Style changes.

acme/acme/challenges.py

@@ -1,13 +1,13 @@
 """ACME Identifier Validation Challenges."""
 import abc
-import dns.resolver
-import dns.exception
 import functools
 import hashlib
 import logging
 import socket
 
 from cryptography.hazmat.primitives import hashes
+import dns.resolver
+import dns.exception
 import OpenSSL
 import requests
 
@@ -217,17 +217,16 @@ class KeyAuthorizationChallenge(_TokenDVChallenge):
                 self.validation(account_key, *args, **kwargs))
 
 
-@ChallengeResponse.register
 class DNS01Response(KeyAuthorizationChallengeResponse):
     """ACME "dns-01" challenge response."""
     typ = "dns-01"
 
-    def txt_records_for_name(self, name):
+    def txt_records_for_name(name):
         """Resolve the name and return the TXT records.
 
         :param unicode name: Domain name being verified.
 
-        :returns: A list of txt records, or None if the name could not be resolved
+        :returns: A list of txt records, if empty the name could not be resolved
         :rtype: list of unicode
 
         """
@@ -235,17 +234,17 @@ class DNS01Response(KeyAuthorizationChallengeResponse):
             dns_response = dns.resolver.query(name, 'TXT')
         except dns.exception.DNSException as error:
             logger.error("Unable to resolve %s: %s", name, error)
-            return None
-        return sum([rdata.strings for rdata in dns_response], [])
+            return []
+        return [txt_rec in dns_response for txt_rec in rdata.strings]
 
+@ChallengeResponse.register
     def simple_verify(self, chall, domain, account_public_key):
         """Simple verify.
 
         :param challenges.DNS01 chall: Corresponding challenge.
         :param unicode domain: Domain name being verified.
         :param account_public_key: Public key for the key pair
-            being authorized. If ``None`` key verification is not
-            performed!
+            being authorized.
         :param JWK account_public_key:
 
         :returns: ``True`` iff validation with the TXT records resolved from a
@@ -260,14 +259,9 @@ class DNS01Response(KeyAuthorizationChallengeResponse):
         validation_domain_name = chall.validation_domain_name(domain)
         validation = chall.validation(account_public_key)
         logger.debug("Verifying %s at %s...", chall.typ, validation_domain_name)
-        txt_records = self.txt_records_for_name(validation_domain_name)
-        if txt_records == None:
-            return False
-
-        for txt_record in txt_records:
-            if txt_record == validation:
-                return True
 
+        if validation in txt_records_for_name(validation_domain_name):
+            return True
         logger.debug("Key authorization from response (%r) doesn't match any "
                      "DNS response in %r", self.key_authorization, txt_records)
         return False
@@ -289,8 +283,8 @@ class DNS01(KeyAuthorizationChallenge):
         :rtype: unicode
 
         """
-        key_authorization = self.key_authorization(account_key)
-        return jose.b64encode(hashlib.sha256(key_authorization).digest())
+        return jose.b64encode(hashlib.sha256(
+            self.key_authorization(account_key)).digest())
 
     def validation_domain_name(self, name):
         """Domain name for TXT validation record.

acme/acme/challenges_test.py

@@ -77,6 +77,7 @@ class KeyAuthorizationChallengeResponseTest(unittest.TestCase):
             key_authorization='.foo.oKGqedy-b-acd5eoybm2f-NVFxvyOoET5CNy3xnv8WY')
         self.assertFalse(response.verify(self.chall, KEY.public_key()))
 
+
 class DNS01ResponseTest(unittest.TestCase):
     # pylint: disable=too-many-instance-attributes
 
@@ -108,8 +109,7 @@ class DNS01ResponseTest(unittest.TestCase):
 
     def test_from_json(self):
         from acme.challenges import DNS01Response
-        self.assertEqual(
-            self.msg, DNS01Response.from_json(self.jmsg))
+        self.assertEqual(self.msg, DNS01Response.from_json(self.jmsg))
 
     def test_from_json_hashable(self):
         from acme.challenges import DNS01Response