Files
simple-nixos-mailserver/mail-server/systemd.nix
T
Martin Weinelt 6ff4a50f02 Add support for DKIM key management
After bumping the generation of new DKIM keys to RSA 2048 in NixOS 25.11
key rotation for existing users could not be done safely.

To resolve this situation we now support multiple generations of
selectors per domain to enable proper DKIM key transitions as described
in RFC6376 3.1. The added documentation introduces and motivates DKIM
and guides the user through a DKIM key rotation.

Additionally, DKIM key material can now also be treated as a managed
secrets when autogenerated state on the mail server host is undesirable.

This change is fully backwards compatible in behavior and will continue
to use the previously generated DKIM key without any additional
configuration up until the point when DKIM selectors are configured
explicitly.
2026-03-11 22:37:49 +01:00

75 lines
2.1 KiB
Nix

# nixos-mailserver: a simple mail server
# Copyright (C) 2016-2018 Robin Raymond
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>
{
config,
options,
pkgs,
lib,
...
}:
with (import ./common.nix {
inherit
config
options
lib
pkgs
;
});
let
cfg = config.mailserver;
certificateDeps = lib.optionals withACME [
"acme-order-renew-${cfg.x509.useACMEHost}.service"
];
in
{
config = lib.mkIf cfg.enable {
systemd.services.dovecot = {
wants = certificateDeps;
after = certificateDeps;
preStart =
let
directories = lib.strings.escapeShellArgs (
[ cfg.mailDirectory ] ++ lib.optional (cfg.indexDir != null) cfg.indexDir
);
in
''
# Create mail directory and set permissions. See
# <https://doc.dovecot.org/main/core/config/shared_mailboxes.html#filesystem-permissions-1>.
# Prevent world-readable paths, even temporarily.
umask 007
mkdir -p ${directories}
chgrp "${cfg.vmailGroupName}" ${directories}
chmod 02770 ${directories}
'';
};
# Postfix requires dovecot lmtp socket, dovecot auth socket and certificate to work
systemd.services.postfix = {
wants = certificateDeps;
after = [
"dovecot.service"
]
++ lib.optional cfg.dkim.enable "rspamd.service"
++ certificateDeps;
requires = [ "dovecot.service" ] ++ lib.optional cfg.dkim.enable "rspamd.service";
};
};
}