{ config, lib, pkgs, ... }: with lib; let cfg = config.security.acme; certOpts = { name, ... }: { options = { webroot = mkOption { type = types.str; example = "/var/lib/acme/acme-challenges"; description = '' Where the webroot of the HTTP vhost is located. .well-known/acme-challenge/ directory will be created below the webroot if it doesn't exist. http://example.org/.well-known/acme-challenge/ must also be available (notice unencrypted HTTP). ''; }; domain = mkOption { type = types.str; default = name; description = "Domain to fetch certificate for (defaults to the entry name)"; }; email = mkOption { type = types.nullOr types.str; default = null; description = "Contact email address for the CA to be able to reach you."; }; user = mkOption { type = types.str; default = "root"; description = "User running the ACME client."; }; group = mkOption { type = types.str; default = "root"; description = "Group running the ACME client."; }; allowKeysForGroup = mkOption { type = types.bool; default = false; description = '' Give read permissions to the specified group () to read SSL private certificates. ''; }; postRun = mkOption { type = types.lines; default = ""; example = "systemctl reload nginx.service"; description = '' Commands to run after new certificates go live. Typically the web server and other servers using certificates need to be reloaded. Executed in the same directory with the new certificate. ''; }; plugins = mkOption { type = types.listOf (types.enum [ "cert.der" "cert.pem" "chain.pem" "external.sh" "fullchain.pem" "full.pem" "key.der" "key.pem" "account_key.json" ]); default = [ "fullchain.pem" "full.pem" "key.pem" "account_key.json" ]; description = '' Plugins to enable. With default settings simp_le will store public certificate bundle in fullchain.pem, private key in key.pem and those two previous files combined in full.pem in its state directory. ''; }; directory = mkOption { type = types.str; readOnly = true; default = "/var/lib/acme/${name}"; description = "Directory where certificate and other state is stored."; }; extraDomains = mkOption { type = types.attrsOf (types.nullOr types.str); default = {}; example = literalExample '' { "example.org" = "/srv/http/nginx"; "mydomain.org" = null; } ''; description = '' A list of extra domain names, which are included in the one certificate to be issued, with their own server roots if needed. ''; }; }; }; in { ###### interface options = { security.acme = { validMin = mkOption { type = types.int; default = 30 * 24 * 3600; description = "Minimum remaining validity before renewal in seconds."; }; renewInterval = mkOption { type = types.str; default = "weekly"; description = '' Systemd calendar expression when to check for renewal. See systemd.time 7. ''; }; preliminarySelfsigned = mkOption { type = types.bool; default = true; description = '' Whether a preliminary self-signed certificate should be generated before doing ACME requests. This can be useful when certificates are required in a webserver, but ACME needs the webserver to make its requests. With preliminary self-signed certificate the webserver can be started and can later reload the correct ACME certificates. ''; }; production = mkOption { type = types.bool; default = true; description = '' If set to true, use Let's Encrypt's production environment instead of the staging environment. The main benefit of the staging environment is to get much higher rate limits. See https://letsencrypt.org/docs/staging-environment for more detail. ''; }; certs = mkOption { default = { }; type = with types; attrsOf (submodule certOpts); description = '' Attribute set of certificates to get signed and renewed. Creates acme-''${cert}.{service,timer} systemd units for each certificate defined here. Other services can add dependencies to those units if they rely on the certificates being present, or trigger restarts of the service if certificates get renewed. ''; example = literalExample '' { "example.com" = { webroot = "/var/www/challenges/"; email = "foo@example.com"; extraDomains = { "www.example.com" = null; "foo.example.com" = "/var/www/foo/"; }; }; "bar.example.com" = { webroot = "/var/www/challenges/"; email = "bar@example.com"; }; } ''; }; }; }; ###### implementation config = mkMerge [ (mkIf (cfg.certs != { }) { systemd.services = let services = concatLists servicesLists; servicesLists = mapAttrsToList certToServices cfg.certs; certToServices = cert: data: let lpath = "acme/${cert}"; rights = if data.allowKeysForGroup then "750" else "700"; cmdline = [ "-v" "-d" data.domain "--default_root" data.webroot "--valid_min" cfg.validMin ] ++ optionals (data.email != null) [ "--email" data.email ] ++ concatMap (p: [ "-f" p ]) data.plugins ++ concatLists (mapAttrsToList (name: root: [ "-d" (if root == null then name else "${name}:${root}")]) data.extraDomains) ++ optionals (!cfg.production) ["--server" "https://acme-staging.api.letsencrypt.org/directory"]; acmeService = { description = "Renew ACME Certificate for ${cert}"; after = [ "network.target" "network-online.target" ]; wants = [ "network-online.target" ]; serviceConfig = { Type = "oneshot"; SuccessExitStatus = [ "0" "1" ]; User = data.user; Group = data.group; PrivateTmp = true; StateDirectory = lpath; StateDirectoryMode = rights; WorkingDirectory = "/var/lib/${lpath}"; ExecStart = "${pkgs.simp_le}/bin/simp_le ${escapeShellArgs cmdline}"; ExecStopPost = let script = pkgs.writeScript "acme-post-stop" '' #!${pkgs.runtimeShell} -e ${data.postRun} ''; in "+${script}"; }; }; selfsignedService = { description = "Create preliminary self-signed certificate for ${cert}"; path = [ pkgs.openssl ]; script = '' workdir="$(mktemp -d)" # Create CA openssl genrsa -des3 -passout pass:xxxx -out $workdir/ca.pass.key 2048 openssl rsa -passin pass:xxxx -in $workdir/ca.pass.key -out $workdir/ca.key openssl req -new -key $workdir/ca.key -out $workdir/ca.csr \ -subj "/C=UK/ST=Warwickshire/L=Leamington/O=OrgName/OU=Security Department/CN=example.com" openssl x509 -req -days 1 -in $workdir/ca.csr -signkey $workdir/ca.key -out $workdir/ca.crt # Create key openssl genrsa -des3 -passout pass:xxxx -out $workdir/server.pass.key 2048 openssl rsa -passin pass:xxxx -in $workdir/server.pass.key -out $workdir/server.key openssl req -new -key $workdir/server.key -out $workdir/server.csr \ -subj "/C=UK/ST=Warwickshire/L=Leamington/O=OrgName/OU=IT Department/CN=example.com" openssl x509 -req -days 1 -in $workdir/server.csr -CA $workdir/ca.crt \ -CAkey $workdir/ca.key -CAserial $workdir/ca.srl -CAcreateserial \ -out $workdir/server.crt # Copy key to destination cp $workdir/server.key /var/lib/${lpath}/key.pem # Create fullchain.pem (same format as "simp_le ... -f fullchain.pem" creates) cat $workdir/{server.crt,ca.crt} > "/var/lib/${lpath}/fullchain.pem" # Create full.pem for e.g. lighttpd cat $workdir/{server.key,server.crt,ca.crt} > "/var/lib/${lpath}/full.pem" # Give key acme permissions chown '${data.user}:${data.group}' "/var/lib/${lpath}/"{key,fullchain,full}.pem chmod ${rights} "/var/lib/${lpath}/"{key,fullchain,full}.pem ''; serviceConfig = { Type = "oneshot"; PrivateTmp = true; StateDirectory = lpath; User = data.user; Group = data.group; }; unitConfig = { # Do not create self-signed key when key already exists ConditionPathExists = "!/var/lib/${lpath}/key.pem"; }; }; in ( [ { name = "acme-${cert}"; value = acmeService; } ] ++ optional cfg.preliminarySelfsigned { name = "acme-selfsigned-${cert}"; value = selfsignedService; } ); servicesAttr = listToAttrs services; in servicesAttr; systemd.tmpfiles.rules = flip mapAttrsToList cfg.certs (cert: data: "d ${data.webroot}/.well-known/acme-challenge - ${data.user} ${data.group}"); systemd.timers = flip mapAttrs' cfg.certs (cert: data: nameValuePair ("acme-${cert}") ({ description = "Renew ACME Certificate for ${cert}"; wantedBy = [ "timers.target" ]; timerConfig = { OnCalendar = cfg.renewInterval; Unit = "acme-${cert}.service"; Persistent = "yes"; AccuracySec = "5m"; RandomizedDelaySec = "1h"; }; }) ); }) ]; meta = { maintainers = with lib.maintainers; [ abbradar fpletz globin ]; doc = ./acme.xml; }; }