nixos/c2fmzq-server: init module

Co-authored-by: Peder Bergebakken Sundt <[e-mail]>
Co-authored-by: Anselm Schüler <[e-mail]>
Co-authored-by: h7x4 <[e-mail]>

nixos/doc/manual/release-notes/rl-2311.section.md

···
 
 - [Rosenpass](https://rosenpass.eu/), a service for post-quantum-secure VPNs with WireGuard. Available as [services.rosenpass](#opt-services.rosenpass.enable).
 
+- [c2FmZQ](https://github.com/c2FmZQ/c2FmZQ/), an application that can securely encrypt, store, and share files, including but not limited to pictures and videos. Available as [services.c2fmzq-server](#opt-services.c2fmzq-server.enable).
+
 ## Backward Incompatibilities {#sec-release-23.11-incompatibilities}
 
 - `network-online.target` has been fixed to no longer time out for systems with `networking.useDHCP = true` and `networking.useNetworkd = true`.

nixos/modules/module-list.nix

···
   ./services/web-apps/atlassian/jira.nix
   ./services/web-apps/audiobookshelf.nix
   ./services/web-apps/bookstack.nix
+  ./services/web-apps/c2fmzq-server.nix
   ./services/web-apps/calibre-web.nix
   ./services/web-apps/coder.nix
   ./services/web-apps/changedetection-io.nix

nixos/modules/services/web-apps/c2fmzq-server.md

···
+# c2FmZQ {#module-services-c2fmzq}
+
+c2FmZQ is an application that can securely encrypt, store, and share files,
+including but not limited to pictures and videos.
+
+The service `c2fmzq-server` can be enabled by setting
+```
+{
+  services.c2fmzq-server.enable = true;
+}
+```
+This will spin up an instance of the server which is API-compatible with
+[Stingle Photos](https://stingle.org) and an experimental Progressive Web App
+(PWA) to interact with the storage via the browser.
+
+In principle the server can be exposed directly on a public interface and there
+are command line options to manage HTTPS certificates directly, but the module
+is designed to be served behind a reverse proxy or only accessed via localhost.
+
+```
+{
+  services.c2fmzq-server = {
+    enable = true;
+    bindIP = "127.0.0.1"; # default
+    port = 8080; # default
+  };
+
+  services.nginx = {
+    enable = true;
+    recommendedProxySettings = true;
+    virtualHosts."example.com" = {
+      enableACME = true;
+      forceSSL = true;
+      locations."/" = {
+        proxyPass = "http://127.0.0.1:8080";
+      };
+    };
+  };
+}
+```
+
+For more information, see <https://github.com/c2FmZQ/c2FmZQ/>.

nixos/modules/services/web-apps/c2fmzq-server.nix

···
+{ lib, pkgs, config, ... }:
+
+let
+  inherit (lib) mkEnableOption mkPackageOption mkOption types;
+
+  cfg = config.services.c2fmzq-server;
+
+  argsFormat = {
+    type = with lib.types; nullOr (oneOf [ bool int str ]);
+    generate = lib.cli.toGNUCommandLineShell { };
+  };
+in {
+  options.services.c2fmzq-server = {
+    enable = mkEnableOption "c2fmzq-server";
+
+    bindIP = mkOption {
+      type = types.str;
+      default = "127.0.0.1";
+      description = "The local address to use.";
+    };
+
+    port = mkOption {
+      type = types.port;
+      default = 8080;
+      description = "The local port to use.";
+    };
+
+    passphraseFile = mkOption {
+      type = types.str;
+      example = "/run/secrets/c2fmzq/pwfile";
+      description = "Path to file containing the database passphrase";
+    };
+
+    package = mkPackageOption pkgs "c2fmzq" { };
+
+    settings = mkOption {
+      type = types.submodule {
+        freeformType = argsFormat.type;
+
+        options = {
+          address = mkOption {
+            internal = true;
+            type = types.str;
+            default = "${cfg.bindIP}:${toString cfg.port}";
+          };
+
+          database = mkOption {
+            type = types.str;
+            default = "%S/c2fmzq-server/data";
+            description = "Path of the database";
+          };
+
+          verbose = mkOption {
+            type = types.ints.between 1 3;
+            default = 2;
+            description = "The level of logging verbosity: 1:Error 2:Info 3:Debug";
+          };
+        };
+      };
+      description = ''
+        Configuration for c2FmZQ-server passed as CLI arguments.
+        Run {command}`c2FmZQ-server help` for supported values.
+      '';
+      example = {
+        verbose = 3;
+        allow-new-accounts = true;
+        auto-approve-new-accounts = true;
+        encrypt-metadata = true;
+        enable-webapp = true;
+      };
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.services.c2fmzq-server = {
+      description = "c2FmZQ-server";
+      documentation = [ "https://github.com/c2FmZQ/c2FmZQ/blob/main/README.md" ];
+      wantedBy = [ "multi-user.target" ];
+      after = [ "network.target" "network-online.target" ];
+
+      serviceConfig = {
+        ExecStart = "${lib.getExe cfg.package} ${argsFormat.generate cfg.settings}";
+        AmbientCapabilities = "";
+        CapabilityBoundingSet = "";
+        DynamicUser = true;
+        Environment = "C2FMZQ_PASSPHRASE_FILE=%d/passphrase-file";
+        IPAccounting = true;
+        IPAddressAllow = cfg.bindIP;
+        IPAddressDeny = "any";
+        LoadCredential = "passphrase-file:${cfg.passphraseFile}";
+        LockPersonality = true;
+        MemoryDenyWriteExecute = true;
+        NoNewPrivileges = true;
+        PrivateDevices = true;
+        PrivateIPC = true;
+        PrivateTmp = true;
+        PrivateUsers = true;
+        ProtectClock = true;
+        ProtectControlGroups = true;
+        ProtectHome = true;
+        ProtectHostname = true;
+        ProtectKernelLogs = true;
+        ProtectKernelModules = true;
+        ProtectKernelTunables = true;
+        ProtectProc = "invisible";
+        ProtectSystem = "strict";
+        RemoveIPC = true;
+        RestrictAddressFamilies = [ "AF_INET" "AF_INET6" ];
+        RestrictNamespaces = true;
+        RestrictRealtime = true;
+        RestrictSUIDSGID = true;
+        SocketBindAllow = cfg.port;
+        SocketBindDeny = "any";
+        StateDirectory = "c2fmzq-server";
+        SystemCallArchitectures = "native";
+        SystemCallFilter = [ "@system-service" "~@privileged @obsolete" ];
+      };
+    };
+  };
+
+  meta = {
+    doc = ./c2fmzq-server.md;
+    maintainers = with lib.maintainers; [ hmenke ];
+  };
+}