{ config, lib, pkgs, ... }: with lib; let cfg = config.services.stunnel; yesNo = val: if val then "yes" else "no"; verifyRequiredField = type: field: n: c: { assertion = hasAttr field c; message = "stunnel: \"${n}\" ${type} configuration - Field ${field} is required."; }; verifyChainPathAssert = n: c: { assertion = (c.verifyHostname or null) == null || (c.verifyChain || c.verifyPeer); message = "stunnel: \"${n}\" client configuration - hostname verification " + "is not possible without either verifyChain or verifyPeer enabled"; }; removeNulls = mapAttrs (_: filterAttrs (_: v: v != null)); mkValueString = v: if v == true then "yes" else if v == false then "no" else generators.mkValueStringDefault {} v; generateConfig = c: generators.toINI { mkSectionName = id; mkKeyValue = k: v: "${k} = ${mkValueString v}"; } (removeNulls c); in { ###### interface options = { services.stunnel = { enable = mkOption { type = types.bool; default = false; description = lib.mdDoc "Whether to enable the stunnel TLS tunneling service."; }; user = mkOption { type = with types; nullOr str; default = "nobody"; description = lib.mdDoc "The user under which stunnel runs."; }; group = mkOption { type = with types; nullOr str; default = "nogroup"; description = lib.mdDoc "The group under which stunnel runs."; }; logLevel = mkOption { type = types.enum [ "emerg" "alert" "crit" "err" "warning" "notice" "info" "debug" ]; default = "info"; description = lib.mdDoc "Verbosity of stunnel output."; }; fipsMode = mkOption { type = types.bool; default = false; description = lib.mdDoc "Enable FIPS 140-2 mode required for compliance."; }; enableInsecureSSLv3 = mkOption { type = types.bool; default = false; description = lib.mdDoc "Enable support for the insecure SSLv3 protocol."; }; servers = mkOption { description = lib.mdDoc '' Define the server configurations. See "SERVICE-LEVEL OPTIONS" in {manpage}`stunnel(8)`. ''; type = with types; attrsOf (attrsOf (nullOr (oneOf [bool int str]))); example = { fancyWebserver = { accept = 443; connect = 8080; cert = "/path/to/pem/file"; }; }; default = { }; }; clients = mkOption { description = lib.mdDoc '' Define the client configurations. By default, verifyChain and OCSPaia are enabled and a CAFile is provided from pkgs.cacert. See "SERVICE-LEVEL OPTIONS" in {manpage}`stunnel(8)`. ''; type = with types; attrsOf (attrsOf (nullOr (oneOf [bool int str]))); apply = let applyDefaults = c: { CAFile = "${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt"; OCSPaia = true; verifyChain = true; } // c; setCheckHostFromVerifyHostname = c: # To preserve backward-compatibility with the old NixOS stunnel module # definition, allow "verifyHostname" as an alias for "checkHost". c // { checkHost = c.checkHost or c.verifyHostname or null; verifyHostname = null; # Not a real stunnel configuration setting }; forceClient = c: c // { client = true; }; in mapAttrs (_: c: forceClient (setCheckHostFromVerifyHostname (applyDefaults c))); example = { foobar = { accept = "0.0.0.0:8080"; connect = "nixos.org:443"; verifyChain = false; }; }; default = { }; }; }; }; ###### implementation config = mkIf cfg.enable { assertions = concatLists [ (singleton { assertion = (length (attrValues cfg.servers) != 0) || ((length (attrValues cfg.clients)) != 0); message = "stunnel: At least one server- or client-configuration has to be present."; }) (mapAttrsToList verifyChainPathAssert cfg.clients) (mapAttrsToList (verifyRequiredField "client" "accept") cfg.clients) (mapAttrsToList (verifyRequiredField "client" "connect") cfg.clients) (mapAttrsToList (verifyRequiredField "server" "accept") cfg.servers) (mapAttrsToList (verifyRequiredField "server" "cert") cfg.servers) (mapAttrsToList (verifyRequiredField "server" "connect") cfg.servers) ]; environment.systemPackages = [ pkgs.stunnel ]; environment.etc."stunnel.cfg".text = '' ${ if cfg.user != null then "setuid = ${cfg.user}" else "" } ${ if cfg.group != null then "setgid = ${cfg.group}" else "" } debug = ${cfg.logLevel} ${ optionalString cfg.fipsMode "fips = yes" } ${ optionalString cfg.enableInsecureSSLv3 "options = -NO_SSLv3" } ; ----- SERVER CONFIGURATIONS ----- ${ generateConfig cfg.servers } ; ----- CLIENT CONFIGURATIONS ----- ${ generateConfig cfg.clients } ''; systemd.services.stunnel = { description = "stunnel TLS tunneling service"; after = [ "network.target" ]; wants = [ "network.target" ]; wantedBy = [ "multi-user.target" ]; restartTriggers = [ config.environment.etc."stunnel.cfg".source ]; serviceConfig = { ExecStart = "${pkgs.stunnel}/bin/stunnel ${config.environment.etc."stunnel.cfg".source}"; Type = "forking"; }; }; meta.maintainers = with maintainers; [ # Server side lschuermann # Client side das_j ]; }; }