diff options
Diffstat (limited to 'Lib/zipfile.py')
| -rw-r--r-- | Lib/zipfile.py | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/Lib/zipfile.py b/Lib/zipfile.py index 79ca1527f9..3d2d57b205 100644 --- a/Lib/zipfile.py +++ b/Lib/zipfile.py @@ -472,6 +472,12 @@ class ZipExtFile: 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 @@ class ZipExtFile: 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 @@ class ZipExtFile: # 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 @@ 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': |