An authenticator is an executable or script used for token-based
authentication. During HTTP handshake, webfuse will scan for the
configured HTTP header and invoke the authenticator.
authenticator TOKEN
The provided `token` contains the contents of the HTTP header.
## Header restrictions
Note that not any HTTP header can be specified using `--wf-auth-header`
option. The following headers are supported:
-`X-Auth-Token`
-`Authorization`
In addition to that, any non-standard header can be specified.
Due to implementation limitation, most standard headers can not be used by now. Please let us know, when you intend to use a header that is not supported yet. Please create an issue in that case.