Скачивание файла в Delphi с использованием WinInet (http/https)

 Код Delphi:
...
type tPageOpenMethod = (tpomGet,tpomPost);
type tPageStatus = record
                    code: ansistring;
                    err: word;
                    header: AnsiString;
                   end;
type tRequestData = record
                     Connection: AnsiString;
                     UserAgent: AnsiString;
                     Referer: AnsiString;
                     Origin: AnsiString;
                     ContentType: AnsiString;
                     Accept: AnsiString;
                     AcceptLanguage: AnsiString;
                     AcceptEncoding: AnsiString;
                     Cookie: AnsiString;
                     CustomHeaders: tStringList;
                     Body: AnsiString;
                    end;
...
function WiOpenURL(Method:tPageOpenMethod; RequestData:tRequestData; URL_Base, URL_Page:WideString): tPageStatus;
var
  hInet, hCon, hReq: HINTERNET;
  Status, StatusSize, Index: DWORD;
  bytes, b, posi: Cardinal;
  ResponseString: AnsiString;
  dwFlag: Cardinal;
  URL_base_c: WideString;
  tPS: tPageStatus;
  fMethod: PChar;
  fFlag: Cardinal;
  Header: WideString;
  UA: AnsiString;
  Response: array [0..2047] of WideChar;
  ResponseL: longword;
  EndPos: longword;
  i: longword;
begin
 ResponseL:=SizeOf(Response);
 Response:='';
 if (Method=tpomGet) then
  fMethod:='GET'
 else
  fMethod:='POST';
  fFlag:= INTERNET_FLAG_RELOAD
          or INTERNET_FLAG_SECURE
          or INTERNET_FLAG_IGNORE_CERT_CN_INVALID
          or INTERNET_FLAG_IGNORE_CERT_DATE_INVALID;
 if (RequestData.Connection='keep-alive') then
  fFlag:=fFlag or INTERNET_FLAG_KEEP_CONNECTION;
 if (AnsiPos('://',URL_Base)>0) then
  URL_base_c:=Copy(URL_Base,AnsiPos('://',URL_Base)+3,length(URL_Base))
 else
  URL_base_c:=URL_Base;
 if (RequestData.UserAgent<>'') then
  UA:=RequestData.UserAgent
 else
  UA:='Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.90 Safari/537.36';
 Header:='Host: '+URL_base_c+sLineBreak;
 Header:=Header+'User-Agent: '+UA+sLineBreak;
 if (RequestData.Origin<>'') then
  Header:=Header+'Origin: '+RequestData.Origin+sLineBreak;
 if (RequestData.ContentType<>'') then
  Header:=Header+'Content-Type: '+RequestData.ContentType+sLineBreak;
 if (RequestData.Accept<>'') then
  Header:=Header+'Accept: '+RequestData.Accept+sLineBreak;
 if (RequestData.AcceptLanguage<>'') then
  Header:=Header+'Accept-Language: '+RequestData.AcceptLanguage+sLineBreak;
 if (RequestData.AcceptEncoding<>'') then
  Header:=Header+'Accept-Encoding: '+RequestData.AcceptEncoding+sLineBreak;
 if (RequestData.Connection='keep-alive') then
  Header:=Header+'Connection: keep-alive'+sLineBreak;
 if (RequestData.Referer<>'') then
  Header:=Header+'Referer: '+RequestData.Referer+sLineBreak;
 if (RequestData.Cookie<>'') then
  Header:=Header+'Cookie: '+RequestData.Cookie+sLineBreak;
 if (Method=tpomPOST) then
  Header:=Header+'Content-Length: '+IntToStr(length(RequestData.Body))+sLineBreak;
 Header:=Header+sLineBreak;
 // Инициализируем
 hInet := InternetOpenA(PAnsiChar(UA),
                        INTERNET_OPEN_TYPE_PRECONFIG, // Прокси в зависимости от утсановок системы
                        nil,
                        nil,
                        0);
 if not Assigned(hInet) then
  begin
   FormSlezka.ToLog('Ошибка при выполнении функции InternetOpen' + sLineBreak + SysErrorMessage(GetLastError),clRed);
   exit;
  end;
 try
  hCon := InternetConnect(hInet, PWideChar(URL_base_c), INTERNET_DEFAULT_HTTPS_PORT, nil, nil, INTERNET_SERVICE_HTTP, 0, 0);
  if not Assigned(hCon) then
   begin
    FormSlezka.ToLog('Ошибка при выполнении функции InternetConnect' + sLineBreak + SysErrorMessage(GetLastError),clRed);
    exit;
   end;
  try
   hReq := HttpOpenRequest(hCon, fMethod, PChar(URL_Page), 'HTTP/1.1', nil, nil,
                           fFlag, 0);
   HttpAddRequestHeaders(hReq,PWideChar(Header),length(Header),HTTP_ADDREQ_FLAG_ADD);
   if not Assigned(hReq) then
    begin
     FormSlezka.ToLog('Ошибка при выполнении функции HttpOpenRequest' + sLineBreak + SysErrorMessage(GetLastError),clRed);
     exit;
    end;
   try
    if (Method=tpomGet) then
     HttpSendRequest(hReq,'', 0, nil, 0)
    else
     HttpSendRequest(hReq,'', 0, PAnsiChar(RequestData.Body), length(RequestData.Body)+1);
    StatusSize := SizeOf(Status);
    Index := 0;
    HttpQueryInfo(hReq, HTTP_QUERY_FLAG_NUMBER or HTTP_QUERY_STATUS_CODE, @Status, StatusSize, Index);
    tPS.err:=Status;
    HttpQueryInfo(hReq, HTTP_QUERY_RAW_HEADERS_CRLF, @Response, ResponseL, Index);
    posi := 1;
    b := 1;
    ResponseString := '';
    while b > 0 do
     begin
      if not InternetQueryDataAvailable( hReq, bytes, 0, 0 ) then
       begin
        FormSlezka.ToLog('Ошибка при выполнении функции InternetQueryDataAvailable' + sLineBreak
                         + SysErrorMessage(GetLastError),clRed);
        exit;
       end;
      SetLength( ResponseString, Length(ResponseString) + bytes );
      InternetReadFile( hReq, @ResponseString[Posi], bytes, b );
      Inc(Posi, b);
     end;
   finally
    InternetCloseHandle(hReq);
   end;
  finally
   InternetCloseHandle(hCon);
  end;
 finally
  InternetCloseHandle(hInet);
 end;
//========== конец получения кода страницы ==========
EndPos:=AnsiPos(#13+#10+#13+#10,Response);
tPS.header:='';
for i := 0 to EndPos do
 tPS.header:=tPS.header+Response[i];
tPS.code:=ResponseString;
Result:=tPS;
end;