servers/mermet/postfix.nix

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