text: // Copyright (c) 2009-2020 The Beans Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include <core_io.h>
  
  #include <primitives/block.h>
  #include <primitives/transaction.h>
  #include <script/script.h>
  #include <script/sign.h>
  #include <serialize.h>
  #include <streams.h>
  #include <univalue.h>
  #include <util/strencodings.h>
  #include <version.h>
  
  #include <boost/algorithm/string/classification.hpp>
  #include <boost/algorithm/string/split.hpp>
  
  #include <algorithm>
  #include <string>
  
  namespace {
  
  opcodetype ParseOpCode(const std::string& s)
  {
      static std::map<std::string, opcodetype> mapOpNames;
  
      if (mapOpNames.empty())
      {
          for (unsigned int op = 0; op <= MAX_OPCODE; op++)
          {
              // Allow OP_RESERVED to get into mapOpNames
              if (op < OP_NOP && op != OP_RESERVED)
                  continue;
  
              std::string strName = GetOpName(static_cast<opcodetype>(op));
              if (strName == "OP_UNKNOWN")
                  continue;
              mapOpNames[strName] = static_cast<opcodetype>(op);
              // Convenience: OP_ADD and just ADD are both recognized:
              if (strName.compare(0, 3, "OP_") == 0) {  // strName starts with "OP_"
                  mapOpNames[strName.substr(3)] = static_cast<opcodetype>(op);
              }
          }
      }
  
      auto it = mapOpNames.find(s);
      if (it == mapOpNames.end()) throw std::runtime_error("script parse error: unknown opcode");
      return it->second;
  }
  
  } // namespace
  
  CScript ParseScript(const std::string& s)
  {
      CScript result;
  
      std::vector<std::string> words;
      boost::algorithm::split(words, s, boost::algorithm::is_any_of(" \t\n"), boost::algorithm::token_compress_on);
  
      for (std::vector<std::string>::const_iterator w = words.begin(); w != words.end(); ++w)
      {
          if (w->empty())
          {
              // Empty string, ignore. (boost::split given '' will return one word)
          }
          else if (std::all_of(w->begin(), w->end(), ::IsDigit) ||
              (w->front() == '-' && w->size() > 1 && std::all_of(w->begin()+1, w->end(), ::IsDigit)))
          {
              // Number
              int64_t n = atoi64(*w);
  
              //limit the range of numbers ParseScript accepts in decimal
              //since numbers outside -0xFFFFFFFF...0xFFFFFFFF are illegal in scripts
              if (n > int64_t{0xffffffff} || n < -1 * int64_t{0xffffffff}) {
                  throw std::runtime_error("script parse error: decimal numeric value only allowed in the "
                                           "range -0xFFFFFFFF...0xFFFFFFFF");
              }
  
              result << n;
          }
          else if (w->substr(0,2) == "0x" && w->size() > 2 && IsHex(std::string(w->begin()+2, w->end())))
          {
              // Raw hex data, inserted NOT pushed onto stack:
              std::vector<unsigned char> raw = ParseHex(std::string(w->begin()+2, w->end()));
              result.insert(result.end(), raw.begin(), raw.end());
          }
          else if (w->size() >= 2 && w->front() == '\'' && w->back() == '\'')
          {
              // Single-quoted string, pushed as data. NOTE: this is poor-man's
              // parsing, spaces/tabs/newlines in single-quoted strings won't work.
              std::vector<unsigned char> value(w->begin()+1, w->end()-1);
              result << value;
          }
          else
          {
              // opcode, e.g. OP_ADD or ADD:
              result << ParseOpCode(*w);
          }
      }
  
      return result;
  }
  
  // Check that all of the input and output scripts of a transaction contains valid opcodes
  static bool CheckTxScriptsSanity(const CMutableTransaction& tx)
  {
      // Check input scripts for non-coinbase txs
      if (!CTransaction(tx).IsCoinBase()) {
          for (unsigned int i = 0; i < tx.vin.size(); i++) {
              if (!tx.vin[i].scriptSig.HasValidOps() || tx.vin[i].scriptSig.size() > MAX_SCRIPT_SIZE) {
                  return false;
              }
          }
      }
      // Check output scripts
      for (unsigned int i = 0; i < tx.vout.size(); i++) {
          if (!tx.vout[i].scriptPubKey.HasValidOps() || tx.vout[i].scriptPubKey.size() > MAX_SCRIPT_SIZE) {
              return false;
          }
      }
  
      return true;
  }
  
  static bool DecodeTx(CMutableTransaction& tx, const std::vector<unsigned char>& tx_data, bool try_no_witness, bool try_witness)
  {
      // General strategy:
      // - Decode both with extended serialization (which interprets the 0x0001 tag as a marker for
      //   the presence of witnesses) and with legacy serialization (which interprets the tag as a
      //   0-input 1-output incomplete transaction).
      //   - Restricted by try_no_witness (which disables legacy if false) and try_witness (which
      //     disables extended if false).
      //   - Ignore serializations that do not fully consume the hex string.
      // - If neither succeeds, fail.
      // - If only one succeeds, return that one.
      // - If both decode attempts succeed:
      //   - If only one passes the CheckTxScriptsSanity check, return that one.
      //   - If neither or both pass CheckTxScriptsSanity, return the extended one.
  
      CMutableTransaction tx_extended, tx_legacy;
      bool ok_extended = false, ok_legacy = false;
  
      // Try decoding with extended serialization support, and remember if the result successfully
      // consumes the entire input.
      if (try_witness) {
          CDataStream ssData(tx_data, SER_NETWORK, PROTOCOL_VERSION);
          try {
              ssData >> tx_extended;
              if (ssData.empty()) ok_extended = true;
          } catch (const std::exception&) {
              // Fall through.
          }
      }
  
      // Optimization: if extended decoding succeeded and the result passes CheckTxScriptsSanity,
      // don't bother decoding the other way.
      if (ok_extended && CheckTxScriptsSanity(tx_extended)) {
          tx = std::move(tx_extended);
          return true;
      }
  
      // Try decoding with legacy serialization, and remember if the result successfully consumes the entire input.
      if (try_no_witness) {
          CDataStream ssData(tx_data, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS);
          try {
              ssData >> tx_legacy;
              if (ssData.empty()) ok_legacy = true;
          } catch (const std::exception&) {
              // Fall through.
          }
      }
  
      // If legacy decoding succeeded and passes CheckTxScriptsSanity, that's our answer, as we know
      // at this point that extended decoding either failed or doesn't pass the sanity check.
      if (ok_legacy && CheckTxScriptsSanity(tx_legacy)) {
          tx = std::move(tx_legacy);
          return true;
      }
  
      // If extended decoding succeeded, and neither decoding passes sanity, return the extended one.
      if (ok_extended) {
          tx = std::move(tx_extended);
          return true;
      }
  
      // If legacy decoding succeeded and extended didn't, return the legacy one.
      if (ok_legacy) {
          tx = std::move(tx_legacy);
          return true;
      }
  
      // If none succeeded, we failed.
      return false;
  }
  
  bool DecodeHexTx(CMutableTransaction& tx, const std::string& hex_tx, bool try_no_witness, bool try_witness)
  {
      if (!IsHex(hex_tx)) {
          return false;
      }
  
      std::vector<unsigned char> txData(ParseHex(hex_tx));
      return DecodeTx(tx, txData, try_no_witness, try_witness);
  }
  
  bool DecodeHexBlockHeader(CBlockHeader& header, const std::string& hex_header)
  {
      if (!IsHex(hex_header)) return false;
  
      const std::vector<unsigned char> header_data{ParseHex(hex_header)};
      CDataStream ser_header(header_data, SER_NETWORK, PROTOCOL_VERSION);
      try {
          ser_header >> header;
      } catch (const std::exception&) {
          return false;
      }
      return true;
  }
  
  bool DecodeHexBlk(CBlock& block, const std::string& strHexBlk)
  {
      if (!IsHex(strHexBlk))
          return false;
  
      std::vector<unsigned char> blockData(ParseHex(strHexBlk));
      CDataStream ssBlock(blockData, SER_NETWORK, PROTOCOL_VERSION);
      try {
          ssBlock >> block;
      }
      catch (const std::exception&) {
          return false;
      }
  
      return true;
  }
  
  bool ParseHashStr(const std::string& strHex, uint256& result)
  {
      if ((strHex.size() != 64) || !IsHex(strHex))
          return false;
  
      result.SetHex(strHex);
      return true;
  }
  
  std::vector<unsigned char> ParseHexUV(const UniValue& v, const std::string& strName)
  {
      std::string strHex;
      if (v.isStr())
          strHex = v.getValStr();
      if (!IsHex(strHex))
          throw std::runtime_error(strName + " must be hexadecimal string (not '" + strHex + "')");
      return ParseHex(strHex);
  }
  
  int ParseSighashString(const UniValue& sighash)
  {
      int hash_type = SIGHASH_ALL;
      if (!sighash.isNull()) {
          static std::map<std::string, int> map_sighash_values = {
              {std::string("ALL"), int(SIGHASH_ALL)},
              {std::string("ALL|ANYONECANPAY"), int(SIGHASH_ALL|SIGHASH_ANYONECANPAY)},
              {std::string("NONE"), int(SIGHASH_NONE)},
              {std::string("NONE|ANYONECANPAY"), int(SIGHASH_NONE|SIGHASH_ANYONECANPAY)},
              {std::string("SINGLE"), int(SIGHASH_SINGLE)},
              {std::string("SINGLE|ANYONECANPAY"), int(SIGHASH_SINGLE|SIGHASH_ANYONECANPAY)},
          };
          std::string strHashType = sighash.get_str();
          const auto& it = map_sighash_values.find(strHashType);
          if (it != map_sighash_values.end()) {
              hash_type = it->second;
          } else {
              throw std::runtime_error(strHashType + " is not a valid sighash parameter.");
          }
      }
      return hash_type;
  }
  