How do I authenticate proxy server in WinInet for HTTPS? - delphi

Question

According to Microsoft-Support: How To Handle Proxy Authorization with WinInet
and other Delphi examples (http://forum.codecall.net/topic/51366-internetopen-tthreads-maxconnectionsperserver/, https://pastebin.com/f1ea3a752), I wrote following test code to try out the proper way to access a https page through an authenticated proxy server:
program Project35;
{$APPTYPE CONSOLE}
uses
SysUtils, WinInet, Windows, Classes;
Function sslGet(Const AServer, AUrl : string): AnsiString;
var
aBuffer : Array[0..4096] of Char;
BufStream : TMemoryStream;
sMethod : AnsiString;
BytesRead : Cardinal;
pSession : HINTERNET;
pConnection : HINTERNET;
pRequest : HINTERNET;
LUsername: string;
LPassword: string;
LProxy, LBypass: string;
LAgent: string;
LStatusCode, LStatusLen, LIndex : DWORD;
begin
Result := '';
LUsername := 'User-002' ;
LPassword := 'test2';
LProxy := 'myproxyserver:808';//https=https://
LBypass := '<local>';
LAgent := 'Bo-Test';
//pSession := InternetOpen(PChar(LAgent), INTERNET_OPEN_TYPE_DIRECT, nil, nil, 0);
pSession := InternetOpen(PChar(LAgent), INTERNET_OPEN_TYPE_PROXY , PChar(LProxy), PChar(LBypass), 0);
//pSession := InternetOpen(PChar(LAgent), INTERNET_OPEN_TYPE_PRECONFIG_WITH_NO_AUTOPROXY , nil, nil, 0);
if Assigned(pSession) then
try
// pConnection := InternetConnect(pSession, PChar(AServer), INTERNET_DEFAULT_HTTPS_PORT, PChar(LUsername), PChar(LPassword), INTERNET_SERVICE_HTTP, 0, 0);
pConnection := InternetConnect(pSession, PChar(AServer), INTERNET_DEFAULT_HTTPS_PORT, nil, nil, INTERNET_SERVICE_HTTP, 0, 0);
if Assigned(pConnection) then
try
sMethod := 'GET';
pRequest := HTTPOpenRequest(pConnection, PChar(sMethod), PChar(AURL), nil, nil, nil,
INTERNET_FLAG_SECURE or
INTERNET_FLAG_KEEP_CONNECTION or
INTERNET_FLAG_NO_CACHE_WRITE or
INTERNET_FLAG_PRAGMA_NOCACHE or
INTERNET_FLAG_NO_AUTH or
INTERNET_FLAG_IGNORE_CERT_CN_INVALID or
INTERNET_FLAG_IGNORE_CERT_DATE_INVALID or
INTERNET_FLAG_NO_UI or
INTERNET_FLAG_IGNORE_REDIRECT_TO_HTTPS or
SECURITY_FLAG_IGNORE_UNKNOWN_CA, 0); //or INTERNET_FLAG_NO_AUTH
if Assigned(pRequest) then
try
if HTTPSendRequest(pRequest, nil, 0, nil, 0) then
begin
LStatusLen := SizeOf(LStatusCode);
LIndex := 0;
// expecting a 407 returned
HttpQueryInfo(pRequest, HTTP_QUERY_STATUS_CODE or HTTP_QUERY_FLAG_NUMBER,
#LStatusCode, LStatusLen, LIndex);
Write('Status code=');
writeln(LStatusCode);
// resend after 407
InternetSetOption(pRequest, INTERNET_OPTION_PROXY_USERNAME, PChar(LUsername) , length(LUsername));
InternetSetOption(pRequest, INTERNET_OPTION_PROXY_PASSWORD, PChar(LPassword), length(LPassword));
HTTPSendRequest(pRequest, nil, 0, nil, 0);
HttpQueryInfo(pRequest, HTTP_QUERY_STATUS_CODE or HTTP_QUERY_FLAG_NUMBER,
#LStatusCode, LStatusLen, LIndex);
Write('Resend status code=');
writeln(LStatusCode);
BufStream := TMemoryStream.Create;
try
while InternetReadFile(pRequest, #aBuffer, SizeOf(aBuffer), BytesRead) do
begin
if (BytesRead = 0) then Break;
BufStream.Write(aBuffer, BytesRead);
end;
aBuffer[0] := #0;
BufStream.Write(aBuffer, 1);
Result := PChar(BufStream.Memory);
finally
FreeAndNil(BufStream);
end;
end
else begin
Writeln(GetLastError());
end;
finally
InternetCloseHandle(pRequest);
end;
finally
InternetCloseHandle(pConnection);
end;
finally
InternetCloseHandle(pSession);
end;
end;
var
StopEnter: string;
begin
try
// the wsdl is only available with ssl, i.e., https://services.staging.referralnet.com.au/services/Referral_Service_51?wsdl
// it is invalid for http://services.staging.referralnet.com.au/services/Referral_Service_51?wsdl
Writeln(sslGet('services.staging.referralnet.com.au', '/services/Referral_Service_51?wsdl'));
Write('Press Enter to stop ...');
Readln(StopEnter);
except
on E:Exception do
Writeln(E.Classname, ': ', E.Message);
end;
end.
I am using CCProxy as the proxy server for this testing.
I tried with two machines, one modified the hosts file so that the server of the wsdl page is pointing to 127.0.0.1, another one modified its firewall, so all the traffic to the server is blocked.
Both testings returned two 407 code, i.e., original and resend request both failed with 407.
What could be wrong? Or somebody can point me to an working example?

Answer 1

Take a look at how the THttpRIo component handles this. Just follow the proxy property usage in the code.