diff --git a/README.rst b/README.rst
index 29bf158..fe75546 100644
--- a/README.rst
+++ b/README.rst
@@ -22,7 +22,6 @@ Features
 - Simple.  Sort of.
 - Fail open (optional).
 - OTP and Push (use push as password for push, passcode:123456 as password for OTP, where 123456 is your OTP).
-- MozDef support.
 - Optional-username hack, in case you use emails as certificate CN but only the first part of the email as login.
 - Deferred call.
 
diff --git a/duo_openvpn_mozilla/openvpn_credentials.py b/duo_openvpn_mozilla/openvpn_credentials.py
index a6899a5..d9e2f92 100644
--- a/duo_openvpn_mozilla/openvpn_credentials.py
+++ b/duo_openvpn_mozilla/openvpn_credentials.py
@@ -89,11 +89,9 @@ def load_variables_from_environment(self):
             __unsafe_username = ''
 
         # the environmental variable 'password' is what they typed in/sent.
-        __password = os.environ.get('password')
-        if __password is None:
-            __password = ''
+        __password = os.environ.get('password', '')
 
-        if __unsafe_username != '' and __password == '':
+        if __unsafe_username != '' and __password == '':  # nosec hardcoded_password_string
             # At this step, we have a username of some sort, but no password.
             #
             # Based on changes dating back to 2015, as an aid to
diff --git a/test/integration/test_duo_openvpn.py b/test/integration/test_duo_openvpn.py
index 150ddf1..261ecb5 100644
--- a/test/integration/test_duo_openvpn.py
+++ b/test/integration/test_duo_openvpn.py
@@ -69,7 +69,7 @@ def test_init(self):
     def test_bogus_user(self):
         """ A bogus user is denied """
         os.environ['common_name'] = 'user-who-does-not-exist'
-        os.environ['password'] = 'push'
+        os.environ['password'] = 'push'  # nosec hardcoded_password_string
         library = DuoOpenVPN()
         res = library.main_authentication()
         self.assertFalse(res, 'invalid users must be denied')
@@ -81,7 +81,7 @@ def test_1fa_user_attempts_2fa(self):
         if not self.one_fa_user:  # pragma: no cover
             return self.skipTest('No testing/one_fa_user defined')
         os.environ['common_name'] = self.one_fa_user
-        os.environ['password'] = 'push'
+        os.environ['password'] = 'push'  # nosec hardcoded_password_string
         library = DuoOpenVPN()
         res = library.main_authentication()
         self.assertFalse(res, '1fa user attempting to 2fa must be denied')
@@ -91,7 +91,7 @@ def test_1fa_user_bad_pw(self):
         if not self.one_fa_user:  # pragma: no cover
             return self.skipTest('No testing/one_fa_user defined')
         os.environ['common_name'] = self.one_fa_user
-        os.environ['password'] = 'a-bad-password'
+        os.environ['password'] = 'a-bad-password'  # nosec hardcoded_password_string
         library = DuoOpenVPN()
         res = library.main_authentication()
         self.assertFalse(res, '1fa user with bad password must be denied')
@@ -115,7 +115,7 @@ def test_2fa_user_bad(self):
         if not self.normal_user:  # pragma: no cover
             return self.skipTest('No testing/normal_user defined')
         os.environ['common_name'] = self.normal_user
-        os.environ['password'] = 'push'
+        os.environ['password'] = 'push'  # nosec hardcoded_password_string
         library = DuoOpenVPN()
         res = library.main_authentication()
         self.assertFalse(res, '2fa user with a deny must be False')
@@ -127,7 +127,7 @@ def test_2fa_user_good(self):
         if not self.normal_user:  # pragma: no cover
             return self.skipTest('No testing/normal_user defined')
         os.environ['common_name'] = self.normal_user
-        os.environ['password'] = 'push'
+        os.environ['password'] = 'push'  # nosec hardcoded_password_string
         library = DuoOpenVPN()
         res = library.main_authentication()
         self.assertTrue(res, '2fa user with an allow must be True')
diff --git a/test/unit/test_duo_auth.py b/test/unit/test_duo_auth.py
index 271e45e..b3da569 100644
--- a/test/unit/test_duo_auth.py
+++ b/test/unit/test_duo_auth.py
@@ -23,7 +23,7 @@ class TestDuoAPIAuthUnit(unittest.TestCase):
         DuoAPIAuth class without going out to Duo.
     """
 
-    testing_conffile = '/tmp/TestDuoAPIAuthUnit.txt'
+    testing_conffile = '/tmp/TestDuoAPIAuthUnit.txt'  # nosec hardcoded_tmp_directory
 
     def setUp(self):
         """ Preparing test rig """
@@ -288,7 +288,7 @@ def test_33_auth_auto(self):
 
     def test_34_auth_passcode(self):
         """ Test passcode on auth checks. """
-        os.environ['password'] = '123456'
+        os.environ['password'] = '123456'  # nosec hardcoded_password_string
         creds = OpenVPNCredentials()
         creds.load_variables_from_environment()
         self.library.user_config = creds
diff --git a/test/unit/test_duo_openvpn.py b/test/unit/test_duo_openvpn.py
index b2046ef..fb6b972 100644
--- a/test/unit/test_duo_openvpn.py
+++ b/test/unit/test_duo_openvpn.py
@@ -6,20 +6,16 @@
 
 import unittest
 import os
-import sys
 import datetime
 import json
 import syslog
 import configparser
+from io import StringIO
 import test.context  # pylint: disable=unused-import
 import mock
 from duo_openvpn_mozilla.duo_auth import DuoAPIAuth
 from duo_openvpn_mozilla.openvpn_credentials import OpenVPNCredentials
 from duo_openvpn_mozilla import DuoOpenVPN, DuoTimeoutError
-if sys.version_info.major >= 3:
-    from io import StringIO  # pragma: no cover
-else:
-    from io import BytesIO as StringIO  # pragma: no cover
 
 
 class TestDuoOpenVPNUnit(unittest.TestCase):
@@ -28,7 +24,7 @@ class TestDuoOpenVPNUnit(unittest.TestCase):
         DuoOpenVPN class without going out to Duo.
     """
 
-    testing_conffile = '/tmp/TestDuoOpenVPNUnit.txt'
+    testing_conffile = '/tmp/TestDuoOpenVPNUnit.txt'  # nosec hardcoded_tmp_directory
 
     def setUp(self):
         """ Preparing test rig """
@@ -66,8 +62,9 @@ def test_03_ingest_no_config_files(self):
 
     def test_04_ingest_no_config_file(self):
         """ With all missing config files, get an exception """
+        _not_a_real_file = '/tmp/no-such-file.txt'  # nosec hardcoded_tmp_directory
         with mock.patch.object(DuoOpenVPN, 'CONFIG_FILE_LOCATIONS',
-                               new=['/tmp/no-such-file.txt']):
+                               new=[_not_a_real_file]):
             with self.assertRaises(IOError):
                 self.library._ingest_config_from_file()
 
@@ -80,12 +77,13 @@ def test_05_ingest_bad_config_file(self):
 
     def test_06_ingest_config_from_file(self):
         """ With an actual config file, get a populated ConfigParser """
-        test_reading_file = '/tmp/test-reader.txt'
+        _not_a_real_file = '/tmp/no-such-file.txt'  # nosec hardcoded_tmp_directory
+        test_reading_file = '/tmp/test-reader.txt'  # nosec hardcoded_tmp_directory
         with open(test_reading_file, 'w', encoding='utf-8') as filepointer:
             filepointer.write('[aa]\nbb = cc\n')
         filepointer.close()
         with mock.patch.object(DuoOpenVPN, 'CONFIG_FILE_LOCATIONS',
-                               new=['/tmp/no-such-file.txt', test_reading_file]):
+                               new=[_not_a_real_file, test_reading_file]):
             result = self.library._ingest_config_from_file()
         os.remove(test_reading_file)
         self.assertIsInstance(result, configparser.ConfigParser,
@@ -248,7 +246,7 @@ def test_23_auth_1fa_garbage_pw(self):
         """ 1fa user with a 2fa / bonkers 'password' """
         os.environ['untrusted_ip'] = 'testing-ip-Unknown-is-OK'
         os.environ['common_name'] = 'bob'
-        os.environ['password'] = 'push'
+        os.environ['password'] = 'push'  # nosec hardcoded_password_string
         with mock.patch.object(DuoOpenVPN, 'log') as mock_log:
             with mock.patch('iamvpnlibrary.IAMVPNLibrary') as mock_iam, \
                     mock.patch.object(mock_iam.return_value, 'user_allowed_to_vpn',
@@ -264,7 +262,7 @@ def test_24_auth_1fa_bad_pw(self):
         """ 1fa user with a bad password """
         os.environ['untrusted_ip'] = 'testing-ip-Unknown-is-OK'
         os.environ['common_name'] = 'bob'
-        os.environ['password'] = 'hunter2'
+        os.environ['password'] = 'hunter2'  # nosec hardcoded_password_string
         with mock.patch.object(DuoOpenVPN, 'log') as mock_log:
             with mock.patch('iamvpnlibrary.IAMVPNLibrary') as mock_iam, \
                     mock.patch.object(mock_iam.return_value, 'user_allowed_to_vpn',
@@ -282,7 +280,7 @@ def test_25_auth_1fa_good_pw(self):
         """ 1fa user with a good password """
         os.environ['untrusted_ip'] = 'testing-ip-Unknown-is-OK'
         os.environ['common_name'] = 'bob'
-        os.environ['password'] = 'hunter2'
+        os.environ['password'] = 'hunter2'  # nosec hardcoded_password_string
         with mock.patch.object(DuoOpenVPN, 'log') as mock_log:
             with mock.patch('iamvpnlibrary.IAMVPNLibrary') as mock_iam, \
                     mock.patch.object(mock_iam.return_value, 'user_allowed_to_vpn',
diff --git a/test/unit/test_openvpn_credentials.py b/test/unit/test_openvpn_credentials.py
index 19c17de..12ea6a8 100644
--- a/test/unit/test_openvpn_credentials.py
+++ b/test/unit/test_openvpn_credentials.py
@@ -166,7 +166,7 @@ def test_loadvar_00(self):
         """ user '' pass '' """
         os.environ['common_name'] = self.realish_user
         os.environ['username'] = ''
-        os.environ['password'] = ''
+        os.environ['password'] = ''  # nosec hardcoded_password_string
         self.library.load_variables_from_environment()
         self.assertTrue(self.library.is_valid())
         self.assertEqual(self.library.username, self.realish_user)
@@ -243,7 +243,7 @@ def test_loadvar_05(self):
 
     def test_loadvar_06(self):
         """ user '' pass a_pa:ss:wo:rd """
-        _pass = 'some:password'
+        _pass = 'some:password'  # nosec hardcoded_password_string
         os.environ['common_name'] = self.realish_user
         os.environ['username'] = ''
         os.environ['password'] = _pass
@@ -256,7 +256,7 @@ def test_loadvar_06(self):
 
     def test_loadvar_07(self):
         """ user '' pass a_password """
-        _pass = 'some_password'
+        _pass = 'some_password'  # nosec hardcoded_password_string
         os.environ['common_name'] = self.realish_user
         os.environ['username'] = ''
         os.environ['password'] = _pass
@@ -277,7 +277,7 @@ def test_loadvar_10(self):
         for wordu in list(self.library.DUO_RESERVED_WORDS):
             os.environ['common_name'] = self.realish_user
             os.environ['username'] = wordu
-            os.environ['password'] = ''
+            os.environ['password'] = ''  # nosec hardcoded_password_string
             self.library.load_variables_from_environment()
             self.assertTrue(self.library.is_valid())
             self.assertEqual(self.library.username, self.realish_user)
@@ -359,7 +359,7 @@ def test_loadvar_15(self):
 
     def test_loadvar_16(self):
         """ user DUO_RESERVED_WORDS pass a_pa:ss:wo:rd """
-        _pass = 'some:password'
+        _pass = 'some:password'  # nosec hardcoded_password_string
         for wordu in list(self.library.DUO_RESERVED_WORDS):
             os.environ['common_name'] = self.realish_user
             os.environ['username'] = wordu
@@ -373,7 +373,7 @@ def test_loadvar_16(self):
 
     def test_loadvar_17(self):
         """ user DUO_RESERVED_WORDS pass a_password """
-        _pass = 'some_password'
+        _pass = 'some_password'  # nosec hardcoded_password_string
         for wordu in list(self.library.DUO_RESERVED_WORDS):
             os.environ['common_name'] = self.realish_user
             os.environ['username'] = wordu
@@ -403,7 +403,7 @@ def test_loadvar_20(self):
         # or have a non-factor result.  So:
         os.environ['common_name'] = self.realish_user
         os.environ['username'] = 'someuser'
-        os.environ['password'] = ''
+        os.environ['password'] = ''  # nosec hardcoded_password_string
         try:
             self.library.load_variables_from_environment()
         except ValueError:  # pragma: no cover
@@ -487,7 +487,7 @@ def test_loadvar_25(self):
 
     def test_loadvar_26(self):
         """ user someuser pass a_pa:ss:wo:rd """
-        _pass = 'some:password'
+        _pass = 'some:password'  # nosec hardcoded_password_string
         os.environ['common_name'] = self.realish_user
         os.environ['username'] = 'someuser'
         os.environ['password'] = _pass
@@ -500,7 +500,7 @@ def test_loadvar_26(self):
 
     def test_loadvar_27(self):
         """ user someuser pass a_password """
-        _pass = 'some_password'
+        _pass = 'some_password'  # nosec hardcoded_password_string
         os.environ['common_name'] = self.realish_user
         os.environ['username'] = 'someuser'
         os.environ['password'] = _pass
diff --git a/test/unit/test_openvpn_script.py b/test/unit/test_openvpn_script.py
index 175ca12..eda340d 100644
--- a/test/unit/test_openvpn_script.py
+++ b/test/unit/test_openvpn_script.py
@@ -6,16 +6,12 @@
 
 import unittest
 import os
-import sys
 import time
 import test.context  # pylint: disable=unused-import
+from io import StringIO
 import mock
 import duo_openvpn
 from duo_openvpn_mozilla import DuoOpenVPN  # pylint: disable=unused-import
-if sys.version_info.major >= 3:
-    from io import StringIO  # pragma: no cover
-else:
-    from io import BytesIO as StringIO  # pragma: no cover
 
 
 class TestOpenVPNScript(unittest.TestCase):
@@ -32,7 +28,7 @@ def test_01_no_control_file(self):
 
     def test_05_write_failed(self):
         """ When we can't write out auth_control_file, we must die """
-        os.environ['auth_control_file'] = '/tmp/foo'
+        os.environ['auth_control_file'] = '/tmp/foo'  # nosec hardcoded_tmp_directory
         with mock.patch('duo_openvpn.DuoOpenVPN'), \
                 self.assertRaises(SystemExit) as exiting, \
                 mock.patch('duo_openvpn.open', create=True, side_effect=IOError):
@@ -41,7 +37,7 @@ def test_05_write_failed(self):
 
     def test_10_access_denied(self):
         """ When auth is refused, don't let someone in. """
-        os.environ['auth_control_file'] = '/tmp/foo'
+        os.environ['auth_control_file'] = '/tmp/foo'  # nosec hardcoded_tmp_directory
         with mock.patch('duo_openvpn.DuoOpenVPN') as mock_duo, \
                 self.assertRaises(SystemExit) as exiting, \
                 mock.patch('duo_openvpn.open', create=True,
@@ -54,7 +50,7 @@ def test_10_access_denied(self):
 
     def test_11_access_granted(self):
         """ When auth is allowed, let someone in. """
-        os.environ['auth_control_file'] = '/tmp/foo'
+        os.environ['auth_control_file'] = '/tmp/foo'  # nosec hardcoded_tmp_directory
         with mock.patch('duo_openvpn.DuoOpenVPN') as mock_duo, \
                 self.assertRaises(SystemExit) as exiting, \
                 mock.patch('duo_openvpn.open', create=True,
@@ -67,7 +63,7 @@ def test_11_access_granted(self):
 
     def test_12_access_timeout(self):
         """ When Duo is down, handle it well. """
-        os.environ['auth_control_file'] = '/tmp/foo'
+        os.environ['auth_control_file'] = '/tmp/foo'  # nosec hardcoded_tmp_directory
         def too_slow_authentication():
             '''
                 This function is waiting 5 seconds and the responding true.