text: // Copyright (c) 2018-2019 The Dash Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "deterministicmns.h"
  #include "providertx.h"
  #include "specialtx.h"
  
  #include "base58.h"
  #include "chainparams.h"
  #include "clientversion.h"
  #include "core_io.h"
  #include "hash.h"
  #include "messagesigner.h"
  #include "script/standard.h"
  #include "streams.h"
  #include "univalue.h"
  #include "validation.h"
  
  template <typename ProTx>
  static bool CheckService(const uint256& proTxHash, const ProTx& proTx, CValidationState& state)
  {
      if (!proTx.addr.IsValid()) {
          return state.DoS(10, false, REJECT_INVALID, "bad-protx-addr");
      }
      if (Params().NetworkIDString() != CBaseChainParams::REGTEST && !proTx.addr.IsRoutable()) {
          return state.DoS(10, false, REJECT_INVALID, "bad-protx-addr");
      }
  
      int mainnetDefaultPort = Params(CBaseChainParams::MAIN).GetDefaultPort();
      if (Params().NetworkIDString() == CBaseChainParams::MAIN) {
          if (proTx.addr.GetPort() != mainnetDefaultPort) {
              return state.DoS(10, false, REJECT_INVALID, "bad-protx-addr-port");
          }
      } else if (proTx.addr.GetPort() == mainnetDefaultPort) {
          return state.DoS(10, false, REJECT_INVALID, "bad-protx-addr-port");
      }
  
      if (!proTx.addr.IsIPv4()) {
          return state.DoS(10, false, REJECT_INVALID, "bad-protx-addr");
      }
  
      return true;
  }
  
  template <typename ProTx>
  static bool CheckHashSig(const ProTx& proTx, const CKeyID& keyID, CValidationState& state)
  {
      std::string strError;
      if (!CHashSigner::VerifyHash(::SerializeHash(proTx), keyID, proTx.vchSig, strError)) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-sig", false, strError);
      }
      return true;
  }
  
  template <typename ProTx>
  static bool CheckStringSig(const ProTx& proTx, const CKeyID& keyID, CValidationState& state)
  {
      std::string strError;
      if (!CMessageSigner::VerifyMessage(keyID, proTx.vchSig, proTx.MakeSignString(), strError)) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-sig", false, strError);
      }
      return true;
  }
  
  template <typename ProTx>
  static bool CheckHashSig(const ProTx& proTx, const CBLSPublicKey& pubKey, CValidationState& state)
  {
      if (!proTx.sig.VerifyInsecure(pubKey, ::SerializeHash(proTx))) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-sig", false);
      }
      return true;
  }
  
  template <typename ProTx>
  static bool CheckInputsHash(const CTransaction& tx, const ProTx& proTx, CValidationState& state)
  {
      uint256 inputsHash = CalcTxInputsHash(tx);
      if (inputsHash != proTx.inputsHash) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-inputs-hash");
      }
  
      return true;
  }
  
  bool CheckProRegTx(const CTransaction& tx, const CBlockIndex* pindexPrev, CValidationState& state)
  {
      if (tx.nType != TRANSACTION_PROVIDER_REGISTER) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-type");
      }
  
      CProRegTx ptx;
      if (!GetTxPayload(tx, ptx)) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-payload");
      }
  
      if (ptx.nVersion == 0 || ptx.nVersion > CProRegTx::CURRENT_VERSION) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-version");
      }
      if (ptx.nType != 0) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-type");
      }
      if (ptx.nMode != 0) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-mode");
      }
  
      if (ptx.keyIDOwner.IsNull() || !ptx.pubKeyOperator.IsValid() || ptx.keyIDVoting.IsNull()) {
          return state.DoS(10, false, REJECT_INVALID, "bad-protx-key-null");
      }
      if (!ptx.scriptPayout.IsPayToPublicKeyHash() && !ptx.scriptPayout.IsPayToScriptHash()) {
          return state.DoS(10, false, REJECT_INVALID, "bad-protx-payee");
      }
  
      CTxDestination payoutDest;
      if (!ExtractDestination(ptx.scriptPayout, payoutDest)) {
          // should not happen as we checked script types before
          return state.DoS(10, false, REJECT_INVALID, "bad-protx-payee-dest");
      }
      // don't allow reuse of payout key for other keys (don't allow people to put the payee key onto an online server)
      if (payoutDest == CTxDestination(ptx.keyIDOwner) || payoutDest == CTxDestination(ptx.keyIDVoting)) {
          return state.DoS(10, false, REJECT_INVALID, "bad-protx-payee-reuse");
      }
  
      // It's allowed to set addr to 0, which will put the MN into PoSe-banned state and require a ProUpServTx to be issues later
      // If any of both is set, it must be valid however
      if (ptx.addr != CService() && !CheckService(tx.GetHash(), ptx, state)) {
          return false;
      }
  
      if (ptx.nOperatorReward > 10000) {
          return state.DoS(10, false, REJECT_INVALID, "bad-protx-operator-reward");
      }
  
      CTxDestination collateralTxDest;
      CKeyID keyForPayloadSig;
      COutPoint collateralOutpoint;
  
      if (!ptx.collateralOutpoint.hash.IsNull()) {
          Coin coin;
          if (!GetUTXOCoin(ptx.collateralOutpoint, coin) || coin.out.nValue != 10000 * COIN) {
              return state.DoS(10, false, REJECT_INVALID, "bad-protx-collateral");
          }
  
          if (!ExtractDestination(coin.out.scriptPubKey, collateralTxDest)) {
              return state.DoS(10, false, REJECT_INVALID, "bad-protx-collateral-dest");
          }
  
          // Extract key from collateral. This only works for P2PK and P2PKH collaterals and will fail for P2SH.
          // Issuer of this ProRegTx must prove ownership with this key by signing the ProRegTx
          if (!CBitcoinAddress(collateralTxDest).GetKeyID(keyForPayloadSig)) {
              return state.DoS(10, false, REJECT_INVALID, "bad-protx-collateral-pkh");
          }
  
          collateralOutpoint = ptx.collateralOutpoint;
      } else {
          if (ptx.collateralOutpoint.n >= tx.vout.size()) {
              return state.DoS(10, false, REJECT_INVALID, "bad-protx-collateral-index");
          }
          if (tx.vout[ptx.collateralOutpoint.n].nValue != 10000 * COIN) {
              return state.DoS(10, false, REJECT_INVALID, "bad-protx-collateral");
          }
  
          if (!ExtractDestination(tx.vout[ptx.collateralOutpoint.n].scriptPubKey, collateralTxDest)) {
              return state.DoS(10, false, REJECT_INVALID, "bad-protx-collateral-dest");
          }
  
          collateralOutpoint = COutPoint(tx.GetHash(), ptx.collateralOutpoint.n);
      }
  
      // don't allow reuse of collateral key for other keys (don't allow people to put the collateral key onto an online server)
      // this check applies to internal and external collateral, but internal collaterals are not necessarely a P2PKH
      if (collateralTxDest == CTxDestination(ptx.keyIDOwner) || collateralTxDest == CTxDestination(ptx.keyIDVoting)) {
          return state.DoS(10, false, REJECT_INVALID, "bad-protx-collateral-reuse");
      }
  
      if (pindexPrev) {
          auto mnList = deterministicMNManager->GetListForBlock(pindexPrev->GetBlockHash());
  
          // only allow reusing of addresses when it's for the same collateral (which replaces the old MN)
          if (mnList.HasUniqueProperty(ptx.addr) && mnList.GetUniquePropertyMN(ptx.addr)->collateralOutpoint != collateralOutpoint) {
              return state.DoS(10, false, REJECT_DUPLICATE, "bad-protx-dup-addr");
          }
  
          // never allow duplicate keys, even if this ProTx would replace an existing MN
          if (mnList.HasUniqueProperty(ptx.keyIDOwner) || mnList.HasUniqueProperty(ptx.pubKeyOperator)) {
              return state.DoS(10, false, REJECT_DUPLICATE, "bad-protx-dup-key");
          }
  
          if (!deterministicMNManager->IsDIP3Enforced(pindexPrev->nHeight)) {
              if (ptx.keyIDOwner != ptx.keyIDVoting) {
                  return state.DoS(10, false, REJECT_INVALID, "bad-protx-key-not-same");
              }
          }
      }
  
      if (!CheckInputsHash(tx, ptx, state)) {
          return false;
      }
  
      if (!keyForPayloadSig.IsNull()) {
          // collateral is not part of this ProRegTx, so we must verify ownership of the collateral
          if (!CheckStringSig(ptx, keyForPayloadSig, state)) {
              return false;
          }
      } else {
          // collateral is part of this ProRegTx, so we know the collateral is owned by the issuer
          if (!ptx.vchSig.empty()) {
              return state.DoS(100, false, REJECT_INVALID, "bad-protx-sig");
          }
      }
  
      return true;
  }
  
  bool CheckProUpServTx(const CTransaction& tx, const CBlockIndex* pindexPrev, CValidationState& state)
  {
      if (tx.nType != TRANSACTION_PROVIDER_UPDATE_SERVICE) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-type");
      }
  
      CProUpServTx ptx;
      if (!GetTxPayload(tx, ptx)) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-payload");
      }
  
      if (ptx.nVersion == 0 || ptx.nVersion > CProRegTx::CURRENT_VERSION) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-version");
      }
  
      if (!CheckService(ptx.proTxHash, ptx, state)) {
          return false;
      }
  
      if (pindexPrev) {
          auto mnList = deterministicMNManager->GetListForBlock(pindexPrev->GetBlockHash());
          auto mn = mnList.GetMN(ptx.proTxHash);
          if (!mn) {
              return state.DoS(100, false, REJECT_INVALID, "bad-protx-hash");
          }
  
          // don't allow updating to addresses already used by other MNs
          if (mnList.HasUniqueProperty(ptx.addr) && mnList.GetUniquePropertyMN(ptx.addr)->proTxHash != ptx.proTxHash) {
              return state.DoS(10, false, REJECT_DUPLICATE, "bad-protx-dup-addr");
          }
  
          if (ptx.scriptOperatorPayout != CScript()) {
              if (mn->nOperatorReward == 0) {
                  // don't allow to set operator reward payee in case no operatorReward was set
                  return state.DoS(10, false, REJECT_INVALID, "bad-protx-operator-payee");
              }
              if (!ptx.scriptOperatorPayout.IsPayToPublicKeyHash() && !ptx.scriptOperatorPayout.IsPayToScriptHash()) {
                  return state.DoS(10, false, REJECT_INVALID, "bad-protx-operator-payee");
              }
          }
  
          // we can only check the signature if pindexPrev != NULL and the MN is known
          if (!CheckInputsHash(tx, ptx, state)) {
              return false;
          }
          if (!CheckHashSig(ptx, mn->pdmnState->pubKeyOperator.Get(), state)) {
              return false;
          }
      }
  
      return true;
  }
  
  bool CheckProUpRegTx(const CTransaction& tx, const CBlockIndex* pindexPrev, CValidationState& state)
  {
      if (tx.nType != TRANSACTION_PROVIDER_UPDATE_REGISTRAR) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-type");
      }
  
      CProUpRegTx ptx;
      if (!GetTxPayload(tx, ptx)) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-payload");
      }
  
      if (ptx.nVersion == 0 || ptx.nVersion > CProRegTx::CURRENT_VERSION) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-version");
      }
      if (ptx.nMode != 0) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-mode");
      }
  
      if (!ptx.pubKeyOperator.IsValid() || ptx.keyIDVoting.IsNull()) {
          return state.DoS(10, false, REJECT_INVALID, "bad-protx-key-null");
      }
      if (!ptx.scriptPayout.IsPayToPublicKeyHash() && !ptx.scriptPayout.IsPayToScriptHash()) {
          return state.DoS(10, false, REJECT_INVALID, "bad-protx-payee");
      }
  
      CTxDestination payoutDest;
      if (!ExtractDestination(ptx.scriptPayout, payoutDest)) {
          // should not happen as we checked script types before
          return state.DoS(10, false, REJECT_INVALID, "bad-protx-payee-dest");
      }
  
      if (pindexPrev) {
          auto mnList = deterministicMNManager->GetListForBlock(pindexPrev->GetBlockHash());
          auto dmn = mnList.GetMN(ptx.proTxHash);
          if (!dmn) {
              return state.DoS(100, false, REJECT_INVALID, "bad-protx-hash");
          }
  
          // don't allow reuse of payee key for other keys (don't allow people to put the payee key onto an online server)
          if (payoutDest == CTxDestination(dmn->pdmnState->keyIDOwner) || payoutDest == CTxDestination(ptx.keyIDVoting)) {
              return state.DoS(10, false, REJECT_INVALID, "bad-protx-payee-reuse");
          }
  
          Coin coin;
          if (!GetUTXOCoin(dmn->collateralOutpoint, coin)) {
              // this should never happen (there would be no dmn otherwise)
              return state.DoS(100, false, REJECT_INVALID, "bad-protx-collateral");
          }
  
          // don't allow reuse of collateral key for other keys (don't allow people to put the collateral key onto an online server)
          CTxDestination collateralTxDest;
          if (!ExtractDestination(coin.out.scriptPubKey, collateralTxDest)) {
              return state.DoS(100, false, REJECT_INVALID, "bad-protx-collateral-dest");
          }
          if (collateralTxDest == CTxDestination(dmn->pdmnState->keyIDOwner) || collateralTxDest == CTxDestination(ptx.keyIDVoting)) {
              return state.DoS(10, false, REJECT_INVALID, "bad-protx-collateral-reuse");
          }
  
          if (mnList.HasUniqueProperty(ptx.pubKeyOperator)) {
              auto otherDmn = mnList.GetUniquePropertyMN(ptx.pubKeyOperator);
              if (ptx.proTxHash != otherDmn->proTxHash) {
                  return state.DoS(10, false, REJECT_DUPLICATE, "bad-protx-dup-key");
              }
          }
  
          if (!deterministicMNManager->IsDIP3Enforced(pindexPrev->nHeight)) {
              if (dmn->pdmnState->keyIDOwner != ptx.keyIDVoting) {
                  return state.DoS(10, false, REJECT_INVALID, "bad-protx-key-not-same");
              }
          }
  
          if (!CheckInputsHash(tx, ptx, state)) {
              return false;
          }
          if (!CheckHashSig(ptx, dmn->pdmnState->keyIDOwner, state)) {
              return false;
          }
      }
  
      return true;
  }
  
  bool CheckProUpRevTx(const CTransaction& tx, const CBlockIndex* pindexPrev, CValidationState& state)
  {
      if (tx.nType != TRANSACTION_PROVIDER_UPDATE_REVOKE) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-type");
      }
  
      CProUpRevTx ptx;
      if (!GetTxPayload(tx, ptx)) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-payload");
      }
  
      if (ptx.nVersion == 0 || ptx.nVersion > CProRegTx::CURRENT_VERSION) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-version");
      }
  
      // ptx.nReason < CProUpRevTx::REASON_NOT_SPECIFIED is always `false` since
      // ptx.nReason is unsigned and CProUpRevTx::REASON_NOT_SPECIFIED == 0
      if (ptx.nReason > CProUpRevTx::REASON_LAST) {
          return state.DoS(100, false, REJECT_INVALID, "bad-protx-reason");
      }
  
      if (pindexPrev) {
          auto mnList = deterministicMNManager->GetListForBlock(pindexPrev->GetBlockHash());
          auto dmn = mnList.GetMN(ptx.proTxHash);
          if (!dmn)
              return state.DoS(100, false, REJECT_INVALID, "bad-protx-hash");
  
          if (!CheckInputsHash(tx, ptx, state))
              return false;
          if (!CheckHashSig(ptx, dmn->pdmnState->pubKeyOperator.Get(), state))
              return false;
      }
  
      return true;
  }
  
  std::string CProRegTx::MakeSignString() const
  {
      std::string s;
  
      // We only include the important stuff in the string form...
  
      CTxDestination destPayout;
      CBitcoinAddress addrPayout;
      std::string strPayout;
      if (ExtractDestination(scriptPayout, destPayout) && addrPayout.Set(destPayout)) {
          strPayout = addrPayout.ToString();
      } else {
          strPayout = HexStr(scriptPayout.begin(), scriptPayout.end());
      }
  
      s += strPayout + "|";
      s += strprintf("%d", nOperatorReward) + "|";
      s += CBitcoinAddress(keyIDOwner).ToString() + "|";
      s += CBitcoinAddress(keyIDVoting).ToString() + "|";
  
      // ... and also the full hash of the payload as a protection agains malleability and replays
      s += ::SerializeHash(*this).ToString();
  
      return s;
  }
  
  std::string CProRegTx::ToString() const
  {
      CTxDestination dest;
      std::string payee = "unknown";
      if (ExtractDestination(scriptPayout, dest)) {
          payee = CBitcoinAddress(dest).ToString();
      }
  
      return strprintf("CProRegTx(nVersion=%d, collateralOutpoint=%s, addr=%s, nOperatorReward=%f, ownerAddress=%s, pubKeyOperator=%s, votingAddress=%s, scriptPayout=%s)",
          nVersion, collateralOutpoint.ToStringShort(), addr.ToString(), (double)nOperatorReward / 100, CBitcoinAddress(keyIDOwner).ToString(), pubKeyOperator.ToString(), CBitcoinAddress(keyIDVoting).ToString(), payee);
  }
  
  void CProRegTx::ToJson(UniValue& obj) const
  {
      obj.clear();
      obj.setObject();
      obj.push_back(Pair("version", nVersion));
      obj.push_back(Pair("collateralHash", collateralOutpoint.hash.ToString()));
      obj.push_back(Pair("collateralIndex", (int)collateralOutpoint.n));
      obj.push_back(Pair("service", addr.ToString(false)));
      obj.push_back(Pair("ownerAddress", CBitcoinAddress(keyIDOwner).ToString()));
      obj.push_back(Pair("votingAddress", CBitcoinAddress(keyIDVoting).ToString()));
  
      CTxDestination dest;
      if (ExtractDestination(scriptPayout, dest)) {
          CBitcoinAddress bitcoinAddress(dest);
          obj.push_back(Pair("payoutAddress", bitcoinAddress.ToString()));
      }
      obj.push_back(Pair("pubKeyOperator", pubKeyOperator.ToString()));
      obj.push_back(Pair("operatorReward", (double)nOperatorReward / 100));
  
      obj.push_back(Pair("inputsHash", inputsHash.ToString()));
  }
  
  std::string CProUpServTx::ToString() const
  {
      CTxDestination dest;
      std::string payee = "unknown";
      if (ExtractDestination(scriptOperatorPayout, dest)) {
          payee = CBitcoinAddress(dest).ToString();
      }
  
      return strprintf("CProUpServTx(nVersion=%d, proTxHash=%s, addr=%s, operatorPayoutAddress=%s)",
          nVersion, proTxHash.ToString(), addr.ToString(), payee);
  }
  
  void CProUpServTx::ToJson(UniValue& obj) const
  {
      obj.clear();
      obj.setObject();
      obj.push_back(Pair("version", nVersion));
      obj.push_back(Pair("proTxHash", proTxHash.ToString()));
      obj.push_back(Pair("service", addr.ToString(false)));
      CTxDestination dest;
      if (ExtractDestination(scriptOperatorPayout, dest)) {
          CBitcoinAddress bitcoinAddress(dest);
          obj.push_back(Pair("operatorPayoutAddress", bitcoinAddress.ToString()));
      }
      obj.push_back(Pair("inputsHash", inputsHash.ToString()));
  }
  
  std::string CProUpRegTx::ToString() const
  {
      CTxDestination dest;
      std::string payee = "unknown";
      if (ExtractDestination(scriptPayout, dest)) {
          payee = CBitcoinAddress(dest).ToString();
      }
  
      return strprintf("CProUpRegTx(nVersion=%d, proTxHash=%s, pubKeyOperator=%s, votingAddress=%s, payoutAddress=%s)",
          nVersion, proTxHash.ToString(), pubKeyOperator.ToString(), CBitcoinAddress(keyIDVoting).ToString(), payee);
  }
  
  void CProUpRegTx::ToJson(UniValue& obj) const
  {
      obj.clear();
      obj.setObject();
      obj.push_back(Pair("version", nVersion));
      obj.push_back(Pair("proTxHash", proTxHash.ToString()));
      obj.push_back(Pair("votingAddress", CBitcoinAddress(keyIDVoting).ToString()));
      CTxDestination dest;
      if (ExtractDestination(scriptPayout, dest)) {
          CBitcoinAddress bitcoinAddress(dest);
          obj.push_back(Pair("payoutAddress", bitcoinAddress.ToString()));
      }
      obj.push_back(Pair("pubKeyOperator", pubKeyOperator.ToString()));
      obj.push_back(Pair("inputsHash", inputsHash.ToString()));
  }
  
  std::string CProUpRevTx::ToString() const
  {
      return strprintf("CProUpRevTx(nVersion=%d, proTxHash=%s, nReason=%d)",
          nVersion, proTxHash.ToString(), nReason);
  }
  
  void CProUpRevTx::ToJson(UniValue& obj) const
  {
      obj.clear();
      obj.setObject();
      obj.push_back(Pair("version", nVersion));
      obj.push_back(Pair("proTxHash", proTxHash.ToString()));
      obj.push_back(Pair("reason", (int)nReason));
      obj.push_back(Pair("inputsHash", inputsHash.ToString()));
  }
  