Don't look to be directly applicable, but either Authen::Smb or Authen::Simple::SMB might at least give you starting points. They're indented for authenticating web clients against an NT domain.

Thinking about it some more that almost sounds like the converse of what you're trying to do so it may be a dead end, but at least you've got some people who might be more familiar with SMB/CIFS authentication.