How do I set a password to connect to a client authenticated web service for KeyFile?

I need to write a program (Delphi XE5, Indy 10: TIdHTTP and TIdSSLIOHandlerSocketOpenSSL) that can connect to a web service with client authentication. With a few days of work, it finally became successful. I can connect using authentication by setting the SSLOptions.CertFile and SSLOptions.KeyFile properties for the TIdSSLIOHandlerSocketOpenSSLs. It's okay. (I have a pfx file from my partner, I exported it to certificate and private key file with OpenSSL, so I use these 2 files in the program.)

I have one component TButton, TMemo and TIdHTTP in a form.

Source code (button click event - string IdHTTP1.Request.ContentType: = '.......' is only needed for communication due to server settings):

procedure TForm1.Button1Click(Sender: TObject);
var
  URL: string;
  XML: TStrings;
  S: string;
  Req: TStream;
  SL: TStringList;
  SSL1 : TIdSSLIOHandlerSocketOpenSSL;

begin
  XML := TStringList.Create;

  XML.Add('<soap:Envelope xmlns:ns="http://docs.oasis-open.org/ws-sx/ws-trust/200512" ' +
    'xmlns:soap="http://www.w3.org/2003/05/soap-envelope">');
…
  XML.Add('   <soap:Body>');
…
  XML.Add('   </soap:Body>');
  XML.Add('</soap:Envelope>');
  URL := 'https://…………………….';
  end

  Req := TStringStream.Create(XML.Text, TEncoding.UTF8);
  try
    SSL1 := TIdSSLIOHandlerSocketOpenSSL.Create(nil);
    SSL1.SSLOptions.CertFile := 'd:\certificate.pem';
    SSL1.SSLOptions.KeyFile := 'd:\private.pem';
    SSL1.SSLOptions.Mode := sslmClient;
    try
      SSL1.SSLOptions.Method := sslvSSLv23;
      IdHTTP1.IOHandler := SSL1;
      IdHTTP1.Request.ContentType := 'application/soap+xml;charset=UTF-8;action="http://docs.oasis-open.org/ws-sx/ws-trust/200512/RST/Issue"';
      S := IdHTTP1.Post(URL, Req);
    finally
      SSl1.Free;
    end;
  finally
    Req.Free;
  end;

  ResultMemo.Lines.Add(Format('Response Code: %d', [IdHTTP1.ResponseCode]));
  ResultMemo.Lines.Add(Format('Response Text: %s', [IdHTTP1.ResponseText]));

  SL := TStringList.Create;
  try
    SL.Text := S;
    ResultMemo.Lines.AddStrings(SL);
  finally
    SL.Free;
  end;

end;

      

        
        
        
      

    

The problem is this: my partner said that this is not the best case if the file I am using is not password protected. They told me how to create a password protected (and encrypted) file for KeyFile with OpenSSL. When I install this password protected file in the SSLOptions.KeyFile, I get the following error message: "Failed to load key, verify password. Error: 0906A068: PEM routines: PEM_do_header: Invalid password."

I tried to set a password in the idHTTP1.Request.Password property, but the result is the same.

Question: how and where should I set a password for the KeyFile if I need to use a password protected key file? Since I have to publish the certificate files, the best solution would be to set a password in the program and use a password protected KeyFile instead of using a non password protected KeyFile.

Many thanks.

Best regards, Attila