Merged revisions 83959-83960 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k
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r83959 | antoine.pitrou | 2010-08-12 17:11:50 +0200 (jeu., 12 août 2010) | 5 lines
Issue #7467: when a file from a ZIP archive, its CRC is checked and a
BadZipfile error is raised if it doesn't match (as used to be the
case in Python 2.5 and earlier).
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r83960 | antoine.pitrou | 2010-08-12 17:15:01 +0200 (jeu., 12 août 2010) | 3 lines
Typo.
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diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
index 55cfaa9..474ec58 100644
--- a/Lib/test/test_zipfile.py
+++ b/Lib/test/test_zipfile.py
@@ -582,6 +582,27 @@
class OtherTests(unittest.TestCase):
+ zips_with_bad_crc = {
+ zipfile.ZIP_STORED: (
+ b'PK\003\004\024\0\0\0\0\0 \213\212;:r'
+ b'\253\377\f\0\0\0\f\0\0\0\005\0\0\000af'
+ b'ilehello,AworldP'
+ b'K\001\002\024\003\024\0\0\0\0\0 \213\212;:'
+ b'r\253\377\f\0\0\0\f\0\0\0\005\0\0\0\0'
+ b'\0\0\0\0\0\0\0\200\001\0\0\0\000afi'
+ b'lePK\005\006\0\0\0\0\001\0\001\0003\000'
+ b'\0\0/\0\0\0\0\0'),
+ zipfile.ZIP_DEFLATED: (
+ b'PK\x03\x04\x14\x00\x00\x00\x08\x00n}\x0c=FA'
+ b'KE\x10\x00\x00\x00n\x00\x00\x00\x05\x00\x00\x00af'
+ b'ile\xcbH\xcd\xc9\xc9W(\xcf/\xcaI\xc9\xa0'
+ b'=\x13\x00PK\x01\x02\x14\x03\x14\x00\x00\x00\x08\x00n'
+ b'}\x0c=FAKE\x10\x00\x00\x00n\x00\x00\x00\x05'
+ b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x80\x01\x00\x00\x00'
+ b'\x00afilePK\x05\x06\x00\x00\x00\x00\x01\x00'
+ b'\x01\x003\x00\x00\x003\x00\x00\x00\x00\x00'),
+ }
+
def testUnicodeFilenames(self):
zf = zipfile.ZipFile(TESTFN, "w")
zf.writestr("foo.txt", "Test for unicode filename")
@@ -809,6 +830,55 @@
self.assertEqual(zipfr.comment, comment2)
zipfr.close()
+ def check_testzip_with_bad_crc(self, compression):
+ """Tests that files with bad CRCs return their name from testzip."""
+ zipdata = self.zips_with_bad_crc[compression]
+
+ zipf = zipfile.ZipFile(io.BytesIO(zipdata), mode="r")
+ # testzip returns the name of the first corrupt file, or None
+ self.assertEqual('afile', zipf.testzip())
+ zipf.close()
+
+ def test_testzip_with_bad_crc_stored(self):
+ self.check_testzip_with_bad_crc(zipfile.ZIP_STORED)
+
+ if zlib:
+ def test_testzip_with_bad_crc_deflated(self):
+ self.check_testzip_with_bad_crc(zipfile.ZIP_DEFLATED)
+
+ def check_read_with_bad_crc(self, compression):
+ """Tests that files with bad CRCs raise a BadZipfile exception when read."""
+ zipdata = self.zips_with_bad_crc[compression]
+
+ # Using ZipFile.read()
+ zipf = zipfile.ZipFile(io.BytesIO(zipdata), mode="r")
+ self.assertRaises(zipfile.BadZipfile, zipf.read, 'afile')
+ zipf.close()
+
+ # Using ZipExtFile.read()
+ zipf = zipfile.ZipFile(io.BytesIO(zipdata), mode="r")
+ corrupt_file = zipf.open('afile', 'r')
+ self.assertRaises(zipfile.BadZipfile, corrupt_file.read)
+ corrupt_file.close()
+ zipf.close()
+
+ # Same with small reads (in order to exercise the buffering logic)
+ zipf = zipfile.ZipFile(io.BytesIO(zipdata), mode="r")
+ corrupt_file = zipf.open('afile', 'r')
+ corrupt_file.MIN_READ_SIZE = 2
+ with self.assertRaises(zipfile.BadZipfile):
+ while corrupt_file.read(2):
+ pass
+ corrupt_file.close()
+ zipf.close()
+
+ def test_read_with_bad_crc_stored(self):
+ self.check_read_with_bad_crc(zipfile.ZIP_STORED)
+
+ if zlib:
+ def test_read_with_bad_crc_deflated(self):
+ self.check_read_with_bad_crc(zipfile.ZIP_DEFLATED)
+
def tearDown(self):
support.unlink(TESTFN)
support.unlink(TESTFN2)
diff --git a/Lib/zipfile.py b/Lib/zipfile.py
index 79ca152..3d2d57b 100644
--- a/Lib/zipfile.py
+++ b/Lib/zipfile.py
@@ -472,6 +472,12 @@
if self.compress_type == ZIP_DEFLATED:
self.dc = zlib.decompressobj(-15)
+ if hasattr(zipinfo, 'CRC'):
+ self._expected_crc = zipinfo.CRC
+ self._running_crc = crc32(b'') & 0xffffffff
+ else:
+ self._expected_crc = None
+
def set_univ_newlines(self, univ_newlines):
self.univ_newlines = univ_newlines
@@ -565,6 +571,16 @@
result.append(line)
return result
+ def _update_crc(self, newdata, eof):
+ # Update the CRC using the given data.
+ if self._expected_crc is None:
+ # No need to compute the CRC if we don't have a reference value
+ return
+ self._running_crc = crc32(newdata, self._running_crc) & 0xffffffff
+ # Check the CRC if we're at the end of the file
+ if eof and self._running_crc != self._expected_crc:
+ raise BadZipfile("Bad CRC-32 for file %r" % self.name)
+
def read(self, size = None):
# act like file obj and return empty string if size is 0
if size == 0:
@@ -628,9 +644,11 @@
# prevent decompressor from being used again
self.dc = None
+ self._update_crc(newdata, eof=(
+ self.compress_size == self.bytes_read and
+ len(self.rawbuffer) == 0))
self.readbuffer += newdata
-
# return what the user asked for
if size is None or len(self.readbuffer) <= size:
data = self.readbuffer
@@ -1382,7 +1400,9 @@
print(USAGE)
sys.exit(1)
zf = ZipFile(args[1], 'r')
- zf.testzip()
+ badfile = zf.testzip()
+ if badfile:
+ print("The following enclosed file is corrupted: {!r}".format(badfile))
print("Done testing")
elif args[0] == '-e':
diff --git a/Misc/NEWS b/Misc/NEWS
index fd30974..b386182 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -93,6 +93,10 @@
Library
-------
+- Issue #7467: when reading a file from a ZIP archive, its CRC is checked
+ and a BadZipfile error is raised if it doesn't match (as used to be the
+ case in Python 2.5 and earlier).
+
- Issue #9550: a BufferedReader could issue an additional read when the
original read request had been satisfied, which could block indefinitely
when the underlying raw IO channel was e.g. a socket. Report and original