[lkml]   [2007]   [Dec]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: /dev/urandom uses uninit bytes, leaks user data
    Andrew Lutomirski wrote:
    > I understand that there's no way that /dev/random can provide good
    > output if there's insufficient entropy. But it still shouldn't leak
    > arbitrary bits of user data that were never meant to be put into the
    > pool at all.

    It doesn't leak it though, it consumes it, and it then vanishes into the
    entropy pool, never to be seen again.

    > Step 1: Boot a system without a usable entropy source.
    > Step 2: add some (predictable) "entropy" from userspace which isn't a
    > multiple of 4, so up to three extra bytes get added.
    > Step 3: Read a few bytes of /dev/random and send them over the network.

    Only root can do 1 and 2, at which point, it's already game over.

     \ /
      Last update: 2007-12-20 21:19    [W:0.054 / U:75.144 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site