From owner-freebsd-security Tue Jul 11 14:50:50 2000 Delivered-To: freebsd-security@freebsd.org Received: from freefall.freebsd.org (freefall.FreeBSD.ORG [204.216.27.21]) by hub.freebsd.org (Postfix) with ESMTP id 6715137B7DA; Tue, 11 Jul 2000 14:50:47 -0700 (PDT) (envelope-from kris@FreeBSD.org) Received: from localhost (kris@localhost) by freefall.freebsd.org (8.9.3/8.9.2) with ESMTP id OAA93798; Tue, 11 Jul 2000 14:50:47 -0700 (PDT) (envelope-from kris@FreeBSD.org) X-Authentication-Warning: freefall.freebsd.org: kris owned process doing -bs Date: Tue, 11 Jul 2000 14:50:47 -0700 (PDT) From: Kris Kennaway To: Harold Gutch Cc: Brett Glass , Dave , security@FreeBSD.ORG Subject: Re: OpenSSH in 4.0 doesn't seem to work out of the box In-Reply-To: <20000711210540.B17911@foobar.franken.de> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Tue, 11 Jul 2000, Harold Gutch wrote: > > P.S. -- I've always wondered why El Gamal wasn't one of the encryption > > options, since it's unencumbered and already used in PGP. > > The ElGamal encryption algorithm I know of doubles the size of > the plaintext; that's not really a problem with PGP, since the > actual encryption algorithm uses a private key, which is > transferred after being encrypted with a public key algorithm. ITYM "session key" - RSA and DSA modes work by negotiating a session key which is used with a conventional (symmetric) cipher to encrypt the bulk data. I don't know much about El Gamal, but if it can negotiate a session key then there's nothing preventing you from using it as a SSH2 key format in the same way, except that no other clients or servers out there will support you :-) The real reason RSA is used in OpenSSH SSH1 mode is because that's what was implemented in the SSH1 protocol, probably because it's the most suitable public-key algorithm for the job. SSH1 didn't allow for other algorithms, and SSH2, which does, uses DSA (an algorithm which is patented but usable without restrictions) which does everything you'd need. Kris -- In God we Trust -- all others must submit an X.509 certificate. -- Charles Forsythe To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message