servers/mermet/postfix.nix

   1 { pkgs, lib, config, ... }:
   2 let
   3   inherit (builtins) attrNames concatStringsSep readFile toPath;
   4   inherit (builtins.extraBuiltins) pass;
   5   inherit (lib) types;
   6   inherit (pkgs.lib) loadFile unlines unwords unlinesAttrs;
   7   inherit (config) networking users;
   8   inherit (config.services) postfix dovecot2 openldap;
   9 in
  10 {
  11 imports = [
  12   postfix/sourcephile.fr.nix
  13   postfix/autogeree.net.nix
  14 ];
  15 options = {
  16   services.postfix = {
  17     tls_server_sni_maps = lib.mkOption {
  18       type = types.attrsOf (types.listOf types.path);
  19       default = {};
  20       apply = m: pkgs.writeText "sni" (lib.concatStringsSep "\n" (lib.mapAttrsToList (domain: x509: ''
  21         ${domain} ${unwords x509}
  22       '') m));
  23     };
  24   };
  25 };
  26 config = {
  27 users.groups.acme.members = [ postfix.user ];
  28 systemd.services.postfix = {
  29   after = ["openldap.service"];
  30   preStart = ''
  31     install -m 400 -o root -g root ${postfix.tls_server_sni_maps} /run/keys/postfix-sni
  32     ${pkgs.postfix}/bin/postmap -F hash:/run/keys/postfix-sni
  33   '';
  34 };
  35 services.postfix = {
  36   enable = true;
  37   networksStyle = "host";
  38   hostname ="${networking.hostName}.${networking.domain}";
  39   domain = networking.domain;
  40   origin = "$myhostname";
  41   destination = [
  42     "localhost"
  43     "localhost.localdomain"
  44     "$myhostname"
  45   ];
  46   postmasterAlias = "root";
  47   rootAlias = "root@${networking.domain}";
  48   sslCert = loadFile (../../../sec/openssl + "/${networking.domain}/cert.self-signed.pem");
  49   sslKey = "/run/keys/${networking.domain}.key.pem";
  50   networks = [
  51     "127.0.0.0/8"
  52     "[::1]/128"
  53   ];
  54   setSendmail = true;
  55   # Parse the extension in email address, eg. contact+extension@
  56   recipientDelimiter = "+";
  57   config = {
  58     debug_peer_level = "4";
  59     debug_peer_list = [
  60       #"chomsky.autogeree.net"
  61       #"localhost"
  62       #"mail.sourcephile.fr"
  63     ];
  64
  65     #
  66     # Sending to the world
  67     #
  68     # Appending .domain is the MUA's job
  69     append_dot_mydomain = false;
  70     smtp_body_checks = "";
  71     #smtp_cname_overrides_servername = false;
  72     smtp_connect_timeout = "60s";
  73     #smtp_header_checks = "regexp:/var/lib/postfix/smtp_header_checks";
  74     smtp_mime_header_checks = "";
  75     smtp_nested_header_checks = "";
  76     smtp_tls_exclude_ciphers = [ "ADH" "MD5" "CAMELLIA" "SEED" "3DES" "DES" "RC4" "eNULL" "aNULL" ];
  77     #smtp_tls_fingerprint_digest = "sha1";
  78     smtp_tls_loglevel = "1";
  79     #smtp_tls_note_starttls_offer = true;
  80     #smtp_tls_policy_maps = "hash:/var/lib/postfix/conf/tls_policy";
  81     # Only allow TLSv* protocols
  82     smtp_tls_protocols = [ "!SSLv2" "!SSLv3" ];
  83     #smtp_tls_scert_verifydepth = "5";
  84     #smtp_tls_secure_cert_match = [ "nexthop" "dot-nexthop" ];
  85     smtp_tls_security_level = "may";
  86     smtp_tls_session_cache_database = "btree:$data_directory/smtp_tls_session_cache";
  87     #smtp_tls_session_cache_timeout = "3600s";
  88     #smtp_tls_verify_cert_match = "hostname";
  89
  90     #
  91     # Receiving from the world
  92     #
  93     message_size_limit = "20480000";
  94     maximal_queue_lifetime = "5d";
  95     default_extra_recipient_limit = "5000";
  96     line_length_limit = "2048";
  97     duplicate_filter_limit = "5000";
  98     # Stops mail from poorly written software
  99     strict_rfc821_envelopes = true;
 100     mime_header_checks = [];
 101     milter_header_checks = [];
 102     nested_header_checks = [];
 103     body_checks = [];
 104     content_filter = "";
 105     permit_mx_backup_networks = [];
 106     propagate_unmatched_extensions = [ "canonical" "virtual" "alias" ];
 107     #masquerade_classes = [ "envelope_sender" "header_sender" "header_recipient" ];
 108     #masquerade_domains = "";
 109     #masquerade_exceptions = "root";
 110     queue_minfree = "0";
 111     # Stops some techniques used to harvest email addresses
 112     disable_vrfy_command = true;
 113     enable_long_queue_ids = false;
 114     # Useful to test restrictions
 115     smtpd_authorized_xclient_hosts = "127.0.0.1";
 116     smtpd_banner = "$myhostname ESMTP $mail_name (NixOS)";
 117     smtpd_client_connection_count_limit = "50";
 118     smtpd_client_connection_rate_limit = "0";
 119     smtpd_client_event_limit_exceptions = "$mynetworks";
 120     smtpd_client_message_rate_limit = "0";
 121     smtpd_client_new_tls_session_rate_limit = "0";
 122     smtpd_client_port_logging = false;
 123     smtpd_client_recipient_rate_limit = "0";
 124     # Ban 5 sec on error
 125     smtpd_error_sleep_time = "5";
 126     # Needed to enforce reject_unknown_helo_hostname
 127     smtpd_helo_required = true;
 128     smtpd_helo_restrictions = [
 129       "reject_invalid_helo_hostname"
 130       "reject_non_fqdn_helo_hostname"
 131       # Don't talk to mail systems that don't know their own hostname.
 132       "reject_unknown_helo_hostname"
 133       "permit"
 134     ];
 135     smtpd_client_restrictions = [
 136     ];
 137     # Set in postfix/*.nix and used in submissions/smptd
 138     # with reject_sender_login_mismatch
 139     smtpd_sender_login_maps = [];
 140     smtpd_sender_restrictions = [
 141       "reject_non_fqdn_sender"
 142       "permit"
 143     ];
 144     smtpd_reject_unlisted_recipient = true;
 145     # Check the RCPT TO, before smtpd_recipient_restrictions
 146     # Restrictions based on what is allowed or not,
 147     # these are applied before smtpd_recipient_restrictions
 148     smtpd_relay_restrictions = [
 149       "permit_mynetworks"
 150       # Check the recipient's address in virtual_mailbox_domains and virtual_mailbox_maps
 151       "permit_auth_destination"
 152       # The world is only authorized to use our relay for the above destinations.
 153       "reject"
 154     ];
 155     # Restrictions based on what is working or not
 156     smtpd_recipient_restrictions = [
 157       # Reject if the domain is not fully qualified
 158       "reject_non_fqdn_recipient"
 159       # Reject if the domain is not working, even before bothering to check the address
 160       "reject_unknown_recipient_domain"
 161       # Reject if the address is not working
 162       # WARNING: verify(8) has a cache, dumpable if verify(8) is stopped, with:
 163       # postmap -s btree:/var/lib/postfix/data/verify_cache
 164       "reject_unverified_recipient"
 165       "permit"
 166     ];
 167     # Trust the verify database
 168     unverified_recipient_reject_code = "550";
 169     smtpd_data_restrictions = [
 170       # Force the smtpd's client to wait OK before sending
 171       "reject_unauth_pipelining"
 172       "permit"
 173     ];
 174     smtpd_end_of_data_restrictions = [
 175       # Enforce mail volume quota via policy service callouts.
 176       #check_policy_service unix:private/policy
 177     ];
 178     #smtpd_milters = "";
 179     smtpd_peername_lookup = true;
 180     smtpd_recipient_limit = "5000";
 181     smtpd_recipient_overshoot_limit = "5000";
 182     #smtpd_restriction_classes = "";
 183     #smtpd_sasl_auth_enable = true;
 184     #smtpd_sasl_path = "private/auth";
 185     #smtpd_sasl_security_options = "noanonymous";
 186     #smtpd_sasl_type = "dovecot";
 187     smtpd_starttls_timeout = "300s";
 188     #smtpd_tls_always_issue_session_ids = true;
 189     #smtpd_tls_CApath = "/etc/postfix/x509/ca/";
 190     smtpd_tls_ask_ccert = false;
 191     #smtpd_tls_ccert_verifydepth = "5";
 192     smtpd_tls_ciphers = "high";
 193     smtpd_tls_eecdh_grade = "auto";
 194     # Disable weak ciphers as reported by https://ssl-tools.net
 195     # https://serverfault.com/questions/744168/how-to-disable-rc4-on-postfix
 196     smtpd_tls_exclude_ciphers = [ "ADH" "MD5" "CAMELLIA" "SEED" "3DES" "DES" "RC4" "eNULL" "aNULL" ];
 197     smtpd_tls_fingerprint_digest = "sha512";
 198     # Log only a summary message on TLS handshake completion
 199     smtpd_tls_loglevel = "1";
 200     smtpd_tls_mandatory_ciphers = "high";
 201     smtpd_tls_mandatory_protocols = [ "!SSLv2" "!SSLv3" ];
 202     # Only allow TLSv*
 203     smtpd_tls_protocols = [ "!SSLv2" "!SSLv3" ];
 204     #smtpd_tls_received_header = false;
 205     smtpd_tls_req_ccert = false;
 206     # Postfix 2.3 and later
 207     # encrypt
 208     #  Mandatory TLS encryption: announce STARTTLS support to SMTP clients, and require that clients use TLS
 209     #  encryption. According to [1720]RFC 2487 this MUST NOT be applied in case of a publicly-referenced
 210     #  SMTP server. Instead, this option should be used only on dedicated servers.
 211     smtpd_tls_security_level = "may";
 212     smtpd_tls_session_cache_database = "btree:$data_directory/smtpd_tls_session_cache";
 213     #smtpd_tls_session_cache_timeout = "3600s";
 214     #smtpd_tls_chain_files =
 215
 216     relayhost = [];
 217     #relay_clientcerts = hash:/var/lib/postfix/conf/relay_clientcerts
 218     # This is where to put backup MX domains
 219     relay_domains = [];
 220     relay_recipient_maps = [];
 221
 222     # Use a non blocking source of randomness
 223     tls_random_source = "dev:/dev/urandom";
 224     # Map each domain to a specific X.509 certificate
 225     tls_server_sni_maps = "hash:/run/keys/postfix-sni";
 226
 227     # Only explicitely aliased accounts have a mail, not all the passwd
 228     local_recipient_maps = "$alias_maps";
 229     # Note that the local transport rewrites the envelope recipient
 230     # according to the alias_maps, and thus the aliasing is transparent
 231     # to the nexthop (eg. dovecot)
 232     #local_transport = local:$myhostname
 233     # No console bell on new mail
 234     biff = false;
 235     forward_path = [
 236       /*
 237       "$home/.forward''${recipient_delimiter}''${extension}"
 238       "$home/.forward"
 239       */
 240     ];
 241
 242     # Filled by the postfix/*.nix
 243     virtual_mailbox_domains = [];
 244     # Completed by the postfix/*.nix
 245     virtual_mailbox_maps = [
 246       "hash:/etc/postfix/virtual"
 247     ];
 248     virtual_transport = "lmtp:unix:private/dovecot-lmtp";
 249     /*
 250     dovecot_destination_recipient_limit = "1";
 251     virtual_transport = "dovecot";
 252     */
 253
 254     # There is no fallback
 255     fallback_transport = "";
 256   };
 257   virtualMapType = "hash";
 258   masterConfig =
 259     let
 260       mkVal = value:
 261         if lib.isList value
 262         then concatStringsSep "," value
 263         else
 264           if value == true then "yes"
 265           else if value == false then "no"
 266           else toString value;
 267       mkKeyVal = opt: val: [ "-o" (opt + "=" + mkVal val) ];
 268       mkArgs = args: lib.concatLists (lib.mapAttrsToList mkKeyVal args);
 269     in {
 270     pickup = {
 271       args = mkArgs {
 272         cleanup_service_name = "submissions-header-cleanup";
 273       };
 274     };
 275     # Implicit TLS on port 465
 276     # https://tools.ietf.org/html/rfc8314#section-3.3
 277     submissions = {
 278       type = "inet";
 279       private = false;
 280       command = "smtpd";
 281       args = mkArgs {
 282         syslog_name = "postfix/submissions";
 283         # Implicit TLS, not STARTTLS
 284         smtpd_tls_wrappermode = true;
 285         smtpd_tls_mandatory_protocols = [
 286           "TLSv1.3"
 287           # K-9 Mail 5.600 still requires this..
 288           "TLSv1.2"
 289         ];
 290         milter_macro_daemon_name = "ORIGINATING";
 291         smtpd_relay_restrictions = [
 292           # SASL authorizes to send to the world
 293           "permit_sasl_authenticated"
 294           "reject"
 295         ];
 296         smtpd_sasl_auth_enable = true;
 297         smtpd_sasl_type = "dovecot";
 298         smtpd_sasl_path = "private/auth";
 299         smtpd_sasl_local_domain = "";
 300         # Offer SASL authentication only after a TLS-encrypted session has been established
 301         smtpd_tls_auth_only = true;
 302         smtpd_sasl_tls_security_options = [ "noanonymous" ];
 303         # Do not put SASL logins in mail headers
 304         smtpd_sasl_authenticated_header = false;
 305         # Who cares about (old) Outlook
 306         broken_sasl_auth_clients = false;
 307         smtpd_sender_restrictions = [
 308           "reject_non_fqdn_sender"
 309           # Check that the SASL user is using only its own
 310           # mail addresses on the envelope, as indicated in smtpd_sender_login_maps
 311           "reject_sender_login_mismatch"
 312           "permit"
 313         ];
 314         # No X.509 certificates for users, for now
 315         smtpd_tls_ask_ccert = false;
 316         smtpd_tls_ccert_verifydepth = 0;
 317         smtpd_tls_loglevel = 1;
 318         smtpd_tls_req_ccert = false;
 319         cleanup_service_name = "submissions-header-cleanup";
 320       };
 321     };
 322     submissions-header-cleanup = {
 323       type = "unix";
 324       private = false;
 325       maxproc = 0;
 326       command = "cleanup";
 327       args = mkArgs {
 328         header_checks = "pcre:" + pkgs.writeText "submission_header_cleanup_rules" ''
 329           # Removes sensitive headers from mails handed in via the submission or smtps port.
 330           # See https://thomas-leister.de/mailserver-debian-stretch/
 331           # Uses "pcre" style regex.
 332
 333           /^Received:/         IGNORE
 334           /^User-Agent:/       IGNORE
 335           /^X-Enigmail:/       IGNORE
 336           /^X-Mailer:/         IGNORE
 337           /^X-Originating-IP:/ IGNORE
 338         '';
 339       };
 340     };
 341     /*
 342     dovecot = {
 343       type = "unix";
 344       privileged = true;
 345       chroot = false;
 346       command = "pipe";
 347       args = let
 348         # rspamd could be used as a milter, but then it cannot apply
 349         # its checks "per user" (milter is not yet dispatched to
 350         # users), so we wrap dovecot-lda inside rspamc per recipient
 351         # here.
 352         rspamc_dovecot = pkgs.writeScriptBin "rspamc_dovecot" ''
 353           #!${pkgs.stdenv.shell}
 354           sender="$1"
 355           original_recipient="$2"
 356           user="$3"
 357           ${pkgs.coreutils}/bin/cat - | \
 358             (${pkgs.rspamd}/bin/rspamc -h ${config.myServices.mail.rspamd.sockets.worker-controller} -c bayes -d "$user" --mime || true) | \
 359             ${pkgs.dovecot}/libexec/dovecot/dovecot-lda -f "$sender" -a "$original_recipient" -d "$user"
 360           '';
 361       in [
 362         "flags=DRhu" "user=vhost:vhost"
 363         "argv=${rspamc_dovecot}/bin/rspamc_dovecot \${sender} \${original_recipient} \${user}@\${nexthop}"
 364       ];
 365     };
 366     */
 367   };
 368   extraMasterConf = ''
 369     #spfcheck    unix  -        n       n       -        0        spawn
 370     #  user=policyd-spf argv=/usr/sbin/postfix-policyd-spf-perl
 371     # -o smtpd_sender_restrictions=reject_sender_login_mismatch
 372     # -o smtpd_sender_login_maps=hash:/etc/postfix/vaccounts
 373     # -o cleanup_service_name=submissions-header-cleanup
 374     #spfcheck  unix  -       n       n       -       0       spawn
 375     #  user=policyd-spf argv=/usr/bin/postfix-policyd-spf-perl
 376     #uucp      unix  -       n       n       -       -       pipe
 377     #  flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
 378     #smtp      inet  n       -       -       -       -       smtpd
 379     #  -o cleanup_service_name=pre-cleanup
 380     #  -o content_filter=amavis:[127.0.0.1]:10024
 381     #  -o smtpd_sender_restrictions=reject_unauth_pipelining,reject_non_fqdn_sender,permit
 382     #  -o receive_override_options=no_address_mappings
 383     #amavis    unix  -       -       n        -      2       lmtp
 384     #  -o lmtp_data_done_timeout=1200
 385     #  -o lmtp_send_xforward_command=yes
 386     #  -o lmtp_tls_note_starttls_offer=no
 387     #127.0.0.1:10025 inet n  -       n       -       -       smtpd
 388     #  -o content_filter=
 389     #  -o local_header_rewrite_clients=
 390     #  -o local_recipient_maps=
 391     #  -o mynetworks=127.0.0.0/8
 392     #  -o receive_override_options=no_header_body_checks,no_milters,no_unknown_recipient_checks
 393     #  -o relay_recipient_maps=
 394     #  -o smtpd_client_connection_count_limit=0
 395     #  -o smtpd_client_connection_rate_limit=0
 396     #  -o smtpd_client_restrictions=permit_mynetworks,reject
 397     #  -o smtpd_data_restrictions=reject_unauth_pipelining
 398     #  -o smtpd_delay_reject=no
 399     #  -o smtpd_end_of_data_restrictions=
 400     #  -o smtpd_error_sleep_time=0
 401     #  -o smtpd_hard_error_limit=1000
 402     #  -o smtpd_helo_restrictions=
 403     #  -o smtpd_milters=
 404     #  -o smtpd_recipient_restrictions=permit_mynetworks,reject
 405     #  -o smtpd_restriction_classes=
 406     #  -o smtpd_sender_restrictions=
 407     #  -o smtpd_soft_error_limit=1001
 408     #  -o strict_rfc821_envelopes=yes
 409     #submission inet n       -       -       -       -       smtpd
 410     #  -o cleanup_service_name=pre-cleanup
 411     #  -o content_filter=amavis:[127.0.0.1]:10024
 412     #  -o milter_macro_daemon_name=ORIGINATING
 413     #  -o receive_override_options=no_address_mappings
 414     #  -o smtpd_sender_restrictions=permit_tls_clientcerts,reject
 415     #  -o smtpd_tls_ask_ccert=yes
 416     #  -o smtpd_tls_auth_only=yes
 417     #  -o smtpd_tls_ccert_verifydepth=2
 418     #  -o smtpd_tls_loglevel=1
 419     #  -o smtpd_tls_req_ccert=yes
 420     #  -o smtpd_tls_security_level=encrypt
 421     #smtps     inet  n       -       -       -       -       smtpd
 422     #  -o milter_macro_daemon_name=ORIGINATING
 423     #  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
 424     #  -o smtpd_sasl_auth_enable=yes
 425     #  -o smtpd_tls_ask_ccert=yes
 426     #  -o smtpd_tls_auth_only=yes
 427     #  -o smtpd_tls_ccert_verifydepth=0
 428     #  -o smtpd_tls_loglevel=1
 429     #  -o smtpd_tls_req_ccert=no
 430     #  -o smtpd_tls_security_level=encrypt
 431     #  -o smtpd_tls_wrappermode=yes
 432     #pickup    fifo  n       -       -       60      1       pickup
 433     #  -o cleanup_service_name=pre-cleanup
 434     #  -o content_filter=amavis:[127.0.0.1]:10024
 435     #pre-cleanup unix n      -       -       -       0       cleanup
 436     #  -o virtual_alias_maps=
 437     #cleanup   unix  n       -       -       -       0       cleanup
 438     #  -o mime_header_checks=
 439     #  -o nested_header_checks=
 440     #  -o body_checks=
 441     #  -o header_checks=
 442     #-- SYMPA begin
 443     #sympa unix - n n - - pipe
 444     #  flags=R user=sympa argv=/usr/lib/sympa/bin/queue ''${recipient}
 445     #sympabounce unix - n n - - pipe
 446     #  flags=R user=sympa argv=/usr/lib/sympa/bin/bouncequeue ''${recipient}
 447     #-- SYMPA end
 448   '';
 449    #noclue    unix  -       n       n       -       -       pipe
 450    #  flags=q user=noclue argv=/usr/local/bin/noclue-delivery ${recipient} ${sender}
 451 };
 452 };
 453 }