How to add su to /rescue ?

[Julian H. Stacey]

Guy Helmer wrote:
> > On Jul 9, 2018, at 6:54 AM, Julian H. Stacey <jhs at berklix.com> wrote:
> > Hi current@
> > I want to add su to /rescue, but got stuck on pam.
> > Old unix su didn't suffer from pam.
> > There's no #define in su to turn off pam.
> > Man src.conf says WITHOUT_PAM is deprecated & does nothing.
> > 
> > Can someone please offer a solution ?
> > Or better to include a simple BSD su pre pam ?
> > I would happily develop a patch for that.
> Hi,
> Aside from not being able to use pam from a static executable, please don’t try to make the crunched hard-linked executable in /rescue setuid-root (su is useless without it). That would mean anyone running /rescue/sh gets a root shell :-)

Thanks Guy !  Yes all SUID 0 would be very wrong.


> Conceptually, a separate crunchgen binary could be made for setuid-root purposes, but having a setuid-root binary in /rescue (outside of the normal hierarchy) makes me nervous.

In case other suid things are also needed later, I created a local
src/rescue/suid/ with an old su.c pre PAM, Thanks to Diane Bruce,
& a diff & Makefile to drive it.
	http://berklix.com/~jhs/src/bsd/fixes/freebsd/src/gen/rescue/
It works, but improvements welcome.
	
Cheers,
Julian
-- 
Julian Stacey, Computer Consultant, Systems Engineer, BSD Linux Unix, Munich
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