Resolve "Protect against key decode errors"

Closes #11 (closed)

app/owlca/models.py

@@ -214,6 +214,9 @@ class CertificateSigningRequest(models.Model):
 
     def extensions(self):
         """Return the subject of the certificate"""
+        if not self._decode():
+            return []
+
         return [(
             e.oid._name,
             e.value,