On Sun, 12 Feb 2023 15:41:55 GMT, Eirik Bjørsnøs <eir...@openjdk.org> wrote:
> ZipInputStream.readEnd currently assumes a Zip64 data descriptor if the > number of compressed or uncompressed bytes read from the inflater is larger > than the Zip64 magic value. > > While the ZIP format mandates that the data descriptor `SHOULD be stored in > ZIP64 format (as 8 byte values) when a file's size exceeds 0xFFFFFFFF`, it > also states that `ZIP64 format MAY be used regardless of the size of a file`. > For such small entries, the above assumption does not hold. > > This PR augments ZipInputStream.readEnd to also assume 8-byte sizes if the > ZipEntry includes a Zip64 extra information field AND at least one of the > 'compressed size' and 'uncompressed size' have the expected Zip64 "magic" > value 0xFFFFFFFF. This brings ZipInputStream into alignment with the APPNOTE > format spec: > > > When extracting, if the zip64 extended information extra > field is present for the file the compressed and > uncompressed sizes will be 8 byte values. > > > While small Zip64 files with 8-byte data descriptors are not commonly found > in the wild, it is possible to create one using the Info-ZIP command line > `-fd` flag: > > `echo hello | zip -fd > hello.zip` > > The PR also adds a test verifying that such a small Zip64 file can be parsed > by ZipInputStream. This pull request has now been integrated. Changeset: 628cd8a4 Author: Eirik Bjørsnøs <eir...@openjdk.org> URL: https://git.openjdk.org/jdk/commit/628cd8a489fd54db18204c3bbaf4339d7ab5e9d6 Stats: 341 lines in 2 files changed: 338 ins; 0 del; 3 mod 8303866: Allow ZipInputStream.readEnd to parse small Zip64 ZIP files Reviewed-by: lancea, jpai ------------- PR: https://git.openjdk.org/jdk/pull/12524
