Search Linux Wireless

Re: [PATCH v2] RANDOM: ATH9K RNG delivers zero bits of entropy

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Aug 09, 2016 at 02:04:44PM +0000, Jason Cooper wrote:
> 
> iiuc, Ted, you're saying using the hw_random framework would be
> disasterous because despite most drivers having a default quality of 0,
> rngd assumes 1 bit of entropy for every bit read?

Sorry, what I was trying to say (but failed) was that bypassing the
hwrng framework and injecting entropy directly the entropy pool was
disatrous.

> Thankfully, most hw_random drivers don't set the quality.  So unless the
> user sets the default_quality param, it's zero.

The fact that this is "most" and not "all" does scare me a little.

As far as I'm concerned *all* hw_random drivers should set quality to
zero, since it should be up to the system administrator.  Perhaps the
one exception is virtio_rng, since if you don't trust the hypvervisor,
the security of the VM is hopeless.  That being said, I have seen
configurations of KVM which use:

	-object rng-random,filename=/dev/urandom,id=rng0 \
	-device virtio-rng-pci,rng=rng0

Which is somewhat non-ideal.  (Try running od -x /dev/random on such a
guest system....)

					- Ted

--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Host AP]     [ATH6KL]     [Linux Wireless Personal Area Network]     [Linux Bluetooth]     [Linux Netdev]     [Kernel Newbies]     [Linux Kernel]     [IDE]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite Hiking]     [MIPS Linux]     [ARM Linux]     [Linux RAID]

  Powered by Linux