Remove VAPIDKeyset.public_key, generate on demand

Also rename `gen_vapid_keys` to `gen_vapid_key`, and merge migrations

djangoldp_webpushnotification/admin.py

@@ -12,5 +12,8 @@ class VAPIDKeysetAdmin(DjangoLDPAdmin):
 	def private_key_view(self, obj):
 		return obj.private_key.tobytes()
 
+	class Meta:
+		verbose_name = 'VAPID key-set'
+
 
 admin.site.register(VAPIDKeyset, VAPIDKeysetAdmin)

djangoldp_webpushnotification/management/commands/gen_vapid_key.py

@@ -11,10 +11,8 @@ class Command(BaseCommand):
 
 	def handle(self, *args, **options):
 		priv_key = SigningKey.generate(curve=ecdsa.NIST256p)
-		pub_key = priv_key.get_verifying_key()
 
 		VAPIDKeyset.objects.create(
-			public_key=urlsafe_b64encode(b"\x04" + pub_key.to_string()).strip(b"="),
 			private_key=urlsafe_b64encode(priv_key.to_string()).strip(b"=")
 		)
 

djangoldp_webpushnotification/migrations/0001_initial.py

@@ -0,0 +1,21 @@
+# Generated by Django 2.2.19 on 2021-04-07 14:38
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='VAPIDKeyset',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('private_key', models.BinaryField(max_length=43)),
+            ],
+        ),
+    ]

djangoldp_webpushnotification/migrations/0012_vapidkeyset.py

@@ -1,19 +0,0 @@
-from django.db import migrations, models
-
-
-class Migration(migrations.Migration):
-
-	dependencies = [
-		('djangoldp_notification', '0011_auto_20210218_1145'),
-	]
-
-	operations = [
-		migrations.CreateModel(
-			name='VAPIDKeyset',
-			fields=[
-				('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
-				('public_key', models.BinaryField(max_length=87)),
-				('private_key', models.BinaryField(max_length=43)),
-			],
-		),
-	]

djangoldp_webpushnotification/models.py

@@ -1,14 +1,24 @@
+from ecdsa import SigningKey, NIST256p
 from django.db import models
+from base64 import urlsafe_b64decode, urlsafe_b64encode
 
-def send_request(target, object_iri, instance, created):
-	ActivityQueueService.send_activity(target, json)
 
 class VAPIDKeyset(models.Model):
-	public_key = models.BinaryField(max_length=87)
 	private_key = models.BinaryField(max_length=43)
- 
+
 	def __str__(self):
 		return "public_key:{}... private_key:{}...".format(
-			self.public_key.tobytes()[:10], 
+			self.public_key.tobytes()[:10],
 			self.private_key.tobytes()[:10]
 		)
+
+	@property
+	def public_key(self):
+		key_str = self.private_key.tobytes()
+		padding = len(key_str) % 4
+		key_str += b"=" * padding
+		key = SigningKey.from_string(
+			urlsafe_b64decode(key_str),
+			curve=NIST256p
+		).get_verifying_key()
+		return urlsafe_b64encode(b"\x04" + key.to_string()).strip(b"=")