Initial implementation with tests, docs to follow

1 files changed, 85 insertions, 0 deletions

diff --git a/tests/hazmat/primitives/test_padding.py b/tests/hazmat/primitives/test_padding.py
new file mode 100644
index 00000000..a41edac1
--- /dev/null
+++ b/tests/hazmat/primitives/test_padding.py
@@ -0,0 +1,85 @@
+# 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.
+
+import pytest
+
+from cryptography.hazmat.primitives import padding
+
+
+class TestPKCS7(object):
+    @pytest.mark.parametrize("size", [127, 4096, -2])
+    def test_invalid_block_size(self, size):
+        with pytest.raises(ValueError):
+            padding.PKCS7(size)
+
+    @pytest.mark.parametrize(("size", "padded"), [
+        (128, b"1111"),
+        (128, b"1111111111111111"),
+        (128, b"111111111111111\x06"),
+        (128, b""),
+    ])
+    def test_invalid_padding(self, size, padded):
+        padder = padding.PKCS7(size)
+
+        with pytest.raises(ValueError):
+            padder.unpad(padded)
+
+    @pytest.mark.parametrize(("size", "unpadded", "padded"), [
+        (
+            128,
+            b"1111111111",
+            b"1111111111\x06\x06\x06\x06\x06\x06",
+        ),
+        (
+            128,
+            b"111111111111111122222222222222",
+            b"111111111111111122222222222222\x02\x02",
+        ),
+    ])
+    def test_pad(self, size, unpadded, padded):
+        padder = padding.PKCS7(size)
+        assert padder.pad(unpadded) == padded
+
+    @pytest.mark.parametrize(("size", "unpadded", "padded"), [
+        (
+            128,
+            b"1111111111",
+            b"1111111111\x06\x06\x06\x06\x06\x06",
+        ),
+        (
+            128,
+            b"111111111111111122222222222222",
+            b"111111111111111122222222222222\x02\x02",
+        ),
+    ])
+    def test_unpad(self, size, unpadded, padded):
+        padder = padding.PKCS7(size)
+        assert padder.unpad(padded) == unpadded
+
+    def test_use_after_finalize(self):
+        p = padding.PKCS7(128)
+
+        padder = p.padder()
+        b = padder.finalize()
+        with pytest.raises(ValueError):
+            padder.update(b"")
+        with pytest.raises(ValueError):
+            padder.finalize()
+
+        unpadder = p.unpadder()
+        unpadder.update(b)
+        unpadder.finalize()
+        with pytest.raises(ValueError):
+            unpadder.update(b"")
+        with pytest.raises(ValueError):
+            unpadder.finalize()