runas Magic

If you have followed any of the “Running as non-admin”
traffic that’s been fairly prevalent of late, you’ve probably heard of
the runas command. Runas lets
you  launch a process with alternate credentials in the current window station.
Generally, you use this to do things like fire up a new instance of Visual Studio
under administrative credentials so you can debug ASP.NET applications or something.

Today I ran across an entirely new option: the /netonly switch.
Using it means that the credentials you supply don’t
have to be valid on the machine you’re running it on, but will still be passed
on when remote calls are made! So
cool. Why? Because I’m doing work with Microsoft, and I need to do things against
their servers that require authentication. I don’t want to join my machine to
their domain, which means I can’t get a process running under my Microsoft domain
account. However, using this switch, I can make a process look to remote systems as
if it were running under my Microsoft domain account. This turned out to be crucially
important for getting our build process working on my machine.

The one caveat is that since it doesn’t do an actual login, it’ll
take whatever password you throw at it. Even if it’s wrong – you won’t
find out until you try to actually use those credentials.