text: // Copyright (c) 2010 Satoshi Nakamoto
  // Copyright (c) 2009-2014 The Bitcoin developers
  // Copyright (c) 2014 The Mini-Blockchain Project
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "rpcprotocol.h"
  
  #include "util.h"
  
  #include <stdint.h>
  
  #include <boost/algorithm/string.hpp>
  #include <boost/asio.hpp>
  #include <boost/asio/ssl.hpp>
  #include <boost/bind.hpp>
  #include <boost/filesystem.hpp>
  #include <boost/iostreams/concepts.hpp>
  #include <boost/iostreams/stream.hpp>
  #include <boost/shared_ptr.hpp>
  #include "json/json_spirit_writer_template.h"
  
  using namespace std;
  using namespace boost;
  using namespace boost::asio;
  using namespace json_spirit;
  
  //
  // HTTP protocol
  //
  // This ain't Apache.  We're just using HTTP header for the length field
  // and to be compatible with other JSON-RPC implementations.
  //
  
  string HTTPPost(const string& strMsg, const map<string,string>& mapRequestHeaders)
  {
      ostringstream s;
      s << "POST / HTTP/1.1\r\n"
        << "User-Agent: cryptonite-json-rpc/" << FormatFullVersion() << "\r\n"
        << "Host: 127.0.0.1\r\n"
        << "Content-Type: application/json\r\n"
        << "Content-Length: " << strMsg.size() << "\r\n"
        << "Connection: close\r\n"
        << "Accept: application/json\r\n";
      for (const std::pair<string, string>& item : mapRequestHeaders)
          s << item.first << ": " << item.second << "\r\n";
      s << "\r\n" << strMsg;
  
      return s.str();
  }
  
  static string rfc1123Time()
  {
      char buffer[64];
      time_t now;
      time(&now);
      struct tm* now_gmt = gmtime(&now);
      string locale(setlocale(LC_TIME, nullptr));
      setlocale(LC_TIME, "C"); // we want POSIX (aka "C") weekday/month strings
      strftime(buffer, sizeof(buffer), "%a, %d %b %Y %H:%M:%S +0000", now_gmt);
      setlocale(LC_TIME, locale.c_str());
      return string(buffer);
  }
  
  string HTTPReply(int nStatus, const string& strMsg, bool keepalive)
  {
      if (nStatus == HTTP_UNAUTHORIZED)
          return strprintf("HTTP/1.0 401 Authorization Required\r\n"
              "Date: %s\r\n"
              "Server: cryptonite-json-rpc/%s\r\n"
              "WWW-Authenticate: Basic realm=\"jsonrpc\"\r\n"
              "Content-Type: text/html\r\n"
              "Content-Length: 296\r\n"
              "\r\n"
              "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\"\r\n"
              "\"http://www.w3.org/TR/1999/REC-html401-19991224/loose.dtd\">\r\n"
              "<HTML>\r\n"
              "<HEAD>\r\n"
              "<TITLE>Error</TITLE>\r\n"
              "<META HTTP-EQUIV='Content-Type' CONTENT='text/html; charset=ISO-8859-1'>\r\n"
              "</HEAD>\r\n"
              "<BODY><H1>401 Unauthorized.</H1></BODY>\r\n"
              "</HTML>\r\n", rfc1123Time(), FormatFullVersion());
      const char *cStatus;
           if (nStatus == HTTP_OK) cStatus = "OK";
      else if (nStatus == HTTP_BAD_REQUEST) cStatus = "Bad Request";
      else if (nStatus == HTTP_FORBIDDEN) cStatus = "Forbidden";
      else if (nStatus == HTTP_NOT_FOUND) cStatus = "Not Found";
      else if (nStatus == HTTP_INTERNAL_SERVER_ERROR) cStatus = "Internal Server Error";
      else cStatus = "";
      return strprintf(
              "HTTP/1.1 %d %s\r\n"
              "Date: %s\r\n"
              "Connection: %s\r\n"
              "Content-Length: %" PRIszu "\r\n"
              "Content-Type: application/json\r\n"
              "Server: cryptonite-json-rpc/%s\r\n"
              "\r\n"
              "%s",
          nStatus,
          cStatus,
          rfc1123Time(),
          keepalive ? "keep-alive" : "close",
          strMsg.size(),
          FormatFullVersion(),
          strMsg);
  }
  
  bool ReadHTTPRequestLine(std::basic_istream<char>& stream, int &proto,
                           string& http_method, string& http_uri)
  {
      string str;
      getline(stream, str);
  
      // HTTP request line is space-delimited
      vector<string> vWords;
      boost::split(vWords, str, boost::is_any_of(" "));
      if (vWords.size() < 2)
          return false;
  
      // HTTP methods permitted: GET, POST
      http_method = vWords[0];
      if (http_method != "GET" && http_method != "POST")
          return false;
  
      // HTTP URI must be an absolute path, relative to current host
      http_uri = vWords[1];
      if (http_uri.size() == 0 || http_uri[0] != '/')
          return false;
  
      // parse proto, if present
      string strProto = "";
      if (vWords.size() > 2)
          strProto = vWords[2];
  
      proto = 0;
      const char *ver = strstr(strProto.c_str(), "HTTP/1.");
      if (ver != nullptr)
          proto = atoi(ver+7);
  
      return true;
  }
  
  int ReadHTTPStatus(std::basic_istream<char>& stream, int &proto)
  {
      string str;
      getline(stream, str);
      vector<string> vWords;
      boost::split(vWords, str, boost::is_any_of(" "));
      if (vWords.size() < 2)
          return HTTP_INTERNAL_SERVER_ERROR;
      proto = 0;
      const char *ver = strstr(str.c_str(), "HTTP/1.");
      if (ver != nullptr)
          proto = atoi(ver+7);
      return atoi(vWords[1].c_str());
  }
  
  int ReadHTTPHeaders(std::basic_istream<char>& stream, map<string, string>& mapHeadersRet)
  {
      int nLen = 0;
      while (true)
      {
          string str;
          std::getline(stream, str);
          if (str.empty() || str == "\r")
              break;
          string::size_type nColon = str.find(":");
          if (nColon != string::npos)
          {
              string strHeader = str.substr(0, nColon);
              boost::trim(strHeader);
              boost::to_lower(strHeader);
              string strValue = str.substr(nColon+1);
              boost::trim(strValue);
              mapHeadersRet[strHeader] = strValue;
              if (strHeader == "content-length")
                  nLen = atoi(strValue.c_str());
          }
      }
      return nLen;
  }
  
  
  int ReadHTTPMessage(std::basic_istream<char>& stream, map<string,
                      string>& mapHeadersRet, string& strMessageRet,
                      int nProto)
  {
      mapHeadersRet.clear();
      strMessageRet = "";
  
      // Read header
      int nLen = ReadHTTPHeaders(stream, mapHeadersRet);
      if (nLen < 0 || nLen > (int)MAX_SIZE)
          return HTTP_INTERNAL_SERVER_ERROR;
  
      // Read message
      if (nLen > 0)
      {
          vector<char> vch(nLen);
          stream.read(&vch[0], nLen);
          strMessageRet = string(vch.begin(), vch.end());
      }
  
      string sConHdr = mapHeadersRet["connection"];
  
      if ((sConHdr != "close") && (sConHdr != "keep-alive"))
      {
          if (nProto >= 1)
              mapHeadersRet["connection"] = "keep-alive";
          else
              mapHeadersRet["connection"] = "close";
      }
  
      return HTTP_OK;
  }
  
  //
  // JSON-RPC protocol.  Bitcoin speaks version 1.0 for maximum compatibility,
  // but uses JSON-RPC 1.1/2.0 standards for parts of the 1.0 standard that were
  // unspecified (HTTP errors and contents of 'error').
  //
  // 1.0 spec: http://json-rpc.org/wiki/specification
  // 1.2 spec: http://jsonrpc.org/historical/json-rpc-over-http.html
  // http://www.codeproject.com/KB/recipes/JSON_Spirit.aspx
  //
  
  string JSONRPCRequest(const string& strMethod, const Array& params, const Value& id)
  {
      Object request;
      request.push_back(Pair("method", strMethod));
      request.push_back(Pair("params", params));
      request.push_back(Pair("id", id));
      return write_string(Value(request), false) + "\n";
  }
  
  Object JSONRPCReplyObj(const Value& result, const Value& error, const Value& id)
  {
      Object reply;
      if (error.type() != null_type)
          reply.push_back(Pair("result", Value::null));
      else
          reply.push_back(Pair("result", result));
      reply.push_back(Pair("error", error));
      reply.push_back(Pair("id", id));
      return reply;
  }
  
  string JSONRPCReply(const Value& result, const Value& error, const Value& id)
  {
      Object reply = JSONRPCReplyObj(result, error, id);
      return write_string(Value(reply), false) + "\n";
  }
  
  Object JSONRPCError(int code, const string& message)
  {
      Object error;
      error.push_back(Pair("code", code));
      error.push_back(Pair("message", message));
      return error;
  }
  