[6/7] qmgr: Add support for Basic authentication.

[Hans Leidekker]

On Tue, 2015-06-09 at 12:34 +0200, Jacek Caban wrote:
> On 06/08/15 17:10, Hans Leidekker wrote:
> > On Mon, 2015-06-08 at 16:51 +0200, Jacek Caban wrote:
> >> On 06/08/15 16:44, Hans Leidekker wrote:
> >>> Hi Jacek,
> >>>> It doesn't sound like a good idea to manually handle that here. We
> >>>> should most likely use IAuthenticate (although it's not yet supported in
> >>>> urlmon).
> >>> I considered that but it doesn't seem possible to select the authentication
> >>> target (server vs. proxy) or scheme with IAuthenticate.
> >> Quick research suggests that IAuthenticateEx allows that.
> > Right, IAuthenticateEx allows specifying the target but it doesn't give the
> > same control over schemes that IBackgroundCopyJob2::SetCredentials does.
> 
> I think it does. AUTHENTICATEINFO passes requested scheme.

AUTHENTICATEINFO allows specifying whether Basic authentication may be used but
doesn't give control over any other specific scheme.

I see no way to properly implement this with urlmon/wininet other than by inserting
headers manually. It occurred to me that IBackgroundCopyJob2::SetCredentials
maps cleanly to WinHttpSetCredentials and some googling revealed that native
does indeed use winhttp:

https://support.microsoft.com/en-us/kb/842773
https://msdn.microsoft.com/en-us/library/aa964260%28v=vs.85%29.aspx (remarks section).