Interesting problem

Charles.Dougherty@choicepoint.net Charles.Dougherty@choicepoint.net
Mon Jun 17 14:03:01 2002


Hello...

I am relatively new to gpg, and have run into an interesting problem.  I am
running GPG 1.0.6 on a Alpha Tru64 UNIX platform.  I have created a
public/secure key pair, and am trying to encrypt/decrypt a 4.7 GB ASCII
file.  The file encrypts fine, but when I try to decrypt it I get the
following error:

gpg: armor header: Version: GnuPG v1.0.6 (OSF1)
gpg: armor header: Comment: For info see http://www.gnupg.org
gpg: public key is 061A78D9
gpg: using secondary key 061A78D9 instead of primary key 79D84453

You need a passphrase to unlock the secret key for
user: "datacomm"
gpg: using secondary key 061A78D9 instead of primary key 79D84453
2048-bit ELG-E key, ID 061A78D9, created 2002-06-03 (main key ID 79D84453)

gpg: encrypted with 2048-bit ELG-E key, ID 061A78D9, created 2002-06-03
      "datacomm"
gpg: CAST5 encrypted data
gpg: original file name='webinv.txt'
gpg: [don't know]: invalid packet (ctb=20)
gpg: [don't know]: invalid packet (ctb=20)
gpg: [don't know]: invalid packet (ctb=20)
gpg: no valid OpenPGP data found.


Here are the commands I use to encrypt/decrypt the file:
encryption:

gpg --homedir $HOME/.gnupg -v --batch  --compress-algo 1 --cipher-algo
CAST5 --charset iso-8859-1 --output /ap/p/ftp/enp/tmp/webinv.pgp -a
--recipient "datacomm" --encrypt /ap/p/ftp/enp/tmp/webinv.txt

decryption:

gpg --homedir $HOME/.gnupg -v --compress-algo 1 --cipher-algo CAST5
--charset iso-8859-1 --output /ap/p/ftp/enp/tmp/webinv.test -a  --decrypt
/ap/p/ftp/enp/tmp/webinv.pgp

I have created a 4.2 GB file, and have had no problem with it.  I have
gzip'd the file in question, then encrypted/decrypted it with no problem.
I have tried different algorhythms, different cyphers, and different
compressions with no luck.   The decryption fails at the same point
everytime.  The decrypted file size is exactly 398944641 bytes at the time
of failure, EVERY time.  No matter what I do.  Now to the question:

Is there a character/set of characters that would cause the
encryption/decryption to fail?
Is there a compression routine or number that anyone can suggest that I
use?

I appreciate any help anyone can give me on this!

Thanks so much!

Chuck Dougherty
Data Communications Analyst
770-752-3563