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    SubjectRe: [PATCH] API for true Random Number Generators to add entropy (2.6.11)
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    On Fri, 2005-03-25 at 18:25 +1100, Herbert Xu wrote:
    > On Fri, Mar 25, 2005 at 10:19:55AM +0300, Evgeniy Polyakov wrote:
    > >
    > > Noone will complain on Linux if NIC is broken and produces wrong
    > > checksum
    > > and HW checksum offloading is enabled using ethtools.
    >
    > This is completely different. The worst that can happen with checksum
    > offloading is that the packet is dropped. That's something people deal
    > with on a daily basis since the Internet as a whole does not guarantee
    > the delivery of packets.

    It will just completely stop network dataflow.
    It is of course not as catastrophic as removing strong random numbers
    from system.
    But nevertheless - write cahce in disks may corrupt data on power-down,
    but people do not turn it off, crypto HW can be broken and does not
    encrypt dataflow, but people want it, broken NIC can corrupt data with
    various sg/offload combinations, but it can be enabled.

    It is a feature, that _may_ broke thing badly.
    But if all is ok - it is extremly usefull.

    And as I said there may be other [HW/driver] validating techniques,
    not only userspace daemon.

    > On the other hand, /dev/random is something that has always promised
    > to deliver random numbers that are totally unpredictable. People out
    > there *depend* on this.
    >
    > If that assumption is violated the result could be catastrophic.
    >
    > That's why it's OK to have hardware RNG spit out unverified numbers
    > in /dev/hw_random, but it's absolutely unaccpetable for the same
    > numbers to add entropy to /dev/random without verification.

    Userspace daemon can read data from /dev/random and validate it
    in background, if it fells it is broken - turn feature off.

    --
    Evgeniy Polyakov

    Crash is better than data corruption -- Arthur Grabowski
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