From 60c3e8a4d369ce854986bee38d473fb4d9215d95 Mon Sep 17 00:00:00 2001 From: Tulir Asokan Date: Sat, 13 Oct 2018 15:58:23 +0300 Subject: [PATCH] Update zipimport backport --- tmp/fzipimport.py | 38 +++++++++++++++++++++++++++++++------- 1 file changed, 31 insertions(+), 7 deletions(-) diff --git a/tmp/fzipimport.py b/tmp/fzipimport.py index 7315a47..f829309 100644 --- a/tmp/fzipimport.py +++ b/tmp/fzipimport.py @@ -12,8 +12,6 @@ used by the builtin import mechanism for sys.path items that are paths to Zip archives. """ -#from importlib import _bootstrap_external -#from importlib import _bootstrap # for _verbose_message from importlib import _bootstrap_external from importlib import _bootstrap # for _verbose_message import _imp # for check_hash_based_pycs @@ -48,6 +46,9 @@ _zip_directory_cache = {} _module_type = type(sys) +END_CENTRAL_DIR_SIZE = 22 +STRING_END_ARCHIVE = b'PK\x05\x06' +MAX_COMMENT_LEN = (1 << 16) - 1 class zipimporter: """zipimporter(archivepath) -> zipimporter object @@ -367,16 +368,39 @@ def _read_directory(archive): with fp: try: - fp.seek(-22, 2) + fp.seek(-END_CENTRAL_DIR_SIZE, 2) header_position = fp.tell() - buffer = fp.read(22) + buffer = fp.read(END_CENTRAL_DIR_SIZE) except OSError: raise ZipImportError(f"can't read Zip file: {archive!r}", path=archive) - if len(buffer) != 22: + if len(buffer) != END_CENTRAL_DIR_SIZE: raise ZipImportError(f"can't read Zip file: {archive!r}", path=archive) - if buffer[:4] != b'PK\x05\x06': + if buffer[:4] != STRING_END_ARCHIVE: # Bad: End of Central Dir signature - raise ZipImportError(f'not a Zip file: {archive!r}', path=archive) + # Check if there's a comment. + try: + fp.seek(0, 2) + file_size = fp.tell() + except OSError: + raise ZipImportError(f"can't read Zip file: {archive!r}", + path=archive) + max_comment_start = max(file_size - MAX_COMMENT_LEN - + END_CENTRAL_DIR_SIZE, 0) + try: + fp.seek(max_comment_start) + data = fp.read() + except OSError: + raise ZipImportError(f"can't read Zip file: {archive!r}", + path=archive) + pos = data.rfind(STRING_END_ARCHIVE) + if pos < 0: + raise ZipImportError(f'not a Zip file: {archive!r}', + path=archive) + buffer = data[pos:pos+END_CENTRAL_DIR_SIZE] + if len(buffer) != END_CENTRAL_DIR_SIZE: + raise ZipImportError(f"corrupt Zip file: {archive!r}", + path=archive) + header_position = file_size - len(data) + pos header_size = _unpack_uint32(buffer[12:16]) header_offset = _unpack_uint32(buffer[16:20])