modules/private/mail/postfix.nix

   1 { lib, pkgs, config, nodes, ... }:
   2 {
   3   config = lib.mkIf config.myServices.mail.enable {
   4     secrets.keys = {
   5       "postfix/mysql_alias_maps" = {
   6         user = config.services.postfix.user;
   7         group = config.services.postfix.group;
   8         permissions = "0440";
   9         text = ''
  10           # We need to specify that option to trigger ssl connection
  11           tls_ciphers = TLSv1.2
  12           user = ${config.myEnv.mail.postfix.mysql.user}
  13           password = ${config.myEnv.mail.postfix.mysql.password}
  14           hosts = unix:${config.myEnv.mail.postfix.mysql.socket}
  15           dbname = ${config.myEnv.mail.postfix.mysql.database}
  16           query = SELECT DISTINCT destination
  17             FROM forwardings
  18             WHERE
  19               ((regex = 1 AND '%s' REGEXP CONCAT('^',source,'$') ) OR (regex = 0 AND source = '%s'))
  20               AND active = 1
  21               AND '%s' NOT IN
  22               (
  23                 SELECT source
  24                 FROM forwardings_blacklisted
  25                 WHERE source = '%s'
  26               ) UNION
  27               SELECT 'devnull@immae.eu'
  28               FROM forwardings_blacklisted
  29               WHERE source = '%s'
  30           '';
  31       };
  32       "postfix/ldap_mailboxes" = {
  33         user = config.services.postfix.user;
  34         group = config.services.postfix.group;
  35         permissions = "0440";
  36         text = ''
  37           server_host = ldaps://${config.myEnv.mail.dovecot.ldap.host}:636
  38           search_base = ${config.myEnv.mail.dovecot.ldap.base}
  39           query_filter = ${config.myEnv.mail.dovecot.ldap.postfix_mailbox_filter}
  40           bind_dn = ${config.myEnv.mail.dovecot.ldap.dn}
  41           bind_pw = ${config.myEnv.mail.dovecot.ldap.password}
  42           result_attribute = immaePostfixAddress
  43           result_format = dummy
  44           version = 3
  45         '';
  46       };
  47       "postfix/mysql_sender_login_maps" = {
  48         user = config.services.postfix.user;
  49         group = config.services.postfix.group;
  50         permissions = "0440";
  51         text = ''
  52           # We need to specify that option to trigger ssl connection
  53           tls_ciphers = TLSv1.2
  54           user = ${config.myEnv.mail.postfix.mysql.user}
  55           password = ${config.myEnv.mail.postfix.mysql.password}
  56           hosts = unix:${config.myEnv.mail.postfix.mysql.socket}
  57           dbname = ${config.myEnv.mail.postfix.mysql.database}
  58           query = SELECT DISTINCT destination
  59             FROM forwardings
  60             WHERE
  61               (
  62                 (regex = 1 AND CONCAT(SUBSTRING_INDEX('%u', '+', 1), '@%d') REGEXP CONCAT('^',source,'$') )
  63               OR
  64                 (regex = 0 AND source = CONCAT(SUBSTRING_INDEX('%u', '+', 1), '@%d'))
  65               )
  66               AND active = 1
  67             UNION SELECT CONCAT(SUBSTRING_INDEX('%u', '+', 1), '@%d') AS destination
  68           '';
  69       };
  70       "postfix/mysql_sender_relays_maps" = {
  71         user = config.services.postfix.user;
  72         group = config.services.postfix.group;
  73         permissions = "0440";
  74         text = ''
  75           # We need to specify that option to trigger ssl connection
  76           tls_ciphers = TLSv1.2
  77           user = ${config.myEnv.mail.postfix.mysql.user}
  78           password = ${config.myEnv.mail.postfix.mysql.password}
  79           hosts = unix:${config.myEnv.mail.postfix.mysql.socket}
  80           dbname = ${config.myEnv.mail.postfix.mysql.database}
  81           # INSERT INTO sender_relays
  82           #   (`from`, owner, relay, login, password, regex, active)
  83           # VALUES
  84           #   ( 'sender@otherhost.org'
  85           #   , 'me@mail.immae.eu'
  86           #   , '[otherhost.org]:587'
  87           #   , 'otherhostlogin'
  88           #   , AES_ENCRYPT('otherhostpassword', '${config.myEnv.mail.postfix.mysql.password_encrypt}')
  89           #   , '0'
  90           #   , '1');
  91
  92           query = SELECT DISTINCT `owner`
  93             FROM sender_relays
  94             WHERE
  95               ((regex = 1 AND '%s' REGEXP CONCAT('^',`from`,'$') ) OR (regex = 0 AND `from` = '%s'))
  96               AND active = 1
  97           '';
  98       };
  99       "postfix/mysql_sender_relays_hosts" = {
 100         user = config.services.postfix.user;
 101         group = config.services.postfix.group;
 102         permissions = "0440";
 103         text = ''
 104           # We need to specify that option to trigger ssl connection
 105           tls_ciphers = TLSv1.2
 106           user = ${config.myEnv.mail.postfix.mysql.user}
 107           password = ${config.myEnv.mail.postfix.mysql.password}
 108           hosts = unix:${config.myEnv.mail.postfix.mysql.socket}
 109           dbname = ${config.myEnv.mail.postfix.mysql.database}
 110
 111           query = SELECT DISTINCT relay
 112             FROM sender_relays
 113             WHERE
 114               ((regex = 1 AND '%s' REGEXP CONCAT('^',`from`,'$') ) OR (regex = 0 AND `from` = '%s'))
 115               AND active = 1
 116           '';
 117       };
 118       "postfix/mysql_sender_relays_creds" = {
 119         user = config.services.postfix.user;
 120         group = config.services.postfix.group;
 121         permissions = "0440";
 122         text = ''
 123           # We need to specify that option to trigger ssl connection
 124           tls_ciphers = TLSv1.2
 125           user = ${config.myEnv.mail.postfix.mysql.user}
 126           password = ${config.myEnv.mail.postfix.mysql.password}
 127           hosts = unix:${config.myEnv.mail.postfix.mysql.socket}
 128           dbname = ${config.myEnv.mail.postfix.mysql.database}
 129
 130           query = SELECT DISTINCT CONCAT(`login`, ':', AES_DECRYPT(`password`, '${config.myEnv.mail.postfix.mysql.password_encrypt}'))
 131             FROM sender_relays
 132             WHERE
 133               ((regex = 1 AND '%s' REGEXP CONCAT('^',`from`,'$') ) OR (regex = 0 AND `from` = '%s'))
 134               AND active = 1
 135           '';
 136       };
 137       "postfix/ldap_ejabberd_users_immae_fr" = {
 138         user = config.services.postfix.user;
 139         group = config.services.postfix.group;
 140         permissions = "0440";
 141         text = ''
 142           server_host = ldaps://${config.myEnv.jabber.ldap.host}:636
 143           search_base = ${config.myEnv.jabber.ldap.base}
 144           query_filter = ${config.myEnv.jabber.postfix_user_filter}
 145           domain = immae.fr
 146           bind_dn = ${config.myEnv.jabber.ldap.dn}
 147           bind_pw = ${config.myEnv.jabber.ldap.password}
 148           result_attribute = immaeXmppUid
 149           result_format = ejabberd@localhost
 150           version = 3
 151           '';
 152       };
 153     } // lib.mapAttrs' (name: v: lib.nameValuePair "postfix/scripts/${name}-env" {
 154       user = "postfixscripts";
 155       group = "root";
 156       permissions = "0400";
 157       text = builtins.toJSON v.env;
 158     }) config.myEnv.mail.scripts;
 159
 160     networking.firewall.allowedTCPPorts = [ 25 465 587 ];
 161
 162     users.users.postfixscripts = {
 163       group = "keys";
 164       uid = config.ids.uids.postfixscripts;
 165       description = "Postfix scripts user";
 166     };
 167     users.users."${config.services.postfix.user}".extraGroups = [ "keys" ];
 168     services.filesWatcher.postfix = {
 169       restart = true;
 170       paths = [
 171         config.secrets.fullPaths."postfix/mysql_alias_maps"
 172         config.secrets.fullPaths."postfix/ldap_mailboxes"
 173         config.secrets.fullPaths."postfix/mysql_sender_login_maps"
 174         config.secrets.fullPaths."postfix/ldap_ejabberd_users_immae_fr"
 175       ];
 176     };
 177     services.postfix = {
 178       extraAliases = let
 179         toScript = name: script: pkgs.writeScript name ''
 180           #! ${pkgs.stdenv.shell}
 181           mail=$(${pkgs.coreutils}/bin/cat -)
 182           output=$(echo "$mail" | ${script} 2>&1)
 183           ret=$?
 184
 185           if [ "$ret" != "0" ]; then
 186             echo "$mail" \
 187               | ${pkgs.procmail}/bin/formail -i "X-Return-Code: $ret" \
 188               | /run/wrappers/bin/sendmail -i scripts_error+${name}@mail.immae.eu
 189
 190           messageId=$(echo "$mail" | ${pkgs.procmail}/bin/formail -x "Message-Id:")
 191           repeat=$(echo "$mail" | ${pkgs.procmail}/bin/formail -X "From:" -X "Received:")
 192
 193           ${pkgs.coreutils}/bin/cat <<EOF | /run/wrappers/bin/sendmail -i scripts_error+${name}@mail.immae.eu
 194           $repeat
 195           To: scripts_error+${name}@mail.immae.eu
 196           Subject: Log from script error
 197           Content-Type: text/plain; charset="UTF-8"
 198           Content-Transfer-Encoding: 8bit
 199           References:$messageId
 200           MIME-Version: 1.0
 201           X-Return-Code: $ret
 202
 203           Error code: $ret
 204           Output of message:
 205           --------------
 206           $output
 207           --------------
 208           EOF
 209           fi
 210           '';
 211         scripts = lib.attrsets.mapAttrs (n: v:
 212           toScript n (pkgs.callPackage (builtins.fetchGit { url = v.src.url; ref = "master"; rev = v.src.rev; }) { scriptEnv = config.secrets.fullPaths."postfix/scripts/${n}-env"; })
 213         ) config.myEnv.mail.scripts // {
 214           testmail = pkgs.writeScript "testmail" ''
 215             #! ${pkgs.stdenv.shell}
 216             ${pkgs.coreutils}/bin/touch \
 217               "/var/lib/naemon/checks/email/$(${pkgs.procmail}/bin/formail -x To: | ${pkgs.coreutils}/bin/tr -d ' <>')"
 218             '';
 219         };
 220       in builtins.concatStringsSep "\n" (lib.attrsets.mapAttrsToList (n: v: ''${n}: "|${v}"'') scripts);
 221       mapFiles = let
 222         recipient_maps = let
 223           name = n: i: "relay_${n}_${toString i}";
 224           pair = n: i: m: lib.attrsets.nameValuePair (name n i) (
 225             if m.type == "hash"
 226             then pkgs.writeText (name n i) m.content
 227             else null
 228           );
 229           pairs = n: v: lib.imap1 (i: m: pair n i m) v.recipient_maps;
 230         in lib.attrsets.filterAttrs (k: v: v != null) (
 231           lib.attrsets.listToAttrs (lib.flatten (
 232             lib.attrsets.mapAttrsToList pairs config.myEnv.mail.postfix.backup_domains
 233           ))
 234         );
 235         relay_restrictions = lib.attrsets.filterAttrs (k: v: v != null) (
 236           lib.attrsets.mapAttrs' (n: v:
 237             lib.attrsets.nameValuePair "recipient_access_${n}" (
 238               if lib.attrsets.hasAttr "relay_restrictions" v
 239               then pkgs.writeText "recipient_access_${n}" v.relay_restrictions
 240               else null
 241             )
 242           ) config.myEnv.mail.postfix.backup_domains
 243         );
 244         virtual_map = {
 245           virtual = let
 246             cfg = config.myEnv.monitoring.email_check.eldiron;
 247             address = "${cfg.mail_address}@${cfg.mail_domain}";
 248           in pkgs.writeText "postfix-virtual" (
 249             builtins.concatStringsSep "\n" (
 250               ["${address} testmail@localhost"] ++
 251               lib.attrsets.mapAttrsToList (
 252                 n: v: lib.optionalString v.external ''
 253                   script_${n}@mail.immae.eu ${n}@localhost, scripts@mail.immae.eu
 254                 ''
 255               ) config.myEnv.mail.scripts
 256             )
 257           );
 258         };
 259         sasl_access = {
 260           host_sender_login = with lib.attrsets; let
 261             addresses = zipAttrs (lib.flatten (mapAttrsToList
 262               (n: v: (map (e: { "${e}" = "${n}@immae.eu"; }) v.emails)) config.myEnv.servers));
 263             joined = builtins.concatStringsSep ",";
 264           in pkgs.writeText "host-sender-login"
 265             (builtins.concatStringsSep "\n" (mapAttrsToList (n: v: "${n} ${joined v}") addresses));
 266         };
 267       in
 268         recipient_maps // relay_restrictions // virtual_map // sasl_access;
 269       config = {
 270         ### postfix module overrides
 271         readme_directory = "${pkgs.postfix}/share/postfix/doc";
 272         smtp_tls_CAfile = lib.mkForce "";
 273         smtp_tls_cert_file = lib.mkForce "";
 274         smtp_tls_key_file = lib.mkForce "";
 275
 276         message_size_limit = "1073741824"; # Don't put 0 here, it's not equivalent to "unlimited"
 277         mailbox_size_limit = "1073741825"; # Workaround, local delivered mails should all go through scripts
 278         alias_database = "\$alias_maps";
 279
 280         ### Aliases scripts user
 281         default_privs = "postfixscripts";
 282
 283         ### Virtual mailboxes config
 284         virtual_alias_maps = [
 285           "hash:/etc/postfix/virtual"
 286           "mysql:${config.secrets.fullPaths."postfix/mysql_alias_maps"}"
 287           "ldap:${config.secrets.fullPaths."postfix/ldap_ejabberd_users_immae_fr"}"
 288         ];
 289         virtual_mailbox_domains = config.myEnv.mail.postfix.additional_mailbox_domains
 290         ++ lib.remove null (lib.flatten (map
 291             (zone: map
 292               (e: if e.receive
 293               then "${e.domain}${lib.optionalString (e.domain != "") "."}${zone.name}"
 294               else null
 295               )
 296               (zone.withEmail or [])
 297             )
 298             config.myEnv.dns.masterZones
 299           ));
 300         virtual_mailbox_maps = [
 301           "ldap:${config.secrets.fullPaths."postfix/ldap_mailboxes"}"
 302         ];
 303         dovecot_destination_recipient_limit = "1";
 304         virtual_transport = "dovecot";
 305
 306         ### Relay domains
 307         relay_domains = lib.flatten (lib.attrsets.mapAttrsToList (n: v: v.domains or []) config.myEnv.mail.postfix.backup_domains);
 308         relay_recipient_maps = lib.flatten (lib.attrsets.mapAttrsToList (n: v:
 309           lib.imap1 (i: m: "${m.type}:/etc/postfix/relay_${n}_${toString i}") v.recipient_maps
 310         ) config.myEnv.mail.postfix.backup_domains);
 311         smtpd_relay_restrictions = [
 312           "defer_unauth_destination"
 313         ] ++ lib.flatten (lib.attrsets.mapAttrsToList (n: v:
 314           if lib.attrsets.hasAttr "relay_restrictions" v
 315           then [ "check_recipient_access hash:/etc/postfix/recipient_access_${n}" ]
 316           else []
 317         ) config.myEnv.mail.postfix.backup_domains);
 318
 319         ### Additional smtpd configuration
 320         smtpd_tls_received_header = "yes";
 321         smtpd_tls_loglevel = "1";
 322
 323         ### Email sending configuration
 324         smtp_tls_security_level = "may";
 325         smtp_tls_loglevel = "1";
 326
 327         ### Force ip bind for smtp
 328         smtp_bind_address  = config.hostEnv.ips.main.ip4;
 329         smtp_bind_address6 = builtins.head config.hostEnv.ips.main.ip6;
 330
 331         # Use some relays when authorized senders are not myself
 332         smtp_sasl_mechanism_filter = "plain,login"; # GSSAPI Not correctly supported by postfix
 333         smtp_sasl_auth_enable = "yes";
 334         smtp_sasl_password_maps =
 335           "mysql:${config.secrets.fullPaths."postfix/mysql_sender_relays_creds"}";
 336         smtp_sasl_security_options = "noanonymous";
 337         smtp_sender_dependent_authentication = "yes";
 338         sender_dependent_relayhost_maps =
 339           "mysql:${config.secrets.fullPaths."postfix/mysql_sender_relays_hosts"}";
 340
 341         ### opendkim, opendmarc, openarc milters
 342         non_smtpd_milters = [
 343           "unix:${config.myServices.mail.milters.sockets.opendkim}"
 344         ];
 345         smtpd_milters = [
 346           "unix:${config.myServices.mail.milters.sockets.opendkim}"
 347           "unix:${config.myServices.mail.milters.sockets.openarc}"
 348           "unix:${config.myServices.mail.milters.sockets.opendmarc}"
 349         ];
 350
 351         smtp_use_tls = true;
 352         smtpd_use_tls = true;
 353         smtpd_tls_chain_files = builtins.concatStringsSep "," [ "/var/lib/acme/mail/full.pem" "/var/lib/acme/mail-rsa/full.pem" ];
 354
 355         maximal_queue_lifetime = "6w";
 356         bounce_queue_lifetime = "6w";
 357       };
 358       enable = true;
 359       enableSmtp = true;
 360       enableSubmission = true;
 361       submissionOptions = {
 362         # Don’t use "long form", only commas (cf
 363         # http://www.postfix.org/master.5.html long form is not handled
 364         # well by the submission function)
 365         smtpd_tls_security_level = "encrypt";
 366         smtpd_sasl_auth_enable = "yes";
 367         smtpd_tls_auth_only = "yes";
 368         smtpd_sasl_tls_security_options = "noanonymous";
 369         smtpd_sasl_type = "dovecot";
 370         smtpd_sasl_path = "private/auth";
 371         smtpd_reject_unlisted_recipient = "no";
 372         smtpd_client_restrictions = "permit_sasl_authenticated,reject";
 373         smtpd_relay_restrictions = "permit_sasl_authenticated,reject";
 374         # Refuse to send e-mails with a From that is not handled
 375         smtpd_sender_restrictions =
 376           "reject_sender_login_mismatch,reject_unlisted_sender,permit_sasl_authenticated,reject";
 377         smtpd_sender_login_maps = builtins.concatStringsSep "," [
 378           "hash:/etc/postfix/host_sender_login"
 379           "mysql:${config.secrets.fullPaths."postfix/mysql_sender_relays_maps"}"
 380           "mysql:${config.secrets.fullPaths."postfix/mysql_sender_login_maps"}"
 381         ];
 382         smtpd_recipient_restrictions = "permit_sasl_authenticated,reject";
 383         milter_macro_daemon_name = "ORIGINATING";
 384         smtpd_milters = builtins.concatStringsSep "," [
 385           # FIXME: put it back when opensmtpd is upgraded and able to
 386           # rewrite the from header
 387           #"unix:/run/milter_verify_from/verify_from.sock"
 388           "unix:${config.myServices.mail.milters.sockets.opendkim}"
 389         ];
 390       };
 391       destination = ["localhost"];
 392       # This needs to reverse DNS
 393       hostname = config.hostEnv.fqdn;
 394       setSendmail = true;
 395       recipientDelimiter = "+";
 396       masterConfig = {
 397         submissions = {
 398           type = "inet";
 399           private = false;
 400           command = "smtpd";
 401           args = ["-o" "smtpd_tls_wrappermode=yes" ] ++ (let
 402             mkKeyVal = opt: val: [ "-o" (opt + "=" + val) ];
 403           in lib.concatLists (lib.mapAttrsToList mkKeyVal config.services.postfix.submissionOptions)
 404           );
 405         };
 406         dovecot = {
 407           type = "unix";
 408           privileged = true;
 409           chroot = false;
 410           command = "pipe";
 411           args = let
 412             # rspamd could be used as a milter, but then it cannot apply
 413             # its checks "per user" (milter is not yet dispatched to
 414             # users), so we wrap dovecot-lda inside rspamc per recipient
 415             # here.
 416             rspamc_dovecot = pkgs.writeScriptBin "rspamc_dovecot" ''
 417               #! ${pkgs.stdenv.shell}
 418               sender="$1"
 419               original_recipient="$2"
 420               user="$3"
 421
 422               ${pkgs.coreutils}/bin/cat - | \
 423                 (${pkgs.rspamd}/bin/rspamc -h ${config.myServices.mail.rspamd.sockets.worker-controller} -c bayes -d "$user" --mime || true) | \
 424                 ${pkgs.dovecot}/libexec/dovecot/dovecot-lda -f "$sender" -a "$original_recipient" -d "$user"
 425               '';
 426           in [
 427             "flags=ODRhu" "user=vhost:vhost"
 428             "argv=${rspamc_dovecot}/bin/rspamc_dovecot \${sender} \${original_recipient} \${user}@\${nexthop}"
 429           ];
 430         };
 431       };
 432     };
 433     security.acme.certs."mail" = {
 434       postRun = ''
 435         systemctl restart postfix.service
 436         '';
 437       extraDomains = {
 438         "smtp.immae.eu" = null;
 439       };
 440     };
 441     security.acme.certs."mail-rsa" = {
 442       postRun = ''
 443         systemctl restart postfix.service
 444         '';
 445       extraDomains = {
 446         "smtp.immae.eu" = null;
 447       };
 448     };
 449     system.activationScripts.testmail = {
 450       deps = [ "users" ];
 451       text = let
 452         allCfg = config.myEnv.monitoring.email_check;
 453         cfg = allCfg.eldiron;
 454         reverseTargets = builtins.attrNames (lib.attrsets.filterAttrs (k: v: builtins.elem "eldiron" v.targets) allCfg);
 455         to_email = cfg': host':
 456           let sep = if lib.strings.hasInfix "+" cfg'.mail_address then "_" else "+";
 457           in "${cfg'.mail_address}${sep}${host'}@${cfg'.mail_domain}";
 458         mails_to_receive = builtins.concatStringsSep " " (map (to_email cfg) reverseTargets);
 459       in ''
 460         install -m 0555 -o postfixscripts -g keys -d /var/lib/naemon/checks/email
 461         for f in ${mails_to_receive}; do
 462           if [ ! -f /var/lib/naemon/checks/email/$f ]; then
 463             install -m 0644 -o postfixscripts -g keys /dev/null -T /var/lib/naemon/checks/email/$f
 464             touch -m -d @0 /var/lib/naemon/checks/email/$f
 465           fi
 466         done
 467         '';
 468     };
 469     systemd.services.postfix.serviceConfig.Slice = "mail.slice";
 470   };
 471 }