Re: Emacs RPC security

[Harald Hanche-Olsen]

[Ted Zlatanov <address@hidden> (2011-05-03 01:12:28 UTC)]

> In Common Lisp you can disable many of the Lisp reader's options
> that evaluate code, but I don't know how the Emacs Lisp reader can
> do that.

Perhaps you are thinking of CL's #. syntax, which causes the following
form to be evaluated at read time. There is a switch to turn off this
feature. AFAIK this is not available in elisp, so there is nothing to
disable.

The natural way (and only way, I believe) to provide a restricted
execution environment in Common Lisp is to leave the user in a package
that contains only "safe" symbols. As elisp does not have packages in
the CL sense, the only way I can think of would be to not use the
elisp reader at all, and provide you own – or else go through the read
form and excise forbidden symbols. This seems like a nontrivial (and
somewhat pointless?) endeavour.

- Harald