How to log auth information with simple auth

Hello,

Is it possible to log all username/passwords from a basic auth, e.g, whatever is provided in http://user:password@url.com/ and if so, how ? I suppose I can use the $remote_user variable for the user, not sure how to catch whatever is provided for the password. I can obviously do that with tshark, or other packet analyzers, but was wondering if it's possible with nginx alone.