lkml.org 
[lkml]   [2013]   [Sep]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH] /dev/random: Insufficient of entropy on many architectures
    Date
    Am Dienstag, 10. September 2013, 14:25:24 schrieb Theodore Ts'o:

    Hi Theodore,

    >
    >Also note that the clocksource is not necessarily be the best choice;
    >it may not be the most fine grained sampling that we have available
    >(that is certainly be true for MIPS). So doing something hacky
    >doesn't absolve us from the need to example every single platform that
    >as a no-op get_cycles() function. (Well, at least those platforms
    >that we think really are going to be running security sensitive
    >systems ---- does anyone think we really have production systems
    >running m68k? Maybe, but....)

    That is why I arranged the clocksource call after get_cycles does not
    return anything, so it would only be used if get_cycles does not have
    anything.

    But then, your experience with clocksource really has a point.
    >
    >If we believed that /dev/random was actually returning numbers which
    >are exploitable, because of this, I might agree with the "we must do
    >SOMETHING" attitude. But I don't believe this to be the case. Also
    >note that we're talking about embedded platforms, where upgrade cycles
    >are measured in years --- if you're lucky. There are probably home
    >routers still stuck on 2.6, at which point they will be far more
    >succeptible to the problems described at http://factorable.net.

    The core problem I guess on this matter is again the strange use of
    /dev/random in embedded devices -- no seeding, no spinning disks, no
    heads, no nothing.

    Here my CPU jitter RNG would help, but there seems to be no interest in
    even discussing it... PS: I have my CPU jitter RNG running running as an
    entropy feeder daemon nicely on my router box, though, which happens to
    be a MIPS box...
    >
    >So I don't think we need to rush. I'd much rather make sure we get
    >this fixed right.
    >
    > - Ted


    Ciao
    Stephan


    \
     
     \ /
      Last update: 2013-09-10 21:21    [W:3.384 / U:0.012 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site