>On Mon, 1 Dec 2003, Kyle Sallee wrote: > >> > With devpts and libutempter it is possible to install fully functional >> > screen without suid/sgid. >> >> Does that mean any program that links with libutempter gains >> complete suid/sgid root functionality, or only when executing >> the functions in the libutempter library, please? > >This means you do not need setuid root because devpts sets up the slave >pty owner and group automatically and you do not need direct access to >utmp/wtmp, e.g. via setgid utmp, because libtempter functions call an >external setgid utmp helper called utempter to modify those files (the >calling process is required to hold a corresponding master pty). Nearly exactly like in generic SVR4 where ptys are setup using /usr/lib/pt_chmod; and in Solaris there's the additional "utmp_update" programs which allows you to set utmp entries; this is all hidden behind the libc routines. Casper
