trouble decrypting AES256 symmetric encrypted file

[JIH, DOUG Y.]

I used 7-Zip to archive about 4.6 GB of files, and I used GPG to
encrypt the 7z file.  7-Zip can't seem to open the partially decrypted
file, unfortunately, so I can't get any of the files back.

I was hoping that the whole 7z file was still available in its
encrypted form, and that GPG was simply confused by an overflown
32-bit index or something like that.

In any case, this seems like a serious problem that people should be aware of.


On 9/20/05, Henry Hertz Hobbit <hhhobbit7 at netscape.net> wrote:
>
> John Clizbe wrote:
>
> >Alphax wrote:
> >> JIH, DOUG Y. wrote:
> >>> I got the following messages when I tried to decrypt a file.gpg with
> >>> the size 4,920,412,393 bytes.
> >>>
> >>> gpg: AES256 encrypted data
> >>> gpg: encrypted with 1 passphrase
> >>> gpg: [don't know]: invalid packet (ctb=7e)
> >>> gpg: [don't know]: invalid packet (ctb=32)
> >>> gpg: WARNING: encrypted message has been manipulated!
> >>> gpg: [don't know]: invalid packet (ctb=2c)
> >>>
> >>> The file was produced by encrypting with
> >>>
> >>> gpg -c --cipher aes256 file
> >>>
> >>> When the error messages occured, the output file has a size of
> >>> 614,055,611 bytes.
> >>>
> >>> Can anyone please help!
> >>>
> >>> Using gpg version 1.4.2, official Windows version
> >>>
> >>
> >> I have a feeling Windows has problems with files this large, esp. on NTFS.
> >>
> >I recall this being a common error with GnuPG on Win32.
> >
> >The usual work-around if I recall correctly is to use redirection:
> >
> >    gpg < file.gpg > file.out
> >
> >Has the file been manipulated or moved between systems since it was encrypted?
>
> First, it is NOT a limitation of the file size on an NTFS file system
> (at least in theory).  Check it out (snatched out of the mouth of the
> Lion:
>
> http://tinyurl.com/2ozuo
>
> Quoting the maximum file size from Microsoft:
>
> Theory: 16 exabytes minus 1 KB (2^64 bytes minus 1 KB)
> mplementation: 16 terabytes minus 64 KB (2^44 bytes minus 64 KB)
>
> That is much better than the 2 GB limit of EXT3.  In reality, that
> can't be the limit because a DVD gets broken up into chunks rather
> than being one huge file.  The indirection (< input > output) works,
> but I think you have lost your file.  I suggest regenerating it and
> using the indirection.  I am assuming it is a huge backup and that
> you CAN regenerate it again.  If you can't, Microsoft is your best
> bet at finding out how to get all of the lost clusters back, and I
> strongly suspect you will never see the file again.  What zip program
> did you use to generate such a huge file?
>
> HHH
> --
> Key Name:  "Henry Hertz Hobbit" <hhhobbit at securemecca.net>
> pub   1024D/E1FA6C62 2005-04-11 [expires: 2006-04-11]
> Key fingerprint = ACA0 B65B E20A 552E DFE2 EE1D 75B9 D818 E1FA 6C62
>
>
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