py3: port cli form_signature and unit tests

This patch ports the form_signature cli `swift-form-signature`
and it's corrisponding tests to py3.

In essence in Py3 the HMAC function expects binary strings.

Change-Id: I5dded4ceb80f0cc595403775e8f9c17873e1e37b

swift/cli/form_signature.py

@@ -17,6 +17,7 @@ Script for generating a form signature for use with FormPost middleware.
 """
 from __future__ import print_function
 import hmac
+import six
 from hashlib import sha1
 from os.path import basename
 from time import time
@@ -92,8 +93,14 @@ def main(argv):
         print('For example: /v1/account/container')
         print('         Or: /v1/account/container/object_prefix')
         return 1
-    sig = hmac.new(key, '%s\n%s\n%s\n%s\n%s' % (path, redirect, max_file_size,
-                                                max_file_count, expires),
+    data = '%s\n%s\n%s\n%s\n%s' % (path, redirect, max_file_size,
+                                   max_file_count, expires)
+    if six.PY3:
+        data = data if isinstance(data, six.binary_type) else \
+            data.encode('utf8')
+        key = key if isinstance(key, six.binary_type) else \
+            key.encode('utf8')
+    sig = hmac.new(key, data,
                    sha1).hexdigest()
     print('  Expires:', expires)
     print('Signature:', sig)

test/unit/cli/test_form_signature.py

@@ -17,7 +17,7 @@
 import hashlib
 import hmac
 import mock
-from six import StringIO
+import six
 import unittest
 
 from swift.cli import form_signature
@@ -33,14 +33,19 @@ class TestFormSignature(unittest.TestCase):
         max_file_size = str(int(1024 * 1024 * 1024 * 3.14159))  # π GiB
         max_file_count = '3'
 
-        expected_signature = hmac.new(
-            key,
-            "\n".join((
-                path, redirect, max_file_size, max_file_count,
-                str(int(the_time + expires)))),
-            hashlib.sha1).hexdigest()
+        data = "\n".join((
+            path, redirect, max_file_size, max_file_count,
+            str(int(the_time + expires))))
 
-        out = StringIO()
+        if six.PY3:
+            data = data if isinstance(data, six.binary_type) else \
+                data.encode('utf8')
+            key = key if isinstance(key, six.binary_type) else \
+                key.encode('utf8')
+
+        expected_signature = hmac.new(key, data, hashlib.sha1).hexdigest()
+
+        out = six.StringIO()
         with mock.patch('swift.cli.form_signature.time', lambda: the_time):
             with mock.patch('sys.stdout', out):
                 exitcode = form_signature.main([
@@ -59,7 +64,7 @@ class TestFormSignature(unittest.TestCase):
         self.assertIn(sig_input, out.getvalue())
 
     def test_too_few_args(self):
-        out = StringIO()
+        out = six.StringIO()
         with mock.patch('sys.stdout', out):
             exitcode = form_signature.main([
                 '/path/to/swift-form-signature',
@@ -70,7 +75,7 @@ class TestFormSignature(unittest.TestCase):
         self.assertIn(usage, out.getvalue())
 
     def test_invalid_filesize_arg(self):
-        out = StringIO()
+        out = six.StringIO()
         key = 'secret squirrel'
         with mock.patch('sys.stdout', out):
             exitcode = form_signature.main([
@@ -79,7 +84,7 @@ class TestFormSignature(unittest.TestCase):
         self.assertNotEqual(exitcode, 0)
 
     def test_invalid_filecount_arg(self):
-        out = StringIO()
+        out = six.StringIO()
         key = 'secret squirrel'
         with mock.patch('sys.stdout', out):
             exitcode = form_signature.main([
@@ -88,7 +93,7 @@ class TestFormSignature(unittest.TestCase):
         self.assertNotEqual(exitcode, 0)
 
     def test_invalid_path_arg(self):
-        out = StringIO()
+        out = six.StringIO()
         key = 'secret squirrel'
         with mock.patch('sys.stdout', out):
             exitcode = form_signature.main([
@@ -97,7 +102,7 @@ class TestFormSignature(unittest.TestCase):
         self.assertNotEqual(exitcode, 0)
 
     def test_invalid_seconds_arg(self):
-        out = StringIO()
+        out = six.StringIO()
         key = 'secret squirrel'
         with mock.patch('sys.stdout', out):
             exitcode = form_signature.main([

tox.ini

@@ -30,6 +30,7 @@ setenv = VIRTUAL_ENV={envdir}
 commands =
   nosetests \
       test/unit/cli/test_dispersion_report.py \
+      test/unit/cli/test_form_signature.py \
       test/unit/cli/test_info.py \
       test/unit/cli/test_relinker.py \
       test/unit/cli/test_ring_builder_analyzer.py \