Unfortunately right now there is no way to do this, as Lithium does not expose a way to get permissions via the API.
The only permission-checking Lithium has exposed is the hasPermission check in the CoreNode freemarker context object -- that checks if the current caller has the permission passed in inside of the current node (the board/category/community the page they are on is associated with) and you have to know the permission you want to check.
There is a (somewhat crude) way to find different permission keys on the permissions admin page.
-Doug
