From d5b2197571eaa582c2c417ea1654eedaa94c9a1f Mon Sep 17 00:00:00 2001
From: Jeffrey Forman <jforman@malbec.home.jeffreyforman.net>
Date: Fri, 30 Nov 2012 22:40:58 -0500
Subject: [PATCH] Merge keyutils into a method inside the Key class. Delete
 keyutils.py

---
 binder/helpers.py | 46 ++++++++--------------------------------------
 binder/models.py  | 30 +++++++++++++++++++++---------
 2 files changed, 29 insertions(+), 47 deletions(-)

diff --git a/binder/helpers.py b/binder/helpers.py
index 3b1678a..bdd7b47 100644
--- a/binder/helpers.py
+++ b/binder/helpers.py
@@ -84,10 +84,10 @@ def delete_record(dns_server, rr_list, key_name):
     """Delete a list of DNS records passed as strings in rr_items."""
 
     try:
-        keyring = create_keyring(key_name)
-    except exceptions.KeyringException, err:
-        return([{ "description" : "Error in deletion process",
-                  "output" : err }])
+        transfer_key = models.Key.objects.get(name=key_name)
+        keyring = transfer_key.create_keyring()
+    except models.Key.DoesNotExist:
+        keyring = None
 
     delete_response = []
     for current_rr in rr_list:
@@ -107,9 +107,10 @@ def create_update(dns_server, zone_name, record_name, record_type, record_data,
     """ Update/Create DNS record of name and type with passed data and ttl. """
 
     try:
-        keyring = create_keyring(key_name)
-    except exceptions.KeyringException, err:
-        return(err)
+        transfer_key = models.Key.objects.get(name=key_name)
+        keyring = transfer_key.create_keyring()
+    except models.Key.DoesNotExist:
+        keyring = None
 
     dns_update = dns.update.Update(zone_name, keyring = keyring)
     dns_update.replace(record_name, ttl, record_type, record_data)
@@ -159,34 +160,3 @@ def send_dns_update(dns_message, dns_server, key_name):
                   "for correctness." % (dns_server, key_name))
 
     return output
-
-def create_keyring(key_name):
-
-    """Return a tsigkeyring object from key name and key data.
-
-    Args:
-      key_name: String representation of Key name object
-
-    Return:
-      None if key_name is none.
-      keyring object with the key name and TSIG secret.
-
-    Raises:
-      KeyringException: For incorrect key data.
-    """
-
-    if key_name is None:
-        return None
-
-    # TODO: Unittest here for key_name that does not exist
-    # Stick this in a try/except and catch models.Key.DoesNotExist
-    this_key = models.Key.objects.get(name=key_name)
-
-    try:
-        keyring = dns.tsigkeyring.from_text({
-                this_key.name : this_key.data
-                })
-    except binascii.Error, err:
-        raise exceptions.KeyringException("Incorrect key data. Verify key: %s. Reason: %s" % (key_name, err))
-
-    return keyring
diff --git a/binder/models.py b/binder/models.py
index f492468..d1944e6 100644
--- a/binder/models.py
+++ b/binder/models.py
@@ -14,7 +14,6 @@ import dns.zone
 # App Imports
 from binder import exceptions
 from django.db import models
-import keyutils
 
 TSIG_ALGORITHMS = (('hmac-md5', 'MD5'),
                    ('hmac-sha1', 'SHA1'),
@@ -34,6 +33,19 @@ class Key(models.Model):
     def __unicode__(self):
         return self.name
 
+    def create_keyring(self):
+        if self.name is None:
+            return None
+
+        try:
+            keyring = dns.tsigkeyring.from_text({
+                    self.name : self.data
+                    })
+        except binascii.Error, err:
+            raise exceptions.KeyringException("Incorrect key data. Verify key: %s. Reason: %s" % (key_name, err))
+
+        return keyring
+
 
 class BindServer(models.Model):
     """ Store DNS servers and attributes for referencing their
@@ -93,10 +105,10 @@ class BindServer(models.Model):
           List of Dicts { String rr_name, String rr_ttl, String rr_class, String rr_type, String rr_data }
         """
 
-        if self.default_transfer_key:
-            keyring = keyutils.create_keyring(self.default_transfer_key.name,
-                                              self.default_transfer_key.data)
-        else:
+        try:
+            transfer_key = Key.objects.get(name=self.default_transfer_key)
+            keyring = transfer_key.create_keyring()
+        except Key.DoesNotExist:
             keyring = None
 
         try:
@@ -107,10 +119,10 @@ class BindServer(models.Model):
         except socket.error, err:
             # Thrown when the DNS server does not respond for a zone transfer (XFR).
             raise exceptions.TransferException("DNS server did not respond for transfer. Reason: %s" % err)
-        # except exception.FormError, err:
-        #     # TODO: What throws this?
-        #     raise exceptions.TransferException("There was an error attempting to list zone records.")
-
+        except dns.exception.FormError:
+            # When the DNS message is malformed.
+            # * Can happen if a TSIG key is required but a default_transfer_key is not specified.
+            raise exceptions.TransferException("There was an error attempting to list zone records. Did you forget to specify a default transfer key?")
 
         names = zone.nodes.keys()
         names.sort()