Some AES Encrypted Files extract to a zero-length file



  • While archiving some emails to upload to the Cloud as encrypted archives, I noticed that when testing the archive, I could not correctly extract the original file. The file would be created but be zero bytes long. The text files I was compressing were approx 100MB long and the archive a zip file with AES128 encryption.

    The issue seems to be with AES encryption (128 192 and 256 bit), but the PK 2.04g encryption seems to allow proper file extraction.

    I managed to re-produce the issue with an 800k text file that contains random characters; this when encrypted with AES128 would extract to a zero-length file. However a 40MB file containing only repeated “1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ” strings (which compresses to 233kB) encrypts and decrypts ok.

    I have only tried this with zip archives.

    I am using PA version 18.00.31.


  • conexware

    @south37 said in Some AES Encrypted Files extract to a zero-length file:

    While archiving some emails to upload to the Cloud as encrypted archives, I noticed that when testing the archive, I could not correctly extract the original file. The file would be created but be zero bytes long. The text files I was compressing were approx 100MB long and the archive a zip file with AES128 encryption.

    The issue seems to be with AES encryption (128 192 and 256 bit), but the PK 2.04g encryption seems to allow proper file extraction.

    I managed to re-produce the issue with an 800k text file that contains random characters; this when encrypted with AES128 would extract to a zero-length file. However a 40MB file containing only repeated “1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ” strings (which compresses to 233kB) encrypts and decrypts ok.

    I have only tried this with zip archives.

    I am using PA version 18.00.31.

    can you please compress that file to .pa and send it over to us at support at conexware dot com. That way we can take a look at it right away.

    thank you!



  • @spwolf
    File sent as unencrypted .pa and sample encrypted zip file


  • conexware

    Thanks for reporting this issue. At certain settings, zip file header was not set properly, hence the issue.

    You can find updated version here:
    https://forums.powerarchiver.com/topic/5933/fast-ring-powerarchiver-2018-18-00-37

    Please check it out and let us know if it works properly now.



  • @spwolf Just tested the new version with the files that were problematic and they all decrypt and extract ok.

    Thanks for the fast fix on this issue.


 

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