Compatibility with PGP

Michael Roth
Wed, 23 Jun 1999 12:49:29 +0200 (CEST)

On Mon, 21 Jun 1999, Brian Galbraith wrote:

> versions of PGP and I installed the rsa and idea extensions over the
> week end, so that I could (hopefully) communicate with users of PGP
> 2.6.x.
> I have come across a few problems.
To encrypt in an PGP2.6x compatible format you need the IDEA and RSA modules (check if you need a license for these patented alogrithms). You should add the loading of these modules to your GnuPG config file. You can check if you installed these modules correctly with the command "gpg --version". In the listing of ciphers and pubkeys their should appear IDEA and RSA. To encrypt or sign in PGP 2.6 readable format, use these options to your gpg commands additionally: --rfc1991 --cipher-algo idea --digest-algo md5 --compress-algo 1 Please note, PGP2.6 could read the resulting message only if all keys you used to encrypt or sign are RSA keys. If you use only one none RSA key, PGP 2.6.x will fail. Further more, you must use files when encrypting or signing. PGP 2.6 is unable to process files you encrypted or signed using stdin/stdout with GnuPG. If you use shells like KMail and/or Geheimnis it may be possible that these programms use stdin/stdout to feed data to and from GnuPG. So creating PGP 2.6 compatible messages with these tools is not possible. cu Michael