text: // Copyright (c) 2012-2020 The BitcoinDX Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include <consensus/tx_verify.h>
  #include <key.h>
  #include <policy/policy.h>
  #include <policy/settings.h>
  #include <script/script.h>
  #include <script/script_error.h>
  #include <script/sign.h>
  #include <script/signingprovider.h>
  #include <test/util/setup_common.h>
  #include <validation.h>
  
  #include <vector>
  
  #include <boost/test/unit_test.hpp>
  
  // Helpers:
  static std::vector<unsigned char>
  Serialize(const CScript& s)
  {
      std::vector<unsigned char> sSerialized(s.begin(), s.end());
      return sSerialized;
  }
  
  static bool
  Verify(const CScript& scriptSig, const CScript& scriptPubKey, bool fStrict, ScriptError& err)
  {
      // Create dummy to/from transactions:
      CMutableTransaction txFrom;
      txFrom.vout.resize(1);
      txFrom.vout[0].scriptPubKey = scriptPubKey;
  
      CMutableTransaction txTo;
      txTo.vin.resize(1);
      txTo.vout.resize(1);
      txTo.vin[0].prevout.n = 0;
      txTo.vin[0].prevout.hash = txFrom.GetHash();
      txTo.vin[0].scriptSig = scriptSig;
      txTo.vout[0].nValue = 1;
  
      return VerifyScript(scriptSig, scriptPubKey, nullptr, fStrict ? SCRIPT_VERIFY_P2SH : SCRIPT_VERIFY_NONE, MutableTransactionSignatureChecker(&txTo, 0, txFrom.vout[0].nValue, MissingDataBehavior::ASSERT_FAIL), &err);
  }
  
  
  BOOST_FIXTURE_TEST_SUITE(script_p2sh_tests, BasicTestingSetup)
  
  BOOST_AUTO_TEST_CASE(sign)
  {
      LOCK(cs_main);
      // Pay-to-script-hash looks like this:
      // scriptSig:    <sig> <sig...> <serialized_script>
      // scriptPubKey: HASH160 <hash> EQUAL
  
      // Test SignSignature() (and therefore the version of Solver() that signs transactions)
      FillableSigningProvider keystore;
      CKey key[4];
      for (int i = 0; i < 4; i++)
      {
          key[i].MakeNewKey(true);
          BOOST_CHECK(keystore.AddKey(key[i]));
      }
  
      // 8 Scripts: checking all combinations of
      // different keys, straight/P2SH, pubkey/pubkeyhash
      CScript standardScripts[4];
      standardScripts[0] << ToByteVector(key[0].GetPubKey()) << OP_CHECKSIG;
      standardScripts[1] = GetScriptForDestination(PKHash(key[1].GetPubKey()));
      standardScripts[2] << ToByteVector(key[1].GetPubKey()) << OP_CHECKSIG;
      standardScripts[3] = GetScriptForDestination(PKHash(key[2].GetPubKey()));
      CScript evalScripts[4];
      for (int i = 0; i < 4; i++)
      {
          BOOST_CHECK(keystore.AddCScript(standardScripts[i]));
          evalScripts[i] = GetScriptForDestination(ScriptHash(standardScripts[i]));
      }
  
      CMutableTransaction txFrom;  // Funding transaction:
      std::string reason;
      txFrom.vout.resize(8);
      for (int i = 0; i < 4; i++)
      {
          txFrom.vout[i].scriptPubKey = evalScripts[i];
          txFrom.vout[i].nValue = COIN;
          txFrom.vout[i+4].scriptPubKey = standardScripts[i];
          txFrom.vout[i+4].nValue = COIN;
      }
      BOOST_CHECK(IsStandardTx(CTransaction(txFrom), reason));
  
      CMutableTransaction txTo[8]; // Spending transactions
      for (int i = 0; i < 8; i++)
      {
          txTo[i].vin.resize(1);
          txTo[i].vout.resize(1);
          txTo[i].vin[0].prevout.n = i;
          txTo[i].vin[0].prevout.hash = txFrom.GetHash();
          txTo[i].vout[0].nValue = 1;
      }
      for (int i = 0; i < 8; i++)
      {
          BOOST_CHECK_MESSAGE(SignSignature(keystore, CTransaction(txFrom), txTo[i], 0, SIGHASH_ALL), strprintf("SignSignature %d", i));
      }
      // All of the above should be OK, and the txTos have valid signatures
      // Check to make sure signature verification fails if we use the wrong ScriptSig:
      for (int i = 0; i < 8; i++) {
          PrecomputedTransactionData txdata(txTo[i]);
          for (int j = 0; j < 8; j++)
          {
              CScript sigSave = txTo[i].vin[0].scriptSig;
              txTo[i].vin[0].scriptSig = txTo[j].vin[0].scriptSig;
              bool sigOK = CScriptCheck(txFrom.vout[txTo[i].vin[0].prevout.n], CTransaction(txTo[i]), 0, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_STRICTENC, false, &txdata)();
              if (i == j)
                  BOOST_CHECK_MESSAGE(sigOK, strprintf("VerifySignature %d %d", i, j));
              else
                  BOOST_CHECK_MESSAGE(!sigOK, strprintf("VerifySignature %d %d", i, j));
              txTo[i].vin[0].scriptSig = sigSave;
          }
      }
  }
  
  BOOST_AUTO_TEST_CASE(norecurse)
  {
      ScriptError err;
      // Make sure only the outer pay-to-script-hash does the
      // extra-validation thing:
      CScript invalidAsScript;
      invalidAsScript << OP_INVALIDOPCODE << OP_INVALIDOPCODE;
  
      CScript p2sh = GetScriptForDestination(ScriptHash(invalidAsScript));
  
      CScript scriptSig;
      scriptSig << Serialize(invalidAsScript);
  
      // Should not verify, because it will try to execute OP_INVALIDOPCODE
      BOOST_CHECK(!Verify(scriptSig, p2sh, true, err));
      BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_BAD_OPCODE, ScriptErrorString(err));
  
      // Try to recur, and verification should succeed because
      // the inner HASH160 <> EQUAL should only check the hash:
      CScript p2sh2 = GetScriptForDestination(ScriptHash(p2sh));
      CScript scriptSig2;
      scriptSig2 << Serialize(invalidAsScript) << Serialize(p2sh);
  
      BOOST_CHECK(Verify(scriptSig2, p2sh2, true, err));
      BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_OK, ScriptErrorString(err));
  }
  
  BOOST_AUTO_TEST_CASE(set)
  {
      LOCK(cs_main);
      // Test the CScript::Set* methods
      FillableSigningProvider keystore;
      CKey key[4];
      std::vector<CPubKey> keys;
      for (int i = 0; i < 4; i++)
      {
          key[i].MakeNewKey(true);
          BOOST_CHECK(keystore.AddKey(key[i]));
          keys.push_back(key[i].GetPubKey());
      }
  
      CScript inner[4];
      inner[0] = GetScriptForDestination(PKHash(key[0].GetPubKey()));
      inner[1] = GetScriptForMultisig(2, std::vector<CPubKey>(keys.begin(), keys.begin()+2));
      inner[2] = GetScriptForMultisig(1, std::vector<CPubKey>(keys.begin(), keys.begin()+2));
      inner[3] = GetScriptForMultisig(2, std::vector<CPubKey>(keys.begin(), keys.begin()+3));
  
      CScript outer[4];
      for (int i = 0; i < 4; i++)
      {
          outer[i] = GetScriptForDestination(ScriptHash(inner[i]));
          BOOST_CHECK(keystore.AddCScript(inner[i]));
      }
  
      CMutableTransaction txFrom;  // Funding transaction:
      std::string reason;
      txFrom.vout.resize(4);
      for (int i = 0; i < 4; i++)
      {
          txFrom.vout[i].scriptPubKey = outer[i];
          txFrom.vout[i].nValue = CENT;
      }
      BOOST_CHECK(IsStandardTx(CTransaction(txFrom), reason));
  
      CMutableTransaction txTo[4]; // Spending transactions
      for (int i = 0; i < 4; i++)
      {
          txTo[i].vin.resize(1);
          txTo[i].vout.resize(1);
          txTo[i].vin[0].prevout.n = i;
          txTo[i].vin[0].prevout.hash = txFrom.GetHash();
          txTo[i].vout[0].nValue = 1*CENT;
          txTo[i].vout[0].scriptPubKey = inner[i];
      }
      for (int i = 0; i < 4; i++)
      {
          BOOST_CHECK_MESSAGE(SignSignature(keystore, CTransaction(txFrom), txTo[i], 0, SIGHASH_ALL), strprintf("SignSignature %d", i));
          BOOST_CHECK_MESSAGE(IsStandardTx(CTransaction(txTo[i]), reason), strprintf("txTo[%d].IsStandard", i));
      }
  }
  
  BOOST_AUTO_TEST_CASE(is)
  {
      // Test CScript::IsPayToScriptHash()
      uint160 dummy;
      CScript p2sh;
      p2sh << OP_HASH160 << ToByteVector(dummy) << OP_EQUAL;
      BOOST_CHECK(p2sh.IsPayToScriptHash());
  
      std::vector<unsigned char> direct = {OP_HASH160, 20};
      direct.insert(direct.end(), 20, 0);
      direct.push_back(OP_EQUAL);
      BOOST_CHECK(CScript(direct.begin(), direct.end()).IsPayToScriptHash());
  
      // Not considered pay-to-script-hash if using one of the OP_PUSHDATA opcodes:
      std::vector<unsigned char> pushdata1 = {OP_HASH160, OP_PUSHDATA1, 20};
      pushdata1.insert(pushdata1.end(), 20, 0);
      pushdata1.push_back(OP_EQUAL);
      BOOST_CHECK(!CScript(pushdata1.begin(), pushdata1.end()).IsPayToScriptHash());
      std::vector<unsigned char> pushdata2 = {OP_HASH160, OP_PUSHDATA2, 20, 0};
      pushdata2.insert(pushdata2.end(), 20, 0);
      pushdata2.push_back(OP_EQUAL);
      BOOST_CHECK(!CScript(pushdata2.begin(), pushdata2.end()).IsPayToScriptHash());
      std::vector<unsigned char> pushdata4 = {OP_HASH160, OP_PUSHDATA4, 20, 0, 0, 0};
      pushdata4.insert(pushdata4.end(), 20, 0);
      pushdata4.push_back(OP_EQUAL);
      BOOST_CHECK(!CScript(pushdata4.begin(), pushdata4.end()).IsPayToScriptHash());
  
      CScript not_p2sh;
      BOOST_CHECK(!not_p2sh.IsPayToScriptHash());
  
      not_p2sh.clear(); not_p2sh << OP_HASH160 << ToByteVector(dummy) << ToByteVector(dummy) << OP_EQUAL;
      BOOST_CHECK(!not_p2sh.IsPayToScriptHash());
  
      not_p2sh.clear(); not_p2sh << OP_NOP << ToByteVector(dummy) << OP_EQUAL;
      BOOST_CHECK(!not_p2sh.IsPayToScriptHash());
  
      not_p2sh.clear(); not_p2sh << OP_HASH160 << ToByteVector(dummy) << OP_CHECKSIG;
      BOOST_CHECK(!not_p2sh.IsPayToScriptHash());
  }
  
  BOOST_AUTO_TEST_CASE(switchover)
  {
      // Test switch over code
      CScript notValid;
      ScriptError err;
      notValid << OP_11 << OP_12 << OP_EQUALVERIFY;
      CScript scriptSig;
      scriptSig << Serialize(notValid);
  
      CScript fund = GetScriptForDestination(ScriptHash(notValid));
  
  
      // Validation should succeed under old rules (hash is correct):
      BOOST_CHECK(Verify(scriptSig, fund, false, err));
      BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_OK, ScriptErrorString(err));
      // Fail under new:
      BOOST_CHECK(!Verify(scriptSig, fund, true, err));
      BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_EQUALVERIFY, ScriptErrorString(err));
  }
  
  BOOST_AUTO_TEST_CASE(AreInputsStandard)
  {
      LOCK(cs_main);
      CCoinsView coinsDummy;
      CCoinsViewCache coins(&coinsDummy);
      FillableSigningProvider keystore;
      CKey key[6];
      std::vector<CPubKey> keys;
      for (int i = 0; i < 6; i++)
      {
          key[i].MakeNewKey(true);
          BOOST_CHECK(keystore.AddKey(key[i]));
      }
      for (int i = 0; i < 3; i++)
          keys.push_back(key[i].GetPubKey());
  
      CMutableTransaction txFrom;
      txFrom.vout.resize(7);
  
      // First three are standard:
      CScript pay1 = GetScriptForDestination(PKHash(key[0].GetPubKey()));
      BOOST_CHECK(keystore.AddCScript(pay1));
      CScript pay1of3 = GetScriptForMultisig(1, keys);
  
      txFrom.vout[0].scriptPubKey = GetScriptForDestination(ScriptHash(pay1)); // P2SH (OP_CHECKSIG)
      txFrom.vout[0].nValue = 1000;
      txFrom.vout[1].scriptPubKey = pay1; // ordinary OP_CHECKSIG
      txFrom.vout[1].nValue = 2000;
      txFrom.vout[2].scriptPubKey = pay1of3; // ordinary OP_CHECKMULTISIG
      txFrom.vout[2].nValue = 3000;
  
      // vout[3] is complicated 1-of-3 AND 2-of-3
      // ... that is OK if wrapped in P2SH:
      CScript oneAndTwo;
      oneAndTwo << OP_1 << ToByteVector(key[0].GetPubKey()) << ToByteVector(key[1].GetPubKey()) << ToByteVector(key[2].GetPubKey());
      oneAndTwo << OP_3 << OP_CHECKMULTISIGVERIFY;
      oneAndTwo << OP_2 << ToByteVector(key[3].GetPubKey()) << ToByteVector(key[4].GetPubKey()) << ToByteVector(key[5].GetPubKey());
      oneAndTwo << OP_3 << OP_CHECKMULTISIG;
      BOOST_CHECK(keystore.AddCScript(oneAndTwo));
      txFrom.vout[3].scriptPubKey = GetScriptForDestination(ScriptHash(oneAndTwo));
      txFrom.vout[3].nValue = 4000;
  
      // vout[4] is max sigops:
      CScript fifteenSigops; fifteenSigops << OP_1;
      for (unsigned i = 0; i < MAX_P2SH_SIGOPS; i++)
          fifteenSigops << ToByteVector(key[i%3].GetPubKey());
      fifteenSigops << OP_15 << OP_CHECKMULTISIG;
      BOOST_CHECK(keystore.AddCScript(fifteenSigops));
      txFrom.vout[4].scriptPubKey = GetScriptForDestination(ScriptHash(fifteenSigops));
      txFrom.vout[4].nValue = 5000;
  
      // vout[5/6] are non-standard because they exceed MAX_P2SH_SIGOPS
      CScript sixteenSigops; sixteenSigops << OP_16 << OP_CHECKMULTISIG;
      BOOST_CHECK(keystore.AddCScript(sixteenSigops));
      txFrom.vout[5].scriptPubKey = GetScriptForDestination(ScriptHash(sixteenSigops));
      txFrom.vout[5].nValue = 5000;
      CScript twentySigops; twentySigops << OP_CHECKMULTISIG;
      BOOST_CHECK(keystore.AddCScript(twentySigops));
      txFrom.vout[6].scriptPubKey = GetScriptForDestination(ScriptHash(twentySigops));
      txFrom.vout[6].nValue = 6000;
  
      AddCoins(coins, CTransaction(txFrom), 0);
  
      CMutableTransaction txTo;
      txTo.vout.resize(1);
      txTo.vout[0].scriptPubKey = GetScriptForDestination(PKHash(key[1].GetPubKey()));
  
      txTo.vin.resize(5);
      for (int i = 0; i < 5; i++)
      {
          txTo.vin[i].prevout.n = i;
          txTo.vin[i].prevout.hash = txFrom.GetHash();
      }
      BOOST_CHECK(SignSignature(keystore, CTransaction(txFrom), txTo, 0, SIGHASH_ALL));
      BOOST_CHECK(SignSignature(keystore, CTransaction(txFrom), txTo, 1, SIGHASH_ALL));
      BOOST_CHECK(SignSignature(keystore, CTransaction(txFrom), txTo, 2, SIGHASH_ALL));
      // SignSignature doesn't know how to sign these. We're
      // not testing validating signatures, so just create
      // dummy signatures that DO include the correct P2SH scripts:
      txTo.vin[3].scriptSig << OP_11 << OP_11 << std::vector<unsigned char>(oneAndTwo.begin(), oneAndTwo.end());
      txTo.vin[4].scriptSig << std::vector<unsigned char>(fifteenSigops.begin(), fifteenSigops.end());
  
      BOOST_CHECK(::AreInputsStandard(CTransaction(txTo), coins, false));
      // 22 P2SH sigops for all inputs (1 for vin[0], 6 for vin[3], 15 for vin[4]
      BOOST_CHECK_EQUAL(GetP2SHSigOpCount(CTransaction(txTo), coins), 22U);
  
      CMutableTransaction txToNonStd1;
      txToNonStd1.vout.resize(1);
      txToNonStd1.vout[0].scriptPubKey = GetScriptForDestination(PKHash(key[1].GetPubKey()));
      txToNonStd1.vout[0].nValue = 1000;
      txToNonStd1.vin.resize(1);
      txToNonStd1.vin[0].prevout.n = 5;
      txToNonStd1.vin[0].prevout.hash = txFrom.GetHash();
      txToNonStd1.vin[0].scriptSig << std::vector<unsigned char>(sixteenSigops.begin(), sixteenSigops.end());
  
      BOOST_CHECK(!::AreInputsStandard(CTransaction(txToNonStd1), coins, false));
      BOOST_CHECK_EQUAL(GetP2SHSigOpCount(CTransaction(txToNonStd1), coins), 16U);
  
      CMutableTransaction txToNonStd2;
      txToNonStd2.vout.resize(1);
      txToNonStd2.vout[0].scriptPubKey = GetScriptForDestination(PKHash(key[1].GetPubKey()));
      txToNonStd2.vout[0].nValue = 1000;
      txToNonStd2.vin.resize(1);
      txToNonStd2.vin[0].prevout.n = 6;
      txToNonStd2.vin[0].prevout.hash = txFrom.GetHash();
      txToNonStd2.vin[0].scriptSig << std::vector<unsigned char>(twentySigops.begin(), twentySigops.end());
  
      BOOST_CHECK(!::AreInputsStandard(CTransaction(txToNonStd2), coins, false));
      BOOST_CHECK_EQUAL(GetP2SHSigOpCount(CTransaction(txToNonStd2), coins), 20U);
  }
  
  BOOST_AUTO_TEST_SUITE_END()
  