mbutrovich commented on code in PR #3969: URL: https://github.com/apache/iceberg-python/pull/3969#discussion_r4095008452
########## tests/encryption/test_stream.py: ########## @@ -0,0 +1,232 @@ +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you 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 pyiceberg.encryption.ciphers import AesGcmCipher, SecureKey +from pyiceberg.encryption.stream import ( + BLOCK_OVERHEAD, + CIPHER_BLOCK_SIZE, + GCM_STREAM_HEADER_LENGTH, + GCM_STREAM_MAGIC, + MAX_BLOCKS, + PLAIN_BLOCK_SIZE, + Ags1Layout, + calculate_plaintext_length, + decode_stream_header, + encode_stream_header, + stream_block_aad, +) + +KEY = SecureKey(b"0123456789012345") +AAD_PREFIX = b"0123456789abcdef" + +# The header a Java `AesGcmOutputStream` writes: "AGS1" then 1 MiB as a little-endian int32. +JAVA_HEADER = b"AGS1\x00\x00\x10\x00" + + +def build_stream(plaintext: bytes, aad_prefix: bytes | None = AAD_PREFIX) -> bytes: + """Encrypt `plaintext` into an AGS1 stream, as an output stream implementation would.""" + blocks = [ + AesGcmCipher(KEY).encrypt(plaintext[start : start + PLAIN_BLOCK_SIZE], stream_block_aad(aad_prefix, index)) + for index, start in enumerate(range(0, len(plaintext), PLAIN_BLOCK_SIZE)) + ] + return encode_stream_header() + b"".join(blocks) + + +def test_format_constants() -> None: + assert GCM_STREAM_MAGIC == b"AGS1" + assert PLAIN_BLOCK_SIZE == 1024 * 1024 + assert GCM_STREAM_HEADER_LENGTH == 8 + assert BLOCK_OVERHEAD == 28 + assert CIPHER_BLOCK_SIZE == PLAIN_BLOCK_SIZE + BLOCK_OVERHEAD + assert MAX_BLOCKS == 2**32 - 1 + + +def test_encode_stream_header_matches_java() -> None: + assert encode_stream_header() == JAVA_HEADER + + +def test_decode_stream_header() -> None: + assert decode_stream_header(JAVA_HEADER) == PLAIN_BLOCK_SIZE + assert decode_stream_header(encode_stream_header()) == PLAIN_BLOCK_SIZE + + +def test_decode_stream_header_ignores_trailing_block_bytes() -> None: + assert decode_stream_header(JAVA_HEADER + b"block bytes") == PLAIN_BLOCK_SIZE + + [email protected]("length", [0, 4, 7]) +def test_decode_stream_header_rejects_a_short_header(length: int) -> None: + with pytest.raises(ValueError, match=f"Invalid AGS1 header: expected 8 bytes, got {length}"): + decode_stream_header(bytes(length)) + + +def test_decode_stream_header_rejects_the_wrong_magic() -> None: + with pytest.raises(ValueError, match="magic b'AGS2' does not match b'AGS1'"): + decode_stream_header(b"AGS2\x00\x00\x10\x00") + + +def test_decode_stream_header_rejects_an_unsupported_block_size() -> None: + with pytest.raises(ValueError, match=f"Unsupported AGS1 block size: 512 \\(expected {PLAIN_BLOCK_SIZE}\\)"): + decode_stream_header(GCM_STREAM_MAGIC + (512).to_bytes(4, "little")) + + [email protected]( + "block_index, expected", + [(0, b"\x00\x00\x00\x00"), (1, b"\x01\x00\x00\x00"), (258, b"\x02\x01\x00\x00"), (MAX_BLOCKS, b"\xff\xff\xff\xff")], +) +def test_stream_block_aad_encodes_the_index_little_endian(block_index: int, expected: bytes) -> None: + assert stream_block_aad(None, block_index) == expected + assert stream_block_aad(b"", block_index) == expected + assert stream_block_aad(AAD_PREFIX, block_index) == AAD_PREFIX + expected + + [email protected]( + "encrypted_length, expected", + [ + (GCM_STREAM_HEADER_LENGTH, 0), + (GCM_STREAM_HEADER_LENGTH + BLOCK_OVERHEAD, 0), + (GCM_STREAM_HEADER_LENGTH + BLOCK_OVERHEAD + 100, 100), + (GCM_STREAM_HEADER_LENGTH + CIPHER_BLOCK_SIZE, PLAIN_BLOCK_SIZE), + (GCM_STREAM_HEADER_LENGTH + CIPHER_BLOCK_SIZE + BLOCK_OVERHEAD + 5, PLAIN_BLOCK_SIZE + 5), + (GCM_STREAM_HEADER_LENGTH + 2 * CIPHER_BLOCK_SIZE, 2 * PLAIN_BLOCK_SIZE), + ], +) +def test_calculate_plaintext_length(encrypted_length: int, expected: int) -> None: + assert calculate_plaintext_length(encrypted_length) == expected + + [email protected]("encrypted_length", [0, 1, 7]) +def test_calculate_plaintext_length_rejects_a_stream_shorter_than_the_header(encrypted_length: int) -> None: + with pytest.raises(ValueError, match=f"expected at least 8 bytes, got {encrypted_length}"): + calculate_plaintext_length(encrypted_length) + + [email protected]("last_block_size", [1, 27]) +def test_calculate_plaintext_length_rejects_a_truncated_last_block(last_block_size: int) -> None: + with pytest.raises(ValueError, match=f"last block is {last_block_size} bytes, expected at least 28"): + calculate_plaintext_length(GCM_STREAM_HEADER_LENGTH + CIPHER_BLOCK_SIZE + last_block_size) + + [email protected]( + "encrypted_length, plaintext_length, num_blocks, last_cipher_block_size", + [ + (GCM_STREAM_HEADER_LENGTH, 0, 0, 0), + (GCM_STREAM_HEADER_LENGTH + BLOCK_OVERHEAD, 0, 1, BLOCK_OVERHEAD), + (GCM_STREAM_HEADER_LENGTH + BLOCK_OVERHEAD + 100, 100, 1, BLOCK_OVERHEAD + 100), + (GCM_STREAM_HEADER_LENGTH + CIPHER_BLOCK_SIZE, PLAIN_BLOCK_SIZE, 1, CIPHER_BLOCK_SIZE), + (GCM_STREAM_HEADER_LENGTH + CIPHER_BLOCK_SIZE + BLOCK_OVERHEAD + 5, PLAIN_BLOCK_SIZE + 5, 2, BLOCK_OVERHEAD + 5), + (GCM_STREAM_HEADER_LENGTH + 2 * CIPHER_BLOCK_SIZE, 2 * PLAIN_BLOCK_SIZE, 2, CIPHER_BLOCK_SIZE), + ], +) +def test_layout_from_encrypted_length( + encrypted_length: int, plaintext_length: int, num_blocks: int, last_cipher_block_size: int +) -> None: + layout = Ags1Layout.from_encrypted_length(encrypted_length) + + assert layout == Ags1Layout( + plaintext_length=plaintext_length, num_blocks=num_blocks, last_cipher_block_size=last_cipher_block_size + ) + + +def test_layout_rejects_more_blocks_than_the_index_can_address() -> None: + encrypted_length = GCM_STREAM_HEADER_LENGTH + (MAX_BLOCKS + 1) * CIPHER_BLOCK_SIZE + + with pytest.raises(ValueError, match=f"AGS1 streams hold at most {MAX_BLOCKS} blocks"): + Ags1Layout.from_encrypted_length(encrypted_length) + + +def test_layout_block_sizes_and_offsets() -> None: + layout = Ags1Layout.from_encrypted_length(GCM_STREAM_HEADER_LENGTH + 2 * CIPHER_BLOCK_SIZE + BLOCK_OVERHEAD + 7) + + assert layout.num_blocks == 3 + assert layout.cipher_block_size(0) == layout.cipher_block_size(1) == CIPHER_BLOCK_SIZE + assert layout.plain_block_size(0) == layout.plain_block_size(1) == PLAIN_BLOCK_SIZE + assert layout.cipher_block_size(2) == BLOCK_OVERHEAD + 7 + assert layout.plain_block_size(2) == 7 + assert layout.encrypted_block_offset(0) == GCM_STREAM_HEADER_LENGTH + assert layout.encrypted_block_offset(1) == GCM_STREAM_HEADER_LENGTH + CIPHER_BLOCK_SIZE + assert layout.encrypted_block_offset(2) == GCM_STREAM_HEADER_LENGTH + 2 * CIPHER_BLOCK_SIZE + + [email protected]("block_index", [-1, 1, 2]) +def test_layout_rejects_an_out_of_range_block_index(block_index: int) -> None: + layout = Ags1Layout.from_encrypted_length(GCM_STREAM_HEADER_LENGTH + CIPHER_BLOCK_SIZE) + + with pytest.raises(ValueError, match=f"Block index out of range: {block_index} \\(stream holds 1 blocks\\)"): + layout.cipher_block_size(block_index) + + with pytest.raises(ValueError, match=f"Block index out of range: {block_index}"): + layout.encrypted_block_offset(block_index) + + [email protected]( + "plaintext_offset, expected", + [(0, 0), (1, 0), (PLAIN_BLOCK_SIZE - 1, 0), (PLAIN_BLOCK_SIZE, 1), (PLAIN_BLOCK_SIZE + 6, 1)], +) +def test_layout_block_index_for_plaintext_offset(plaintext_offset: int, expected: int) -> None: + layout = Ags1Layout.from_encrypted_length(GCM_STREAM_HEADER_LENGTH + CIPHER_BLOCK_SIZE + BLOCK_OVERHEAD + 7) + + assert layout.block_index_for(plaintext_offset) == expected + + [email protected]("plaintext_offset", [-1, PLAIN_BLOCK_SIZE]) +def test_layout_rejects_an_out_of_range_plaintext_offset(plaintext_offset: int) -> None: + layout = Ags1Layout.from_encrypted_length(GCM_STREAM_HEADER_LENGTH + CIPHER_BLOCK_SIZE) + + with pytest.raises(ValueError, match=f"Plaintext offset out of range: {plaintext_offset}"): + layout.block_index_for(plaintext_offset) + + [email protected]("plaintext_length", [1, 100, PLAIN_BLOCK_SIZE, PLAIN_BLOCK_SIZE + 7, 2 * PLAIN_BLOCK_SIZE]) Review Comment: With the reader requiring one block, `build_stream(b"")` at the head commit still returns the 8 byte header, and `_Ags1Layout.from_encrypted_length(8)` raises `Invalid AGS1 stream: expected at least 36 bytes, got 8`. Could `build_stream` iterate over `range(0, len(plaintext), _PLAIN_BLOCK_SIZE) or [0]`, and `0` go into the `test_layout_describes_a_real_stream` cases? The `num_blocks` assertion there would become `max(1, -(-plaintext_length // _PLAIN_BLOCK_SIZE))`. I tried that locally and the empty case produces a 36 byte stream with one block. It pins the form the output stream PR has to write. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
