Remove padding code and tests in the p11 plugin

Added new tox target "coverage" for generating html coverage.
To run: tox -e coverage

Change-Id: Ia60a0ed0749c27d9f9ee17058b0b027adc485e30

barbican/crypto/p11_crypto.py

@@ -63,16 +63,6 @@ class P11CryptoPlugin(CryptoPluginBase):
         self.rw_session = self.pkcs11.openSession(1, PyKCS11.CKF_RW_SESSION)
         self.rw_session.login(conf.p11_crypto_plugin.login)
 
-    def _pad(self, unencrypted):
-        """Adds padding to unencrypted byte string."""
-        pad_length = self.block_size - (len(unencrypted) % self.block_size)
-        return unencrypted + (chr(pad_length) * pad_length)
-
-    def _strip_pad(self, unencrypted):
-        pad_length = ord(unencrypted[-1:])
-        unpadded = unencrypted[:-pad_length]
-        return unpadded
-
     def _check_error(self, value):
         if value != PyKCS11.CKR_OK:
             # TODO: probably shouldn't raise PyKCS11 error here
@@ -107,13 +97,11 @@ class P11CryptoPlugin(CryptoPluginBase):
         return gcm
 
     def encrypt(self, unencrypted, kek_meta_tenant, tenant):
-        # TODO: GCM should not require padding.
-        padded_data = self._pad(unencrypted)
         key = self._get_key_by_label(kek_meta_tenant.kek_label)
         iv = self._generate_iv()
         gcm = self._build_gcm_params(iv)
         mech = PyKCS11.Mechanism(self.algorithm, gcm)
-        encrypted = self.session.encrypt(key, padded_data, mech)
+        encrypted = self.session.encrypt(key, unencrypted, mech)
         cyphertext = b''.join(chr(i) for i in encrypted)
         kek_meta_extended = json.dumps({
             'iv': base64.b64encode(iv)
@@ -128,8 +116,8 @@ class P11CryptoPlugin(CryptoPluginBase):
         gcm = self._build_gcm_params(iv)
         mech = PyKCS11.Mechanism(self.algorithm, gcm)
         decrypted = self.session.decrypt(key, encrypted, mech)
-        padded_secret = b''.join(chr(i) for i in decrypted)
+        secret = b''.join(chr(i) for i in decrypted)
-        return self._strip_pad(padded_secret)
+        return secret
 
     def bind_kek_metadata(self, kek_metadata):
         # Enforce idempotency: If we've already generated a key for the

barbican/tests/crypto/test_p11_crypto.py

@@ -13,7 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from Crypto import Random
 from mock import MagicMock
 from mock import patch
 import unittest
@@ -41,32 +40,6 @@ class WhenTestingP11CryptoPlugin(unittest.TestCase):
     def tearDown(self):
         self.patcher.stop()
 
-    def test_pad_binary_string(self):
-        binary_string = b'some_binary_string'
-        padded_string = (
-            b'some_binary_string' +
-            b'\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e'
-        )
-        self.assertEqual(self.plugin._pad(binary_string), padded_string)
-
-    def test_pad_random_bytes(self):
-        random_bytes = Random.get_random_bytes(10)
-        padded_bytes = random_bytes + b'\x06\x06\x06\x06\x06\x06'
-        self.assertEqual(self.plugin._pad(random_bytes), padded_bytes)
-
-    def test_strip_padding_from_binary_string(self):
-        binary_string = b'some_binary_string'
-        padded_string = (
-            b'some_binary_string' +
-            b'\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e'
-        )
-        self.assertEqual(self.plugin._strip_pad(padded_string), binary_string)
-
-    def test_strip_padding_from_random_bytes(self):
-        random_bytes = Random.get_random_bytes(10)
-        padded_bytes = random_bytes + b'\x06\x06\x06\x06\x06\x06'
-        self.assertEqual(self.plugin._strip_pad(padded_bytes), random_bytes)
-
     def test_create_calls_generate_random(self):
         self.session.generateRandom.return_value = [1, 2, 3, 4, 5, 6, 7,
                                                     8, 9, 10, 11, 12, 13,
@@ -171,7 +144,7 @@ class WhenTestingP11CryptoPlugin(unittest.TestCase):
 
         self.p11_mock.Mechanism.assert_called_once()
         self.session.encrypt.assert_called_once_with(key,
-                                                     self.plugin._pad(payload),
+                                                     payload,
                                                      mech)
         self.assertEqual(b'\x01\x02\x03\x04\x05', cyphertext)
         self.assertEqual('{"iv": "AQIDBAUGBwgJCgsMDQ4PEA=="}',
@@ -181,7 +154,7 @@ class WhenTestingP11CryptoPlugin(unittest.TestCase):
         key = 'key1'
         ct = MagicMock()
         self.session.findObjects.return_value = [key]
-        self.session.decrypt.return_value = [100, 101, 102, 103] + [12] * 12
+        self.session.decrypt.return_value = [100, 101, 102, 103]
         mech = MagicMock()
         self.p11_mock.Mechanism.return_value = mech
         kek_meta_extended = '{"iv": "AQIDBAUGBwgJCgsMDQ4PEA=="}'

tox.ini

@@ -19,6 +19,9 @@ commands = pep8 barbican --ignore=E711 --count --repeat --show-source --exclude=
 [testenv:py27]
 commands = nosetests {posargs:--with-xcoverage --all-modules --cover-inclusive --traverse-namespace --with-xunit --cover-package=barbican}
 
+[testenv:coverage]
+commands = coverage html {posargs:--include="*barbican*"}
+
 [testenv:hacking]
 commands = {toxinidir}/tools/hacking.sh