即使设置了 SslOptions，我仍然有“Socket Error # 10054 Connection reset by peer”。 在 Indy 中使用 TIdHTTP 从 https url 获取

Question

I am using TIdHTTP to get from a https URL, my code works fine until http is used, but on https i have

Socket Error # 10054 Connection reset by peer.

In many SO answers I Read about TLS 1.0 being the default so I tried to set it to TLS 1.2

I experimented by changing many properties in TIdHTTP and TIdSSLIOHandlerSocketOpenSSL but with no success.

The URL against which this fails is https://nesufficio.my.qualibus.it/FeriePermessiDemo/DOQualibus/QappCommandHandler .

There is an handshake issue I am not able to overcome, if I disable the firewall and proxy and connect to the http URL directly it works (even if in that case I must use the full URL to have a meaningful behavior). So my problem is purely in Indy: how to connect to that URL successfully?

This is the code i use:

procedure TForm1.btnGetFromMyWebserver(Sender: TObject);
var
  IdHTTP: TIdHTTP;
  IdSSLIOHandlerSocketOpenSSL: TIdSSLIOHandlerSocketOpenSSL;
  response, url: string;
begin
  IdHTTP := TIdHTTP.Create;
  // here i set the custom headers that are not relevant
  // to study the connection closed by peer problem
  try

      try
        IdSSLIOHandlerSocketOpenSSL :=  TIdSSLIOHandlerSocketOpenSSL.Create(IdHTTP);
        IdSSLIOHandlerSocketOpenSSL.Port := 443; // I tried to force the port to 443
        IdSSLIOHandlerSocketOpenSSL.SSLOptions.Mode       := sslmClient;
        IdSSLIOHandlerSocketOpenSSL.SSLOptions.SSLVersions:= [sslvTLSv1_2];
        IdHTTP.IOHandler := IdSSLIOHandlerSocketOpenSSL;
        IdHTTP.HandleRedirects := True;
        url := 'https://nesufficio.my.qualibus.it/FeriePermessiDemo/DOQualibus/QappCommandHandler'; // this is not the actual endpoint but it is enough to reproduce the handshaking error
        response := IdHTTP.Get(url);
      except
        on e:Exception
        do
          response := e.message;
      end;
  finally
    IdHTTP.Free;
  end;
  ShowMessage('Response was:' + response);
end;

Could you please give me a hand and help me pinpoint where the problem is?

My indy version is 10.6.2.5298 and I use Delphi 10 Seattle.

Thanks in advance.

Answer 1

I realized I was using very old Open SSL dlls, by getting the latest from GitHub , as advised by Remy Lebeau I managed to make the gethttp call work properly even with a https endpoint.

So the solution is just use a recent version of the Open SSl dlls.