| # Copyright 2020 Google LLC |
| # |
| # 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. |
| """Tests for tink.python.tink.streaming_aead_key_manager.""" |
| |
| import io |
| |
| from absl.testing import absltest |
| from absl.testing import parameterized |
| from tink.proto import aes_ctr_hmac_streaming_pb2 |
| from tink.proto import aes_gcm_hkdf_streaming_pb2 |
| from tink.proto import common_pb2 |
| from tink.proto import tink_pb2 |
| from tink import core |
| from tink import streaming_aead |
| from tink.streaming_aead import _raw_streaming_aead |
| from tink.testing import bytes_io |
| |
| # Using malformed UTF-8 sequences to ensure there is no accidental decoding. |
| B_X80 = b'\x80' |
| |
| |
| def setUpModule(): |
| streaming_aead.register() |
| |
| |
| def new_raw_primitive(): |
| key_data = core.Registry.new_key_data( |
| streaming_aead.streaming_aead_key_templates |
| .AES128_CTR_HMAC_SHA256_4KB) |
| return core.Registry.primitive(key_data, |
| _raw_streaming_aead.RawStreamingAead) |
| |
| |
| class StreamingAeadKeyManagerTest(parameterized.TestCase): |
| |
| def test_new_aes_gcm_hkdf_key_data(self): |
| key_template = ( |
| streaming_aead.streaming_aead_key_templates.AES128_GCM_HKDF_4KB) |
| key_data = core.Registry.new_key_data(key_template) |
| self.assertEqual(key_data.type_url, key_template.type_url) |
| self.assertEqual(key_data.key_material_type, tink_pb2.KeyData.SYMMETRIC) |
| key = aes_gcm_hkdf_streaming_pb2.AesGcmHkdfStreamingKey.FromString( |
| key_data.value) |
| self.assertEqual(key.version, 0) |
| self.assertLen(key.key_value, 16) |
| self.assertEqual(key.params.hkdf_hash_type, common_pb2.HashType.SHA256) |
| self.assertEqual(key.params.derived_key_size, 16) |
| self.assertEqual(key.params.ciphertext_segment_size, 4096) |
| |
| def test_new_aes_ctr_hmac_key_data(self): |
| key_template = ( |
| streaming_aead.streaming_aead_key_templates.AES128_CTR_HMAC_SHA256_4KB) |
| key_data = core.Registry.new_key_data(key_template) |
| self.assertEqual(key_data.type_url, key_template.type_url) |
| self.assertEqual(key_data.key_material_type, tink_pb2.KeyData.SYMMETRIC) |
| key = aes_ctr_hmac_streaming_pb2.AesCtrHmacStreamingKey.FromString( |
| key_data.value) |
| self.assertEqual(key.version, 0) |
| self.assertLen(key.key_value, 16) |
| self.assertEqual(key.params.hkdf_hash_type, common_pb2.HashType.SHA256) |
| self.assertEqual(key.params.derived_key_size, 16) |
| self.assertEqual(key.params.hmac_params.hash, common_pb2.HashType.SHA256) |
| self.assertEqual(key.params.hmac_params.tag_size, 32) |
| self.assertEqual(key.params.ciphertext_segment_size, 4096) |
| |
| def test_invalid_aes_gcm_hkdf_params_throw_exception(self): |
| tmpls = streaming_aead.streaming_aead_key_templates |
| key_template = tmpls.create_aes_gcm_hkdf_streaming_key_template( |
| 63, common_pb2.HashType.SHA1, 65, 55) |
| with self.assertRaisesRegex(core.TinkError, |
| 'key_size must not be smaller than'): |
| core.Registry.new_key_data(key_template) |
| |
| def test_invalid_aes_ctr_hmac_params_throw_exception(self): |
| tmpls = streaming_aead.streaming_aead_key_templates |
| key_template = tmpls.create_aes_ctr_hmac_streaming_key_template( |
| 63, common_pb2.HashType.SHA1, 65, common_pb2.HashType.SHA256, 55, 2) |
| with self.assertRaisesRegex(core.TinkError, |
| 'key_size must not be smaller than'): |
| core.Registry.new_key_data(key_template) |
| |
| def test_raw_encrypt_decrypt_readall(self): |
| raw_primitive = new_raw_primitive() |
| plaintext = b'plaintext' + B_X80 |
| aad = b'associated_data' + B_X80 |
| |
| # Encrypt |
| ct_destination = bytes_io.BytesIOWithValueAfterClose() |
| with raw_primitive.new_raw_encrypting_stream(ct_destination, aad) as es: |
| self.assertLen(plaintext, es.write(plaintext)) |
| # context manager closes es, which also closes ciphertext_dest |
| self.assertTrue(ct_destination.closed) |
| |
| # Decrypt, with and without close_ciphertext_source |
| for close_ciphertext_source in [True, False]: |
| ct_source = io.BytesIO(ct_destination.value_after_close()) |
| with raw_primitive.new_raw_decrypting_stream( |
| ct_source, aad, |
| close_ciphertext_source=close_ciphertext_source) as ds: |
| output = ds.readall() |
| self.assertEqual(ct_source.closed, close_ciphertext_source) |
| self.assertEqual(output, plaintext) |
| |
| def test_raw_encrypt_decrypt_read(self): |
| raw_primitive = new_raw_primitive() |
| plaintext = b'plaintext' |
| aad = b'aad' |
| |
| ct_destination = bytes_io.BytesIOWithValueAfterClose() |
| with raw_primitive.new_raw_encrypting_stream(ct_destination, aad) as es: |
| es.write(plaintext) |
| |
| ct_source = io.BytesIO(ct_destination.value_after_close()) |
| with raw_primitive.new_raw_decrypting_stream( |
| ct_source, aad, close_ciphertext_source=True) as ds: |
| self.assertEqual(ds.read(5), b'plain') |
| self.assertEqual(ds.read(5), b'text') |
| |
| def test_raw_encrypt_decrypt_readinto(self): |
| raw_primitive = new_raw_primitive() |
| plaintext = b'plaintext' |
| aad = b'aad' |
| |
| ct_destination = bytes_io.BytesIOWithValueAfterClose() |
| with raw_primitive.new_raw_encrypting_stream(ct_destination, aad) as es: |
| es.write(plaintext) |
| |
| ct_source = io.BytesIO(ct_destination.value_after_close()) |
| with raw_primitive.new_raw_decrypting_stream( |
| ct_source, aad, close_ciphertext_source=True) as ds: |
| data = bytearray(b'xxxxx') |
| n = ds.readinto(data) # writes 5 bytes into data. |
| self.assertEqual(n, 5) |
| self.assertEqual(data, b'plain') |
| n = ds.readinto(data) # writes remaining 4 bytes, leave the rest |
| self.assertEqual(n, 4) |
| self.assertEqual(data, b'textn') |
| |
| def test_raw_encrypt_decrypt_empty(self): |
| raw_primitive = new_raw_primitive() |
| plaintext = b'' |
| aad = b'' |
| ct_destination = bytes_io.BytesIOWithValueAfterClose() |
| with raw_primitive.new_raw_encrypting_stream(ct_destination, aad) as es: |
| es.write(plaintext) |
| |
| ct_source = io.BytesIO(ct_destination.value_after_close()) |
| with raw_primitive.new_raw_decrypting_stream( |
| ct_source, aad, close_ciphertext_source=True) as ds: |
| self.assertEqual(ds.read(5), b'') |
| |
| def test_raw_read_after_eof_returns_empty_bytes(self): |
| raw_primitive = new_raw_primitive() |
| plaintext = b'plaintext' + B_X80 |
| aad = b'associated_data' + B_X80 |
| |
| ct_destination = bytes_io.BytesIOWithValueAfterClose() |
| with raw_primitive.new_raw_encrypting_stream(ct_destination, aad) as es: |
| self.assertLen(plaintext, es.write(plaintext)) |
| |
| ct_source = io.BytesIO(ct_destination.value_after_close()) |
| with raw_primitive.new_raw_decrypting_stream( |
| ct_source, aad, close_ciphertext_source=True) as ds: |
| _ = ds.readall() |
| self.assertEqual(ds.read(100), b'') |
| |
| def test_raw_encrypt_decrypt_close(self): |
| raw_primitive = new_raw_primitive() |
| plaintext = b'plaintext' + B_X80 |
| aad = b'associated_data' + B_X80 |
| |
| # Encrypt |
| ct_destination = bytes_io.BytesIOWithValueAfterClose() |
| es = raw_primitive.new_raw_encrypting_stream(ct_destination, aad) |
| es.write(plaintext) |
| self.assertFalse(ct_destination.closed) |
| self.assertFalse(es.closed) |
| es.close() |
| self.assertTrue(ct_destination.closed) |
| self.assertTrue(es.closed) |
| |
| # Decrypt, with and without close_ciphertext_source |
| for close_ciphertext_source in [True, False]: |
| ct_source = io.BytesIO(ct_destination.value_after_close()) |
| ds = raw_primitive.new_raw_decrypting_stream( |
| ct_source, aad, |
| close_ciphertext_source=close_ciphertext_source) |
| self.assertFalse(ct_source.closed) |
| self.assertFalse(ds.closed) |
| ds.close() |
| self.assertEqual(ct_source.closed, close_ciphertext_source) |
| self.assertTrue(ds.closed) |
| |
| def test_raw_encrypt_decrypt_wrong_aad(self): |
| raw_primitive = new_raw_primitive() |
| plaintext = b'plaintext' + B_X80 |
| aad = b'associated_data' + B_X80 |
| |
| # Encrypt |
| ct_destination = bytes_io.BytesIOWithValueAfterClose() |
| with raw_primitive.new_raw_encrypting_stream(ct_destination, aad) as es: |
| self.assertLen(plaintext, es.write(plaintext)) |
| self.assertNotEqual(ct_destination.value_after_close(), plaintext) |
| |
| # Decrypt |
| ct_source = io.BytesIO(ct_destination.value_after_close()) |
| with raw_primitive.new_raw_decrypting_stream( |
| ct_source, b'bad' + aad, close_ciphertext_source=True) as ds: |
| with self.assertRaises(core.TinkError): |
| ds.read() |
| |
| if __name__ == '__main__': |
| absltest.main() |