diff options
Diffstat (limited to 'Lib/zipfile.py')
-rw-r--r-- | Lib/zipfile.py | 25 |
1 files changed, 23 insertions, 2 deletions
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': |