Respond to review:

- Refactor both the base64 encoding and decoding into utility functions.

Also:

- Mechanically fix some other broken untested code.

9 files changed, 42 insertions, 71 deletions

diff --git a/cloudinit/config/cc_seed_random.py b/cloudinit/config/cc_seed_random.py
index 981e1b08..bb64b0f5 100644
--- a/cloudinit/config/cc_seed_random.py
+++ b/cloudinit/config/cc_seed_random.py
@@ -38,13 +38,7 @@ def _decode(data, encoding=None):
     if not encoding or encoding.lower() in ['raw']:
         return data
     elif encoding.lower() in ['base64', 'b64']:
-        # Try to give us a native string in both Python 2 and 3, and remember
-        # that b64decode() returns bytes in Python 3.
-        decoded = base64.b64decode(data)
-        try:
-            return decoded.decode('utf-8')
-        except UnicodeDecodeError:
-            return decoded
+        return util.b64d(data)
     elif encoding.lower() in ['gzip', 'gz']:
         return util.decomp_gzip(data, quiet=False)
     else:
diff --git a/cloudinit/config/cc_ssh_authkey_fingerprints.py b/cloudinit/config/cc_ssh_authkey_fingerprints.py
index 51580633..6ce831bc 100644
--- a/cloudinit/config/cc_ssh_authkey_fingerprints.py
+++ b/cloudinit/config/cc_ssh_authkey_fingerprints.py
@@ -32,7 +32,7 @@ from cloudinit import util
 
 def _split_hash(bin_hash):
     split_up = []
-    for i in xrange(0, len(bin_hash), 2):
+    for i in range(0, len(bin_hash), 2):
         split_up.append(bin_hash[i:i + 2])
     return split_up
 
diff --git a/cloudinit/sources/DataSourceOpenNebula.py b/cloudinit/sources/DataSourceOpenNebula.py
index a0275cda..61709c1b 100644
--- a/cloudinit/sources/DataSourceOpenNebula.py
+++ b/cloudinit/sources/DataSourceOpenNebula.py
@@ -426,12 +426,7 @@ def read_context_disk_dir(source_dir, asuser=None):
                                context.get('USER_DATA_ENCODING'))
         if encoding == "base64":
             try:
-                userdata = base64.b64decode(results['userdata'])
-                # In Python 3 we still expect a str, but b64decode will return
-                # bytes.  Convert to str.
-                if isinstance(userdata, bytes):
-                    userdata = userdata.decode('utf-8')
-                results['userdata'] = userdata
+                results['userdata'] = util.b64d(results['userdata'])
             except TypeError:
                 LOG.warn("Failed base64 decoding of userdata")
 
diff --git a/cloudinit/sources/DataSourceSmartOS.py b/cloudinit/sources/DataSourceSmartOS.py
index f59ad3d6..9d48beab 100644
--- a/cloudinit/sources/DataSourceSmartOS.py
+++ b/cloudinit/sources/DataSourceSmartOS.py
@@ -351,16 +351,7 @@ def query_data(noun, seed_device, seed_timeout, strip=False, default=None,
 
     if b64:
         try:
-            # Generally, we want native strings in the values.  Python 3's
-            # b64decode will return bytes though, so decode them to utf-8 if
-            # possible.  If that fails, return the bytes.
-            decoded = base64.b64decode(resp)
-            try:
-                if isinstance(decoded, bytes):
-                    return decoded.decode('utf-8')
-            except UnicodeDecodeError:
-                pass
-            return decoded
+            return util.b64d(resp)
         # Bogus input produces different errors in Python 2 and 3; catch both.
         except (TypeError, binascii.Error):
             LOG.warn("Failed base64 decoding key '%s'", noun)
diff --git a/cloudinit/util.py b/cloudinit/util.py
index 766f8e32..8916cc11 100644
--- a/cloudinit/util.py
+++ b/cloudinit/util.py
@@ -44,6 +44,7 @@ import sys
 import tempfile
 import time
 
+from base64 import b64decode, b64encode
 from six.moves.urllib import parse as urlparse
 
 import six
@@ -90,6 +91,25 @@ def encode_text(text, encoding='utf-8'):
         return text
     return text.encode(encoding)
 
+
+def b64d(source):
+    # Base64 decode some data, accepting bytes or unicode/str, and returning
+    # str/unicode if the result is utf-8 compatible, otherwise returning bytes.
+    decoded = b64decode(source)
+    if isinstance(decoded, bytes):
+        try:
+            return decoded.decode('utf-8')
+        except UnicodeDecodeError:
+            return decoded
+
+def b64e(source):
+    # Base64 encode some data, accepting bytes or unicode/str, and returning
+    # str/unicode if the result is utf-8 compatible, otherwise returning bytes.
+    if not isinstance(source, bytes):
+        source = source.encode('utf-8')
+    return b64encode(source).decode('utf-8')
+
+
 # Path for DMI Data
 DMI_SYS_PATH = "/sys/class/dmi/id"
 
diff --git a/tests/unittests/test_datasource/test_azure.py b/tests/unittests/test_datasource/test_azure.py
index 97a53bee..965bce4b 100644
--- a/tests/unittests/test_datasource/test_azure.py
+++ b/tests/unittests/test_datasource/test_azure.py
@@ -1,5 +1,5 @@
 from cloudinit import helpers
-from cloudinit.util import load_file
+from cloudinit.util import b64e, load_file
 from cloudinit.sources import DataSourceAzure
 from ..helpers import TestCase, populate_dir
 
@@ -12,7 +12,6 @@ try:
 except ImportError:
     from contextlib2 import ExitStack
 
-import base64
 import crypt
 import os
 import stat
@@ -22,13 +21,6 @@ import tempfile
 import unittest
 
 
-def b64(source):
-    # In Python 3, b64encode only accepts bytes and returns bytes.
-    if not isinstance(source, bytes):
-        source = source.encode('utf-8')
-    return base64.b64encode(source).decode('us-ascii')
-
-
 def construct_valid_ovf_env(data=None, pubkeys=None, userdata=None):
     if data is None:
         data = {'HostName': 'FOOHOST'}
@@ -58,7 +50,7 @@ def construct_valid_ovf_env(data=None, pubkeys=None, userdata=None):
         content += "<%s%s>%s</%s>\n" % (key, attrs, val, key)
 
     if userdata:
-        content += "<UserData>%s</UserData>\n" % (b64(userdata))
+        content += "<UserData>%s</UserData>\n" % (b64e(userdata))
 
     if pubkeys:
         content += "<SSH><PublicKeys>\n"
@@ -189,7 +181,7 @@ class TestAzureDataSource(TestCase):
         # set dscfg in via base64 encoded yaml
         cfg = {'agent_command': "my_command"}
         odata = {'HostName': "myhost", 'UserName': "myuser",
-                'dscfg': {'text': b64(yaml.dump(cfg)),
+                'dscfg': {'text': b64e(yaml.dump(cfg)),
                           'encoding': 'base64'}}
         data = {'ovfcontent': construct_valid_ovf_env(data=odata)}
 
@@ -241,7 +233,7 @@ class TestAzureDataSource(TestCase):
 
     def test_userdata_found(self):
         mydata = "FOOBAR"
-        odata = {'UserData': b64(mydata)}
+        odata = {'UserData': b64e(mydata)}
         data = {'ovfcontent': construct_valid_ovf_env(data=odata)}
 
         dsrc = self._get_ds(data)
@@ -289,7 +281,7 @@ class TestAzureDataSource(TestCase):
                                    'command': 'my-bounce-command',
                                    'hostname_command': 'my-hostname-command'}}
         odata = {'HostName': "xhost",
-                'dscfg': {'text': b64(yaml.dump(cfg)),
+                'dscfg': {'text': b64e(yaml.dump(cfg)),
                           'encoding': 'base64'}}
         data = {'ovfcontent': construct_valid_ovf_env(data=odata)}
         self._get_ds(data).get_data()
@@ -304,7 +296,7 @@ class TestAzureDataSource(TestCase):
         # config specifying set_hostname off should not bounce
         cfg = {'set_hostname': False}
         odata = {'HostName': "xhost",
-                'dscfg': {'text': b64(yaml.dump(cfg)),
+                'dscfg': {'text': b64e(yaml.dump(cfg)),
                           'encoding': 'base64'}}
         data = {'ovfcontent': construct_valid_ovf_env(data=odata)}
         self._get_ds(data).get_data()
@@ -333,7 +325,7 @@ class TestAzureDataSource(TestCase):
         # Make sure that user can affect disk aliases
         dscfg = {'disk_aliases': {'ephemeral0': '/dev/sdc'}}
         odata = {'HostName': "myhost", 'UserName': "myuser",
-                'dscfg': {'text': b64(yaml.dump(dscfg)),
+                'dscfg': {'text': b64e(yaml.dump(dscfg)),
                           'encoding': 'base64'}}
         usercfg = {'disk_setup': {'/dev/sdc': {'something': '...'},
                                   'ephemeral0': False}}
@@ -370,7 +362,7 @@ class TestAzureDataSource(TestCase):
 
     def test_existing_ovf_same(self):
         # waagent/SharedConfig left alone if found ovf-env.xml same as cached
-        odata = {'UserData': b64("SOMEUSERDATA")}
+        odata = {'UserData': b64e("SOMEUSERDATA")}
         data = {'ovfcontent': construct_valid_ovf_env(data=odata)}
 
         populate_dir(self.waagent_d,
@@ -394,9 +386,9 @@ class TestAzureDataSource(TestCase):
         # 'get_data' should remove SharedConfig.xml in /var/lib/waagent
         # if ovf-env.xml differs.
         cached_ovfenv = construct_valid_ovf_env(
-            {'userdata': b64("FOO_USERDATA")})
+            {'userdata': b64e("FOO_USERDATA")})
         new_ovfenv = construct_valid_ovf_env(
-            {'userdata': b64("NEW_USERDATA")})
+            {'userdata': b64e("NEW_USERDATA")})
 
         populate_dir(self.waagent_d,
             {'ovf-env.xml': cached_ovfenv,
diff --git a/tests/unittests/test_datasource/test_opennebula.py b/tests/unittests/test_datasource/test_opennebula.py
index e5a4bd18..27adf21b 100644
--- a/tests/unittests/test_datasource/test_opennebula.py
+++ b/tests/unittests/test_datasource/test_opennebula.py
@@ -3,19 +3,12 @@ from cloudinit.sources import DataSourceOpenNebula as ds
 from cloudinit import util
 from ..helpers import TestCase, populate_dir
 
-from base64 import b64encode
 import os
 import pwd
 import shutil
 import tempfile
 import unittest
 
-def b64(source):
-    # In Python 3, b64encode only accepts bytes and returns bytes.
-    if not isinstance(source, bytes):
-        source = source.encode('utf-8')
-    return b64encode(source).decode('us-ascii')
-
 
 TEST_VARS = {
     'VAR1': 'single',
@@ -186,7 +179,7 @@ class TestOpenNebulaDataSource(TestCase):
             self.assertEqual(USER_DATA, results['userdata'])
 
     def test_user_data_encoding_required_for_decode(self):
-        b64userdata = b64(USER_DATA)
+        b64userdata = util.b64e(USER_DATA)
         for k in ('USER_DATA', 'USERDATA'):
             my_d = os.path.join(self.tmp, k)
             populate_context_dir(my_d, {k: b64userdata})
@@ -198,7 +191,7 @@ class TestOpenNebulaDataSource(TestCase):
     def test_user_data_base64_encoding(self):
         for k in ('USER_DATA', 'USERDATA'):
             my_d = os.path.join(self.tmp, k)
-            populate_context_dir(my_d, {k: b64(USER_DATA),
+            populate_context_dir(my_d, {k: util.b64e(USER_DATA),
                                         'USERDATA_ENCODING': 'base64'})
             results = ds.read_context_disk_dir(my_d)
 
diff --git a/tests/unittests/test_datasource/test_smartos.py b/tests/unittests/test_datasource/test_smartos.py
index b5ebf94d..8b62b1b1 100644
--- a/tests/unittests/test_datasource/test_smartos.py
+++ b/tests/unittests/test_datasource/test_smartos.py
@@ -24,9 +24,9 @@
 
 from __future__ import print_function
 
-import base64
 from cloudinit import helpers as c_helpers
 from cloudinit.sources import DataSourceSmartOS
+from cloudinit.util import b64e
 from .. import helpers
 import os
 import os.path
@@ -36,12 +36,6 @@ import tempfile
 import stat
 import uuid
 
-def b64(source):
-    # In Python 3, b64encode only accepts bytes and returns bytes.
-    if not isinstance(source, bytes):
-        source = source.encode('utf-8')
-    return base64.b64encode(source).decode('us-ascii')
-
 
 MOCK_RETURNS = {
     'hostname': 'test-host',
@@ -239,7 +233,7 @@ class TestSmartOSDataSource(helpers.FilesystemMockingTestCase):
         my_returns = MOCK_RETURNS.copy()
         my_returns['base64_all'] = "true"
         for k in ('hostname', 'cloud-init:user-data'):
-            my_returns[k] = b64(my_returns[k])
+            my_returns[k] = b64e(my_returns[k])
 
         dsrc = self._get_ds(mockdata=my_returns)
         ret = dsrc.get_data()
@@ -260,7 +254,7 @@ class TestSmartOSDataSource(helpers.FilesystemMockingTestCase):
         my_returns['b64-cloud-init:user-data'] = "true"
         my_returns['b64-hostname'] = "true"
         for k in ('hostname', 'cloud-init:user-data'):
-            my_returns[k] = b64(my_returns[k])
+            my_returns[k] = b64e(my_returns[k])
 
         dsrc = self._get_ds(mockdata=my_returns)
         ret = dsrc.get_data()
@@ -276,7 +270,7 @@ class TestSmartOSDataSource(helpers.FilesystemMockingTestCase):
         my_returns = MOCK_RETURNS.copy()
         my_returns['base64_keys'] = 'hostname,ignored'
         for k in ('hostname',):
-            my_returns[k] = b64(my_returns[k])
+            my_returns[k] = b64e(my_returns[k])
 
         dsrc = self._get_ds(mockdata=my_returns)
         ret = dsrc.get_data()
diff --git a/tests/unittests/test_handler/test_handler_seed_random.py b/tests/unittests/test_handler/test_handler_seed_random.py
index d3f18fa0..0bcdcb31 100644
--- a/tests/unittests/test_handler/test_handler_seed_random.py
+++ b/tests/unittests/test_handler/test_handler_seed_random.py
@@ -18,7 +18,6 @@
 
 from cloudinit.config import cc_seed_random
 
-import base64
 import gzip
 import tempfile
 
@@ -38,13 +37,6 @@ import logging
 LOG = logging.getLogger(__name__)
 
 
-def b64(source):
-    # In Python 3, b64encode only accepts bytes and returns bytes.
-    if not isinstance(source, bytes):
-        source = source.encode('utf-8')
-    return base64.b64encode(source).decode('us-ascii')
-
-
 class TestRandomSeed(t_help.TestCase):
     def setUp(self):
         super(TestRandomSeed, self).setUp()
@@ -141,7 +133,7 @@ class TestRandomSeed(t_help.TestCase):
         self.assertEquals("big-toe", contents)
 
     def test_append_random_base64(self):
-        data = b64('bubbles')
+        data = util.b64e('bubbles')
         cfg = {
             'random_seed': {
                 'file': self._seed_file,
@@ -154,7 +146,7 @@ class TestRandomSeed(t_help.TestCase):
         self.assertEquals("bubbles", contents)
 
     def test_append_random_b64(self):
-        data = b64('kit-kat')
+        data = util.b64e('kit-kat')
         cfg = {
             'random_seed': {
                 'file': self._seed_file,