MagicKey: generate data: URI for href value

also fix indentation

models.py

@@ -8,34 +8,38 @@ from oauth_dropins.webutil.models import StringIdModel
 
 
 class MagicKey(StringIdModel):
-  """Stores a user's public/private key pair used for Magic Signatures.
+    """Stores a user's public/private key pair used for Magic Signatures.
 
-  The key name is USERNAME@DOMAIN.
+    The key name is USERNAME@DOMAIN.
 
-  The modulus and exponent properties are all encoded as base64url (ie URL-safe
-  base64) strings as described in RFC 4648 and section 5.1 of the Magic
-  Signatures spec.
+    The modulus and exponent properties are all encoded as base64url (ie URL-safe
+    base64) strings as described in RFC 4648 and section 5.1 of the Magic
+    Signatures spec.
 
-  Magic Signatures are used to sign Salmon slaps. Details:
-  http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html
-  http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-salmon-00.html
-  """
-  mod = ndb.StringProperty(required=True)
-  public_exponent = ndb.StringProperty(required=True)
-  private_exponent = ndb.StringProperty(required=True)
+    Magic Signatures are used to sign Salmon slaps. Details:
+    http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-magicsig-01.html
+    http://salmon-protocol.googlecode.com/svn/trunk/draft-panzer-salmon-00.html
+    """
+    mod = ndb.StringProperty(required=True)
+    public_exponent = ndb.StringProperty(required=True)
+    private_exponent = ndb.StringProperty(required=True)
 
-  @staticmethod
-  @ndb.transactional
-  def get_or_create(uri):
-    """Loads and returns a MagicKey from the datastore. Creates it if necessary."""
-    key = MagicKey.get_by_id(uri)
+    @staticmethod
+    @ndb.transactional
+    def get_or_create(uri):
+        """Loads and returns a MagicKey. Creates it if necessary."""
+        key = MagicKey.get_by_id(uri)
 
-    if not key:
-      # this uses urandom(), and does some nontrivial math, so it can take a
-      # while depending on the amount of randomness available on the system.
-      pubexp, mod, privexp = magicsigs.generate()
-      key = MagicKey(id=uri, mod=mod, public_exponent=pubexp,
-                     private_exponent=privexp)
-      key.put()
+        if not key:
+            # this uses urandom(), and does nontrivial math, so it can take a
+            # while depending on the amount of randomness available.
+            pubexp, mod, privexp = magicsigs.generate()
+            key = MagicKey(id=uri, mod=mod, public_exponent=pubexp,
+                           private_exponent=privexp)
+            key.put()
 
-    return key
+        return key
+
+    def href(self):
+        return 'data:application/magic-public-key,RSA.%s.%s' % (
+            self.mod, self.public_exponent)

test/test_models.py

@@ -28,3 +28,10 @@ class ModelsTest(unittest.TestCase):
 
         same = models.MagicKey.get_or_create('x@y.z')
         self.assertEquals(same, key)
+
+    def test_href(self):
+        key = models.MagicKey.get_or_create('x@y.z')
+        href = key.href()
+        self.assertTrue(href.startswith('data:application/magic-public-key,RSA.'), href)
+        self.assertIn(key.mod, href)
+        self.assertIn(key.public_exponent, href)