realm_reactivation: Prevent realm reactivation link reuse.

This uses the approach analogical to EmailChangeStatus for email change
confirmation links.

analytics/views/support.py

@@ -36,6 +36,7 @@ from zerver.models import (
     MultiuseInvite,
     PreregistrationUser,
     Realm,
+    RealmReactivationStatus,
     UserProfile,
     get_org_type_display_name,
     get_realm,
@@ -313,8 +314,9 @@ def support(
         ]
         confirmations += get_confirmations([Confirmation.MULTIUSE_INVITE], multiuse_invite_ids)
 
+        realm_reactivation_status_objects = RealmReactivationStatus.objects.filter(realm__in=realms)
         confirmations += get_confirmations(
-            [Confirmation.REALM_REACTIVATION], [realm.id for realm in realms]
+            [Confirmation.REALM_REACTIVATION], [obj.id for obj in realm_reactivation_status_objects]
         )
 
         context["confirmations"] = confirmations

zerver/actions/realm_settings.py

@@ -21,6 +21,7 @@ from zerver.models import (
     Attachment,
     Realm,
     RealmAuditLog,
+    RealmReactivationStatus,
     RealmUserDefault,
     ScheduledEmail,
     Stream,
@@ -460,7 +461,9 @@ def do_change_realm_plan_type(
 
 
 def do_send_realm_reactivation_email(realm: Realm, *, acting_user: Optional[UserProfile]) -> None:
-    url = create_confirmation_link(realm, Confirmation.REALM_REACTIVATION)
+    obj = RealmReactivationStatus.objects.create(realm=realm)
+
+    url = create_confirmation_link(obj, Confirmation.REALM_REACTIVATION)
     RealmAuditLog.objects.create(
         realm=realm,
         acting_user=acting_user,

zerver/lib/export.py

@@ -145,6 +145,7 @@ ALL_ZULIP_TABLES = {
     "zerver_realmemoji",
     "zerver_realmfilter",
     "zerver_realmplayground",
+    "zerver_realmreactivationstatus",
     "zerver_realmuserdefault",
     "zerver_recipient",
     "zerver_scheduledemail",
@@ -184,6 +185,7 @@ NON_EXPORTED_TABLES = {
     "zerver_multiuseinvite_streams",
     "zerver_preregistrationuser",
     "zerver_preregistrationuser_streams",
+    "zerver_realmreactivationstatus",
     # Missed message addresses are low value to export since
     # missed-message email addresses include the server's hostname and
     # expire after a few days.

zerver/migrations/0400_realmreactivationstatus.py

@@ -0,0 +1,32 @@
+# Generated by Django 4.0.6 on 2022-07-25 20:31
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("zerver", "0399_preregistrationuser_multiuse_invite"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="RealmReactivationStatus",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True, primary_key=True, serialize=False, verbose_name="ID"
+                    ),
+                ),
+                ("status", models.IntegerField(default=0)),
+                (
+                    "realm",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE, to="zerver.realm"
+                    ),
+                ),
+            ],
+        ),
+    ]

zerver/models.py

@@ -2315,6 +2315,15 @@ class EmailChangeStatus(models.Model):
     realm: Realm = models.ForeignKey(Realm, on_delete=CASCADE)
 
 
+class RealmReactivationStatus(models.Model):
+    id: int = models.AutoField(auto_created=True, primary_key=True, verbose_name="ID")
+    # status: whether an object has been confirmed.
+    #   if confirmed, set to confirmation.settings.STATUS_USED
+    status: int = models.IntegerField(default=0)
+
+    realm: Realm = models.ForeignKey(Realm, on_delete=CASCADE)
+
+
 class AbstractPushDeviceToken(models.Model):
     APNS = 1
     GCM = 2

zerver/tests/test_realm.py

@@ -31,6 +31,7 @@ from zerver.models import (
     Message,
     Realm,
     RealmAuditLog,
+    RealmReactivationStatus,
     RealmUserDefault,
     ScheduledEmail,
     Stream,
@@ -354,7 +355,9 @@ class RealmTest(ZulipTestCase):
         realm = get_realm("zulip")
         do_deactivate_realm(realm, acting_user=None)
         self.assertTrue(realm.deactivated)
-        confirmation_url = create_confirmation_link(realm, Confirmation.REALM_REACTIVATION)
+
+        obj = RealmReactivationStatus.objects.create(realm=realm)
+        confirmation_url = create_confirmation_link(obj, Confirmation.REALM_REACTIVATION)
         response = self.client_get(confirmation_url)
         self.assert_in_success_response(
             ["Your organization has been successfully reactivated"], response
@@ -362,6 +365,11 @@ class RealmTest(ZulipTestCase):
         realm = get_realm("zulip")
         self.assertFalse(realm.deactivated)
 
+        # Make sure the link can't be reused.
+        do_deactivate_realm(realm, acting_user=None)
+        response = self.client_get(confirmation_url)
+        self.assertEqual(response.status_code, 404)
+
     def test_realm_reactivation_confirmation_object(self) -> None:
         realm = get_realm("zulip")
         do_deactivate_realm(realm, acting_user=None)

zerver/views/realm.py

@@ -38,7 +38,7 @@ from zerver.lib.validator import (
     check_string_or_int,
     to_non_negative_int,
 )
-from zerver.models import Realm, RealmUserDefault, UserProfile
+from zerver.models import Realm, RealmReactivationStatus, RealmUserDefault, UserProfile
 from zerver.views.user_settings import check_settings_values
 
 ORG_TYPE_IDS: List[int] = [t["id"] for t in Realm.ORG_TYPES.values()]
@@ -327,14 +327,16 @@ def check_subdomain_available(request: HttpRequest, subdomain: str) -> HttpRespo
 
 def realm_reactivation(request: HttpRequest, confirmation_key: str) -> HttpResponse:
     try:
-        realm = get_object_from_key(
+        obj = get_object_from_key(
-            confirmation_key, [Confirmation.REALM_REACTIVATION], mark_object_used=False
+            confirmation_key, [Confirmation.REALM_REACTIVATION], mark_object_used=True
         )
     except ConfirmationKeyException:
         return render(request, "zerver/realm_reactivation_link_error.html", status=404)
-    assert isinstance(realm, Realm)
+
+    assert isinstance(obj, RealmReactivationStatus)
+    realm = obj.realm
+
     do_reactivate_realm(realm)
-    # TODO: After reactivating the realm, the confirmation link needs to be revoked in some way.
 
     context = {"realm": realm}
     return render(request, "zerver/realm_reactivation.html", context)