TIdHTTPServer + TIdServerIOHandlerSSLOpenSSL = unstable work - delphi

Question

I placed TIdHTTPServer and TIdServerIOHandlerSSLOpenSSL on the form, set sertificate file path for the TIdServerIOHandlerSSLOpenSSL
In the TIdHTTPServer onCommandGet event I send answer in this way:
FullResponce:=RespHeaders+#13#10+RespData;
//dump for debug
FileHandle := CreateFileW('c:\lastresp.txt', GENERIC_WRITE, FILE_SHARE_READ, nil, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);
if FileHandle <> INVALID_HANDLE_VALUE then
begin
try
WriteFile(FileHandle, FullResponce[1], length(FullResponce), LongWord(ReadRes), nil);
finally
CloseHandle(FileHandle);
end;
end;
//response
AContext.Connection.IOHandler.WriteDirect(#FullResponce[1],length(FullResponce),0);
exit;
When I'm trying to open address '127.0.0.1:433' in the Internet Explorer, sometimes it opens page, sometimes says "unable to display page"
There is no any pattern or logic in this, I just refresh the page in the explorer 10 times, and for example, attempts 1,2,4,6,7,9,10 had open the page, and the rest ended with an error
Dupm of the answer in the lastresp.txt is always correct and always the same
When the error occurs, IE in the network console shows that he received 0 bytes
Any ideas how to fix this?
Bugs in Indy?
Update
Solved, problem was not in code but in sniffer app used to control traffic(

Answer 1

How you have implemented the OnCommandGet event is not the correct way to send a response to the client.
First off, you are not supposed to use TIdIOHandler.WriteDirect() directly at all. But if you do, you must pass it a TIdBytes, ie a dynamic array of bytes, not a string.
But more importantly, to send an HTTP response to the client, the correct way is to populate the AResponseInfo parameter and let TIdHTTPServer handle the actual socket writing for you.
For example:
procedure TMyForm.IdHTTPServer1CommandGet(AContext: TIdContext;
ARequestInfo: TIdHTTPRequestInfo; AResponseInfo: TIdHTTPResponseInfo);
begin
...
AResponseInfo.ResponseCode := 200;
AResponseInfo.ContentText := RespData;
// set other AResponseInfo properties as needed, like ContentType, etc...
end;
When the OnCommandGet handler exits, TIdHTTPServer will send the contents of the AResponseInfo to the client, if it has not already been sent.
Also, your use of WriteFile() is incorrect if you are using Delphi 2009+ and FullResponce is a normal string (ie, a UnicodeString). It would need to look like this instead:
WriteFile(FileHandle, PChar(FullResponce)^, Length(FullResponce) * SizeOf(Char), LongWord(ReadRes), nil);
Consider using TFile.WriteAllText() instead:
TFile.WriteAllText('c:\lastresp.txt', FullResponce);
However, another way to add logging to your TIdHTTPServer code is to instead assign a TIdLogFile component to the AContext.Connection.IOHandler.Intercept property and let Indy itself log exactly what it sends to the client, eg:
uses
..., IdLogFile;
procedure TMyForm.IdHTTPServer1CommandGet(AContext: TIdContext;
ARequestInfo: TIdHTTPRequestInfo; AResponseInfo: TIdHTTPResponseInfo);
var
Log: TIdLogFile;
begin
Log := TIdLogFile.Create(nil);
try
Log.Filename := 'c:\lastresp.txt';
Log.LogTime := False;
Log.ReplaceCRLF := False;
Log.Active := True;
AContext.Connection.IOHandler.Intercept := Log;
...
AResponseInfo.ResponseCode := 200;
AResponseInfo.ContentText := RespData;
// set other AResponse properties as needed, like ContentType, etc...
...
AResponse.WriteContent;
finally
Log.Free;
end;
end;