Bug - Compression method 99



  • When adding a file to a zip archive from Action-Add, when Method ‘Deflate’ is selected, it’s saved into the archive as ‘compression method’ 99 (unknown) instead of 08 (deflate). This causes issues with Windows Explore native Zip reader, it can’t extract the file.



  • Same goes for right-clicking on a file, selecting ‘Compress with Options’ (we encrypt with AES128, if that matters). The file is also method 99

    This is the debug info `zipinfo’ gives me when I parse the archive’s header.

    The central-directory extra field contains:

    • A subfield with ID 0x9901 (unknown) and 7 data bytes:
      02 00 41 45 01 08 00.

  • conexware

    can you please confirm what version of PA and what version of Windows? Also, what did you use to check compression method?

    I quickly checked and it seems fine… shows as deflate and opens up in Windows Explorer.

    Thanks!


  • conexware

    @csohns:

    Same goes for right-clicking on a file, selecting ‘Compress with Options’ (we encrypt with AES128, if that matters). The file is also method 99

    This is the debug info `zipinfo’ gives me when I parse the archive’s header.

    The central-directory extra field contains:

    • A subfield with ID 0x9901 (unknown) and 7 data bytes:
      02 00 41 45 01 08 00.

    Now I see your 2nd post… so basically reason this does not work is that Windows does not support AES encryption… the library that they use is very old and company went out of business, thus their zip support is limited.

    Just to make sure something new did not happen, I checked with WinZip, SecureZIP and few other ZIP programs and Windows will not read any of them… I was using latest 8.1 release.



  • My apologies, I’m new to this whole “reporting a bug” thing.

    PA 15.01.05
    Windows 7 SP1, full updates.

    This issue has been reproduced on 2 separate systems, both are the same OS and PA version.

    I can reproduce this by using any of the AES encryption ciphers, it doesn’t happen with the old 2.04g cipher and non-encrypted files.

    This is an example file. Explorer isn’t able to open the first AES file.
    http://hackthegibson.net/tmp/test%20file.zip

    On the broken AES file (exact duplicate of the other AES file), also notice the ‘packed’ size is different and the ‘CRC’ is blank in PA.

    Everything works properly when I drag-drop the file into the archive, Windows 7 can read AES128.



  • I’ve pasted the full output of `zipinfo’ to http://pastebin.com/Vsvbmq9w

    Look at file #3:
    test file encrypted aes128.txt
    compression method: unknown (99)
    32-bit CRC value (hex): 00000000

    While the functioning AES128 file, #4, reads as:
    test file encrypted aes128 - WORKS.txt
    compression method: deflated
    32-bit CRC value (hex): 20e267dd


  • conexware

    can you cab that file and send it to us via email? support@conexware.com
    I cant download it from that site for some reason.

    Are you sure that zip crypto is not being used in the case where it works? You can check method in PowerArchiver, right click on any of the list view columns and click on Method.

    Thanks a lot!



  • All the files show as “DFLT-X”

    As requested, the cab file has been emailed.


  • conexware

    @csohns:

    All the files show as “DFLT-X”

    As requested, the cab file has been emailed.

    thanks - I will check it out and let you know.


  • conexware

    Chris - how did you create one that works, via drag and drop? There seems to be a problem there, since that file is encrypted using zip crypto method (from 2.04g spec).

    Keep in mind that there is a central and local directory in zip archive. Now our compression guys are already out, but I would not be surprised if this is done for compatibility reasons, so you would not try to enter password for unknown encryption dozen times.


  • conexware

    i have written bug report for drag & drop - zip crypto creation… this should be corrected in next upcoming release, which should be quite soon. I will update this thread once we have that ready… thanks a lot for the report.

    I am also setting up Win7 test computer to see if it actually supports aes, unfortunately i dont think thats the case - it was likely just confusion due to the bug in drag and drop.

    thank you!!!



  • Correct, it worked when I used drag & drop. Thanks for finding the issue!


  • conexware

    @csohns:

    Correct, it worked when I used drag & drop. Thanks for finding the issue!

    sorry about that Chris but big thanks for the report.


  • conexware

    Here is the updated PA 2015 15.02.1 which fixes the bug with zipcrypto instead of AES when using drag and drop:
    http://www.powerarchiver.com/test/release15/powarc150201.exe

    thank you for the report!


 

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