Problem with /dev/random?

Vladimir G. Ivanovic vladimir at acm.org
Fri May 14 13:13:31 UTC 2004


What I meant is that there are no error messages related to random in my
current syslog. Unfortunately the service was started up normally (and was
logged in a rotated log file).

Thanks for catching the typo in my command. It should be:

   # cat entropy_avail
   # dd if=/dev/urandom of=/dev/random count=512
   # cat entropy_avail
   0
   512+0 records in
   512+0 records out
   0

I am not trying to initialize /dev/random; I'm trying to create some
entropy (even if it's of poor quality). According to Kent, you do this
by writing to /dev/random. But this test still doesn't produce any
entropy.

--- Vladimir

------------------------------------------------------------------------
Vladimir G. Ivanovic                        http://leonora.org/~vladimir
2770 Cowper St.                                         vladimir at acm.org
Palo Alto, CA 94306-2447                                 +1 650 678 8014
------------------------------------------------------------------------
>>>>> "ckj" == Christopher K Johnson <ckjohnson at gwi.net> writes:

    ckj> 
    ckj> Vladimir G. Ivanovic wrote:
    >> The text "random" doesn't apprear in either /var/log/messages or
    >> dmesg.
    >> 
    >> 
    >> 
    ckj> That is interesting.  There is a service named random to save/restore
    ckj> the entropy pool and it produces a message at each startup and shutdown.
    ckj> It is provided by the initscripts rpm.
    ckj> May 13 05:56:58 chris random: Initializing random number generator:
    ckj> succeeded
    ckj> May 13 20:01:35 chris random: Saving random seed:  succeeded
    ckj> 
    ckj> chkconfig --list random
    ckj> random          0:off   1:off   2:on    3:on    4:on    5:on    6:off
    ckj> 
    ckj> And it initializes things differently.
    ckj> 
    ckj> There is a problem with how you initialized /dev/urandom, in that it is
    ckj> used as input, not output in your dd statement:
    ckj> 
    ckj> dd if=/dev/urandom of=/dev/random-seed count=512
    ckj> 
    ckj> Understandably this does not create any random data.  You cannot simply
    ckj> reverse it because there is no /dev/random-seed to take data from (at
    ckj> least not on my system).
    ckj> 
    ckj> Try
    ckj> service random start
    ckj> 
    ckj> -- 
    ckj> -----------------------------------------------------------
    ckj>    "Spend less!  Do more!  Go Open Source..." -- Dirigo.net
    ckj>    Chris Johnson, RHCE #807000448202021
    ckj> 
    ckj> 
    ckj> 
    ckj> -- 
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    ckj> 





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