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diff --git a/tests/files/README b/tests/files/README new file mode 100644 index 0000000..119cac4 --- /dev/null +++ b/tests/files/README @@ -0,0 +1,409 @@ + +.xz and .lzma Test Files +------------------------ + +0. Introduction + + This directory contains bunch of files to test handling of .xz, + .lzma (LZMA_Alone), and .lz (lzip) files in decoder implementations. + Many of the files have been created by hand with a hex editor, thus + there is no better "source code" than the files themselves. All the + test files and this README have been put into the public domain. + + +1. File Types + + Good files (good-*) must decode successfully without requiring + a lot of CPU time or RAM. + + Unsupported files (unsupported-*) are good files, but headers + indicate features not supported by the current file format + specification. + + Bad files (bad-*) must cause the decoder to give an error. Like + with the good files, these files must not require a lot of CPU + time or RAM before they get detected to be broken. + + +2. Descriptions of Individual .xz Files + +2.1. Good Files + + good-0-empty.xz has one Stream with no Blocks. + + good-0pad-empty.xz has one Stream with no Blocks followed by + four-byte Stream Padding. + + good-0cat-empty.xz has two zero-Block Streams concatenated without + Stream Padding. + + good-0catpad-empty.xz has two zero-Block Streams concatenated with + four-byte Stream Padding between the Streams. + + good-1-check-none.xz has one Stream with one Block with two + uncompressed LZMA2 chunks and no integrity check. + + good-1-check-crc32.xz has one Stream with one Block with two + uncompressed LZMA2 chunks and CRC32 check. + + good-1-check-crc64.xz is like good-1-check-crc32.xz but with CRC64. + + good-1-check-sha256.xz is like good-1-check-crc32.xz but with + SHA256. + + good-2-lzma2.xz has one Stream with two Blocks with one uncompressed + LZMA2 chunk in each Block. + + good-1-block_header-1.xz has both Compressed Size and Uncompressed + Size in the Block Header. This has also four extra bytes of Header + Padding. + + good-1-block_header-2.xz has known Compressed Size. + + good-1-block_header-3.xz has known Uncompressed Size. + + good-1-delta-lzma2.tiff.xz is an image file that compresses + better with Delta+LZMA2 than with plain LZMA2. + + good-1-x86-lzma2.xz uses the x86 filter (BCJ) and LZMA2. The + uncompressed file is compress_prepared_bcj_x86 found from the tests + directory. + + good-1-sparc-lzma2.xz uses the SPARC filter and LZMA2. The + uncompressed file is compress_prepared_bcj_sparc found from the tests + directory. + + good-1-arm64-lzma2-1.xz uses the ARM64 filter and LZMA2. The + uncompressed data is constructed so that it tests integer + wrap around and sign extension. + + good-1-arm64-lzma2-2.xz is like good-1-arm64-lzma2-1.xz but with + non-zero start offset. XZ Embedded doesn't support this file. + + good-1-lzma2-1.xz has two LZMA2 chunks, of which the second sets + new properties. + + good-1-lzma2-2.xz has two LZMA2 chunks, of which the second resets + the state without specifying new properties. + + good-1-lzma2-3.xz has two LZMA2 chunks, of which the first is + uncompressed and the second is LZMA. The first chunk resets dictionary + and the second sets new properties. + + good-1-lzma2-4.xz has three LZMA2 chunks: First is LZMA, second is + uncompressed with dictionary reset, and third is LZMA with new + properties but without dictionary reset. + + good-1-lzma2-5.xz has an empty LZMA2 stream with only the end of + payload marker. XZ Utils 5.0.1 and older incorrectly see this file + as corrupt. + + good-1-3delta-lzma2.xz has three Delta filters and LZMA2. + + good-1-empty-bcj-lzma2.xz has an empty Block that uses PowerPC BCJ + and LZMA2. liblzma from XZ Utils 5.0.1 and older may incorrectly + return LZMA_BUF_ERROR in some cases. See commit message + d8db706acb8316f9861abd432cfbe001dd6d0c5c for the details. + + +2.2. Unsupported Files + + unsupported-check.xz uses Check ID 0x02 which isn't supported by + the current version of the file format. It is implementation-defined + how this file handled (it may reject it, or decode it possibly with + a warning). + + unsupported-block_header.xz has a non-null byte in Header Padding, + which may indicate presence of a new unsupported field. + + unsupported-filter_flags-1.xz has unsupported Filter ID 0x7F. + + unsupported-filter_flags-2.xz specifies only Delta filter in the + List of Filter Flags, but Delta isn't allowed as the last filter in + the chain. It could be a little more correct to detect this file as + corrupt instead of unsupported, but saying it is unsupported is + simpler in case of liblzma. + + unsupported-filter_flags-3.xz specifies two LZMA2 filters in the + List of Filter Flags. LZMA2 is allowed only as the last filter in the + chain. It could be a little more correct to detect this file as + corrupt instead of unsupported, but saying it is unsupported is + simpler in case of liblzma. + + +2.3. Bad Files + + bad-0pad-empty.xz has one Stream with no Blocks followed by + five-byte Stream Padding. Stream Padding must be a multiple of four + bytes, thus this file is corrupt. + + bad-0catpad-empty.xz has two zero-Block Streams concatenated with + five-byte Stream Padding between the Streams. + + bad-0cat-alone.xz is good-0-empty.xz concatenated with an empty + LZMA_Alone file. + + bad-0cat-header_magic.xz is good-0cat-empty.xz but with one byte + wrong in the Header Magic Bytes field of the second Stream. liblzma + gives LZMA_DATA_ERROR for this. (LZMA_FORMAT_ERROR is used only if + the first Stream of a file has invalid Header Magic Bytes.) + + bad-0-header_magic.xz is good-0-empty.xz but with one byte wrong + in the Header Magic Bytes field. liblzma gives LZMA_FORMAT_ERROR for + this. + + bad-0-footer_magic.xz is good-0-empty.xz but with one byte wrong + in the Footer Magic Bytes field. liblzma gives LZMA_DATA_ERROR for + this. + + bad-0-empty-truncated.xz is good-0-empty.xz without the last byte + of the file. + + bad-0-nonempty_index.xz has no Blocks but Index claims that there is + one Block. + + bad-0-backward_size.xz has wrong Backward Size in Stream Footer. + + bad-1-stream_flags-1.xz has different Stream Flags in Stream Header + and Stream Footer. + + bad-1-stream_flags-2.xz has wrong CRC32 in Stream Header. + + bad-1-stream_flags-3.xz has wrong CRC32 in Stream Footer. + + bad-1-vli-1.xz has two-byte variable-length integer in the + Uncompressed Size field in Block Header while one-byte would be enough + for that value. It's important that the file gets rejected due to too + big integer encoding instead of due to Uncompressed Size not matching + the value stored in the Block Header. That is, the decoder must not + try to decode the Compressed Data field. + + bad-1-vli-2.xz has ten-byte variable-length integer as Uncompressed + Size in Block Header. It's important that the file gets rejected due + to too big integer encoding instead of due to Uncompressed Size not + matching the value stored in the Block Header. That is, the decoder + must not try to decode the Compressed Data field. + + bad-1-block_header-1.xz has Block Header that ends in the middle of + the Filter Flags field. + + bad-1-block_header-2.xz has Block Header that has Compressed Size and + Uncompressed Size but no List of Filter Flags field. + + bad-1-block_header-3.xz has wrong CRC32 in Block Header. + + bad-1-block_header-4.xz has too big Compressed Size in Block Header + (2^63 - 1 bytes while maximum is a little less, because the whole + Block must stay smaller than 2^63). It's important that the file + gets rejected due to invalid Compressed Size value; the decoder + must not try decoding the Compressed Data field. + + bad-1-block_header-5.xz has zero as Compressed Size in Block Header. + + bad-1-block_header-6.xz has corrupt Block Header which may crash + xz -lvv in XZ Utils 5.0.3 and earlier. It was fixed in the commit + c0297445064951807803457dca1611b3c47e7f0f. + + bad-2-index-1.xz has wrong Unpadded Sizes in Index. + + bad-2-index-2.xz has wrong Uncompressed Sizes in Index. + + bad-2-index-3.xz has non-null byte in Index Padding. + + bad-2-index-4.xz wrong CRC32 in Index. + + bad-2-index-5.xz has zero as Unpadded Size. It is important that the + file gets rejected specifically due to Unpadded Size having an invalid + value. + + bad-3-index-uncomp-overflow.xz has Index whose Uncompressed Size + fields have huge values whose sum exceeds the maximum allowed size + of 2^63 - 1 bytes. In this file the sum is exactly 2^64. + lzma_index_append() in liblzma <= 5.2.6 lacks the integer overflow + check for the uncompressed size and thus doesn't catch the error + when decoding the Index field in this file. This makes "xz -l" + not detect the error and will display 0 as the uncompressed size. + Note that regular decompression isn't affected by this bug because + it uses lzma_index_hash_append() instead. + + bad-2-compressed_data_padding.xz has non-null byte in the padding of + the Compressed Data field of the first Block. + + bad-1-check-crc32.xz has wrong Check (CRC32). + + bad-1-check-crc32-2.xz has Compressed Size and Uncompressed Size in + Block Header but wrong Check (CRC32) in the actual data. This file + differs by one byte from good-1-block_header-1.xz: the last byte of + the Check field is wrong. This file is useful for testing error + detection in the threaded decoder when a worker thread is configured + to pass input one byte at a time to the Block decoder. + + bad-1-check-crc64.xz has wrong Check (CRC64). + + bad-1-check-sha256.xz has wrong Check (SHA-256). + + bad-1-lzma2-1.xz has LZMA2 stream whose first chunk (uncompressed) + doesn't reset the dictionary. + + bad-1-lzma2-2.xz has two LZMA2 chunks, of which the second chunk + indicates dictionary reset, but the LZMA compressed data tries to + repeat data from the previous chunk. + + bad-1-lzma2-3.xz sets new invalid properties (lc=8, lp=0, pb=0) in + the middle of Block. + + bad-1-lzma2-4.xz has two LZMA2 chunks, of which the first is + uncompressed and the second is LZMA. The first chunk resets dictionary + as it should, but the second chunk tries to reset state without + specifying properties for LZMA. + + bad-1-lzma2-5.xz is like bad-1-lzma2-4.xz but doesn't try to reset + anything in the header of the second chunk. + + bad-1-lzma2-6.xz has reserved LZMA2 control byte value (0x03). + + bad-1-lzma2-7.xz has EOPM at LZMA level. + + bad-1-lzma2-8.xz is like good-1-lzma2-4.xz but doesn't set new + properties in the third LZMA2 chunk. + + bad-1-lzma2-9.xz has LZMA2 stream that is truncated at the end of + a LZMA2 chunk (no end marker). The uncompressed size of the partial + LZMA2 stream exceeds the value stored in the Block Header. + + bad-1-lzma2-10.xz has LZMA2 stream that, from point of view of a + LZMA2 decoder, extends past the end of Block (and even the end of + the file). Uncompressed Size in Block Header is bigger than the + invalid LZMA2 stream may produce (even if a decoder reads until + the end of the file). The Check type is None to nullify certain + simple size-based sanity checks in a Block decoder. + + bad-1-lzma2-11.xz has LZMA2 stream that lacks the end of + payload marker. When Compressed Size bytes have been decoded, + Uncompressed Size bytes of output will have been produced but + the LZMA2 decoder doesn't indicate end of stream. + + +3. Descriptions of Individual .lzma Files + +3.1. Good Files + + good-unknown_size-with_eopm.lzma has unknown size in the header + and end of payload marker at the end. + + good-known_size-without_eopm.lzma has a known size in the header + and no end of payload marker at the end. + + good-known_size-with_eopm.lzma has a known size in the header + and end of payload marker at the end. XZ Utils 5.2.5 and older + will give an error at the end of the file after producing the + correct uncompressed output. + + +3.2. Bad Files + + bad-unknown_size-without_eopm.lzma has unknown size in the header + but no end of payload marker at the end. This file might be seen + by a decoder as if it were truncated. + + bad-too_big_size-with_eopm.lzma has too big uncompressed size in + the header and the end of payload marker will be detected before + the specified number of bytes have been decoded. + + bad-too_small_size-without_eopm-1.lzma has too small uncompressed + size in the header. The decoder will look for end of payload marker + but instead find a literal that would produce more output. + + bad-too_small_size-without_eopm-2.lzma is like -1 above but instead + of a literal the problem occurs with a short repeated match. + + bad-too_small_size-without_eopm-3.lzma is like -1 above but instead + of a literal the problem occurs in the middle of a match. + + +4. Descriptions of Individual .lz (lzip) Files + +4.1. Good Files + + good-1-v0.lz contains a single version 0 member. lzip 1.17 and + *older* can decompress this; support for version 0 was removed + in lzip 1.18. + + good-1-v0-trailing-1.lz is like good-1-v0.lz but contains + trailing data that the decompressor must ignore. + + good-1-v1.lz contains a single version 1 member. lzip 1.3 and + newer can decompress this. + + good-1-v1-trailing-1.lz is like good-1-v1.lz but contains + trailing data that the decompressor must ignore. + + good-1-v1-trailing-2.lz is like good-1-v1.lz but contains + trailing data whose first three bytes match the .lz magic bytes. + With lzip >= 1.20 this file results in an error unless one uses + the command line option --loose-trailing. lzip 1.3 to 1.19 decode + this file successfully by default. XZ Utils uses the old behavior + because it allows lzma_code() to stop at the first byte of the + trailing data as long as the first byte isn't 0x4C (L in US-ASCII); + otherwise the first 1-3 bytes that equal to the magic bytes are + consumed and lost in lzma_code(), and this is visible in xz too: + + $ ( xz -dc ; cat ) < good-1-v1-trailing-2.lz + Hello + World! + Trailing garbage + + $ ( xz -dc --single-stream ; cat ) < good-1-v1-trailing-2.lz + Hello + World! + LZITrailing garbage + + good-2-v0-v1.lz contains two members of which the first is + version 0 and the second version 1. lzip versions 1.3 to 1.17 + (inclusive) can decompress this. + + good-2-v1-v0.lz contains two members of which the first is + version 1 and the second version 0. lzip versions 1.3 to 1.17 + (inclusive) can decompress this. + + good-2-v1-v1.lz contains two version 1 members. lzip versions 1.3 + and newer can decompress this. + + +4.2. Unsupported Files + + unsupported-1-v234.lz is like good-1-v1.lz except the version + field has been set to 234 (0xEA) which, as of writing, isn't + defined or supported by any .lz implementation. + + +4.3. Bad Files + + bad-1-v1-magic-1.lz is like good-1-v1.lz but the first magic byte + is wrong. + + bad-1-v1-magic-2.lz is like good-1-v1.lz but the last (fourth) + magic byte is wrong. + + bad-1-v1-dict-1.lz has too low value in the dictionary size field. + + bad-1-v1-dict-2.lz has too high value in the dictionary size field. + + bad-1-v1-crc32.lz has wrong CRC32 value. + + bad-1-v0-uncomp-size.lz is version 0 format with incorrect value + in the uncompressed size field. + + bad-1-v1-uncomp-size.lz is version 1 format with incorrect value + in the uncompressed size field. + + bad-1-v1-member-size.lz has incorrect value in the member size + field. + + bad-1-v1-trailing-magic.lz has the four .lz magic bytes as trailing + data. This should be detected as a truncated file and thus result + in an error. That is, the last four bytes of the file should not be + ignored as trailing garbage. lzip >= 1.18 matches this behavior + while older versions ignore the last four bytes and don't indicate + an error. + |