On Tue, Dec 11, 2007 at 12:06:43AM +0100, Marc Haber wrote: > On Sun, Dec 09, 2007 at 10:16:05AM -0600, Matt Mackall wrote: > > On Sun, Dec 09, 2007 at 01:42:00PM +0100, Marc Haber wrote: > > > On Wed, Dec 05, 2007 at 03:26:47PM -0600, Matt Mackall wrote: > > > > The distinction between /dev/random and /dev/urandom boils down to one > > > > word: paranoia. If you are not paranoid enough to mistrust your > > > > network, then /dev/random IS NOT FOR YOU. Use /dev/urandom. > > > > > > But currently, people who use /dev/urandom to obtain low-quality > > > entropy do a DoS for the paranoid people. > > > > Not true, as I've already pointed out in this thread. > > I must have missed this. Can you please explain again? For a layman it > looks like a paranoid application cannot read 500 Bytes from > /dev/random without blocking if some other application has previously > read 10 Kilobytes from /dev/urandom.
/dev/urandom always leaves enough entropy in the input pool for /dev/random to reseed. Thus, as long as entropy is coming in, it is not possible for /dev/urandom readers to starve /dev/random readers. But /dev/random readers may still block temporarily and they should damn well expect to block if they read 500 bytes out of a 512 byte pool. -- Mathematics is the supreme nostalgia of our time. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/