903c95a5c9 100644
--- 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;
diff --git a/test/functional/rpc_signrawtransaction.py b/test/functional/rpc_signrawtransaction.py
index 2fbbdbbdf0..60b4d1c744 100755
--- a/test/functional/rpc_signrawtransaction.py
+++ b/test/functional/rpc_signrawtransaction.py
@@ -4,16 +4,17 @@
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Test transaction signing using the signrawtransaction* RPCs."""
 
-from test_framework.address import check_script, script_to_p2sh
+from test_framework.address import check_script, script_to_p2sh, script_to_p2wsh
 from test_framework.key import ECKey
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import assert_equal, assert_raises_rpc_error, find_vout_for_address, hex_str_to_bytes
-from test_framework.messages import sha256
-from test_framework.script import CScript, OP_0, OP_CHECKSIG
+from test_framework.messages import sha256, CTransaction, CTxInWitness
+from test_framework.script import CScript, OP_0, OP_CHECKSIG, OP_CHECKSEQUENCEVERIFY, OP_CHECKLOCKTIMEVERIFY, OP_DROP, OP_TRUE
 from test_framework.script_util import key_to_p2pkh_script, script_to_p2sh_p2wsh_script, script_to_p2wsh_script
 from test_framework.wallet_util import bytes_to_wif
 
-from decimal import Decimal
+from decimal import Decimal, getcontext
+from io import BytesIO
 
 class SignRawTransactionsTest(BitcoinTestFramework):
     def set_test_params(self):
@@ -238,6 +239,78 @@ class SignRawTransactionsTest(BitcoinTestFramework):
         txn = self.nodes[0].signrawtransactionwithwallet(hex_str, prev_txs)
         assert txn["complete"]
 
+    def test_signing_with_csv(self):
+        self.log.info("Test signing a transaction containing a fully signed CSV input")
+        self.nodes[0].walletpassphrase("password", 9999)
+        getcontext().prec = 8
+
+        # Make sure CSV is active
+        self.nodes[0].generate(500)
+
+        # Create a P2WSH script with CSV
+        script = CScript([1, OP_CHECKSEQUENCEVERIFY, OP_DROP])
+        address = script_to_p2wsh(script)
+
+        # Fund that address and make the spend
+        txid = self.nodes[0].sendtoaddress(address, 1)
+        vout = find_vout_for_address(self.nodes[0], txid, address)
+        self.nodes[0].generate(1)
+        utxo = self.nodes[0].listunspent()[0]
+        amt = Decimal(1) + utxo["amount"] - Decimal(0.00001)
+        tx = self.nodes[0].createrawtransaction(
+            [{"txid": txid, "vout": vout, "sequence": 1},{"txid": utxo["txid"], "vout": utxo["vout"]}],
+            [{self.nodes[0].getnewaddress(): amt}],
+            self.nodes[0].getblockcount()
+        )
+
+        # Set the witness script
+        ctx = CTransaction()
+        ctx.deserialize(BytesIO(hex_str_to_bytes(tx)))
+        ctx.wit.vtxinwit.append(CTxInWitness())
+        ctx.wit.vtxinwit[0].scriptWitness.stack = [CScript([OP_TRUE]), script]
+        tx = ctx.serialize_with_witness().hex()
+
+        # Sign and send the transaction
+        signed = self.nodes[0].signrawtransactionwithwallet(tx)
+        assert_equal(signed["complete"], True)
+        self.nodes[0].sendrawtransaction(signed["hex"])
+
+    def test_signing_with_cltv(self):
+        self.log.info("Test signing a transaction containing a fully signed CLTV input")
+        self.nodes[0].walletpassphrase("password", 9999)
+        getcontext().prec = 8
+
+        # Make sure CSV is active
+        self.nodes[0].generate(1500)
+
+        # Create a P2WSH script with CLTV
+        script = CScript([1000, OP_CHECKLOCKTIMEVERIFY, OP_DROP])
+        address = script_to_p2wsh(script)
+
+        # Fund that address and make the spend
+        txid = self.nodes[0].sendtoaddress(address, 1)
+        vout = find_vout_for_address(self.nodes[0], txid, address)
+        self.nodes[0].generate(1)
+        utxo = self.nodes[0].listunspent()[0]
+        amt = Decimal(1) + utxo["amount"] - Decimal(0.00001)
+        tx = self.nodes[0].createrawtransaction(
+            [{"txid": txid, "vout": vout},{"txid": utxo["txid"], "vout": utxo["vout"]}],
+            [{self.nodes[0].getnewaddress(): amt}],
+            self.nodes[0].getblockcount()
+        )
+
+        # Set the witness script
+        ctx = CTransaction()
+        ctx.deserialize(BytesIO(hex_str_to_bytes(tx)))
+        ctx.wit.vtxinwit.append(CTxInWitness())
+        ctx.wit.vtxinwit[0].scriptWitness.stack = [CScript([OP_TRUE]), script]
+        tx = ctx.serialize_with_witness().hex()
+
+        # Sign and send the transaction
+        signed = self.nodes[0].signrawtransactionwithwallet(tx)
+        assert_equal(signed["complete"], True)
+        self.nodes[0].sendrawtransaction(signed["hex"])
+
     def run_test(self):
         self.successful_signing_test()
         self.script_verification_error_test()
@@ -245,6 +318,8 @@ class SignRawTransactionsTest(BitcoinTestFramework):
         self.OP_1NEGATE_test()
         self.test_with_lock_outputs()
         self.test_fully_signed_tx()
+        self.test_signing_with_csv()
+        self.test_signing_with_cltv()
 
 
 if __name__ == '__main__':