[Nix-dev] How to install pmount properly?

[Harald van Dijk]

On 14/05/2015 10:00, Matthias Beyer wrote:
> Hi,
>
> I want to use pmount for mounting external devices - but after
> installing it, when using it, it tells me
>
>      Error: this program needs to be installed suid root
>
> How to do that properly? I installed via
>
>      nix-env -iA nixpkgs.pmount

Packages cannot contain setuid binaries. It would be a big security 
problem if they could, as regular users are able to create and build 
custom packages.

NixOS has the config.security.setuidPrograms setting, at the system 
level, that lets you specify programs for which setuid wrappers should 
be created. You can add pmount to this. You will also need to add pmount 
to the system packages, as only system packages are considered, again 
for security reasons.

See <nixos/modules/security/pam_usb.nix> for a module that uses pmount 
and sets up a setuid wrapper for it. You can put it in your own 
configuration the same way.

If using Nix without NixOS, then something similar should be easy to do 
manually.

Cheers,
Harald van Dijk