You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
347 lines
14 KiB
347 lines
14 KiB
From 066df4fd454d6ff9be66e80b2a65995b10af174f Mon Sep 17 00:00:00 2001
|
|
From: John Jolly <john.jolly@gmail.com>
|
|
Date: Tue, 30 Jan 2018 01:51:35 -0700
|
|
Subject: [PATCH] bpo-22908: Add seek and tell functionality to ZipExtFile
|
|
(GH-4966)
|
|
|
|
This allows for nested zip files, tar files within zip files, zip files within tar files, etc.
|
|
|
|
Contributed by: John Jolly
|
|
---
|
|
Doc/library/zipfile.rst | 6 +-
|
|
Lib/test/test_zipfile.py | 34 ++++++++
|
|
Lib/zipfile.py | 82 +++++++++++++++++++
|
|
.../2017-12-21-22-00-11.bpo-22908.cVm89I.rst | 2 +
|
|
4 files changed, 121 insertions(+), 3 deletions(-)
|
|
create mode 100644 Misc/NEWS.d/next/Library/2017-12-21-22-00-11.bpo-22908.cVm89I.rst
|
|
|
|
diff --git a/Doc/library/zipfile.rst b/Doc/library/zipfile.rst
|
|
index d58efe0b417516..7c9a8c80225491 100644
|
|
--- a/Doc/library/zipfile.rst
|
|
+++ b/Doc/library/zipfile.rst
|
|
@@ -246,9 +246,9 @@ ZipFile Objects
|
|
With *mode* ``'r'`` the file-like object
|
|
(``ZipExtFile``) is read-only and provides the following methods:
|
|
:meth:`~io.BufferedIOBase.read`, :meth:`~io.IOBase.readline`,
|
|
- :meth:`~io.IOBase.readlines`, :meth:`__iter__`,
|
|
- :meth:`~iterator.__next__`. These objects can operate independently of
|
|
- the ZipFile.
|
|
+ :meth:`~io.IOBase.readlines`, :meth:`~io.IOBase.seek`,
|
|
+ :meth:`~io.IOBase.tell`, :meth:`__iter__`, :meth:`~iterator.__next__`.
|
|
+ These objects can operate independently of the ZipFile.
|
|
|
|
With ``mode='w'``, a writable file handle is returned, which supports the
|
|
:meth:`~io.BufferedIOBase.write` method. While a writable file handle is open,
|
|
diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
|
|
index 94db858a1517c4..61c3e349a69ef4 100644
|
|
--- a/Lib/test/test_zipfile.py
|
|
+++ b/Lib/test/test_zipfile.py
|
|
@@ -1628,6 +1628,40 @@ def test_open_conflicting_handles(self):
|
|
self.assertEqual(zipf.read('baz'), msg3)
|
|
self.assertEqual(zipf.namelist(), ['foo', 'bar', 'baz'])
|
|
|
|
+ def test_seek_tell(self):
|
|
+ # Test seek functionality
|
|
+ txt = b"Where's Bruce?"
|
|
+ bloc = txt.find(b"Bruce")
|
|
+ # Check seek on a file
|
|
+ with zipfile.ZipFile(TESTFN, "w") as zipf:
|
|
+ zipf.writestr("foo.txt", txt)
|
|
+ with zipfile.ZipFile(TESTFN, "r") as zipf:
|
|
+ with zipf.open("foo.txt", "r") as fp:
|
|
+ fp.seek(bloc, os.SEEK_SET)
|
|
+ self.assertEqual(fp.tell(), bloc)
|
|
+ fp.seek(-bloc, os.SEEK_CUR)
|
|
+ self.assertEqual(fp.tell(), 0)
|
|
+ fp.seek(bloc, os.SEEK_CUR)
|
|
+ self.assertEqual(fp.tell(), bloc)
|
|
+ self.assertEqual(fp.read(5), txt[bloc:bloc+5])
|
|
+ fp.seek(0, os.SEEK_END)
|
|
+ self.assertEqual(fp.tell(), len(txt))
|
|
+ # Check seek on memory file
|
|
+ data = io.BytesIO()
|
|
+ with zipfile.ZipFile(data, mode="w") as zipf:
|
|
+ zipf.writestr("foo.txt", txt)
|
|
+ with zipfile.ZipFile(data, mode="r") as zipf:
|
|
+ with zipf.open("foo.txt", "r") as fp:
|
|
+ fp.seek(bloc, os.SEEK_SET)
|
|
+ self.assertEqual(fp.tell(), bloc)
|
|
+ fp.seek(-bloc, os.SEEK_CUR)
|
|
+ self.assertEqual(fp.tell(), 0)
|
|
+ fp.seek(bloc, os.SEEK_CUR)
|
|
+ self.assertEqual(fp.tell(), bloc)
|
|
+ self.assertEqual(fp.read(5), txt[bloc:bloc+5])
|
|
+ fp.seek(0, os.SEEK_END)
|
|
+ self.assertEqual(fp.tell(), len(txt))
|
|
+
|
|
def tearDown(self):
|
|
unlink(TESTFN)
|
|
unlink(TESTFN2)
|
|
diff --git a/Lib/zipfile.py b/Lib/zipfile.py
|
|
index f9db45f58a2bde..5df7b1bf75b9d9 100644
|
|
--- a/Lib/zipfile.py
|
|
+++ b/Lib/zipfile.py
|
|
@@ -696,6 +696,18 @@ def __init__(self, file, pos, close, lock, writing):
|
|
self._close = close
|
|
self._lock = lock
|
|
self._writing = writing
|
|
+ self.seekable = file.seekable
|
|
+ self.tell = file.tell
|
|
+
|
|
+ def seek(self, offset, whence=0):
|
|
+ with self._lock:
|
|
+ if self.writing():
|
|
+ raise ValueError("Can't reposition in the ZIP file while "
|
|
+ "there is an open writing handle on it. "
|
|
+ "Close the writing handle before trying to read.")
|
|
+ self._file.seek(self._pos)
|
|
+ self._pos = self._file.tell()
|
|
+ return self._pos
|
|
|
|
def read(self, n=-1):
|
|
with self._lock:
|
|
@@ -746,6 +758,9 @@ class ZipExtFile(io.BufferedIOBase):
|
|
# Read from compressed files in 4k blocks.
|
|
MIN_READ_SIZE = 4096
|
|
|
|
+ # Chunk size to read during seek
|
|
+ MAX_SEEK_READ = 1 << 24
|
|
+
|
|
def __init__(self, fileobj, mode, zipinfo, decrypter=None,
|
|
close_fileobj=False):
|
|
self._fileobj = fileobj
|
|
@@ -778,6 +793,17 @@ def __init__(self, fileobj, mode, zipinfo, decrypter=None,
|
|
else:
|
|
self._expected_crc = None
|
|
|
|
+ self._seekable = False
|
|
+ try:
|
|
+ if fileobj.seekable():
|
|
+ self._orig_compress_start = fileobj.tell()
|
|
+ self._orig_compress_size = zipinfo.compress_size
|
|
+ self._orig_file_size = zipinfo.file_size
|
|
+ self._orig_start_crc = self._running_crc
|
|
+ self._seekable = True
|
|
+ except AttributeError:
|
|
+ pass
|
|
+
|
|
def __repr__(self):
|
|
result = ['<%s.%s' % (self.__class__.__module__,
|
|
self.__class__.__qualname__)]
|
|
@@ -963,6 +989,62 @@ def close(self):
|
|
finally:
|
|
super().close()
|
|
|
|
+ def seekable(self):
|
|
+ return self._seekable
|
|
+
|
|
+ def seek(self, offset, whence=0):
|
|
+ if not self._seekable:
|
|
+ raise io.UnsupportedOperation("underlying stream is not seekable")
|
|
+ curr_pos = self.tell()
|
|
+ if whence == 0: # Seek from start of file
|
|
+ new_pos = offset
|
|
+ elif whence == 1: # Seek from current position
|
|
+ new_pos = curr_pos + offset
|
|
+ elif whence == 2: # Seek from EOF
|
|
+ new_pos = self._orig_file_size + offset
|
|
+ else:
|
|
+ raise ValueError("whence must be os.SEEK_SET (0), "
|
|
+ "os.SEEK_CUR (1), or os.SEEK_END (2)")
|
|
+
|
|
+ if new_pos > self._orig_file_size:
|
|
+ new_pos = self._orig_file_size
|
|
+
|
|
+ if new_pos < 0:
|
|
+ new_pos = 0
|
|
+
|
|
+ read_offset = new_pos - curr_pos
|
|
+ buff_offset = read_offset + self._offset
|
|
+
|
|
+ if buff_offset >= 0 and buff_offset < len(self._readbuffer):
|
|
+ # Just move the _offset index if the new position is in the _readbuffer
|
|
+ self._offset = buff_offset
|
|
+ read_offset = 0
|
|
+ elif read_offset < 0:
|
|
+ # Position is before the current position. Reset the ZipExtFile
|
|
+
|
|
+ self._fileobj.seek(self._orig_compress_start)
|
|
+ self._running_crc = self._orig_start_crc
|
|
+ self._compress_left = self._orig_compress_size
|
|
+ self._left = self._orig_file_size
|
|
+ self._readbuffer = b''
|
|
+ self._offset = 0
|
|
+ self._decompressor = zipfile._get_decompressor(self._compress_type)
|
|
+ self._eof = False
|
|
+ read_offset = new_pos
|
|
+
|
|
+ while read_offset > 0:
|
|
+ read_len = min(self.MAX_SEEK_READ, read_offset)
|
|
+ self.read(read_len)
|
|
+ read_offset -= read_len
|
|
+
|
|
+ return self.tell()
|
|
+
|
|
+ def tell(self):
|
|
+ if not self._seekable:
|
|
+ raise io.UnsupportedOperation("underlying stream is not seekable")
|
|
+ filepos = self._orig_file_size - self._left - len(self._readbuffer) + self._offset
|
|
+ return filepos
|
|
+
|
|
|
|
class _ZipWriteFile(io.BufferedIOBase):
|
|
def __init__(self, zf, zinfo, zip64):
|
|
diff --git a/Misc/NEWS.d/next/Library/2017-12-21-22-00-11.bpo-22908.cVm89I.rst b/Misc/NEWS.d/next/Library/2017-12-21-22-00-11.bpo-22908.cVm89I.rst
|
|
new file mode 100644
|
|
index 00000000000000..4f3cc0166019f1
|
|
--- /dev/null
|
|
+++ b/Misc/NEWS.d/next/Library/2017-12-21-22-00-11.bpo-22908.cVm89I.rst
|
|
@@ -0,0 +1,2 @@
|
|
+Added seek and tell to the ZipExtFile class. This only works if the file
|
|
+object used to open the zipfile is seekable.
|
|
|
|
|
|
From 55beb125db2942b5362454e05542e9661e964a65 Mon Sep 17 00:00:00 2001
|
|
From: Serhiy Storchaka <storchaka@gmail.com>
|
|
Date: Tue, 23 Apr 2024 14:29:31 +0200
|
|
Subject: [PATCH] gh-109858: Protect zipfile from "quoted-overlap" zipbomb
|
|
(GH-110016) (GH-113916)
|
|
|
|
Raise BadZipFile when try to read an entry that overlaps with other entry or
|
|
central directory.
|
|
(cherry picked from commit 66363b9a7b9fe7c99eba3a185b74c5fdbf842eba)
|
|
---
|
|
Lib/test/test_zipfile.py | 60 +++++++++++++++++++
|
|
Lib/zipfile.py | 12 ++++
|
|
...-09-28-13-15-51.gh-issue-109858.43e2dg.rst | 3 +
|
|
3 files changed, 75 insertions(+)
|
|
create mode 100644 Misc/NEWS.d/next/Library/2023-09-28-13-15-51.gh-issue-109858.43e2dg.rst
|
|
|
|
diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
|
|
index 7f82586..0379909 100644
|
|
--- a/Lib/test/test_zipfile.py
|
|
+++ b/Lib/test/test_zipfile.py
|
|
@@ -1644,6 +1644,66 @@ class OtherTests(unittest.TestCase):
|
|
fp.seek(0, os.SEEK_END)
|
|
self.assertEqual(fp.tell(), len(txt))
|
|
|
|
+ @requires_zlib
|
|
+ def test_full_overlap(self):
|
|
+ data = (
|
|
+ b'PK\x03\x04\x14\x00\x00\x00\x08\x00\xa0lH\x05\xe2\x1e'
|
|
+ b'8\xbb\x10\x00\x00\x00\t\x04\x00\x00\x01\x00\x00\x00a\xed'
|
|
+ b'\xc0\x81\x08\x00\x00\x00\xc00\xd6\xfbK\\d\x0b`P'
|
|
+ b'K\x01\x02\x14\x00\x14\x00\x00\x00\x08\x00\xa0lH\x05\xe2'
|
|
+ b'\x1e8\xbb\x10\x00\x00\x00\t\x04\x00\x00\x01\x00\x00\x00\x00'
|
|
+ b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00aPK'
|
|
+ b'\x01\x02\x14\x00\x14\x00\x00\x00\x08\x00\xa0lH\x05\xe2\x1e'
|
|
+ b'8\xbb\x10\x00\x00\x00\t\x04\x00\x00\x01\x00\x00\x00\x00\x00'
|
|
+ b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00bPK\x05'
|
|
+ b'\x06\x00\x00\x00\x00\x02\x00\x02\x00^\x00\x00\x00/\x00\x00'
|
|
+ b'\x00\x00\x00'
|
|
+ )
|
|
+ with zipfile.ZipFile(io.BytesIO(data), 'r') as zipf:
|
|
+ self.assertEqual(zipf.namelist(), ['a', 'b'])
|
|
+ zi = zipf.getinfo('a')
|
|
+ self.assertEqual(zi.header_offset, 0)
|
|
+ self.assertEqual(zi.compress_size, 16)
|
|
+ self.assertEqual(zi.file_size, 1033)
|
|
+ zi = zipf.getinfo('b')
|
|
+ self.assertEqual(zi.header_offset, 0)
|
|
+ self.assertEqual(zi.compress_size, 16)
|
|
+ self.assertEqual(zi.file_size, 1033)
|
|
+ self.assertEqual(len(zipf.read('a')), 1033)
|
|
+ with self.assertRaisesRegex(zipfile.BadZipFile, 'File name.*differ'):
|
|
+ zipf.read('b')
|
|
+
|
|
+ @requires_zlib
|
|
+ def test_quoted_overlap(self):
|
|
+ data = (
|
|
+ b'PK\x03\x04\x14\x00\x00\x00\x08\x00\xa0lH\x05Y\xfc'
|
|
+ b'8\x044\x00\x00\x00(\x04\x00\x00\x01\x00\x00\x00a\x00'
|
|
+ b'\x1f\x00\xe0\xffPK\x03\x04\x14\x00\x00\x00\x08\x00\xa0l'
|
|
+ b'H\x05\xe2\x1e8\xbb\x10\x00\x00\x00\t\x04\x00\x00\x01\x00'
|
|
+ b'\x00\x00b\xed\xc0\x81\x08\x00\x00\x00\xc00\xd6\xfbK\\'
|
|
+ b'd\x0b`PK\x01\x02\x14\x00\x14\x00\x00\x00\x08\x00\xa0'
|
|
+ b'lH\x05Y\xfc8\x044\x00\x00\x00(\x04\x00\x00\x01'
|
|
+ b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
|
|
+ b'\x00aPK\x01\x02\x14\x00\x14\x00\x00\x00\x08\x00\xa0l'
|
|
+ b'H\x05\xe2\x1e8\xbb\x10\x00\x00\x00\t\x04\x00\x00\x01\x00'
|
|
+ b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00$\x00\x00\x00'
|
|
+ b'bPK\x05\x06\x00\x00\x00\x00\x02\x00\x02\x00^\x00\x00'
|
|
+ b'\x00S\x00\x00\x00\x00\x00'
|
|
+ )
|
|
+ with zipfile.ZipFile(io.BytesIO(data), 'r') as zipf:
|
|
+ self.assertEqual(zipf.namelist(), ['a', 'b'])
|
|
+ zi = zipf.getinfo('a')
|
|
+ self.assertEqual(zi.header_offset, 0)
|
|
+ self.assertEqual(zi.compress_size, 52)
|
|
+ self.assertEqual(zi.file_size, 1064)
|
|
+ zi = zipf.getinfo('b')
|
|
+ self.assertEqual(zi.header_offset, 36)
|
|
+ self.assertEqual(zi.compress_size, 16)
|
|
+ self.assertEqual(zi.file_size, 1033)
|
|
+ with self.assertRaisesRegex(zipfile.BadZipFile, 'Overlapped entries'):
|
|
+ zipf.read('a')
|
|
+ self.assertEqual(len(zipf.read('b')), 1033)
|
|
+
|
|
def tearDown(self):
|
|
unlink(TESTFN)
|
|
unlink(TESTFN2)
|
|
diff --git a/Lib/zipfile.py b/Lib/zipfile.py
|
|
index 0ab9fac..e6d7676 100644
|
|
--- a/Lib/zipfile.py
|
|
+++ b/Lib/zipfile.py
|
|
@@ -338,6 +338,7 @@ class ZipInfo (object):
|
|
'compress_size',
|
|
'file_size',
|
|
'_raw_time',
|
|
+ '_end_offset',
|
|
)
|
|
|
|
def __init__(self, filename="NoName", date_time=(1980,1,1,0,0,0)):
|
|
@@ -376,6 +377,7 @@ class ZipInfo (object):
|
|
self.volume = 0 # Volume number of file header
|
|
self.internal_attr = 0 # Internal attributes
|
|
self.external_attr = 0 # External file attributes
|
|
+ self._end_offset = None # Start of the next local header or central directory
|
|
# Other attributes are set by class ZipFile:
|
|
# header_offset Byte offset to the file header
|
|
# CRC CRC-32 of the uncompressed file
|
|
@@ -1346,6 +1348,12 @@ class ZipFile:
|
|
if self.debug > 2:
|
|
print("total", total)
|
|
|
|
+ end_offset = self.start_dir
|
|
+ for zinfo in sorted(self.filelist,
|
|
+ key=lambda zinfo: zinfo.header_offset,
|
|
+ reverse=True):
|
|
+ zinfo._end_offset = end_offset
|
|
+ end_offset = zinfo.header_offset
|
|
|
|
def namelist(self):
|
|
"""Return a list of file names in the archive."""
|
|
@@ -1500,6 +1508,10 @@ class ZipFile:
|
|
'File name in directory %r and header %r differ.'
|
|
% (zinfo.orig_filename, fname))
|
|
|
|
+ if (zinfo._end_offset is not None and
|
|
+ zef_file.tell() + zinfo.compress_size > zinfo._end_offset):
|
|
+ raise BadZipFile(f"Overlapped entries: {zinfo.orig_filename!r} (possible zip bomb)")
|
|
+
|
|
# check for encrypted flag & handle password
|
|
is_encrypted = zinfo.flag_bits & 0x1
|
|
zd = None
|
|
diff --git a/Misc/NEWS.d/next/Library/2023-09-28-13-15-51.gh-issue-109858.43e2dg.rst b/Misc/NEWS.d/next/Library/2023-09-28-13-15-51.gh-issue-109858.43e2dg.rst
|
|
new file mode 100644
|
|
index 0000000..be279ca
|
|
--- /dev/null
|
|
+++ b/Misc/NEWS.d/next/Library/2023-09-28-13-15-51.gh-issue-109858.43e2dg.rst
|
|
@@ -0,0 +1,3 @@
|
|
+Protect :mod:`zipfile` from "quoted-overlap" zipbomb. It now raises
|
|
+BadZipFile when try to read an entry that overlaps with other entry or
|
|
+central directory.
|
|
--
|
|
2.44.0
|
|
|