From owner-freebsd-hackers Thu Oct 3 14:45:11 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DCB8B37B401 for ; Thu, 3 Oct 2002 14:45:08 -0700 (PDT) Received: from storm.FreeBSD.org.uk (storm.FreeBSD.org.uk [194.242.157.42]) by mx1.FreeBSD.org (Postfix) with ESMTP id D3EC943E6A for ; Thu, 3 Oct 2002 14:45:07 -0700 (PDT) (envelope-from mark@grimreaper.grondar.org) Received: from storm.FreeBSD.org.uk (uucp@localhost [127.0.0.1]) by storm.FreeBSD.org.uk (8.12.6/8.12.6) with ESMTP id g93Lj6He000608; Thu, 3 Oct 2002 22:45:06 +0100 (BST) (envelope-from mark@grimreaper.grondar.org) Received: (from uucp@localhost) by storm.FreeBSD.org.uk (8.12.6/8.12.6/Submit) with UUCP id g93Lj6Ip000607; Thu, 3 Oct 2002 22:45:06 +0100 (BST) Received: from grimreaper.grondar.org (localhost [127.0.0.1]) by grimreaper.grondar.org (8.12.6/8.12.5) with ESMTP id g93Li620007510; Thu, 3 Oct 2002 22:44:07 +0100 (BST) (envelope-from mark@grimreaper.grondar.org) Message-Id: <200210032144.g93Li620007510@grimreaper.grondar.org> To: "Firsto Lasto" Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: PRNG not seeded - error in non-root ssh inside 4.6.2 jails... References: In-Reply-To: ; from "Firsto Lasto" "Thu, 03 Oct 2002 14:14:31 PDT." Date: Thu, 03 Oct 2002 22:44:06 +0100 From: Mark Murray Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > I can't seed it by banging on the keyboard - it is a headless server in a > rack thousands of miles from me :) > > Perhaps there is another way to do it ? Yes. You need to find sources of entropy in interrupts. Look at a dmesg, and note which IRQ's your network device(s) and mass storage controller(s) (both SCSI and ATA). Use any other irq's that aren't too busy and may be somewhat random. Staring at a 'systat 2 -vmstat' screen (right hand side) may give some clues. Then use rndcontrol(8) to set up the seeding. There is a knob in rc.conf to make this setting survive the next reboot. M > >Date: Thu, 03 Oct 2002 21:54:30 +0100 > > > > > Sorry, here is the rest: > > > > > > Here is the output of the `dd` command using urandom: > > > > > > dd if=/dev/urandom of=/dev/stdout bs=512 count=1 | hexdump -C > > > 1+0 records in > > > 1+0 records out > > > 00000000 a0 69 1a 7c 8f 32 e5 21 ae 7a 33 14 68 0b 8e a6 > > > |.i.|.2.!.z3.h...| > > > >... etc. Looking good. > > > > > $ ls -l /dev/*rand* > > > crw-r--r-- 1 root wheel 2, 3 Sep 3 21:46 /dev/random > > > crw-r--r-- 1 root wheel 2, 4 Sep 3 21:46 /dev/urandom > > > >Also good. > > > > > > > So then, as root I ran: `chmod 0666 /dev/stdout` and then I ran your > > > >`dd` > > > > > command and got: > > > > > > > > > > $ dd if=/dev/random of=/dev/stdout bs=512 count=1 | hexdump -C > > > > > 0+0 records in > > > > > 0+0 records out > > > > > 0 bytes transferred in 0.000036 secs (0 bytes/sec) > > > >Can you try a few of these while furiously abusing your keyboard? > >I'm trying to see if /dev/random can be persuaded to give _any_ > >aoutput at all. > > > >Maybe do it on a vty instead of in X. > > > >M > >-- > >o Mark Murray > >\_ > >O.\_ Warning: this .sig is umop ap!sdn > > > > > _________________________________________________________________ > Chat with friends online, try MSN Messenger: http://messenger.msn.com > -- o Mark Murray \_ O.\_ Warning: this .sig is umop ap!sdn To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message