Feature/blacklist

authserver/mailauth/admin.py

@@ -158,6 +158,7 @@ class MailingListAdmin(admin.ModelAdmin):
 @admin.register(EmailAlias)
 class EmailAliasAdmin(admin.ModelAdmin):
     search_fields = ('mailprefix', 'domain__name',)
+    list_filter = ('blacklisted', 'domain',)
 
     def get_user(self, obj: EmailAlias) -> str:
         ret = "[Error: Unassigned]"
@@ -181,7 +182,7 @@ def get_mailalias(self, obj: EmailAlias) -> str:
         return "%s@%s" % (obj.mailprefix, obj.domain.name)
     get_mailalias.short_description = "Mail alias"  # type: ignore  # (mypy#708)
 
-    list_display = ('get_mailalias', 'get_user',)
+    list_display = ('get_mailalias', 'get_user', 'blacklisted',)
 
 
 @admin.register(MNApplicationPermission)

authserver/mailauth/management/commands/spapi.py

@@ -22,18 +22,43 @@ def _install(self, **options: Any) -> None:
         cur = connection.cursor()  # type: CursorWrapper
         cur.execute("""
             DROP FUNCTION IF EXISTS authserver_resolve_alias(varchar, boolean);
+            DROP FUNCTION IF EXISTS authserver_get_alias(varchar, varchar);
+            CREATE OR REPLACE FUNCTION authserver_get_alias(in_mailprefix varchar, in_domain_name varchar)
+                              RETURNS TABLE (id integer, user_id uuid, domain_id integer,
+                                             forward_to_id integer, mailprefix varchar, blacklisted boolean) AS $$
+            BEGIN
+                RETURN QUERY SELECT "alias".id, "alias".user_id, "alias".domain_id,
+                                     "alias".forward_to_id, "alias".mailprefix, "alias".blacklisted
+                    FROM
+                        mailauth_emailalias AS "alias",
+                        mailauth_domain AS "domain"
+                    WHERE
+                        "alias".domain_id="domain".id AND
+                        "alias".mailprefix=in_mailprefix AND
+                        "domain".name=in_domain_name;
+            END;
+            $$ LANGUAGE plpgsql SECURITY DEFINER;
             CREATE OR REPLACE FUNCTION authserver_resolve_alias(email varchar,
                                                                 resolve_to_virtmail boolean DEFAULT FALSE)
                               RETURNS TABLE (alias varchar) AS $$
             DECLARE
                 user_mailprefix varchar;
                 user_domain varchar;
+                original_mailprefix varchar;
                 primary_email varchar;
                 the_alias record;
                 the_domain record;
             BEGIN
                 SELECT split_part(email, '@', 1) INTO user_mailprefix;
                 SELECT split_part(email, '@', 2) INTO user_domain;
+                original_mailprefix := user_mailprefix;
+
+                SELECT * INTO the_alias FROM
+                        authserver_get_alias(original_mailprefix, user_domain);
+
+                IF the_alias.blacklisted IS TRUE THEN
+                    RETURN;
+                END IF;
 
                 -- handle dashext by resolving it to plusext
                 IF position('-' in user_mailprefix) > 0 THEN
@@ -61,13 +86,17 @@ def _install(self, **options: Any) -> None:
                     END IF;
                 END IF;
 
-                SELECT alias.* INTO the_alias FROM
-                        mailauth_emailalias AS "alias",
-                        mailauth_domain AS "domain"
-                    WHERE
-                        "alias".domain_id="domain".id AND
-                        "alias".mailprefix=user_mailprefix AND
-                        "domain".name=user_domain;
+                -- block if the normalized alias is explicitly blacklisted
+                SELECT * INTO the_alias FROM
+                        authserver_get_alias(user_mailprefix, user_domain);
+
+                IF the_alias.blacklisted IS TRUE THEN
+                    RETURN;
+                END IF;
+
+                IF NOT FOUND THEN
+                    RETURN;
+                END IF;
 
                 -- check for mailing lists (foreign keys to mailauth_mailinglist)
                 IF the_alias.forward_to_id IS NOT NULL THEN
@@ -82,19 +111,14 @@ def _install(self, **options: Any) -> None:
                 END IF;
 
                 SELECT primary_alias.mailprefix || '@' || primary_domain.name INTO primary_email FROM
-                        mailauth_emailalias AS "alias",
-                        mailauth_domain AS "domain",
                         mailauth_emailalias AS "primary_alias",
                         mailauth_domain AS "primary_domain",
                         mailauth_mnuser AS "user"
                     WHERE
                         "primary_alias".user_id="user".uuid AND
                         "primary_domain".id="primary_alias".domain_id AND
                         "user".delivery_mailbox_id="primary_alias".id AND
-                        "user".uuid="alias".user_id AND
-                        "alias".domain_id="domain".id AND
-                        "alias".mailprefix=user_mailprefix AND
-                        "domain".name=user_domain AND
+                        "user".uuid=the_alias.user_id AND
                         "user".is_active=TRUE;
 
                 IF primary_email = email AND resolve_to_virtmail IS TRUE THEN

authserver/mailauth/migrations/0022_emailalias_blacklisted.py

@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('mailauth', '0021_alter_mnapplication_authorization_grant_type'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='emailalias',
+            name='blacklisted',
+            field=models.BooleanField(default=False),
+        ),
+    ]

authserver/mailauth/models.py

@@ -120,6 +120,7 @@ class Meta:
     domain = models.ForeignKey(Domain, verbose_name="On domain",
                                                                   on_delete=models.CASCADE)
     mailprefix = models.CharField("Mail prefix", max_length=255)
+    blacklisted = models.BooleanField(default=False)
     forward_to = models.ForeignKey(MailingList, verbose_name="Forward to list",
                                                                    on_delete=models.CASCADE, null=True, blank=True)
 

authserver/maildaemons/forwarder/server.py

@@ -62,6 +62,20 @@ def add_rcptto(mfrom: str, rcpt: Union[str, List]) -> None:
             rcptto = rcpttos[ix].lower()
             rcptuser, rcptdomain = rcptto.split("@", 1)
 
+            # Drop explicitly blacklisted full aliases (including dash/plus extensions).
+            try:
+                if EmailAlias.objects.filter(
+                        mailprefix__iexact=rcptuser,
+                        domain__name__iexact=rcptdomain,
+                        blacklisted=True,
+                ).exists():
+                    _log.info("Dropping blacklisted alias <%s> (from: %s)", rcptto, mailfrom)
+                    del remaining_rcpttos[ix]
+                    continue
+            except OperationalError:
+                _log.exception("Database unavailable.")
+                return "421 Processing problem. Please try again later."
+
             # implement domain catch-all redirect
             domain = None  # type: Optional[Domain]
             try:
@@ -93,6 +107,20 @@ def add_rcptto(mfrom: str, rcpt: Union[str, List]) -> None:
                 # if we had a dashext, or a plusext, we're left with just the prefix after this
                 user_mailprefix = user_mailprefix.split("+", 1)[0]
 
+            # Drop if the normalized alias is blacklisted.
+            try:
+                if EmailAlias.objects.filter(
+                        mailprefix__iexact=user_mailprefix,
+                        domain__name__iexact=rcptdomain,
+                        blacklisted=True,
+                ).exists():
+                    _log.info("Dropping blacklisted alias <%s> (from: %s)", rcptto, mailfrom)
+                    del remaining_rcpttos[ix]
+                    continue
+            except OperationalError:
+                _log.exception("Database unavailable.")
+                return "421 Processing problem. Please try again later."
+
             try:
                 alias = EmailAlias.objects.get(mailprefix__iexact=user_mailprefix,
                                                domain__name__iexact=rcptdomain)  # type: EmailAlias