(This also changes the suggested /etc/nsswitch.conf line to use for
hooking up nss-system to use glibc's [SUCCESS=merge] feature so that we
can properly merge group membership lists).
This also updates the suggested PAM snippet in a number of way:
1. Be closer to the logic nowadays implemented in Fedora where the
auth/account/password stacks are all finished off with
pam_{deny|permit}.so
2. Make pam_unix.so just "sufficient" instead of "required" (paving
ground for pam_systemd_home.so being hooked in as additional
sufficient module.
3. Only do pam_nologin in the "account" stack, since it's about account
validity really.
4. Use modern parameters to pam_unix when changing passwords, i.e.
sha512 and shadow, and use already set up passwords (preparing ground
for pam_systemd_home again)
This changes nss-systemd to use the new varlink user/group APIs for
looking up everything.
(This also changes the factory /etc/nsswitch.conf line to use for
hooking up nss-system to use glibc's [SUCCESS=merge] feature so that we
can properly merge group membership lists).
Fixes: #12492
This way we can use libxcrypt specific functionality such as
crypt_gensalt() and thus take benefit of the newer algorithms libxcrypt
implements. (Also adds support for a new env var $SYSTEMD_CRYPT_PREFIX
which may be used to select the hash algorithm to use for libxcrypt.)
Also, let's move the weird crypt.h inclusion into libcrypt.h so that
there's a single place for it.
Previously we'd allow marking TTY sessions as idle, but when the user
tried to unmark it as idle again it we'd just revert to automatic TTY
atime idle detection, thus making it impossible to mark the session as
non-idle, unless its TTY is atime-touched all the time. But of course,
marking a session as idle is pretty much fatal if you never can mark it
as non-idle again.
This change is triggred by bug reports such as this:
https://github.com/systemd/systemd/issues/14053
With this patch we will now output a clean, clear error message if a
client tries to manipulate the idle state of a non-graphical session.
This means we now have clear rules: "manual" idle logic for graphical
sessions, and TTY based ones for all others that have a TTY of some
form.
I considered allowing the idle state to be overriden both ways for tty
sessions but that's problematic: for sessions that are temporarily
upgraded from tty to graphical and thus suddenly want to manage their
own idle state we'd need to a way to detect when the upgrade goes away
and thus we should revert to old behaviour. Without reverting to the
previous TTY idle auto-magic we'd otherwise be stuck in an eternally
idle or eternally non-idle state, with really bad effects in case
auto-suspend is used. Thus, let's instead generate a proper error
message, saying clearly we don't support it.
(Also includes some other fixes and clean-ups in related code)
Closes: #14053
