Add mandatory headers to files touched by this branch
diff --git a/cryptography/bindings/openssl/api.py b/cryptography/bindings/openssl/api.py
index 65a29b8..d9181d7 100644
--- a/cryptography/bindings/openssl/api.py
+++ b/cryptography/bindings/openssl/api.py
@@ -11,6 +11,8 @@
# See the License for the specific language governing permissions and
# limitations under the License.
+from __future__ import absolute_import, division, print_function
+
import cffi
diff --git a/cryptography/primitives/block/__init__.py b/cryptography/primitives/block/__init__.py
index e49fcf3..a0c6d03 100644
--- a/cryptography/primitives/block/__init__.py
+++ b/cryptography/primitives/block/__init__.py
@@ -1,3 +1,18 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import absolute_import, division, print_function
+
from cryptography.primitives.block.base import BlockCipher
diff --git a/cryptography/primitives/block/base.py b/cryptography/primitives/block/base.py
index 2018138..f4a04b3 100644
--- a/cryptography/primitives/block/base.py
+++ b/cryptography/primitives/block/base.py
@@ -11,6 +11,8 @@
# See the License for the specific language governing permissions and
# limitations under the License.
+from __future__ import absolute_import, division, print_function
+
# TODO: which binding is used should be an option somewhere
from enum import Enum
diff --git a/cryptography/primitives/block/ciphers.py b/cryptography/primitives/block/ciphers.py
index 3d76afa..2e47870 100644
--- a/cryptography/primitives/block/ciphers.py
+++ b/cryptography/primitives/block/ciphers.py
@@ -11,6 +11,8 @@
# See the License for the specific language governing permissions and
# limitations under the License.
+from __future__ import absolute_import, division, print_function
+
class AES(object):
name = "AES"
diff --git a/cryptography/primitives/block/modes.py b/cryptography/primitives/block/modes.py
index 02f0219..de31f08 100644
--- a/cryptography/primitives/block/modes.py
+++ b/cryptography/primitives/block/modes.py
@@ -11,6 +11,8 @@
# See the License for the specific language governing permissions and
# limitations under the License.
+from __future__ import absolute_import, division, print_function
+
class CBC(object):
name = "CBC"
diff --git a/tests/primitives/test_block.py b/tests/primitives/test_block.py
index 0407b0f..774409c 100644
--- a/tests/primitives/test_block.py
+++ b/tests/primitives/test_block.py
@@ -11,6 +11,8 @@
# See the License for the specific language governing permissions and
# limitations under the License.
+from __future__ import absolute_import, division, print_function
+
import binascii
import pretend
diff --git a/tests/primitives/test_ciphers.py b/tests/primitives/test_ciphers.py
index 891c5cf..5ee9f22 100644
--- a/tests/primitives/test_ciphers.py
+++ b/tests/primitives/test_ciphers.py
@@ -11,6 +11,8 @@
# See the License for the specific language governing permissions and
# limitations under the License.
+from __future__ import absolute_import, division, print_function
+
import binascii
import pytest
diff --git a/tests/primitives/test_nist.py b/tests/primitives/test_nist.py
index dc26543..db5e034 100644
--- a/tests/primitives/test_nist.py
+++ b/tests/primitives/test_nist.py
@@ -14,6 +14,9 @@
"""
Test using the NIST Test Vectors
"""
+
+from __future__ import absolute_import, division, print_function
+
import binascii
import os