install/logical/friot/postfix.nix

   1 {pkgs, lib, config, nodes, ...}:
   2 let inherit (builtins) attrNames toFile;
   3     inherit (lib) types;
   4     inherit (config.services) x509 postfix dovecot2 postgrey openldap;
   5     unlines = lib.concatStringsSep "\n";
   6     unwords = lib.concatStringsSep " ";
   7     when    = x: y: if x == null then "" else y;
   8
   9     submissionHeaderCleanupRules = pkgs.writeText "submission_header_cleanup_rules" ''
  10       # Removes sensitive headers from mails handed in via the submission or smtps port.
  11       # See https://thomas-leister.de/mailserver-debian-stretch/
  12       # Uses "pcre" style regex.
  13
  14       /^Received:/         IGNORE
  15       /^User-Agent:/       IGNORE
  16       /^X-Enigmail:/       IGNORE
  17       /^X-Mailer:/         IGNORE
  18       /^X-Originating-IP:/ IGNORE
  19     '';
  20 in
  21 {
  22 options.services.postfix.aliases = lib.mkOption {
  23   type    = with types; attrsOf (listOf str);
  24   default = {};
  25   example = { "root@${config.networking.domain}" = [
  26                 "user1@${config.networking.domain}"
  27                 "user2@${config.networking.domain}"
  28               ];
  29               "@example.coop" = ["user1@${config.networking.domain}"];
  30             };
  31 };
  32 config = {
  33   systemd.services.postfix.after =
  34     if x509.scheme == "letsencrypt"
  35     then [ "nginx.service" ] # XXX: not sure if this is enough
  36     else [];
  37   services.postfix = {
  38     enable = true;
  39     #hostname = config.networking.domain;
  40     #domain = "localdomain";
  41     networksStyle = "host";
  42     #mapFiles."valias" = toFile "valias" (unlines (all_valiases_postfix ++ catchAllPostfix));
  43     # See https://blog.grimneko.de/2011/12/24/a-bunch-of-tips-for-improving-your-postfix-setup/
  44     # for details on how this file looks. By using the same file as valias,
  45     # every alias is uniquely owned by its user.
  46     # The user's own address is already in all_valiases_postfix.
  47     #mapFiles."vaccounts" = toFile "vaccounts" (unlines all_valiases_postfix);
  48     mapFiles."virtual_alias_maps" =
  49       toFile "virtual_alias_maps"
  50        (unlines
  51          (lib.mapAttrsToList
  52            (dom: {accounts, ...}:
  53              unlines
  54                (lib.mapAttrsToList
  55                  (user: acct:
  56                    unlines
  57                      (map (from: "${from} ${user}@${dom}")
  58                           acct.aliases))
  59                  accounts))
  60            dovecot2.domains)
  61        + unlines (lib.mapAttrsToList
  62            (from: to: "${from} ${unwords to}")
  63            postfix.aliases));
  64     mapFiles."ldap-virtual_alias_maps.cf" =
  65       toFile "ldap-virtual_alias_maps.cf" ''
  66         version          = 3
  67         debuglevel       = 3
  68         server_host      = ldapi://
  69         bind             = sasl
  70         sasl_mechs       = EXTERNAL
  71         search_base      = ou=posix,${openldap.domainSuffix}
  72         scope            = sub
  73         dereference      = 0
  74         query_filter     = (&(mail=%s))
  75         result_format    = %s
  76         result_attribute = mailAlias
  77       '';
  78     sslCert = x509.cert;
  79     sslKey = x509.key;
  80     #enableSubmission = true;
  81     #enableSmtp = true;
  82     destination = [
  83       "localhost"
  84       "localhost.localdomain"
  85       config.networking.hostName
  86       "${config.networking.hostName}.localdomain"
  87     ];
  88     networks = [
  89       "127.0.0.0/8"
  90       "[::1]/128"
  91     ];
  92     recipientDelimiter = "+";
  93     config = {
  94       # Appending .domain is the MUA's job
  95       append_dot_mydomain = false;
  96       # No console bell on new mail
  97       biff = false;
  98       body_checks = "";
  99       #content_filter = "amavisfeed:[127.0.0.1]:10024";
 100       #debug_peer_level = 4;
 101       #debug_peer_list = ".$myhostname";
 102       default_extra_recipient_limit = "5000";
 103       # Uncomment the next line to generate "delayed mail" warnings
 104       #delay_warning_time = "4h";
 105       # Stops some techniques used to harvest email addresses
 106       disable_vrfy_command = true;
 107       duplicate_filter_limit = "5000";
 108       enable_long_queue_ids = false;
 109       # Pass unexisting $mydestination recipients to dovecot
 110       fallback_transport = "lmtp:unix:private/dovecot-lmtp";
 111       forward_path = [
 112         ''$home/.forward''${recipient_delimiter}''${extension}''
 113         "$home/.forward"
 114       ];
 115       #header_checks = "regexp:/var/lib/postfix/conf/header_checks";
 116       #inet_interfaces = "all";
 117       line_length_limit = "2048";
 118
 119       # Let $fallback_transport check existence of recipients
 120       local_recipient_maps = "";
 121       #mail_spool_directory = "/var/spool/mail";
 122         # NOTE: nixpkgs's default
 123       #local_header_rewrite_clients = "";
 124       #home_mailbox = "Maildir/";
 125       #mailbox_command = ''
 126       #  ${pkgs.procmail}/bin/procmail -t -a "$SENDER" -a "$RECIPIENT" -a "$USER" -a "$EXTENSION" -a "$DOMAIN" -a "$ORIGINAL_RECIPIENT" "$HOME/.procmailrc"
 127       #'';
 128       mailbox_size_limit = "204800000";
 129
 130       masquerade_classes = [ "envelope_sender" "header_sender" "header_recipient" ];
 131       masquerade_domains = "";
 132       masquerade_exceptions = "root";
 133       maximal_queue_lifetime = "5d";
 134       message_size_limit = "20480000";
 135       mime_header_checks = "";
 136       milter_header_checks = "";
 137       nested_header_checks = "";
 138       non_smtpd_milters = "";
 139       parent_domain_matches_subdomains = [
 140         #"debug_peer_list"
 141         #"fast_flush_domains"
 142         #"mynetworks"
 143         #"permit_mx_backup_networks"
 144         #"qmqpd_authorized_clients"
 145         #"smtpd_access_maps"
 146       ];
 147       permit_mx_backup_networks = "";
 148       #policy-spf_time_limit = "3600s";
 149       propagate_unmatched_extensions = [ "canonical" "virtual" "alias" ];
 150       queue_minfree = "0";
 151       #receive_override_options = "no_address_mappings";
 152         # no_unknown_recipient_checks
 153         #         Do not try to reject unknown recipients (SMTP server only).
 154         #         This is typically specified AFTER an external content filter.
 155         # no_address_mappings
 156         #         Disable canonical address mapping, virtual alias map expansion,
 157         #         address masquerading, and automatic BCC (blind carbon-copy) recipients.
 158         #         This is typically specified BEFORE an external content filter (eg. amavis).
 159         # no_header_body_checks
 160         #         Disable header/body_checks. This is typically specified AFTER
 161         #         an external content filter.
 162         # no_milters
 163         #         Disable Milter (mail filter) applications.
 164         #         This is typically specified AFTER an external content filter.
 165       # Parse the extension in email address, eg. contact+extension@
 166       relayhost = "";
 167       #relay_clientcerts = hash:/var/lib/postfix/conf/relay_clientcerts
 168       # This is where to put backup MX domains
 169       relay_domains = "$mydestination";
 170       relay_recipient_maps = "";
 171       smtp_body_checks = "";
 172       #smtp_cname_overrides_servername = false;
 173       smtp_connect_timeout = "60s";
 174       #smtp_header_checks = "regexp:/var/lib/postfix/smtp_header_checks";
 175       smtp_mime_header_checks = "";
 176       smtp_nested_header_checks = "";
 177       smtp_tls_exclude_ciphers = [ "ADH" "MD5" "CAMELLIA" "SEED" "3DES" "DES" "RC4" "eNULL" "aNULL" ];
 178       #smtp_tls_fingerprint_digest = "sha1";
 179       smtp_tls_loglevel = "1";
 180       #smtp_tls_note_starttls_offer = true;
 181       #smtp_tls_policy_maps = "hash:/var/lib/postfix/conf/tls_policy";
 182       # Only allow TLSv* protocols
 183       smtp_tls_protocols = [ "!SSLv2" "!SSLv3" ];
 184       smtp_tls_scert_verifydepth = "5";
 185       #smtp_tls_secure_cert_match = [ "nexthop" "dot-nexthop" ];
 186       smtp_tls_security_level = "may";
 187       smtp_tls_session_cache_database = "btree:$data_directory/smtp_tls_session_cache";
 188       #smtp_tls_session_cache_timeout = "3600s";
 189       #smtp_tls_verify_cert_match = "hostname";
 190       # Useful to test restrictions
 191       smtpd_authorized_xclient_hosts = "127.0.0.1";
 192       smtpd_banner = "${config.networking.fqdn} ESMTP $mail_name (NixOS)";
 193       smtpd_client_connection_count_limit = "50";
 194       smtpd_client_connection_rate_limit = "0";
 195       smtpd_client_event_limit_exceptions = "$mynetworks";
 196       smtpd_client_message_rate_limit = "0";
 197       smtpd_client_new_tls_session_rate_limit = "0";
 198       smtpd_client_port_logging = false;
 199       smtpd_client_recipient_rate_limit = "0";
 200       smtpd_client_restrictions = [
 201         #"check_client_access hash:/var/lib/postfix/conf/client_blacklist"
 202       ];
 203       smtpd_data_restrictions = [
 204         "reject_unauth_pipelining"
 205           # Force the smtp client to wait OK before sending
 206         "permit"
 207       ];
 208       # Disable opportunistic encryption
 209       smtpd_discard_ehlo_keywords = "starttls";
 210       #smtpd_end_of_data_restrictions = "";
 211       # Ban 5 sec on error
 212       smtpd_error_sleep_time = "5";
 213       smtpd_helo_required = true;
 214       smtpd_helo_restrictions = [
 215         "reject_invalid_helo_hostname"
 216         "reject_non_fqdn_helo_hostname"
 217         #"reject_unknown_helo_hostname"
 218           # May be useful to fight spam
 219         "permit"
 220       ];
 221       #smtpd_milters = "";
 222       # Needed by postgrey
 223       smtpd_peername_lookup = true;
 224       smtpd_recipient_limit = "5000";
 225       smtpd_recipient_overshoot_limit = "5000";
 226       smtpd_recipient_restrictions = [
 227         "reject_non_fqdn_recipient"
 228         #"reject_invalid_hostname"
 229         "reject_unknown_recipient_domain"
 230         #"reject_non_fqdn_sender"
 231         "reject_unauth_pipelining"
 232         #"check_policy_service inet:localhost:12340"
 233         # check quota
 234         "permit_mynetworks"
 235         "permit_tls_clientcerts"
 236         "permit_sasl_authenticated"
 237         "reject_unverified_recipient"
 238           # $fallback_transport is responsible of checking the existence of the recipient
 239           # WARNING: verify(8) has a cache, dumpable if verify(8) is stopped, with:
 240           # postmap -s btree:/var/lib/postfix/data/verify_cache
 241         # Bypass SPF check and postgrey if the recipient is not for us or someone in backup_mx
 242         "reject_unauth_destination"
 243         # Check SPF
 244         #"check_policy_service unix:private/spfcheck"
 245         # Greylisting using postgrey
 246         "check_policy_service unix:${postgrey.socket.path}"
 247         # Once postgrey passed, permit what is for us
 248         "permit_auth_destination"
 249         "reject"
 250         #"reject_unknown_sender_domain"
 251           # Maybe better in smtpd_sender_restrictions
 252         #"reject_rbl_client bl.spamcop.net"
 253         #"reject_rbl_client list.dsbl.org"
 254         #"reject_rbl_client zen.spamhaus.org"
 255         #"reject_rbl_client dnsbl.sorbs.net"
 256       ];
 257       smtpd_relay_restrictions = [
 258         "permit_mynetworks"
 259         "permit_sasl_authenticated"
 260           # NOTE: permit auth through dovecot's SASL
 261         "reject_unauth_destination"
 262       ];
 263       #smtpd_restriction_classes = "";
 264       broken_sasl_auth_clients = false;
 265       #smtpd_sasl_auth_enable = true;
 266       #smtpd_sasl_path = "private/auth";
 267       #smtpd_sasl_security_options = "noanonymous";
 268       #smtpd_sasl_type = "dovecot";
 269       smtpd_sender_restrictions = [
 270         "permit_mynetworks"
 271         "permit_tls_clientcerts"
 272         "permit_sasl_authenticated"
 273           # NOTE: permit auth through dovecot's SASL
 274         #"check_sender_access hash:/var/lib/postfix/conf/sender_access"
 275         "reject_unauth_pipelining"
 276         "reject_non_fqdn_sender"
 277         #"reject_sender_login_mismatch"
 278         #"reject_unknown_sender_domain"
 279         "permit"
 280       ];
 281       smtpd_starttls_timeout = "300s";
 282       #smtpd_tls_always_issue_session_ids = true;
 283       # No SASL AUTH without TLS
 284       smtpd_tls_auth_only = true;
 285       #smtpd_tls_CApath = "/etc/postfix/x509/ca/";
 286       smtpd_tls_ask_ccert = false;
 287       #smtpd_tls_ccert_verifydepth = "5";
 288       smtpd_tls_ciphers = "high";
 289       smtpd_tls_eecdh_grade = "ultra";
 290       # Disable weak ciphers as reported by https://ssl-tools.net
 291       # https://serverfault.com/questions/744168/how-to-disable-rc4-on-postfix
 292       smtpd_tls_exclude_ciphers = [ "RC4" "aNULL" ];
 293       smtpd_tls_fingerprint_digest = "sha512";
 294       # Log only a summary message on TLS handshake completion
 295       smtpd_tls_loglevel = "1";
 296       smtpd_tls_mandatory_ciphers = "high";
 297       smtpd_tls_mandatory_protocols = "TLSv1";
 298       # Only allow TLSv*
 299       smtpd_tls_protocols = [ "!SSLv2" "!SSLv3" ];
 300       #smtpd_tls_received_header = false;
 301       smtpd_tls_req_ccert = false;
 302       # Postfix 2.3 and later
 303       # encrypt
 304       #  Mandatory TLS encryption: announce STARTTLS support to SMTP clients, and require that clients use TLS
 305       #  encryption. According to [1720]RFC 2487 this MUST NOT be applied in case of a publicly-referenced
 306       #  SMTP server. Instead, this option should be used only on dedicated servers.
 307       smtpd_tls_security_level = "may";
 308       smtpd_tls_session_cache_database = "btree:$data_directory/smtpd_tls_session_cache";
 309       #smtpd_tls_session_cache_timeout = "3600s";
 310       # Stops mail from poorly written software
 311       strict_rfc821_envelopes = true;
 312       #sympa_destination_recipient_limit = "1";
 313       #sympabounce_destination_recipient_limit = "1";
 314       # postconf(5) discourages to change this
 315       #tls_high_cipherlist = "AES256-SHA";
 316       #tls_random_bytes = "32";
 317       # Must not be in a chroot
 318       #tls_random_exchange_name = "$data_directory/prng_exch";
 319       #tls_random_prng_update_period = "3600s";
 320       #tls_random_reseed_period = "3600s";
 321       # Use a non blocking source of randomness
 322       tls_random_source = "dev:/dev/urandom";
 323       transport_maps = [
 324         #"ldap:transport"
 325         #"hash:/etc/postfix/transport-dovecot"
 326         #"hash:/etc/postfix/$mydomain/transport"
 327         #"hash:/etc/dovecot/transport"
 328         #"regexp:/etc/sympa/transport"
 329       ];
 330       # Rejects immediately what $fallback_transport rejects
 331       unverified_recipient_reject_code = "550";
 332       # Do not specify virtual alias domain names in mydestination
 333       # or relay_domains configuration parameters
 334       #
 335       # With  a  virtual  alias  domain,  the  Postfix SMTP server
 336       # accepts  mail  for  known-user@virtual-alias.domain,   and
 337       # rejects   mail  for  unknown-user@virtual-alias.domain  as
 338       # undeliverable.
 339       virtual_alias_domains = [];
 340       virtual_alias_maps = [
 341         "hash:/etc/postfix/virtual_alias_maps"
 342         #TODO: "ldap:/etc/postfix/ldap-virtual_alias_maps.cf"
 343         #"hash:/etc/postfix/virtual_alias-dovecot"
 344         #"hash:/var/lib/postfix/conf/valias"
 345         #"regexp:/etc/sympa/virtual_alias"
 346       ];
 347       #virtual_uid_maps = "static:5000";
 348       #virtual_gid_maps = "static:5000";
 349       #virtual_mailbox_base = dovecot2.mailDir;
 350       virtual_mailbox_domains = toFile "virtual_mailbox_domains" (unlines (attrNames dovecot2.domains));
 351       #virtual_mailbox_maps = "hash:/etc/postfix/virtual_mailbox_maps";
 352       virtual_transport = "lmtp:unix:private/dovecot-lmtp";
 353     };
 354     #submissionOptions = {
 355     #  smtpd_tls_security_level     = "encrypt";
 356     #  smtpd_sasl_auth_enable       = "yes";
 357     #  smtpd_sasl_type              = "dovecot";
 358     #  smtpd_sasl_path              = "private/auth";
 359     #  smtpd_sasl_security_options  = "noanonymous";
 360     #  smtpd_sasl_local_domain      = "$myhostname";
 361     #  smtpd_client_restrictions    = "permit_sasl_authenticated,reject";
 362     #  smtpd_sender_login_maps      = "hash:/etc/postfix/vaccounts";
 363     #  smtpd_sender_restrictions    = "reject_sender_login_mismatch";
 364     #  smtpd_recipient_restrictions = "reject_non_fqdn_recipient,reject_unknown_recipient_domain,permit_sasl_authenticated,reject";
 365     #  cleanup_service_name         = "submission-header-cleanup";
 366     #};
 367     extraMasterConf = ''
 368       #spfcheck    unix  -        n       n       -        0        spawn
 369       #  user=policyd-spf argv=/usr/sbin/postfix-policyd-spf-perl
 370       465         inet  n        -       -       -        -        smtpd
 371         -o milter_macro_daemon_name=ORIGINATING
 372         -o smtpd_client_restrictions=permit_sasl_authenticated,reject
 373         -o smtpd_recipient_restrictions=reject_non_fqdn_recipient,reject_unknown_recipient_domain,permit_sasl_authenticated,reject
 374         -o smtpd_sasl_auth_enable=yes
 375         -o smtpd_sasl_local_domain=$myhostname
 376         -o smtpd_sasl_path=private/auth
 377         -o smtpd_sasl_security_options=noanonymous
 378         -o smtpd_sasl_type=dovecot
 379         -o smtpd_tls_ask_ccert=no
 380         -o smtpd_tls_auth_only=yes
 381         -o smtpd_tls_ccert_verifydepth=0
 382         -o smtpd_tls_loglevel=1
 383         -o smtpd_tls_req_ccert=no
 384         -o smtpd_tls_security_level=encrypt
 385         -o smtpd_tls_wrappermode=yes
 386       # -o smtpd_sender_restrictions=reject_sender_login_mismatch
 387       # -o smtpd_sender_login_maps=hash:/etc/postfix/vaccounts
 388       # -o cleanup_service_name=submission-header-cleanup
 389       submission-header-cleanup unix n - n    -       0       cleanup
 390         -o header_checks=pcre:${submissionHeaderCleanupRules}
 391       #spfcheck  unix  -       n       n       -       0       spawn
 392       #  user=policyd-spf argv=/usr/bin/postfix-policyd-spf-perl
 393       #uucp      unix  -       n       n       -       -       pipe
 394       #  flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
 395       #smtp      inet  n       -       -       -       -       smtpd
 396       #  -o cleanup_service_name=pre-cleanup
 397       #  -o content_filter=amavis:[127.0.0.1]:10024
 398       #  -o smtpd_sender_restrictions=reject_unauth_pipelining,reject_non_fqdn_sender,permit
 399       #  -o receive_override_options=no_address_mappings
 400       #amavis    unix  -       -       n        -      2       lmtp
 401       #  -o lmtp_data_done_timeout=1200
 402       #  -o lmtp_send_xforward_command=yes
 403       #  -o lmtp_tls_note_starttls_offer=no
 404       #127.0.0.1:10025 inet n  -       n       -       -       smtpd
 405       #  -o content_filter=
 406       #  -o local_header_rewrite_clients=
 407       #  -o local_recipient_maps=
 408       #  -o mynetworks=127.0.0.0/8
 409       #  -o receive_override_options=no_header_body_checks,no_milters,no_unknown_recipient_checks
 410       #  -o relay_recipient_maps=
 411       #  -o smtpd_client_connection_count_limit=0
 412       #  -o smtpd_client_connection_rate_limit=0
 413       #  -o smtpd_client_restrictions=permit_mynetworks,reject
 414       #  -o smtpd_data_restrictions=reject_unauth_pipelining
 415       #  -o smtpd_delay_reject=no
 416       #  -o smtpd_end_of_data_restrictions=
 417       #  -o smtpd_error_sleep_time=0
 418       #  -o smtpd_hard_error_limit=1000
 419       #  -o smtpd_helo_restrictions=
 420       #  -o smtpd_milters=
 421       #  -o smtpd_recipient_restrictions=permit_mynetworks,reject
 422       #  -o smtpd_restriction_classes=
 423       #  -o smtpd_sender_restrictions=
 424       #  -o smtpd_soft_error_limit=1001
 425       #  -o strict_rfc821_envelopes=yes
 426       #submission inet n       -       -       -       -       smtpd
 427       #  -o cleanup_service_name=pre-cleanup
 428       #  -o content_filter=amavis:[127.0.0.1]:10024
 429       #  -o milter_macro_daemon_name=ORIGINATING
 430       #  -o receive_override_options=no_address_mappings
 431       #  -o smtpd_sender_restrictions=permit_tls_clientcerts,reject
 432       #  -o smtpd_tls_ask_ccert=yes
 433       #  -o smtpd_tls_auth_only=yes
 434       #  -o smtpd_tls_ccert_verifydepth=2
 435       #  -o smtpd_tls_loglevel=1
 436       #  -o smtpd_tls_req_ccert=yes
 437       #  -o smtpd_tls_security_level=encrypt
 438       #smtps     inet  n       -       -       -       -       smtpd
 439       #  -o milter_macro_daemon_name=ORIGINATING
 440       #  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
 441       #  -o smtpd_sasl_auth_enable=yes
 442       #  -o smtpd_tls_ask_ccert=yes
 443       #  -o smtpd_tls_auth_only=yes
 444       #  -o smtpd_tls_ccert_verifydepth=0
 445       #  -o smtpd_tls_loglevel=1
 446       #  -o smtpd_tls_req_ccert=no
 447       #  -o smtpd_tls_security_level=encrypt
 448       #  -o smtpd_tls_wrappermode=yes
 449       #pickup    fifo  n       -       -       60      1       pickup
 450       #  -o cleanup_service_name=pre-cleanup
 451       #  -o content_filter=amavis:[127.0.0.1]:10024
 452       #pre-cleanup unix n      -       -       -       0       cleanup
 453       #  -o virtual_alias_maps=
 454       #cleanup   unix  n       -       -       -       0       cleanup
 455       #  -o mime_header_checks=
 456       #  -o nested_header_checks=
 457       #  -o body_checks=
 458       #  -o header_checks=
 459       #-- SYMPA begin
 460       #sympa unix - n n - - pipe
 461       #  flags=R user=sympa argv=/usr/lib/sympa/bin/queue ''${recipient}
 462       #sympabounce unix - n n - - pipe
 463       #  flags=R user=sympa argv=/usr/lib/sympa/bin/bouncequeue ''${recipient}
 464       #-- SYMPA end
 465     '';
 466      #noclue    unix  -       n       n       -       -       pipe
 467      #  flags=q user=noclue argv=/usr/local/bin/noclue-delivery ${recipient} ${sender}
 468   };
 469 };
 470 }