idHTTPProxyServer through another Http proxy
lazarus / 38-Networking and Web Programming

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RDL · 2018-04-05 08:44

Good day.

It is not possible to redirect requests to another proxy server.

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TfrmMain.IdHTTPProxyServerHTTPBeforeCommand(AContext:
TIdHTTPProxyServerContext);vartProxy: TIdCustomTransparentProxy;begint
Proxy:=TIdCustomTransparentProxy.Create(AContext.Connection);tProxy.Ho
st:='127.0.0.1';tProxy.Port:=8888;tProxy.Enabled:=true;AContext.Connec
tion.Socket.TransparentProxy:=tProxy; end;
I need through http (get, post).
I know how to redirect requests using the "Connect" method, but it
does not work with all proxy servers.

I need your help.

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Remy Lebeau · 2018-04-10 17:41

It doesn't work because you are setting it up the wrong way.

TIdCustomTransparentProxy is an abstract base class, do not
instantiate it directly.  You need to use a descendant instead
(TIdSocksInfo for a SOCKS proxy, TIdConnectThroughHttpProxy for an
HTTP proxy, etc).

But more importantly, you are attaching the TransparentProxy to the
wrong TCP connection.  'AContext.Connection' is the existing
established TCP connection with the client that connected to
TIdHTTPProxyServer.  To pass that client's traffic with the target
server through another proxy, you need to attach the TransparentProxy
to 'AContext.OutboundClient' instead.

Try something more like this:

Code: [Select]procedure
TfrmMain.IdHTTPProxyServerHTTPBeforeCommand(AContext:
TIdHTTPProxyServerContext);
var
  tProxy: TIdConnectThroughHttpProxy;
begin
  AContext.OutboundClient.CreateIOHandler;
  tProxy :=
TIdConnectThroughHttpProxy.Create(AContext.OutboundClient.IOHandler);
  tProxy.Host := '127.0.0.1';
  tProxy.Port := 8888;
  tProxy.Enabled := true;
  AContext.OutboundClient.Socket.TransparentProxy := tProxy;
end;