On Tue, 15 Aug 2023 18:43:36 GMT, Lance Andersen <lan...@openjdk.org> wrote:

>> This PR  updates the extra field validation added as part of 
>> [JDK-8302483](https://bugs.openjdk.org/browse/JDK-8302483)  to deal with 
>> issues seen with 3rd party tools/libraries where a ZipException may be 
>> encountered when opening select APK, ZIP or JAR files.  Please see refer to 
>> the links provided at the end the description for the more information ::
>> 
>>> ZipException: Invalid CEN header (invalid zip64 extra data field size)
>> 
>> 1. Extra field includes padding :
>> 
>> 
>> ----------------#1--------------------
>> [Central Directory Header]
>>   0x3374: Signature    : 0x02014b50
>>   0x3378: Created Zip Spec :    0xa [1.0]
>>   0x3379: Created OS   :    0x0 [MS-DOS]
>>   0x337a: VerMadeby    :    0xa [0, 1.0]
>>   0x337b: VerExtract   :    0xa [1.0]
>>   0x337c: Flag      :   0x800
>>   0x337e: Method     :    0x0 [STORED]
>>   0x3380: Last Mod Time  : 0x385ca437 [Thu Feb 28 20:33:46 EST 2008]
>>   0x3384: CRC       : 0x694c6952
>>   0x3388: Compressed Size :   0x624
>>   0x338c: Uncompressed Size:   0x624
>>   0x3390: Name Length   :   0x1b
>>  0x3392: Extra Length  :    0x7
>>              [tag=0xcafe, sz=0, data= ]
>>                              ->[tag=cafe, size=0]
>>   0x3394: Comment Length :    0x0
>>   0x3396: Disk Start   :    0x0
>>   0x3398: Attrs      :    0x0
>>   0x339a: AttrsEx     :    0x0
>>   0x339e: Loc Header Offset:    0x0
>>   0x33a2: File Name    : res/drawable/size_48x48.jpg
>> 
>> 
>> The extra field tag of `0xcafe` has its data size set to `0`.  and the extra 
>> length is `7`.   It is expected that you can use the  tag's data size to 
>> traverse the extra fields.
>> 
>> 
>> 2. The [BND tool](https://github.com/bndtools/bnd) added [problematic data 
>> to the extra field](https://issues.apache.org/jira/browse/FELIX-6622):
>> 
>> 
>> ----------------#359--------------------
>> [Central Directory Header]
>>    0x600b4: Signature        : 0x02014b50
>>    0x600b8: Created Zip Spec :       0x14 [2.0]
>>    0x600b9: Created OS       :        0x0 [MS-DOS]
>>    0x600ba: VerMadeby        :       0x14 [0, 2.0]
>>    0x600bb: VerExtract       :       0x14 [2.0]
>>    0x600bc: Flag             :      0x808
>>    0x600be: Method           :        0x8 [DEFLATED]
>>    0x600c0: Last Mod Time    : 0x2e418983 [Sat Feb 01 17:12:06 EST 2003]
>>    0x600c4: CRC              : 0xd8f689cb
>>    0x600c8: Compressed Size  :      0x23e
>>    0x600cc: Uncompressed Size:      0x392
>>    0x600d0: Name Length      :       0x20
>>    0x600d2: Extra Length     :        0x8
>>              [tag=0xbfef, sz=61373, data=        
>>   0x600d4: Comment Length   ...
>
> Lance Andersen has updated the pull request incrementally with one additional 
> commit since the last revision:
> 
>   Cleaned up spacing and added missing comma

My overall point is that it will be unfortunate if users will be able to open 
some files on Linux/macOS/Windows using default programs but will not be able 
to do that using Java.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/15273#issuecomment-1679933388

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