Reusable Media: Mifare Ultralight AES support (#3335)

src/pretix/base/services/media.py

@@ -0,0 +1,72 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+import secrets
+
+from django.db import IntegrityError
+from django.db.models import Q
+from django_scopes import scopes_disabled
+
+from pretix.base.models import GiftCardAcceptance
+from pretix.base.models.media import MediumKeySet
+
+
+def create_nfc_mf0aes_keyset(organizer):
+    for i in range(20):
+        public_id = secrets.randbelow(2 ** 32)
+        uid_key = secrets.token_bytes(16)
+        diversification_key = secrets.token_bytes(16)
+        try:
+            return MediumKeySet.objects.create(
+                organizer=organizer,
+                media_type="nfc_mf0aes",
+                public_id=public_id,
+                diversification_key=diversification_key,
+                uid_key=uid_key,
+                active=True,
+            )
+        except IntegrityError:  # either race condition with another thread or duplicate public ID
+            try:
+                return MediumKeySet.objects.get(
+                    organizer=organizer,
+                    media_type="nfc_mf0aes",
+                    active=True,
+                )
+            except MediumKeySet.DoesNotExist:
+                continue  # duplicate public ID, let's try again
+
+
+@scopes_disabled()
+def get_keysets_for_organizer(organizer):
+    sets = list(MediumKeySet.objects.filter(
+        Q(organizer=organizer) | Q(organizer__in=GiftCardAcceptance.objects.filter(
+            acceptor=organizer,
+            active=True,
+            reusable_media=True,
+        ).values_list("issuer_id", flat=True))
+    ))
+    if organizer.settings.reusable_media_type_nfc_mf0aes and not any(
+        ks.organizer == organizer and ks.media_type == "nfc_mf0aes" for ks in sets
+    ):
+        new_set = create_nfc_mf0aes_keyset(organizer)
+        if new_set:
+            sets.append(new_set)
+    return sets