RFR: 8336025: Improve ZipOutputSream validation of MAX CEN Header field limits [v2]

[Lance Andersen]

On Mon, 16 Sep 2024 09:36:49 GMT, Eirik Bjørsnøs <eirbjo at openjdk.org> wrote:

>> Lance Andersen has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Update @link ->@linkplain
>
> src/java.base/share/classes/java/util/zip/ZipEntry.java line 41:
> 
>> 39:  * This class is used to represent a ZIP file entry.
>> 40:  * <P>
>> 41:  * The combined length of the entry name, the extra field data, the
> 
> "bytes" is the last word here, so technically this is correct. But an external reader may easily think this refers to the string lengths, not the byte encoded lengths.
> 
> So  maybe being slightly more explicit that the encoded length depends on the chosen charset would reduce ambiguity?

I am not sure it is needed, but could tweak to 

> The combined length, after encoding, of the ......

thoughts?

> src/java.base/share/classes/java/util/zip/ZipOutputStream.java line 642:
> 
>> 640:         if (e.comment != null) {
>> 641:             commentBytes = zc.getBytes(e.comment);
>> 642:             clen = Math.min(commentBytes.length, 0xffff);
> 
> Moving the headerLength enforcement earlier in the method would remove the need for this comment truncation, right?

I left that intentionally for now.  A follow on PR will be updating the ZipEntry javadoc to reduce the max size of the validation check once this PR is finalized.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21003#discussion_r1760977017
PR Review Comment: https://git.openjdk.org/jdk/pull/21003#discussion_r1760962573