appending to gpg file?

[David Shaw]

On Mon, Nov 17, 2008 at 02:41:50PM -0500, David Kennedy wrote:
> Thanks for the help!
> 
> I'm using an app to pipe events (text strings) through an instance of gpg to
> a file.  This works great for me now, in an ideal environment.
> 
> Two issues:
> 1)The problem occurs if/when the app breaks, breaking the pipe and killing
> my stream.  GPG terminates, and the resulting file is unreadable (i get an
> error decrypting it after entering in the passphrase).  so, the whole log is
> no good.
> 
> 2)Then, what if i'd like to start the app again, and stream back to the same
> file?
> 
> My thought is to individually encrypt each "line" in the output file as its
> own gpg encrypted package.  No dependencies on other individual "lines" not
> being corrupt, as long as some sort of delimiter is in place.

(please don't top-post)

Do this:

  echo "my log line" | gpg --armor >> my_log_file.txt

(Use whatever gpg options you like.  The important bit is that you
have --armor in there)

You will end up with a log file that looks like this:

  -----BEGIN PGP MESSAGE-----
  (Lots of base64 stuff)
  -----END PGP MESSAGE-----
  -----BEGIN PGP MESSAGE-----
  (Lots of base64 stuff)
  -----END PGP MESSAGE-----
  -----BEGIN PGP MESSAGE-----
  (Lots of base64 stuff)
  -----END PGP MESSAGE-----

and so on.  To decrypt, split up the file so that each BEGIN/END pair
is in its own file, and decrypt that.

Note this is a pretty space-inefficient way to store things, but it
does answer your question of how to do it.  There might be a better
way to solve the original problem, but I'm not sure what what is from
your email.

David