9.21 beta bug: cipher selection

Tom Myers
2013-07-03
2013-07-13
  • Tom Myers
    Tom Myers
    2013-07-03

    I just stumbled upon the 7zip's changelog. In it there is the following note:

    "- The BUG in 7-Zip 9.21 beta was fixed:
    7-Zip could ignore some options when you created ZIP archives.
    For example, it could use ZipCrypto cipher instead of AES-256."

    Could anyone please clarify/confirm that
    a - This bug ONLY existed in the 9.21 beta version, never in the stable 9.20?
    b - It only affected ZIP archives, not 7Z archives?

    Sorry if this question had been raised before but the forum search did not yield any hit.

    BR,
    Tom

     
    • Tom Myers
      Tom Myers
      2013-07-11

      Igor,

      Any comment on this?

      Thanks,
      Tom

       
  • Shell
    Shell
    2013-07-11

    1) I could not reproduce the bug for ZIP archives in 7-Zip 9.20;
    2) I reproduced the bug for ZIP archives in 7-Zip 9.21 (different, but certainly incorrect behavior for GUI and console versions);
    3) I could not reproduce the bug for 7z archives in 7-Zip 9.21.
    So, what Igor said is what he meant. However, there may be other bugs that are not yet discovered :-)

    You can compare the differences between versions 9.20, 9.21 and 9.22. Version 9.22 has changes in ZIP handling code - mainly verifying that AES mode is specified together with a valid password. Version 9.21 brings many changes from 9.20, I could not quickly analyze them. Strangely enough, the lines changed in version 9.22 have not been modified in version 9.21 - so the error should have snowballed from elsewhere.

     
    Last edit: Shell 2013-07-11
    • Tom Myers
      Tom Myers
      2013-07-13

      Thanks, Shell, for following this up. Your help is much appreciated.

      BR,
      Tom