Add pluggable ticket secret generators (#1809)

src/pretix/base/migrations/0001_squashed_0028_auto_20160816_1242.py

@@ -482,7 +482,7 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='orderposition',
             name='secret',
-            field=models.CharField(db_index=True, default=pretix.base.models.orders.generate_position_secret, max_length=64),
+            field=models.CharField(db_index=True, default="invalid", max_length=64),
         ),
         migrations.AddField(
             model_name='order',

src/pretix/base/migrations/0010_orderposition_secret.py

@@ -17,6 +17,6 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='orderposition',
             name='secret',
-            field=models.CharField(default=pretix.base.models.orders.generate_position_secret, max_length=64),
+            field=models.CharField(default="invalid", max_length=64),
         ),
     ]

src/pretix/base/migrations/0025_auto_20160802_2202.py

@@ -38,7 +38,7 @@ class Migration(migrations.Migration):
         migrations.AlterField(
             model_name='orderposition',
             name='secret',
-            field=models.CharField(db_index=True, default=pretix.base.models.orders.generate_position_secret, max_length=64),
+            field=models.CharField(db_index=True, default="invalid", max_length=64),
         ),
         migrations.AlterField(
             model_name='voucher',

src/pretix/base/migrations/0165_auto_20201015_1924.py

@@ -0,0 +1,29 @@
+# Generated by Django 3.0.10 on 2020-10-15 19:24
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0164_subevent_last_modified'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='orderposition',
+            name='secret',
+            field=models.CharField(db_index=True, max_length=64),
+        ),
+        migrations.CreateModel(
+            name='RevokedTicketSecret',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False)),
+                ('secret', models.TextField(db_index=True)),
+                ('created', models.DateTimeField(auto_now_add=True)),
+                ('event', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='revoked_secrets', to='pretixbase.Event')),
+                ('position', models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='revoked_secrets', to='pretixbase.OrderPosition')),
+            ],
+        ),
+    ]

src/pretix/base/migrations/0166_auto_20201015_2029.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.0.10 on 2020-10-15 20:29
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0165_auto_20201015_1924'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='orderposition',
+            name='secret',
+            field=models.CharField(db_index=True, max_length=255),
+        ),
+    ]