diff options
| -rw-r--r-- | Lib/test/test_zipfile.py | 79 | ||||
| -rw-r--r-- | Lib/zipfile.py | 25 | ||||
| -rw-r--r-- | Misc/NEWS | 4 |
3 files changed, 106 insertions, 2 deletions
diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py index e9a90e5..82b4061 100644 --- a/Lib/test/test_zipfile.py +++ b/Lib/test/test_zipfile.py @@ -662,6 +662,27 @@ class PyZipFileTests(unittest.TestCase): 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 test_unicode_filenames(self): with zipfile.ZipFile(TESTFN, "w") as zf: zf.writestr("foo.txt", "Test for unicode filename") @@ -875,6 +896,49 @@ class OtherTests(unittest.TestCase): with zipfile.ZipFile(TESTFN, mode="r") as zipfr: self.assertEqual(zipfr.comment, comment2) + 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] + + with zipfile.ZipFile(io.BytesIO(zipdata), mode="r") as zipf: + # testzip returns the name of the first corrupt file, or None + self.assertEqual('afile', zipf.testzip()) + + def test_testzip_with_bad_crc_stored(self): + self.check_testzip_with_bad_crc(zipfile.ZIP_STORED) + + @skipUnless(zlib, "requires 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() + with zipfile.ZipFile(io.BytesIO(zipdata), mode="r") as zipf: + self.assertRaises(zipfile.BadZipfile, zipf.read, 'afile') + + # Using ZipExtFile.read() + with zipfile.ZipFile(io.BytesIO(zipdata), mode="r") as zipf: + with zipf.open('afile', 'r') as corrupt_file: + self.assertRaises(zipfile.BadZipfile, corrupt_file.read) + + # Same with small reads (in order to exercise the buffering logic) + with zipfile.ZipFile(io.BytesIO(zipdata), mode="r") as zipf: + with zipf.open('afile', 'r') as corrupt_file: + corrupt_file.MIN_READ_SIZE = 2 + with self.assertRaises(zipfile.BadZipfile): + while corrupt_file.read(2): + pass + + def test_read_with_bad_crc_stored(self): + self.check_read_with_bad_crc(zipfile.ZIP_STORED) + + @skipUnless(zlib, "requires zlib") + def test_read_with_bad_crc_deflated(self): + self.check_read_with_bad_crc(zipfile.ZIP_DEFLATED) + def tearDown(self): unlink(TESTFN) unlink(TESTFN2) @@ -974,6 +1038,11 @@ class TestsWithRandomBinaryFiles(unittest.TestCase): for f in (TESTFN2, TemporaryFile(), io.BytesIO()): self.zip_test(f, zipfile.ZIP_STORED) + @skipUnless(zlib, "requires zlib") + def test_deflated(self): + for f in (TESTFN2, TemporaryFile(), io.BytesIO()): + self.zip_test(f, zipfile.ZIP_DEFLATED) + def zip_open_test(self, f, compression): self.make_test_archive(f, compression) @@ -1007,6 +1076,11 @@ class TestsWithRandomBinaryFiles(unittest.TestCase): for f in (TESTFN2, TemporaryFile(), io.BytesIO()): self.zip_open_test(f, zipfile.ZIP_STORED) + @skipUnless(zlib, "requires zlib") + def test_open_deflated(self): + for f in (TESTFN2, TemporaryFile(), io.BytesIO()): + self.zip_open_test(f, zipfile.ZIP_DEFLATED) + def zip_random_open_test(self, f, compression): self.make_test_archive(f, compression) @@ -1028,6 +1102,11 @@ class TestsWithRandomBinaryFiles(unittest.TestCase): for f in (TESTFN2, TemporaryFile(), io.BytesIO()): self.zip_random_open_test(f, zipfile.ZIP_STORED) + @skipUnless(zlib, "requires zlib") + def test_random_open_deflated(self): + for f in (TESTFN2, TemporaryFile(), io.BytesIO()): + self.zip_random_open_test(f, zipfile.ZIP_DEFLATED) + @skipUnless(zlib, "requires zlib") class TestsWithMultipleOpens(unittest.TestCase): diff --git a/Lib/zipfile.py b/Lib/zipfile.py index f81cc8b..c47c3cc 100644 --- a/Lib/zipfile.py +++ b/Lib/zipfile.py @@ -492,6 +492,12 @@ class ZipExtFile(io.BufferedIOBase): self.mode = mode self.name = zipinfo.filename + if hasattr(zipinfo, 'CRC'): + self._expected_crc = zipinfo.CRC + self._running_crc = crc32(b'') & 0xffffffff + else: + self._expected_crc = None + def readline(self, limit=-1): """Read and return a line from the stream. @@ -569,6 +575,16 @@ class ZipExtFile(io.BufferedIOBase): return buf + 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 read1(self, n): """Read up to n bytes with at most one read() system call.""" @@ -592,6 +608,7 @@ class ZipExtFile(io.BufferedIOBase): data = bytes(map(self._decrypter, data)) if self._compress_type == ZIP_STORED: + self._update_crc(data, eof=(self._compress_left==0)) self._readbuffer = self._readbuffer[self._offset:] + data self._offset = 0 else: @@ -607,9 +624,11 @@ class ZipExtFile(io.BufferedIOBase): ) self._unconsumed = self._decompressor.unconsumed_tail - if len(self._unconsumed) == 0 and self._compress_left == 0: + eof = len(self._unconsumed) == 0 and self._compress_left == 0 + if eof: data += self._decompressor.flush() + self._update_crc(data, eof=eof) self._readbuffer = self._readbuffer[self._offset:] + data self._offset = 0 @@ -1380,7 +1399,9 @@ def main(args = None): 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': @@ -72,6 +72,10 @@ Extensions Library ------- +- 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). + - 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. 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