For anyone interested:
The following commands work, I had these in a bash script. The first command encrypts while the second one decrypts, both without asking for the passphrase. This was done AFTER removing all the keys. No keys are necessary.
gpg --symmetric --batch --passphrase-fd 0 <pass --output encrypted encrypthis
gpg --batch --passphrase-fd 0 <pass -d --output decrypted encrypted
a check shows that the files "encrypthis" and "decrypted" are Identical.
"pass" is a file holding the passphrase and --passphrase-fd 0 expect it to be redirected to it as above or "piped" through "cat" or similar.
I also had a string of 32 bytes of mixed characters (letters, numbers and others) that I found gpg considered as an invalid passphrase.
Hope this is useful to someone.
Last edited by rblampain; 08-16-2005 at 02:04 AM.