{ config, lib, pkgs, ... }: with lib; let cfg = config.services.tor; torDirectory = "/var/lib/tor"; torRunDirectory = "/run/tor"; opt = name: value: optionalString (value != null) "${name} ${value}"; optint = name: value: optionalString (value != null && value != 0) "${name} ${toString value}"; isolationOptions = { type = types.listOf (types.enum [ "IsolateClientAddr" "IsolateSOCKSAuth" "IsolateClientProtocol" "IsolateDestPort" "IsolateDestAddr" ]); default = []; example = [ "IsolateClientAddr" "IsolateSOCKSAuth" "IsolateClientProtocol" "IsolateDestPort" "IsolateDestAddr" ]; description = "Tor isolation options"; }; torRc = '' User tor DataDirectory ${torDirectory} ${optionalString cfg.enableGeoIP '' GeoIPFile ${pkgs.tor.geoip}/share/tor/geoip GeoIPv6File ${pkgs.tor.geoip}/share/tor/geoip6 ''} ${optint "ControlPort" cfg.controlPort} ${optionalString cfg.controlSocket.enable "ControlPort unix:${torRunDirectory}/control GroupWritable RelaxDirModeCheck"} '' # Client connection config + optionalString cfg.client.enable '' SOCKSPort ${cfg.client.socksListenAddress} ${toString cfg.client.socksIsolationOptions} SOCKSPort ${cfg.client.socksListenAddressFaster} ${opt "SocksPolicy" cfg.client.socksPolicy} ${optionalString cfg.client.transparentProxy.enable '' TransPort ${cfg.client.transparentProxy.listenAddress} ${toString cfg.client.transparentProxy.isolationOptions} ''} ${optionalString cfg.client.dns.enable '' DNSPort ${cfg.client.dns.listenAddress} ${toString cfg.client.dns.isolationOptions} AutomapHostsOnResolve 1 AutomapHostsSuffixes ${concatStringsSep "," cfg.client.dns.automapHostsSuffixes} ''} '' # Explicitly disable the SOCKS server if the client is disabled. In # particular, this makes non-anonymous hidden services possible. + optionalString (! cfg.client.enable) '' SOCKSPort 0 '' # Relay config + optionalString cfg.relay.enable '' ORPort ${toString cfg.relay.port} ${opt "Address" cfg.relay.address} ${opt "Nickname" cfg.relay.nickname} ${opt "ContactInfo" cfg.relay.contactInfo} ${optint "RelayBandwidthRate" cfg.relay.bandwidthRate} ${optint "RelayBandwidthBurst" cfg.relay.bandwidthBurst} ${opt "AccountingMax" cfg.relay.accountingMax} ${opt "AccountingStart" cfg.relay.accountingStart} ${if (cfg.relay.role == "exit") then opt "ExitPolicy" cfg.relay.exitPolicy else "ExitPolicy reject *:*"} ${optionalString (elem cfg.relay.role ["bridge" "private-bridge"]) '' BridgeRelay 1 ServerTransportPlugin ${concatStringsSep "," cfg.relay.bridgeTransports} exec ${obfs4}/bin/obfs4proxy managed ExtORPort auto ${optionalString (cfg.relay.role == "private-bridge") '' ExtraInfoStatistics 0 PublishServerDescriptor 0 ''} ''} '' # Hidden services + concatStrings (flip mapAttrsToList cfg.hiddenServices (n: v: '' HiddenServiceDir ${torDirectory}/onion/${v.name} ${optionalString (v.version != null) "HiddenServiceVersion ${toString v.version}"} ${flip concatMapStrings v.map (p: '' HiddenServicePort ${toString p.port} ${p.destination} '')} ${optionalString (v.authorizeClient != null) '' HiddenServiceAuthorizeClient ${v.authorizeClient.authType} ${concatStringsSep "," v.authorizeClient.clientNames} ''} '')) + cfg.extraConfig; torRcFile = pkgs.writeText "torrc" torRc; in { options = { services.tor = { enable = mkOption { type = types.bool; default = false; description = '' Enable the Tor daemon. By default, the daemon is run without relay, exit, bridge or client connectivity. ''; }; enableGeoIP = mkOption { type = types.bool; default = true; description = '' Whenever to configure Tor daemon to use GeoIP databases. Disabling this will disable by-country statistics for bridges and relays and some client and third-party software functionality. ''; }; extraConfig = mkOption { type = types.lines; default = ""; description = '' Extra configuration. Contents will be added verbatim to the configuration file at the end. ''; }; controlPort = mkOption { type = types.nullOr (types.either types.int types.str); default = null; example = 9051; description = '' If set, Tor will accept connections on the specified port and allow them to control the tor process. ''; }; controlSocket = { enable = mkOption { type = types.bool; default = false; description = '' Wheter to enable Tor control socket. Control socket is created in ${torRunDirectory}/control ''; }; }; client = { enable = mkOption { type = types.bool; default = false; description = '' Whether to enable Tor daemon to route application connections. You might want to disable this if you plan running a dedicated Tor relay. ''; }; socksListenAddress = mkOption { type = types.str; default = "127.0.0.1:9050"; example = "192.168.0.1:9100"; description = '' Bind to this address to listen for connections from Socks-speaking applications. Provides strong circuit isolation, separate circuit per IP address. ''; }; socksListenAddressFaster = mkOption { type = types.str; default = "127.0.0.1:9063"; example = "192.168.0.1:9101"; description = '' Bind to this address to listen for connections from Socks-speaking applications. Same as but uses weaker circuit isolation to provide performance suitable for a web browser. ''; }; socksPolicy = mkOption { type = types.nullOr types.str; default = null; example = "accept 192.168.0.0/16, reject *"; description = '' Entry policies to allow/deny SOCKS requests based on IP address. First entry that matches wins. If no SocksPolicy is set, we accept all (and only) requests from . ''; }; socksIsolationOptions = mkOption (isolationOptions // { default = ["IsolateDestAddr"]; }); transparentProxy = { enable = mkOption { type = types.bool; default = false; description = "Whether to enable tor transparent proxy"; }; listenAddress = mkOption { type = types.str; default = "127.0.0.1:9040"; example = "192.168.0.1:9040"; description = '' Bind transparent proxy to this address. ''; }; isolationOptions = mkOption isolationOptions; }; dns = { enable = mkOption { type = types.bool; default = false; description = "Whether to enable tor dns resolver"; }; listenAddress = mkOption { type = types.str; default = "127.0.0.1:9053"; example = "192.168.0.1:9053"; description = '' Bind tor dns to this address. ''; }; isolationOptions = mkOption isolationOptions; automapHostsSuffixes = mkOption { type = types.listOf types.str; default = [".onion" ".exit"]; example = [".onion"]; description = "List of suffixes to use with automapHostsOnResolve"; }; }; privoxy.enable = mkOption { type = types.bool; default = true; description = '' Whether to enable and configure the system Privoxy to use Tor's faster port, suitable for HTTP. To have anonymity, protocols need to be scrubbed of identifying information, and this can be accomplished for HTTP by Privoxy. Privoxy can also be useful for KDE torification. A good setup would be: setting SOCKS proxy to the default Tor port, providing maximum circuit isolation where possible; and setting HTTP proxy to Privoxy to route HTTP traffic over faster, but less isolated port. ''; }; }; relay = { enable = mkOption { type = types.bool; default = false; description = '' Whether to enable relaying TOR traffic for others. See for details. Setting this to true requires setting and options. ''; }; role = mkOption { type = types.enum [ "exit" "relay" "bridge" "private-bridge" ]; description = '' Your role in Tor network. There're several options: exit An exit relay. This allows Tor users to access regular Internet services through your public IP. Running an exit relay may expose you to abuse complaints. See for more info. You can specify which services Tor users may access via your exit relay using option. relay Regular relay. This allows Tor users to relay onion traffic to other Tor nodes, but not to public Internet. Note that some misconfigured and/or disrespectful towards privacy sites will block you even if your relay is not an exit relay. That is, just being listed in a public relay directory can have unwanted consequences. Which means you might not want to use this role if you browse public Internet from the same network as your relay, unless you want to write e-mails to those sites (you should!). See for more info. bridge Regular bridge. Works like a regular relay, but doesn't list you in the public relay directory and hides your Tor node behind obfs4proxy. Using this option will make Tor advertise your bridge to users through various mechanisms like , though. WARNING: THE FOLLOWING PARAGRAPH IS NOT LEGAL ADVICE. Consult with your lawer when in doubt. This role should be safe to use in most situations (unless the act of forwarding traffic for others is a punishable offence under your local laws, which would be pretty insane as it would make ISP illegal). See for more info. private-bridge Private bridge. Works like regular bridge, but does not advertise your node in any way. Using this role means that you won't contribute to Tor network in any way unless you advertise your node yourself in some way. Use this if you want to run a private bridge, for example because you'll give out your bridge address manually to your friends. Switching to this role after measurable time in "bridge" role is pretty useless as some Tor users would have learned about your node already. In the latter case you can still change option. See for more info. ''; }; bridgeTransports = mkOption { type = types.listOf types.str; default = ["obfs4"]; example = ["obfs2" "obfs3" "obfs4" "scramblesuit"]; description = "List of pluggable transports"; }; nickname = mkOption { type = types.str; default = "anonymous"; description = '' A unique handle for your TOR relay. ''; }; contactInfo = mkOption { type = types.nullOr types.str; default = null; example = "admin@relay.com"; description = '' Contact information for the relay owner (e.g. a mail address and GPG key ID). ''; }; accountingMax = mkOption { type = types.nullOr types.str; default = null; example = "450 GBytes"; description = '' Specify maximum bandwidth allowed during an accounting period. This allows you to limit overall tor bandwidth over some time period. See the AccountingMax option by looking at the tor manual tor 1 for more. Note this limit applies individually to upload and download; if you specify "500 GBytes" here, then you may transfer up to 1 TBytes of overall bandwidth (500 GB upload, 500 GB download). ''; }; accountingStart = mkOption { type = types.nullOr types.str; default = null; example = "month 1 1:00"; description = '' Specify length of an accounting period. This allows you to limit overall tor bandwidth over some time period. See the AccountingStart option by looking at the tor manual tor 1 for more. ''; }; bandwidthRate = mkOption { type = types.nullOr types.int; default = null; example = 100; description = '' Specify this to limit the bandwidth usage of relayed (server) traffic. Your own traffic is still unthrottled. Units: bytes/second. ''; }; bandwidthBurst = mkOption { type = types.nullOr types.int; default = cfg.relay.bandwidthRate; example = 200; description = '' Specify this to allow bursts of the bandwidth usage of relayed (server) traffic. The average usage will still be as specified in relayBandwidthRate. Your own traffic is still unthrottled. Units: bytes/second. ''; }; address = mkOption { type = types.nullOr types.str; default = null; example = "noname.example.com"; description = '' The IP address or full DNS name for advertised address of your relay. Leave unset and Tor will guess. ''; }; port = mkOption { type = types.either types.int types.str; example = 143; description = '' What port to advertise for Tor connections. This corresponds to the ORPort section in the Tor manual; see tor 1 for more details. At a minimum, you should just specify the port for the relay to listen on; a common one like 143, 22, 80, or 443 to help Tor users who may have very restrictive port-based firewalls. ''; }; exitPolicy = mkOption { type = types.nullOr types.str; default = null; example = "accept *:6660-6667,reject *:*"; description = '' A comma-separated list of exit policies. They're considered first to last, and the first match wins. If you want to _replace_ the default exit policy, end this with either a reject *:* or an accept *:*. Otherwise, you're _augmenting_ (prepending to) the default exit policy. Leave commented to just use the default, which is available in the man page or at . Look at for issues you might encounter if you use the default exit policy. If certain IPs and ports are blocked externally, e.g. by your firewall, you should update your exit policy to reflect this -- otherwise Tor users will be told that those destinations are down. ''; }; }; hiddenServices = mkOption { description = '' A set of static hidden services that terminate their Tor circuits at this node. Every element in this set declares a virtual onion host. You can specify your onion address by putting corresponding private key to an appropriate place in ${torDirectory}. For services without private keys in ${torDirectory} Tor daemon will generate random key pairs (which implies random onion addresses) on restart. The latter could take a while, please be patient. Hidden services can be useful even if you don't intend to actually hide them, since they can also be seen as a kind of NAT traversal mechanism. E.g. the example will make your sshd, whatever runs on "8080" and your mail server available from anywhere where the Tor network is available (which, with the help from bridges, is pretty much everywhere), even if both client and server machines are behind NAT you have no control over. ''; default = {}; example = literalExample '' { "my-hidden-service-example".map = [ { port = 22; } # map ssh port to this machine's ssh { port = 80; toPort = 8080; } # map http port to whatever runs on 8080 { port = "sip"; toHost = "mail.example.com"; toPort = "imap"; } # because we can ]; } ''; type = types.loaOf (types.submodule ({name, ...}: { options = { name = mkOption { type = types.str; description = '' Name of this tor hidden service. This is purely descriptive. After restarting Tor daemon you should be able to find your .onion address in ${torDirectory}/onion/$name/hostname. ''; }; map = mkOption { default = []; description = "Port mapping for this hidden service."; type = types.listOf (types.submodule ({config, ...}: { options = { port = mkOption { type = types.either types.int types.str; example = 80; description = '' Hidden service port to "bind to". ''; }; destination = mkOption { internal = true; type = types.str; description = "Forward these connections where?"; }; toHost = mkOption { type = types.str; default = "127.0.0.1"; description = "Mapping destination host."; }; toPort = mkOption { type = types.either types.int types.str; example = 8080; description = "Mapping destination port."; }; }; config = { toPort = mkDefault config.port; destination = mkDefault "${config.toHost}:${toString config.toPort}"; }; })); }; authorizeClient = mkOption { default = null; description = "If configured, the hidden service is accessible for authorized clients only."; type = types.nullOr (types.submodule ({...}: { options = { authType = mkOption { type = types.enum [ "basic" "stealth" ]; description = '' Either "basic" for a general-purpose authorization protocol or "stealth" for a less scalable protocol that also hides service activity from unauthorized clients. ''; }; clientNames = mkOption { type = types.nonEmptyListOf (types.strMatching "[A-Za-z0-9+-_]+"); description = '' Only clients that are listed here are authorized to access the hidden service. Generated authorization data can be found in ${torDirectory}/onion/$name/hostname. Clients need to put this authorization data in their configuration file using HidServAuth. ''; }; }; })); }; version = mkOption { default = null; description = "Rendezvous service descriptor version to publish for the hidden service. Currently, versions 2 and 3 are supported. (Default: 2)"; type = types.nullOr (types.enum [ 2 3 ]); }; }; config = { name = mkDefault name; }; })); }; }; }; config = mkIf cfg.enable { # Not sure if `cfg.relay.role == "private-bridge"` helps as tor # sends a lot of stats warnings = optional (cfg.relay.enable && cfg.hiddenServices != {}) '' Running Tor hidden services on a public relay makes the presence of hidden services visible through simple statistical analysis of publicly available data. You can safely ignore this warning if you don't intend to actually hide your hidden services. In either case, you can always create a container/VM with a separate Tor daemon instance. ''; users.groups.tor.gid = config.ids.gids.tor; users.users.tor = { description = "Tor Daemon User"; createHome = true; home = torDirectory; group = "tor"; uid = config.ids.uids.tor; }; # We have to do this instead of using RuntimeDirectory option in # the service below because systemd has no way to set owners of # RuntimeDirectory and putting this into the service below # requires that service to relax it's sandbox since this needs # writable /run systemd.services.tor-init = { description = "Tor Daemon Init"; wantedBy = [ "tor.service" ]; after = [ "local-fs.target" ]; script = '' install -m 0700 -o tor -g tor -d ${torDirectory} ${torDirectory}/onion install -m 0750 -o tor -g tor -d ${torRunDirectory} ''; serviceConfig = { Type = "oneshot"; RemainAfterExit = true; }; }; systemd.services.tor = { description = "Tor Daemon"; path = [ pkgs.tor ]; wantedBy = [ "multi-user.target" ]; after = [ "tor-init.service" "network.target" ]; restartTriggers = [ torRcFile ]; serviceConfig = { Type = "simple"; # Translated from the upstream contrib/dist/tor.service.in ExecStartPre = "${pkgs.tor}/bin/tor -f ${torRcFile} --verify-config"; ExecStart = "${pkgs.tor}/bin/tor -f ${torRcFile}"; ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID"; KillSignal = "SIGINT"; TimeoutSec = 30; Restart = "on-failure"; LimitNOFILE = 32768; # Hardening # this seems to unshare /run despite what systemd.exec(5) says PrivateTmp = mkIf (!cfg.controlSocket.enable) "yes"; PrivateDevices = "yes"; ProtectHome = "yes"; ProtectSystem = "strict"; InaccessiblePaths = "/home"; ReadOnlyPaths = "/"; ReadWritePaths = [ torDirectory torRunDirectory ]; NoNewPrivileges = "yes"; # tor.service.in has this in, but this line it fails to spawn a namespace when using hidden services #CapabilityBoundingSet = "CAP_SETUID CAP_SETGID CAP_NET_BIND_SERVICE"; }; }; environment.systemPackages = [ pkgs.tor ]; services.privoxy = mkIf (cfg.client.enable && cfg.client.privoxy.enable) { enable = true; extraConfig = '' forward-socks4a / ${cfg.client.socksListenAddressFaster} . toggle 1 enable-remote-toggle 0 enable-edit-actions 0 enable-remote-http-toggle 0 ''; }; }; }