From owner-freebsd-hackers Sat Sep 30 00:08:19 1995 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.6.12/8.6.6) id AAA19524 for hackers-outgoing; Sat, 30 Sep 1995 00:08:19 -0700 Received: from grunt.grondar.za (grunt.grondar.za [196.7.18.129]) by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id AAA19519 for ; Sat, 30 Sep 1995 00:08:12 -0700 Received: from grumble.grondar.za (grumble.grondar.za [196.7.18.130]) by grunt.grondar.za (8.6.12/8.6.9) with ESMTP id JAA17203 for ; Sat, 30 Sep 1995 09:07:57 +0200 Received: from localhost (localhost [127.0.0.1]) by grumble.grondar.za (8.6.12/8.6.9) with SMTP id JAA21165 for ; Sat, 30 Sep 1995 09:07:55 +0200 Message-Id: <199509300707.JAA21165@grumble.grondar.za> X-Authentication-Warning: grumble.grondar.za: Host localhost didn't use HELO protocol To: hackers@freebsd.org Subject: Netscape security problem - /dev/random? Date: Sat, 30 Sep 1995 09:07:54 +0200 From: Mark Murray Sender: owner-hackers@freebsd.org Precedence: bulk Hi With the well-publicised crack of Netscape's security, I am of the opinion that the system (in fact the kernel) should cooperate in providing decent random numbers. In this particular case, "decent" could mean a couple of things - - Unguessable. In tthe past folks used to seed their random number generators with the time-of-day to get a different start to the otherwise predidicable sequence. For security purposes this is no good, as an attacker who knows approximately whn you started, has a small set of numbers to play with to crack you. If the kernel could provide a toutally unpredictable value, this would protect the random generator seed. - Uniform. the above is assuming that each caller is only looking for a very small number of values. Such values may be useless if the caller actually needs a large number of uniformly distributed, totally random numbers. These two scenarios are addressed in a pice of code that I have that was written for Linux by Theodore Ts'o, and it provides 2 new devices - /dev/random and /dev/urandom which address these concerns. Those folks interested in exponential key exchange (Diffie-Hellman) and other crypto concerns will be interested. I would like to get this code into the kernel (in a few days). Is anyone else interested? M -- Mark Murray 46 Harvey Rd, Claremont, Cape Town 7700, South Africa +27 21 61-3768 GMT+0200 Finger mark@grumble.grondar.za for PGP key