Date: Sun, 06 Oct 2002 11:31:30 +0100 From: Mark Murray <mark@grondar.za> To: "Firsto Lasto" <firstolasto@hotmail.com> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: PRNG not seeded - error in non-root ssh inside 4.6.2 jails... Message-ID: <200210061031.g96AVUh5011845@grimreaper.grondar.org> In-Reply-To: <F1404zadTMVwVn20lbh00000221@hotmail.com> ; from "Firsto Lasto" <firstolasto@hotmail.com> "Thu, 03 Oct 2002 15:29:01 PDT." References: <F1404zadTMVwVn20lbh00000221@hotmail.com>
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> Ok, I am not sure how I can do that though - I cannot successfully run > `rndcontrol -s X` inside a jail. > > On the other hand, I already have: > > rand_irqs="9 10 11 13 14" > > In my rc.conf on the underlying host machine, and have done several boots > with that in place. So presumably I should be seeded just fine, but if I am > not, I cannot change that in the jail because it seems I cannot set that (I > assume it is a sysctl issue). > > Willing to try whatever you can think of next :) Hokay. Can you grovel around inside OpenSSL (src/crypto/openssl/...) and find where the random device is read? If it is /dev/random, then change that to /dev/urandom. See how that works. M > > > 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 > > > > > _________________________________________________________________ > Send and receive Hotmail on your mobile device: http://mobile.msn.com > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-hackers" in the body of the message -- 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
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