refactor: streamline core modules into dedicated folder

modules/core/sssd.nix

@@ -0,0 +1,41 @@
+{ config, ... }:
+{
+  sops.secrets = {
+    "sssd/env" = { };
+
+  };
+  services.sssd = {
+    enable = true;
+    environmentFile = config.sops.secrets."sssd/env".path;
+    sshAuthorizedKeysIntegration = true;
+    config = ''
+      [sssd]
+      config_file_version = 2
+      services = nss, pam, ssh
+      domains = ldap
+
+      [ssh]
+
+      [nss]
+
+      [pam]
+
+      [domain/ldap]
+      auth_provider = ldap
+      ldap_uri = ldaps://auth.ifsr.de
+      ldap_default_authtok_type = password
+      ldap_default_authtok = $SSSD_LDAP_DEFAULT_AUTHTOK
+      ldap_search_base = dc=ifsr,dc=de
+      id_provider = ldap
+      ldap_default_bind_dn = uid=search,ou=users,dc=ifsr,dc=de
+      cache_credentials = True
+      ldap_tls_cacert = /etc/ssl/certs/ca-bundle.crt
+      ldap_tls_reqcert = hard
+    '';
+
+  };
+  security.pam.services = {
+    sshd.makeHomeDir = true;
+    login.makeHomeDir = true;
+  };
+}