nixos/pam: avoid extra lines in pam files

nixos/modules/security/pam.nix

···
       # Samba stuff to the Samba module.  This requires that the PAM
       # module provides the right hooks.
       text = mkDefault
-        (''
-          # Account management.
-          account required pam_unix.so
-          ${optionalString use_ldap
-              "account sufficient ${pam_ldap}/lib/security/pam_ldap.so"}
-          ${optionalString (config.services.sssd.enable && cfg.sssdStrictAccess==false)
-              "account sufficient ${pkgs.sssd}/lib/security/pam_sss.so"}
-          ${optionalString (config.services.sssd.enable && cfg.sssdStrictAccess)
-              "account [default=bad success=ok user_unknown=ignore] ${pkgs.sssd}/lib/security/pam_sss.so"}
-          ${optionalString config.krb5.enable
-              "account sufficient ${pam_krb5}/lib/security/pam_krb5.so"}
-          ${optionalString cfg.googleOsLoginAccountVerification ''
+        (
+          ''
+            # Account management.
+            account required pam_unix.so
+          '' +
+          optionalString use_ldap ''
+            account sufficient ${pam_ldap}/lib/security/pam_ldap.so
+          '' +
+          optionalString (config.services.sssd.enable && cfg.sssdStrictAccess==false) ''
+            account sufficient ${pkgs.sssd}/lib/security/pam_sss.so
+          '' +
+          optionalString (config.services.sssd.enable && cfg.sssdStrictAccess) ''
+            account [default=bad success=ok user_unknown=ignore] ${pkgs.sssd}/lib/security/pam_sss.so
+          '' +
+          optionalString config.krb5.enable ''
+            account sufficient ${pam_krb5}/lib/security/pam_krb5.so
+          '' +
+          optionalString cfg.googleOsLoginAccountVerification ''
             account [success=ok ignore=ignore default=die] ${pkgs.google-compute-engine-oslogin}/lib/pam_oslogin_login.so
             account [success=ok default=ignore] ${pkgs.google-compute-engine-oslogin}/lib/pam_oslogin_admin.so
-          ''}
+          '' +
+          ''
 
-          # Authentication management.
-          ${optionalString cfg.googleOsLoginAuthentication
-              "auth [success=done perm_denied=bad default=ignore] ${pkgs.google-compute-engine-oslogin}/lib/pam_oslogin_login.so"}
-          ${optionalString cfg.rootOK
-              "auth sufficient pam_rootok.so"}
-          ${optionalString cfg.requireWheel
-              "auth required pam_wheel.so use_uid"}
-          ${optionalString cfg.logFailures
-              "auth required pam_faillock.so"}
-          ${optionalString (config.security.pam.enableSSHAgentAuth && cfg.sshAgentAuth)
-              "auth sufficient ${pkgs.pam_ssh_agent_auth}/libexec/pam_ssh_agent_auth.so file=${lib.concatStringsSep ":" config.services.openssh.authorizedKeysFiles}"}
-          ${let p11 = config.security.pam.p11; in optionalString cfg.p11Auth
-              "auth ${p11.control} ${pkgs.pam_p11}/lib/security/pam_p11.so ${pkgs.opensc}/lib/opensc-pkcs11.so"}
-          ${let u2f = config.security.pam.u2f; in optionalString cfg.u2fAuth
-              "auth ${u2f.control} ${pkgs.pam_u2f}/lib/security/pam_u2f.so ${optionalString u2f.debug "debug"} ${optionalString (u2f.authFile != null) "authfile=${u2f.authFile}"} ${optionalString u2f.interactive "interactive"} ${optionalString u2f.cue "cue"} ${optionalString (u2f.appId != null) "appid=${u2f.appId}"}"}
-          ${optionalString cfg.usbAuth
-              "auth sufficient ${pkgs.pam_usb}/lib/security/pam_usb.so"}
-          ${let oath = config.security.pam.oath; in optionalString cfg.oathAuth
-              "auth requisite ${pkgs.oathToolkit}/lib/security/pam_oath.so window=${toString oath.window} usersfile=${toString oath.usersFile} digits=${toString oath.digits}"}
-          ${let yubi = config.security.pam.yubico; in optionalString cfg.yubicoAuth
-              "auth ${yubi.control} ${pkgs.yubico-pam}/lib/security/pam_yubico.so mode=${toString yubi.mode} ${optionalString (yubi.challengeResponsePath != null) "chalresp_path=${yubi.challengeResponsePath}"} ${optionalString (yubi.mode == "client") "id=${toString yubi.id}"} ${optionalString yubi.debug "debug"}"}
-          ${optionalString cfg.fprintAuth
-              "auth sufficient ${pkgs.fprintd}/lib/security/pam_fprintd.so"}
-        '' +
+            # Authentication management.
+          '' +
+          optionalString cfg.googleOsLoginAuthentication ''
+            auth [success=done perm_denied=bad default=ignore] ${pkgs.google-compute-engine-oslogin}/lib/pam_oslogin_login.so
+          '' +
+          optionalString cfg.rootOK ''
+            auth sufficient pam_rootok.so
+          '' +
+          optionalString cfg.requireWheel ''
+            auth required pam_wheel.so use_uid
+          '' +
+          optionalString cfg.logFailures ''
+            auth required pam_faillock.so
+          '' +
+          optionalString (config.security.pam.enableSSHAgentAuth && cfg.sshAgentAuth) ''
+            auth sufficient ${pkgs.pam_ssh_agent_auth}/libexec/pam_ssh_agent_auth.so file=${lib.concatStringsSep ":" config.services.openssh.authorizedKeysFiles}
+          '' +
+          (let p11 = config.security.pam.p11; in optionalString cfg.p11Auth ''
+            auth ${p11.control} ${pkgs.pam_p11}/lib/security/pam_p11.so ${pkgs.opensc}/lib/opensc-pkcs11.so
+          '') +
+          (let u2f = config.security.pam.u2f; in optionalString cfg.u2fAuth ''
+            auth ${u2f.control} ${pkgs.pam_u2f}/lib/security/pam_u2f.so ${optionalString u2f.debug "debug"} ${optionalString (u2f.authFile != null) "authfile=${u2f.authFile}"} ${optionalString u2f.interactive "interactive"} ${optionalString u2f.cue "cue"} ${optionalString (u2f.appId != null) "appid=${u2f.appId}"}
+          '') +
+          optionalString cfg.usbAuth ''
+            auth sufficient ${pkgs.pam_usb}/lib/security/pam_usb.so
+          '' +
+          (let oath = config.security.pam.oath; in optionalString cfg.oathAuth ''
+            auth requisite ${pkgs.oathToolkit}/lib/security/pam_oath.so window=${toString oath.window} usersfile=${toString oath.usersFile} digits=${toString oath.digits}
+          '') +
+          (let yubi = config.security.pam.yubico; in optionalString cfg.yubicoAuth ''
+            auth ${yubi.control} ${pkgs.yubico-pam}/lib/security/pam_yubico.so mode=${toString yubi.mode} ${optionalString (yubi.challengeResponsePath != null) "chalresp_path=${yubi.challengeResponsePath}"} ${optionalString (yubi.mode == "client") "id=${toString yubi.id}"} ${optionalString yubi.debug "debug"}
+          '') +
+          optionalString cfg.fprintAuth ''
+            auth sufficient ${pkgs.fprintd}/lib/security/pam_fprintd.so
+          '' +
           # Modules in this block require having the password set in PAM_AUTHTOK.
           # pam_unix is marked as 'sufficient' on NixOS which means nothing will run
           # after it succeeds. Certain modules need to run after pam_unix
···
           # earlier point and it will run again with 'sufficient' further down.
           # We use try_first_pass the second time to avoid prompting password twice
           (optionalString (cfg.unixAuth &&
-          (config.security.pam.enableEcryptfs
-            || cfg.pamMount
-            || cfg.enableKwallet
-            || cfg.enableGnomeKeyring
-            || cfg.googleAuthenticator.enable
-            || cfg.gnupg.enable
-            || cfg.duoSecurity.enable)) ''
-              auth required pam_unix.so ${optionalString cfg.allowNullPassword "nullok"} ${optionalString cfg.nodelay "nodelay"} likeauth
-              ${optionalString config.security.pam.enableEcryptfs
-                "auth optional ${pkgs.ecryptfs}/lib/security/pam_ecryptfs.so unwrap"}
-              ${optionalString cfg.pamMount
-                "auth optional ${pkgs.pam_mount}/lib/security/pam_mount.so disable_interactive"}
-              ${optionalString cfg.enableKwallet
-                ("auth optional ${pkgs.plasma5Packages.kwallet-pam}/lib/security/pam_kwallet5.so" +
-                 " kwalletd=${pkgs.plasma5Packages.kwallet.bin}/bin/kwalletd5")}
-              ${optionalString cfg.enableGnomeKeyring
-                "auth optional ${pkgs.gnome.gnome-keyring}/lib/security/pam_gnome_keyring.so"}
-              ${optionalString cfg.gnupg.enable
-                "auth optional ${pkgs.pam_gnupg}/lib/security/pam_gnupg.so"
-                + optionalString cfg.gnupg.storeOnly " store-only"
-               }
-              ${optionalString cfg.googleAuthenticator.enable
-                "auth required ${pkgs.googleAuthenticator}/lib/security/pam_google_authenticator.so no_increment_hotp"}
-              ${optionalString cfg.duoSecurity.enable
-                "auth required ${pkgs.duo-unix}/lib/security/pam_duo.so"}
-            '') + ''
-          ${optionalString cfg.unixAuth
-              "auth sufficient pam_unix.so ${optionalString cfg.allowNullPassword "nullok"} ${optionalString cfg.nodelay "nodelay"} likeauth try_first_pass"}
-          ${optionalString cfg.otpwAuth
-              "auth sufficient ${pkgs.otpw}/lib/security/pam_otpw.so"}
-          ${optionalString use_ldap
-              "auth sufficient ${pam_ldap}/lib/security/pam_ldap.so use_first_pass"}
-          ${optionalString config.services.sssd.enable
-              "auth sufficient ${pkgs.sssd}/lib/security/pam_sss.so use_first_pass"}
-          ${optionalString config.krb5.enable ''
+            (config.security.pam.enableEcryptfs
+              || cfg.pamMount
+              || cfg.enableKwallet
+              || cfg.enableGnomeKeyring
+              || cfg.googleAuthenticator.enable
+              || cfg.gnupg.enable
+              || cfg.duoSecurity.enable))
+            (
+              ''
+                auth required pam_unix.so ${optionalString cfg.allowNullPassword "nullok"} ${optionalString cfg.nodelay "nodelay"} likeauth
+              '' +
+              optionalString config.security.pam.enableEcryptfs ''
+                auth optional ${pkgs.ecryptfs}/lib/security/pam_ecryptfs.so unwrap
+              '' +
+              optionalString cfg.pamMount ''
+                auth optional ${pkgs.pam_mount}/lib/security/pam_mount.so disable_interactive
+              '' +
+              optionalString cfg.enableKwallet ''
+               auth optional ${pkgs.plasma5Packages.kwallet-pam}/lib/security/pam_kwallet5.so kwalletd=${pkgs.plasma5Packages.kwallet.bin}/bin/kwalletd5
+              '' +
+              optionalString cfg.enableGnomeKeyring ''
+                auth optional ${pkgs.gnome.gnome-keyring}/lib/security/pam_gnome_keyring.so
+              '' +
+              optionalString cfg.gnupg.enable ''
+                auth optional ${pkgs.pam_gnupg}/lib/security/pam_gnupg.so ${optionalString cfg.gnupg.storeOnly " store-only"}
+              '' +
+              optionalString cfg.googleAuthenticator.enable ''
+                auth required ${pkgs.googleAuthenticator}/lib/security/pam_google_authenticator.so no_increment_hotp
+              '' +
+              optionalString cfg.duoSecurity.enable ''
+                auth required ${pkgs.duo-unix}/lib/security/pam_duo.so
+              ''
+            )) +
+          optionalString cfg.unixAuth ''
+            auth sufficient pam_unix.so ${optionalString cfg.allowNullPassword "nullok"} ${optionalString cfg.nodelay "nodelay"} likeauth try_first_pass
+          '' +
+          optionalString cfg.otpwAuth ''
+            auth sufficient ${pkgs.otpw}/lib/security/pam_otpw.so
+          '' +
+          optionalString use_ldap ''
+            auth sufficient ${pam_ldap}/lib/security/pam_ldap.so use_first_pass
+          '' +
+          optionalString config.services.sssd.enable ''
+            auth sufficient ${pkgs.sssd}/lib/security/pam_sss.so use_first_pass
+          '' +
+          optionalString config.krb5.enable ''
             auth [default=ignore success=1 service_err=reset] ${pam_krb5}/lib/security/pam_krb5.so use_first_pass
             auth [default=die success=done] ${pam_ccreds}/lib/security/pam_ccreds.so action=validate use_first_pass
             auth sufficient ${pam_ccreds}/lib/security/pam_ccreds.so action=store use_first_pass
-          ''}
-          auth required pam_deny.so
+          '' +
+          ''
+            auth required pam_deny.so
 
-          # Password management.
-          password sufficient pam_unix.so nullok sha512
-          ${optionalString config.security.pam.enableEcryptfs
-              "password optional ${pkgs.ecryptfs}/lib/security/pam_ecryptfs.so"}
-          ${optionalString cfg.pamMount
-              "password optional ${pkgs.pam_mount}/lib/security/pam_mount.so"}
-          ${optionalString use_ldap
-              "password sufficient ${pam_ldap}/lib/security/pam_ldap.so"}
-          ${optionalString config.services.sssd.enable
-              "password sufficient ${pkgs.sssd}/lib/security/pam_sss.so use_authtok"}
-          ${optionalString config.krb5.enable
-              "password sufficient ${pam_krb5}/lib/security/pam_krb5.so use_first_pass"}
-          ${optionalString cfg.enableGnomeKeyring
-              "password optional ${pkgs.gnome.gnome-keyring}/lib/security/pam_gnome_keyring.so use_authtok"}
+            # Password management.
+            password sufficient pam_unix.so nullok sha512
+          '' +
+          optionalString config.security.pam.enableEcryptfs ''
+            password optional ${pkgs.ecryptfs}/lib/security/pam_ecryptfs.so
+          '' +
+          optionalString cfg.pamMount ''
+            password optional ${pkgs.pam_mount}/lib/security/pam_mount.so
+          '' +
+          optionalString use_ldap ''
+            password sufficient ${pam_ldap}/lib/security/pam_ldap.so
+          '' +
+          optionalString config.services.sssd.enable ''
+            password sufficient ${pkgs.sssd}/lib/security/pam_sss.so use_authtok
+          '' +
+          optionalString config.krb5.enable ''
+            password sufficient ${pam_krb5}/lib/security/pam_krb5.so use_first_pass
+          '' +
+          optionalString cfg.enableGnomeKeyring ''
+            password optional ${pkgs.gnome.gnome-keyring}/lib/security/pam_gnome_keyring.so use_authtok
+          '' +
+          ''
 
-          # Session management.
-          ${optionalString cfg.setEnvironment ''
+            # Session management.
+          '' +
+          optionalString cfg.setEnvironment ''
             session required pam_env.so conffile=/etc/pam/environment readenv=0
-          ''}
-          session required pam_unix.so
-          ${optionalString cfg.setLoginUid
-              "session ${
-                if config.boot.isContainer then "optional" else "required"
-              } pam_loginuid.so"}
-          ${optionalString cfg.ttyAudit.enable
-              "session required ${pkgs.pam}/lib/security/pam_tty_audit.so
+          '' +
+          ''
+            session required pam_unix.so
+          '' +
+          optionalString cfg.setLoginUid ''
+            session ${if config.boot.isContainer then "optional" else "required"} pam_loginuid.so
+          '' +
+          optionalString cfg.ttyAudit.enable ''
+            session required ${pkgs.pam}/lib/security/pam_tty_audit.so
                 open_only=${toString cfg.ttyAudit.openOnly}
                 ${optionalString (cfg.ttyAudit.enablePattern != null) "enable=${cfg.ttyAudit.enablePattern}"}
                 ${optionalString (cfg.ttyAudit.disablePattern != null) "disable=${cfg.ttyAudit.disablePattern}"}
-              "}
-          ${optionalString cfg.makeHomeDir
-              "session required ${pkgs.pam}/lib/security/pam_mkhomedir.so silent skel=${config.security.pam.makeHomeDir.skelDirectory} umask=0077"}
-          ${optionalString cfg.updateWtmp
-              "session required ${pkgs.pam}/lib/security/pam_lastlog.so silent"}
-          ${optionalString config.security.pam.enableEcryptfs
-              "session optional ${pkgs.ecryptfs}/lib/security/pam_ecryptfs.so"}
-          ${optionalString cfg.pamMount
-              "session optional ${pkgs.pam_mount}/lib/security/pam_mount.so disable_interactive"}
-          ${optionalString use_ldap
-              "session optional ${pam_ldap}/lib/security/pam_ldap.so"}
-          ${optionalString config.services.sssd.enable
-              "session optional ${pkgs.sssd}/lib/security/pam_sss.so"}
-          ${optionalString config.krb5.enable
-              "session optional ${pam_krb5}/lib/security/pam_krb5.so"}
-          ${optionalString cfg.otpwAuth
-              "session optional ${pkgs.otpw}/lib/security/pam_otpw.so"}
-          ${optionalString cfg.startSession
-              "session optional ${pkgs.systemd}/lib/security/pam_systemd.so"}
-          ${optionalString cfg.forwardXAuth
-              "session optional pam_xauth.so xauthpath=${pkgs.xorg.xauth}/bin/xauth systemuser=99"}
-          ${optionalString (cfg.limits != [])
-              "session required ${pkgs.pam}/lib/security/pam_limits.so conf=${makeLimitsConf cfg.limits}"}
-          ${optionalString (cfg.showMotd && config.users.motd != null)
-              "session optional ${pkgs.pam}/lib/security/pam_motd.so motd=${motd}"}
-          ${optionalString (cfg.enableAppArmor && config.security.apparmor.enable)
-              "session optional ${pkgs.apparmor-pam}/lib/security/pam_apparmor.so order=user,group,default debug"}
-          ${optionalString (cfg.enableKwallet)
-              ("session optional ${pkgs.plasma5Packages.kwallet-pam}/lib/security/pam_kwallet5.so" +
-               " kwalletd=${pkgs.plasma5Packages.kwallet.bin}/bin/kwalletd5")}
-          ${optionalString (cfg.enableGnomeKeyring)
-              "session optional ${pkgs.gnome.gnome-keyring}/lib/security/pam_gnome_keyring.so auto_start"}
-          ${optionalString cfg.gnupg.enable
-              "session optional ${pkgs.pam_gnupg}/lib/security/pam_gnupg.so"
-              + optionalString cfg.gnupg.noAutostart " no-autostart"
-           }
-          ${optionalString (config.virtualisation.lxc.lxcfs.enable)
-               "session optional ${pkgs.lxc}/lib/security/pam_cgfs.so -c all"}
-        '');
+          '' +
+          optionalString cfg.makeHomeDir ''
+            session required ${pkgs.pam}/lib/security/pam_mkhomedir.so silent skel=${config.security.pam.makeHomeDir.skelDirectory} umask=0077
+          '' +
+          optionalString cfg.updateWtmp ''
+            session required ${pkgs.pam}/lib/security/pam_lastlog.so silent
+          '' +
+          optionalString config.security.pam.enableEcryptfs ''
+            session optional ${pkgs.ecryptfs}/lib/security/pam_ecryptfs.so
+          '' +
+          optionalString cfg.pamMount ''
+            session optional ${pkgs.pam_mount}/lib/security/pam_mount.so disable_interactive
+          '' +
+          optionalString use_ldap ''
+            session optional ${pam_ldap}/lib/security/pam_ldap.so
+          '' +
+          optionalString config.services.sssd.enable ''
+            session optional ${pkgs.sssd}/lib/security/pam_sss.so
+          '' +
+          optionalString config.krb5.enable ''
+            session optional ${pam_krb5}/lib/security/pam_krb5.so
+          '' +
+          optionalString cfg.otpwAuth ''
+            session optional ${pkgs.otpw}/lib/security/pam_otpw.so
+          '' +
+          optionalString cfg.startSession ''
+            session optional ${pkgs.systemd}/lib/security/pam_systemd.so
+          '' +
+          optionalString cfg.forwardXAuth ''
+            session optional pam_xauth.so xauthpath=${pkgs.xorg.xauth}/bin/xauth systemuser=99
+          '' +
+          optionalString (cfg.limits != []) ''
+            session required ${pkgs.pam}/lib/security/pam_limits.so conf=${makeLimitsConf cfg.limits}
+          '' +
+          optionalString (cfg.showMotd && config.users.motd != null) ''
+            session optional ${pkgs.pam}/lib/security/pam_motd.so motd=${motd}
+          '' +
+          optionalString (cfg.enableAppArmor && config.security.apparmor.enable) ''
+            session optional ${pkgs.apparmor-pam}/lib/security/pam_apparmor.so order=user,group,default debug
+          '' +
+          optionalString (cfg.enableKwallet) ''
+            session optional ${pkgs.plasma5Packages.kwallet-pam}/lib/security/pam_kwallet5.so kwalletd=${pkgs.plasma5Packages.kwallet.bin}/bin/kwalletd5
+          '' +
+          optionalString (cfg.enableGnomeKeyring) ''
+            session optional ${pkgs.gnome.gnome-keyring}/lib/security/pam_gnome_keyring.so auto_start
+          '' +
+          optionalString cfg.gnupg.enable ''
+            session optional ${pkgs.pam_gnupg}/lib/security/pam_gnupg.so ${optionalString cfg.gnupg.noAutostart " no-autostart"}
+          '' +
+          optionalString (config.virtualisation.lxc.lxcfs.enable) ''
+            session optional ${pkgs.lxc}/lib/security/pam_cgfs.so -c all
+          ''
+        );
     };
 
   };