text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2018 The Cedicoin Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include <wallet/ismine.h>
  
  #include <key.h>
  #include <script/script.h>
  #include <script/sign.h>
  #include <script/signingprovider.h>
  #include <wallet/wallet.h>
  
  typedef std::vector<unsigned char> valtype;
  
  namespace {
  
  /**
   * This is an enum that tracks the execution context of a script, similar to
   * SigVersion in script/interpreter. It is separate however because we want to
   * distinguish between top-level scriptPubKey execution and P2SH redeemScript
   * execution (a distinction that has no impact on consensus rules).
   */
  enum class IsMineSigVersion
  {
      TOP = 0,        //!< scriptPubKey execution
      P2SH = 1,       //!< P2SH redeemScript
      WITNESS_V0 = 2, //!< P2WSH witness script execution
  };
  
  /**
   * This is an internal representation of isminetype + invalidity.
   * Its order is significant, as we return the max of all explored
   * possibilities.
   */
  enum class IsMineResult
  {
      NO = 0,         //!< Not ours
      WATCH_ONLY = 1, //!< Included in watch-only balance
      SPENDABLE = 2,  //!< Included in all balances
      INVALID = 3,    //!< Not spendable by anyone (uncompressed pubkey in segwit, P2SH inside P2SH or witness, witness inside witness)
  };
  
  bool PermitsUncompressed(IsMineSigVersion sigversion)
  {
      return sigversion == IsMineSigVersion::TOP || sigversion == IsMineSigVersion::P2SH;
  }
  
  bool HaveKeys(const std::vector<valtype>& pubkeys, const CWallet& keystore)
  {
      for (const valtype& pubkey : pubkeys) {
          CKeyID keyID = CPubKey(pubkey).GetID();
          if (!keystore.HaveKey(keyID)) return false;
      }
      return true;
  }
  
  IsMineResult IsMineInner(const CWallet& keystore, const CScript& scriptPubKey, IsMineSigVersion sigversion)
  {
      IsMineResult ret = IsMineResult::NO;
  
      std::vector<valtype> vSolutions;
      txnouttype whichType = Solver(scriptPubKey, vSolutions);
  
      CKeyID keyID;
      switch (whichType)
      {
      case TX_NONSTANDARD:
      case TX_NULL_DATA:
      case TX_WITNESS_UNKNOWN:
          break;
      case TX_PUBKEY:
          keyID = CPubKey(vSolutions[0]).GetID();
          if (!PermitsUncompressed(sigversion) && vSolutions[0].size() != 33) {
              return IsMineResult::INVALID;
          }
          if (keystore.HaveKey(keyID)) {
              ret = std::max(ret, IsMineResult::SPENDABLE);
          }
          break;
      case TX_WITNESS_V0_KEYHASH:
      {
          if (sigversion == IsMineSigVersion::WITNESS_V0) {
              // P2WPKH inside P2WSH is invalid.
              return IsMineResult::INVALID;
          }
          if (sigversion == IsMineSigVersion::TOP && !keystore.HaveCScript(CScriptID(CScript() << OP_0 << vSolutions[0]))) {
              // We do not support bare witness outputs unless the P2SH version of it would be
              // acceptable as well. This protects against matching before segwit activates.
              // This also applies to the P2WSH case.
              break;
          }
          ret = std::max(ret, IsMineInner(keystore, GetScriptForDestination(PKHash(uint160(vSolutions[0]))), IsMineSigVersion::WITNESS_V0));
          break;
      }
      case TX_PUBKEYHASH:
          keyID = CKeyID(uint160(vSolutions[0]));
          if (!PermitsUncompressed(sigversion)) {
              CPubKey pubkey;
              if (keystore.GetPubKey(keyID, pubkey) && !pubkey.IsCompressed()) {
                  return IsMineResult::INVALID;
              }
          }
          if (keystore.HaveKey(keyID)) {
              ret = std::max(ret, IsMineResult::SPENDABLE);
          }
          break;
      case TX_SCRIPTHASH:
      {
          if (sigversion != IsMineSigVersion::TOP) {
              // P2SH inside P2WSH or P2SH is invalid.
              return IsMineResult::INVALID;
          }
          CScriptID scriptID = CScriptID(uint160(vSolutions[0]));
          CScript subscript;
          if (keystore.GetCScript(scriptID, subscript)) {
              ret = std::max(ret, IsMineInner(keystore, subscript, IsMineSigVersion::P2SH));
          }
          break;
      }
      case TX_WITNESS_V0_SCRIPTHASH:
      {
          if (sigversion == IsMineSigVersion::WITNESS_V0) {
              // P2WSH inside P2WSH is invalid.
              return IsMineResult::INVALID;
          }
          if (sigversion == IsMineSigVersion::TOP && !keystore.HaveCScript(CScriptID(CScript() << OP_0 << vSolutions[0]))) {
              break;
          }
          uint160 hash;
          CRIPEMD160().Write(&vSolutions[0][0], vSolutions[0].size()).Finalize(hash.begin());
          CScriptID scriptID = CScriptID(hash);
          CScript subscript;
          if (keystore.GetCScript(scriptID, subscript)) {
              ret = std::max(ret, IsMineInner(keystore, subscript, IsMineSigVersion::WITNESS_V0));
          }
          break;
      }
  
      case TX_MULTISIG:
      {
          // Never treat bare multisig outputs as ours (they can still be made watchonly-though)
          if (sigversion == IsMineSigVersion::TOP) {
              break;
          }
  
          // Only consider transactions "mine" if we own ALL the
          // keys involved. Multi-signature transactions that are
          // partially owned (somebody else has a key that can spend
          // them) enable spend-out-from-under-you attacks, especially
          // in shared-wallet situations.
          std::vector<valtype> keys(vSolutions.begin()+1, vSolutions.begin()+vSolutions.size()-1);
          if (!PermitsUncompressed(sigversion)) {
              for (size_t i = 0; i < keys.size(); i++) {
                  if (keys[i].size() != 33) {
                      return IsMineResult::INVALID;
                  }
              }
          }
          if (HaveKeys(keys, keystore)) {
              ret = std::max(ret, IsMineResult::SPENDABLE);
          }
          break;
      }
      }
  
      if (ret == IsMineResult::NO && keystore.HaveWatchOnly(scriptPubKey)) {
          ret = std::max(ret, IsMineResult::WATCH_ONLY);
      }
      return ret;
  }
  
  } // namespace
  
  isminetype IsMine(const CWallet& keystore, const CScript& scriptPubKey)
  {
      switch (IsMineInner(keystore, scriptPubKey, IsMineSigVersion::TOP)) {
      case IsMineResult::INVALID:
      case IsMineResult::NO:
          return ISMINE_NO;
      case IsMineResult::WATCH_ONLY:
          return ISMINE_WATCH_ONLY;
      case IsMineResult::SPENDABLE:
          return ISMINE_SPENDABLE;
      }
      assert(false);
  }
  
  isminetype IsMine(const CWallet& keystore, const CTxDestination& dest)
  {
      CScript script = GetScriptForDestination(dest);
      return IsMine(keystore, script);
  }
  