Permit unix_chkpwd & pam_unix.so to run without being setuid-root.

Remove the hard-coding of the idea that the only way pam_unix.so can
read the shadow file is if it can, in some way, run setuid-root.
Linux capabilities only require cap_dac_override to read the /etc/shadow
file.

This change achieves two things: it opens a path for a linux-pam
application to run without being setuid-root; further, it allows
unix_chkpwd to run non-setuid-root if it is installed:

   sudo setcap cap_dac_override=ep unix_chkpwd

If we wanted to link against libcap, we could install this binary with
cap_dac_override=p, and use cap_set_proc() to raise the effective bit
at runtime. However, some distributions already link unix_chkpwd
against libcap-ng for some, likely spurious, reason so "ep" is fine
for now.

Signed-off-by: Andrew G. Morgan <morgan@kernel.org>

0 files changed, 0 insertions, 0 deletions