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