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: this does not work if the recipient is greylisting.
 163       # WARNING: verify(8) has a cache, dumpable if verify(8) is stopped, with:
 164       # postmap -s btree:/var/lib/postfix/data/verify_cache
 165       #"reject_unverified_recipient"
 166       "permit"
 167     ];
 168     # Trust the verify database
 169     #unverified_recipient_reject_code = "550";
 170     smtpd_data_restrictions = [
 171       # Force the smtpd's client to wait OK before sending
 172       "reject_unauth_pipelining"
 173       "permit"
 174     ];
 175     smtpd_end_of_data_restrictions = [
 176       # Enforce mail volume quota via policy service callouts.
 177       #check_policy_service unix:private/policy
 178     ];
 179     #smtpd_milters = "";
 180     smtpd_peername_lookup = true;
 181     smtpd_recipient_limit = "5000";
 182     smtpd_recipient_overshoot_limit = "5000";
 183     #smtpd_restriction_classes = "";
 184     #smtpd_sasl_auth_enable = true;
 185     #smtpd_sasl_path = "private/auth";
 186     #smtpd_sasl_security_options = "noanonymous";
 187     #smtpd_sasl_type = "dovecot";
 188     smtpd_starttls_timeout = "300s";
 189     #smtpd_tls_always_issue_session_ids = true;
 190     #smtpd_tls_CApath = "/etc/postfix/x509/ca/";
 191     smtpd_tls_ask_ccert = false;
 192     #smtpd_tls_ccert_verifydepth = "5";
 193     smtpd_tls_ciphers = "high";
 194     smtpd_tls_eecdh_grade = "auto";
 195     # Disable weak ciphers as reported by https://ssl-tools.net
 196     # https://serverfault.com/questions/744168/how-to-disable-rc4-on-postfix
 197     smtpd_tls_exclude_ciphers = [ "ADH" "MD5" "CAMELLIA" "SEED" "3DES" "DES" "RC4" "eNULL" "aNULL" ];
 198     smtpd_tls_fingerprint_digest = "sha512";
 199     # Log only a summary message on TLS handshake completion
 200     smtpd_tls_loglevel = "1";
 201     smtpd_tls_mandatory_ciphers = "high";
 202     smtpd_tls_mandatory_protocols = [ "!SSLv2" "!SSLv3" ];
 203     # Only allow TLSv*
 204     smtpd_tls_protocols = [ "!SSLv2" "!SSLv3" ];
 205     #smtpd_tls_received_header = false;
 206     smtpd_tls_req_ccert = false;
 207     # Postfix 2.3 and later
 208     # encrypt
 209     #  Mandatory TLS encryption: announce STARTTLS support to SMTP clients, and require that clients use TLS
 210     #  encryption. According to [1720]RFC 2487 this MUST NOT be applied in case of a publicly-referenced
 211     #  SMTP server. Instead, this option should be used only on dedicated servers.
 212     smtpd_tls_security_level = "may";
 213     smtpd_tls_session_cache_database = "btree:$data_directory/smtpd_tls_session_cache";
 214     #smtpd_tls_session_cache_timeout = "3600s";
 215     #smtpd_tls_chain_files =
 216
 217     relayhost = [];
 218     #relay_clientcerts = hash:/var/lib/postfix/conf/relay_clientcerts
 219     # This is where to put backup MX domains
 220     relay_domains = [];
 221     relay_recipient_maps = [];
 222
 223     # Use a non blocking source of randomness
 224     tls_random_source = "dev:/dev/urandom";
 225     # Map each domain to a specific X.509 certificate
 226     tls_server_sni_maps = "hash:/run/keys/postfix-sni";
 227
 228     # Only explicitely aliased accounts have a mail, not all the passwd
 229     local_recipient_maps = "$alias_maps";
 230     # Note that the local transport rewrites the envelope recipient
 231     # according to the alias_maps, and thus the aliasing is transparent
 232     # to the nexthop (eg. dovecot)
 233     #local_transport = local:$myhostname
 234     # No console bell on new mail
 235     biff = false;
 236     forward_path = [
 237       /*
 238       "$home/.forward''${recipient_delimiter}''${extension}"
 239       "$home/.forward"
 240       */
 241     ];
 242
 243     # Filled by the postfix/*.nix
 244     virtual_mailbox_domains = [];
 245     # Completed by the postfix/*.nix
 246     virtual_mailbox_maps = [
 247       "hash:/etc/postfix/virtual"
 248     ];
 249     virtual_transport = "lmtp:unix:private/dovecot-lmtp";
 250     /*
 251     dovecot_destination_recipient_limit = "1";
 252     virtual_transport = "dovecot";
 253     */
 254
 255     # There is no fallback
 256     fallback_transport = "";
 257   };
 258   virtualMapType = "hash";
 259   masterConfig =
 260     let
 261       mkVal = value:
 262         if lib.isList value
 263         then concatStringsSep "," value
 264         else
 265           if value == true then "yes"
 266           else if value == false then "no"
 267           else toString value;
 268       mkKeyVal = opt: val: [ "-o" (opt + "=" + mkVal val) ];
 269       mkArgs = args: lib.concatLists (lib.mapAttrsToList mkKeyVal args);
 270     in {
 271     pickup = {
 272       args = mkArgs {
 273         cleanup_service_name = "submissions-header-cleanup";
 274       };
 275     };
 276     # Implicit TLS on port 465
 277     # https://tools.ietf.org/html/rfc8314#section-3.3
 278     submissions = {
 279       type = "inet";
 280       private = false;
 281       command = "smtpd";
 282       args = mkArgs {
 283         syslog_name = "postfix/submissions";
 284         # Implicit TLS, not STARTTLS
 285         smtpd_tls_wrappermode = true;
 286         smtpd_tls_mandatory_protocols = [
 287           "TLSv1.3"
 288           # K-9 Mail 5.600 still requires this..
 289           "TLSv1.2"
 290         ];
 291         milter_macro_daemon_name = "ORIGINATING";
 292         smtpd_helo_restrictions = [
 293           "permit_sasl_authenticated"
 294         ] ++ postfix.config.smtpd_helo_restrictions;
 295         smtpd_relay_restrictions = [
 296           # SASL authorizes to send to the world
 297           "permit_sasl_authenticated"
 298           "reject"
 299         ];
 300         smtpd_sasl_auth_enable = true;
 301         smtpd_sasl_type = "dovecot";
 302         smtpd_sasl_path = "private/auth";
 303         smtpd_sasl_local_domain = "";
 304         # Offer SASL authentication only after a TLS-encrypted session has been established
 305         smtpd_tls_auth_only = true;
 306         smtpd_sasl_tls_security_options = [ "noanonymous" ];
 307         # Do not put SASL logins in mail headers
 308         smtpd_sasl_authenticated_header = false;
 309         # Who cares about (old) Outlook
 310         broken_sasl_auth_clients = false;
 311         smtpd_sender_restrictions = [
 312           "reject_non_fqdn_sender"
 313           # Check that the SASL user is using only its own
 314           # mail addresses on the envelope, as indicated in smtpd_sender_login_maps
 315           "reject_sender_login_mismatch"
 316           "permit"
 317         ];
 318         # No X.509 certificates for users, for now
 319         smtpd_tls_ask_ccert = false;
 320         smtpd_tls_ccert_verifydepth = 0;
 321         smtpd_tls_loglevel = 1;
 322         smtpd_tls_req_ccert = false;
 323         cleanup_service_name = "submissions-header-cleanup";
 324       };
 325     };
 326     submissions-header-cleanup = {
 327       type = "unix";
 328       private = false;
 329       maxproc = 0;
 330       command = "cleanup";
 331       args = mkArgs {
 332         header_checks = "pcre:" + pkgs.writeText "submission_header_cleanup_rules" ''
 333           # Removes sensitive headers from mails handed in via the submission or smtps port.
 334           # See https://thomas-leister.de/mailserver-debian-stretch/
 335           # Uses "pcre" style regex.
 336
 337           /^Received:/         IGNORE
 338           /^User-Agent:/       IGNORE
 339           /^X-Enigmail:/       IGNORE
 340           /^X-Mailer:/         IGNORE
 341           /^X-Originating-IP:/ IGNORE
 342         '';
 343       };
 344     };
 345     /*
 346     dovecot = {
 347       type = "unix";
 348       privileged = true;
 349       chroot = false;
 350       command = "pipe";
 351       args = let
 352         # rspamd could be used as a milter, but then it cannot apply
 353         # its checks "per user" (milter is not yet dispatched to
 354         # users), so we wrap dovecot-lda inside rspamc per recipient
 355         # here.
 356         rspamc_dovecot = pkgs.writeScriptBin "rspamc_dovecot" ''
 357           #!${pkgs.stdenv.shell}
 358           sender="$1"
 359           original_recipient="$2"
 360           user="$3"
 361           ${pkgs.coreutils}/bin/cat - | \
 362             (${pkgs.rspamd}/bin/rspamc -h ${config.myServices.mail.rspamd.sockets.worker-controller} -c bayes -d "$user" --mime || true) | \
 363             ${pkgs.dovecot}/libexec/dovecot/dovecot-lda -f "$sender" -a "$original_recipient" -d "$user"
 364           '';
 365       in [
 366         "flags=DRhu" "user=vhost:vhost"
 367         "argv=${rspamc_dovecot}/bin/rspamc_dovecot \${sender} \${original_recipient} \${user}@\${nexthop}"
 368       ];
 369     };
 370     */
 371   };
 372   extraMasterConf = ''
 373     #spfcheck    unix  -        n       n       -        0        spawn
 374     #  user=policyd-spf argv=/usr/sbin/postfix-policyd-spf-perl
 375     # -o smtpd_sender_restrictions=reject_sender_login_mismatch
 376     # -o smtpd_sender_login_maps=hash:/etc/postfix/vaccounts
 377     # -o cleanup_service_name=submissions-header-cleanup
 378     #spfcheck  unix  -       n       n       -       0       spawn
 379     #  user=policyd-spf argv=/usr/bin/postfix-policyd-spf-perl
 380     #uucp      unix  -       n       n       -       -       pipe
 381     #  flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
 382     #smtp      inet  n       -       -       -       -       smtpd
 383     #  -o cleanup_service_name=pre-cleanup
 384     #  -o content_filter=amavis:[127.0.0.1]:10024
 385     #  -o smtpd_sender_restrictions=reject_unauth_pipelining,reject_non_fqdn_sender,permit
 386     #  -o receive_override_options=no_address_mappings
 387     #amavis    unix  -       -       n        -      2       lmtp
 388     #  -o lmtp_data_done_timeout=1200
 389     #  -o lmtp_send_xforward_command=yes
 390     #  -o lmtp_tls_note_starttls_offer=no
 391     #127.0.0.1:10025 inet n  -       n       -       -       smtpd
 392     #  -o content_filter=
 393     #  -o local_header_rewrite_clients=
 394     #  -o local_recipient_maps=
 395     #  -o mynetworks=127.0.0.0/8
 396     #  -o receive_override_options=no_header_body_checks,no_milters,no_unknown_recipient_checks
 397     #  -o relay_recipient_maps=
 398     #  -o smtpd_client_connection_count_limit=0
 399     #  -o smtpd_client_connection_rate_limit=0
 400     #  -o smtpd_client_restrictions=permit_mynetworks,reject
 401     #  -o smtpd_data_restrictions=reject_unauth_pipelining
 402     #  -o smtpd_delay_reject=no
 403     #  -o smtpd_end_of_data_restrictions=
 404     #  -o smtpd_error_sleep_time=0
 405     #  -o smtpd_hard_error_limit=1000
 406     #  -o smtpd_helo_restrictions=
 407     #  -o smtpd_milters=
 408     #  -o smtpd_recipient_restrictions=permit_mynetworks,reject
 409     #  -o smtpd_restriction_classes=
 410     #  -o smtpd_sender_restrictions=
 411     #  -o smtpd_soft_error_limit=1001
 412     #  -o strict_rfc821_envelopes=yes
 413     #submission inet n       -       -       -       -       smtpd
 414     #  -o cleanup_service_name=pre-cleanup
 415     #  -o content_filter=amavis:[127.0.0.1]:10024
 416     #  -o milter_macro_daemon_name=ORIGINATING
 417     #  -o receive_override_options=no_address_mappings
 418     #  -o smtpd_sender_restrictions=permit_tls_clientcerts,reject
 419     #  -o smtpd_tls_ask_ccert=yes
 420     #  -o smtpd_tls_auth_only=yes
 421     #  -o smtpd_tls_ccert_verifydepth=2
 422     #  -o smtpd_tls_loglevel=1
 423     #  -o smtpd_tls_req_ccert=yes
 424     #  -o smtpd_tls_security_level=encrypt
 425     #smtps     inet  n       -       -       -       -       smtpd
 426     #  -o milter_macro_daemon_name=ORIGINATING
 427     #  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
 428     #  -o smtpd_sasl_auth_enable=yes
 429     #  -o smtpd_tls_ask_ccert=yes
 430     #  -o smtpd_tls_auth_only=yes
 431     #  -o smtpd_tls_ccert_verifydepth=0
 432     #  -o smtpd_tls_loglevel=1
 433     #  -o smtpd_tls_req_ccert=no
 434     #  -o smtpd_tls_security_level=encrypt
 435     #  -o smtpd_tls_wrappermode=yes
 436     #pickup    fifo  n       -       -       60      1       pickup
 437     #  -o cleanup_service_name=pre-cleanup
 438     #  -o content_filter=amavis:[127.0.0.1]:10024
 439     #pre-cleanup unix n      -       -       -       0       cleanup
 440     #  -o virtual_alias_maps=
 441     #cleanup   unix  n       -       -       -       0       cleanup
 442     #  -o mime_header_checks=
 443     #  -o nested_header_checks=
 444     #  -o body_checks=
 445     #  -o header_checks=
 446     #-- SYMPA begin
 447     #sympa unix - n n - - pipe
 448     #  flags=R user=sympa argv=/usr/lib/sympa/bin/queue ''${recipient}
 449     #sympabounce unix - n n - - pipe
 450     #  flags=R user=sympa argv=/usr/lib/sympa/bin/bouncequeue ''${recipient}
 451     #-- SYMPA end
 452   '';
 453    #noclue    unix  -       n       n       -       -       pipe
 454    #  flags=q user=noclue argv=/usr/local/bin/noclue-delivery ${recipient} ${sender}
 455 };
 456 };
 457 }