1 files changed, 130 insertions, 14 deletions

diff --git a/hosts/surtr/email/default.nix b/hosts/surtr/email/default.nix
index bb0f6e20..c10f611f 100644
--- a/hosts/surtr/email/default.nix
+++ b/hosts/surtr/email/default.nix
@@ -32,9 +32,63 @@ let
       });
     };
 
+  nftables-nologin-script = pkgs.writeScript "nftables-mail-nologin" ''
+    #!${pkgs.zsh}/bin/zsh
+
+    set -e
+    export PATH="${lib.makeBinPath (with pkgs; [inetutils nftables])}:$PATH"
+
+    typeset -a as_sets mnt_bys route route6
+    as_sets=(${lib.escapeShellArgs config.services.email.nologin.ASSets})
+    mnt_bys=(${lib.escapeShellArgs config.services.email.nologin.MNTBys})
+
+    for as_set in $as_sets; do
+        while IFS=$'\n' read line; do
+            if [[ "''${line}" =~ "^route:\s+(.+)$" ]]; then
+                route+=($match[1])
+            elif [[ "''${line}" =~ "^route6:\s+(.+)$" ]]; then
+                route6+=($match[1])
+            fi
+        done < <(whois -h whois.radb.net "!i''${as_set},1" | egrep -o 'AS[0-9]+' | xargs -- whois -h whois.radb.net -- -i origin)
+    done
+    for mnt_by in $mnt_bys; do
+        while IFS=$'\n' read line; do
+            if [[ "''${line}" =~ "^route:\s+(.+)$" ]]; then
+                route+=($match[1])
+            elif [[ "''${line}" =~ "^route6:\s+(.+)$" ]]; then
+                route6+=($match[1])
+            fi
+        done < <(whois -h whois.radb.net "!o''${mnt_by}")
+    done
+
+    printf -v elements4 '%s,' "''${route[@]}"
+    elements4=''${elements4%,}
+    printf -v elements6 '%s,' "''${route6[@]}"
+    elements6=''${elements6%,}
+    nft -f - <<EOF
+    flush set inet filter mail_nologin4
+    flush set inet filter mail_nologin6
+    add element inet filter mail_nologin4 {''${elements4}}
+    add element inet filter mail_nologin6 {''${elements6}}
+    EOF
+  '';
+
   spmDomains = ["bouncy.email"];
   emailDomains = spmDomains ++ ["kleen.consulting"];
 in {
+  options = {
+    services.email.nologin = {
+      ASSets = mkOption {
+        type = types.listOf types.str;
+        default = [];
+      };
+      MNTBys = mkOption {
+        type = types.listOf types.str;
+        default = [];
+      };
+    };
+  };
+
   config = {
     nixpkgs.overlays = [
       (final: prev: {
@@ -167,6 +221,7 @@ in {
         maximal_backoff_time = "10m";
         maximal_queue_lifetime = "100m";
         bounce_queue_lifetime = "20m";
+        delay_warning_time = "10m";
 
         smtpd_discard_ehlo_keyword_address_maps = "cidr:${pkgs.writeText "esmtp_access" ''
           # Allow DSN requests from local subnet only
@@ -204,17 +259,15 @@ in {
         postscreen_greet_action = "enforce";
       };
       masterConfig = {
-        smtps = {
+        "465" = {
           type = "inet";
           private = false;
-          command = "smtpd";
+          command = "smtpd -v";
           args = [
             "-o" "smtpd_tls_security_level=encrypt"
             "-o" "{smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1, !TLSv1.2}"
             "-o" "{smtpd_tls_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1, !TLSv1.2}"
             "-o" "smtpd_tls_mandatory_ciphers=high"
-            "-o" "smtpd_tls_dh1024_param_file=${toString config.security.dhparams.params."postfix-smtps-1024".path}"
-            "-o" "smtpd_tls_dh512_param_file=${toString config.security.dhparams.params."postfix-smtps-512".path}"
             "-o" "{tls_eecdh_auto_curves = X25519 X448}"
 
             "-o" "smtpd_tls_wrappermode=yes"
@@ -223,22 +276,52 @@ in {
             "-o" "smtpd_tls_received_header=no"
             "-o" "cleanup_service_name=subcleanup"
             "-o" "smtpd_client_restrictions=permit_tls_all_clientcerts,reject"
-            "-o" "{smtpd_data_restrictions = check_policy_service unix:/run/postfwd3/postfwd3.sock}"
-            "-o" "smtpd_relay_restrictions=permit_tls_all_clientcerts,reject"
             "-o" "{smtpd_sender_restrictions = reject_unknown_sender_domain,reject_unverified_sender,check_policy_service unix:/run/postfix-ccert-sender-policy.sock}"
+            "-o" ''{smtpd_recipient_restrictions=reject_unauth_pipelining,reject_non_fqdn_recipient,reject_unknown_recipient_domain,check_recipient_access pgsql:${pkgs.writeText "check_recipient_access.cf" ''
+            hosts = postgresql:///email
+            dbname = email
+            query = SELECT action FROM virtual_mailbox_access WHERE lookup = '%s' OR (lookup = regexp_replace('%s', '\+[^@]*@', '@') AND NOT EXISTS (SELECT 1 FROM virtual_mailbox_access WHERE lookup = '%s'))
+          ''},permit_tls_all_clientcerts,reject}''
+            "-o" "smtpd_relay_restrictions=permit_tls_all_clientcerts,reject"
+            "-o" "{smtpd_data_restrictions = check_policy_service unix:/run/postfwd3/postfwd3.sock}"
             "-o" "unverified_sender_reject_code=550"
             "-o" "unverified_sender_reject_reason={Sender address rejected: undeliverable address}"
+            "-o" "milter_macro_daemon_name=surtr.yggdrasil.li"
+            "-o" ''smtpd_milters=${config.services.opendkim.socket}''
+          ];
+        };
+        "466" = {
+          type = "inet";
+          private = false;
+          command = "smtpd -v";
+          args = [
+            "-o" "smtpd_tls_security_level=encrypt"
+
+            "-o" "smtpd_tls_wrappermode=yes"
+            "-o" "smtpd_tls_ask_ccert=no"
+            "-o" "smtpd_tls_req_ccert=no"
+            "-o" "smtpd_sasl_type=dovecot"
+            "-o" "smtpd_sasl_path=/run/dovecot-sasl"
+            "-o" "smtpd_sasl_auth_enable=yes"
+            "-o" "smtpd_tls_received_header=no"
+            "-o" "cleanup_service_name=subcleanup"
+            "-o" "smtpd_client_restrictions=permit_sasl_authenticated,reject"
+            "-o" "{smtpd_sender_restrictions = reject_unknown_sender_domain,reject_unverified_sender,check_policy_service unix:/run/postfix-ccert-sender-policy.sock}"
             "-o" ''{smtpd_recipient_restrictions=reject_unauth_pipelining,reject_non_fqdn_recipient,reject_unknown_recipient_domain,check_recipient_access pgsql:${pkgs.writeText "check_recipient_access.cf" ''
             hosts = postgresql:///email
             dbname = email
             query = SELECT action FROM virtual_mailbox_access WHERE lookup = '%s' OR (lookup = regexp_replace('%s', '\+[^@]*@', '@') AND NOT EXISTS (SELECT 1 FROM virtual_mailbox_access WHERE lookup = '%s'))
-          ''},permit_tls_all_clientcerts,reject}''
+          ''},permit_sasl_authenticated,reject}''
+            "-o" "smtpd_relay_restrictions=permit_sasl_authenticated,reject"
+            "-o" "{smtpd_data_restrictions = check_policy_service unix:/run/postfwd3/postfwd3.sock}"
+            "-o" "unverified_sender_reject_code=550"
+            "-o" "unverified_sender_reject_reason={Sender address rejected: undeliverable address}"
             "-o" "milter_macro_daemon_name=surtr.yggdrasil.li"
             "-o" ''smtpd_milters=${config.services.opendkim.socket}''
           ];
         };
         subcleanup = {
-          command = "cleanup";
+          command = "cleanup -v";
           private = false;
           maxproc = 0;
           args = [
@@ -256,13 +339,13 @@ in {
         smtp_pass = {
           name = "smtpd";
           type = "pass";
-          command = "smtpd";
+          command = "smtpd -v";
         };
         postscreen = {
           name = "smtp";
           type = "inet";
           private = false;
-          command = "postscreen";
+          command = "postscreen -v";
           maxproc = 1;
         };
         smtp = {};
@@ -417,7 +500,7 @@ in {
         dovecotSqlConf = pkgs.writeText "dovecot-sql.conf" ''
           driver = pgsql
           connect = dbname=email
-          password_query = SELECT NULL as password, 'Y' as nopassword, "user", quota_rule, 'dovecot2' as uid, 'dovecot2' as gid FROM imap_user WHERE "user" = '%n'
+          password_query = SELECT (CASE WHEN '%k' = 'valid' AND '%m' = 'EXTERNAL' THEN NULL ELSE "password" END) as password, (CASE WHEN '%k' = 'valid' AND '%m' = 'EXTERNAL' THEN true WHEN password IS NULL THEN true ELSE NULL END) as nopassword, "user", quota_rule, 'dovecot2' as uid, 'dovecot2' as gid FROM imap_user WHERE "user" = '%n'
           user_query = SELECT "user", quota_rule, 'dovecot2' as uid, 'dovecot2' as gid FROM imap_user WHERE "user" = '%n'
           iterate_query = SELECT "user" FROM imap_user
         '';
@@ -449,7 +532,7 @@ in {
 
         auth_ssl_username_from_cert = yes
         ssl_cert_username_field = commonName
-        auth_mechanisms = external
+        auth_mechanisms = plain login external
 
         auth_verbose = yes
         verbose_ssl = yes
@@ -505,6 +588,15 @@ in {
             group = postfix
           }
         }
+        service auth {
+          vsz_limit = 2G
+
+          unix_listener /run/dovecot-sasl {
+            mode = 0600
+            user = postfix
+            group = postfix
+          }
+        }
 
         namespace inbox {
           separator = /
@@ -869,9 +961,13 @@ in {
 
     services.postfwd = {
       enable = true;
+      cache = false;
       rules = ''
-        id=RCPT01; protocol_state=DATA; protocol_state=END-OF-MESSAGE; action=rcpt(ccert_subject/100/3600/set(HIT_RATELIMIT=1,HIT_RATECOUNT=$$ratecount,HIT_RATELIMIT_LIMIT=100,HIT_RATELIMIT_INTERVAL=3600))
-        id=RCPT02; protocol_state=DATA; protocol_state=END-OF-MESSAGE; action=rcpt(ccert_subject/1000/86400/set(HIT_RATELIMIT=1,HIT_RATECOUNT=$$ratecount,HIT_RATELIMIT_LIMIT=1000,HIT_RATELIMIT_INTERVAL=86400))
+        id=RCPT_SASL01; protocol_state=DATA; protocol_state=END-OF-MESSAGE; sasl_username!=; action=rcpt(sasl_username/100/3600/set(HIT_RATELIMIT=1,HIT_RATECOUNT=$$ratecount,HIT_RATELIMIT_LIMIT=100,HIT_RATELIMIT_INTERVAL=3600))
+        id=RCPT_SASL02; protocol_state=DATA; protocol_state=END-OF-MESSAGE; sasl_username!=; action=rcpt(sasl_username/1000/86400/set(HIT_RATELIMIT=1,HIT_RATECOUNT=$$ratecount,HIT_RATELIMIT_LIMIT=1000,HIT_RATELIMIT_INTERVAL=86400))
+
+        id=RCPT_CCERT01; protocol_state=DATA; protocol_state=END-OF-MESSAGE; ccert_subject!=; action=rcpt(ccert_subject/100/3600/set(HIT_RATELIMIT=1,HIT_RATECOUNT=$$ratecount,HIT_RATELIMIT_LIMIT=100,HIT_RATELIMIT_INTERVAL=3600))
+        id=RCPT_CCERT02; protocol_state=DATA; protocol_state=END-OF-MESSAGE; ccert_subject!=; action=rcpt(ccert_subject/1000/86400/set(HIT_RATELIMIT=1,HIT_RATECOUNT=$$ratecount,HIT_RATELIMIT_LIMIT=1000,HIT_RATELIMIT_INTERVAL=86400))
 
         id=JUMP_REJECT_RL; HIT_RATELIMIT=="1"; action=jump(REJECT_RL)
 
@@ -880,5 +976,25 @@ in {
         id=REJECT_RL; action=450 4.7.1 Exceeding maximum of $$HIT_RATELIMIT_LIMIT recipients per $$HIT_RATELIMIT_INTERVAL seconds [$$HIT_RATECOUNT]
       '';
     };
+
+    services.email.nologin.MNTBys = ["MICROSOFT-MAINT"];
+    systemd.services.nftables.serviceConfig = {
+      ExecStart = lib.mkAfter [ nftables-nologin-script ];
+      ExecReload = lib.mkAfter [ nftables-nologin-script ];
+    };
+    systemd.services."nftables-mail-nologin" = {
+      serviceConfig = {
+        Type = "oneshot";
+        ExecStart = nftables-nologin-script;
+      };
+    };
+    systemd.timers."nftables-mail-nologin" = {
+      wantedBy = [ "nftables.service" ];
+
+      timerConfig = {
+        OnActiveSec = "20h";
+        RandomizedDelaySec = "8h";
+      };
+    };
   };
 }