Define Ciphers config conditionally

We only expose the `Ciphers` config parameter in versions of Python that
support it (i.e., >= Python 2.7).

gunicorn/config.py

@@ -140,25 +140,12 @@ class Config(object):
     def is_ssl(self):
         return self.certfile or self.keyfile
 
-    def _load_attrs(self, attrs, version=sys.version_info):
-        for attr in attrs:
-            # suppress_ragged_eofs/do_handshake_on_connect are booleans that can
-            # be False hence we use hasattr instead of getattr(self, attr, None).
-            if hasattr(self, attr) and version >= sys.version_info:
-                yield (attr, getattr(self, attr))
-
     @property
     def ssl_options(self):
-
         opts = {}
-
-        opts.update(self._load_attrs(('certfile', 'keyfile', 'cert_reqs', 'ssl_version',
-                'ca_certs', 'suppress_ragged_eofs', 'do_handshake_on_connect')))
-
-        # The `ciphers` kwarg was only available in Python 2.7, so don't make
-        # it available for us in older versions on Python.
-        opts.update(self._load_attrs(('ciphers'), version=(2, 7)))
-
+        for name, value in self.settings.items():
+            if value.section == 'Ssl':
+                opts[name] = value.get()
         return opts
 
     @property
@@ -1557,14 +1544,13 @@ class DoHandshakeOnConnect(Setting):
     Whether to perform SSL handshake on socket connect (see stdlib ssl module's)
     """
 
-class Ciphers(Setting):
-    name = "ciphers"
-    section = "Ssl"
-    cli = ["--ciphers"]
-    validator = validate_string
-    default = 'TLSv1'
-    desc = """\
-    Ciphers to use (see stdlib ssl module's)
-
-    Note, this value is only available in Python 2.7+ and is ignored in older versions of Python.
-    """
+if sys.version_info >= (2, 7):
+    class Ciphers(Setting):
+        name = "ciphers"
+        section = "Ssl"
+        cli = ["--ciphers"]
+        validator = validate_string
+        default = 'TLSv1'
+        desc = """\
+        Ciphers to use (see stdlib ssl module's)
+        """

tests/test_007-ssl.py

@@ -8,13 +8,17 @@
 # stdlib
 import inspect
 import ssl
+import sys
 from unittest import TestCase
 
 # gunicorn
 from gunicorn.config import KeyFile, CertFile, SSLVersion, CACerts, \
-     SuppressRaggedEOFs, DoHandshakeOnConnect, Ciphers, Setting, validate_bool, validate_string, \
+     SuppressRaggedEOFs, DoHandshakeOnConnect, Setting, validate_bool, validate_string, \
      validate_pos_int
 
+if sys.version_info >= (2, 7):
+    from gunicorn.config import Ciphers
+
 class SSLTestCase(TestCase):
     def test_settings_classes(self):
         """ Tests all settings options and their defaults.
@@ -59,8 +63,10 @@ class SSLTestCase(TestCase):
         self.assertEquals(DoHandshakeOnConnect.action, 'store_true')
         self.assertEquals(DoHandshakeOnConnect.default, False)
 
-        self.assertTrue(issubclass(Ciphers, Setting))        
-        self.assertEquals(Ciphers.name, 'ciphers')
-        self.assertEquals(Ciphers.section, 'Ssl')
-        self.assertEquals(Ciphers.cli, ['--ciphers'])
-        self.assertEquals(Ciphers.default, 'TLSv1')
+
+        if sys.version_info >= (2, 7):
+            self.assertTrue(issubclass(Ciphers, Setting))        
+            self.assertEquals(Ciphers.name, 'ciphers')
+            self.assertEquals(Ciphers.section, 'Ssl')
+            self.assertEquals(Ciphers.cli, ['--ciphers'])
+            self.assertEquals(Ciphers.default, 'TLSv1')