IMO, a more complex grammar allows for better descriptions. The only real type of grammar simpler than CFG is a regular expression. That's pretty limited, although (the older part of) CSS doesn't need more than that. But as soon as you want a nested construction, hierarchy or simply nested parentheses, you need a CFG. If it's difficult to configure, the problem is the (configuration) language, not the power of its grammar.

And there are excellent parser generators out there. You don't have to fear introducing bugs via them.

Yea I sometimes have to refresh my memory on sudoers or just search for what I want to accomplish, hoping that someone has already handled the potential security gotchas (eg, exact fullpath command should always be specified).

I agree, in some typical cases I only need to specify "<user> can become root" or "<user> can become <user of group>", kinda like doas already does I think.

I'll probably try out doas when the next such special need arises, then resort to sudo if doas is insufficient for some reason.

> [...] as a context free grammar using EBNF notation. This is impressive, but maybe a little more complicated than I want to get with a basic security tool.

I apologize if I'm being trite, but Context Free Grammar doesn't mean that the semantics of whatever that grammar describes is simple. It just means that it's simple to parse into ... something. Parsing a CFG is also not impressive in the slightest. It is, in fact, trivial since the 1970s. Anyway,

You shouldn't be scared of the CFG bit... you should be scared of the semantics.