From: Steve Grubb <sgrubb@xxxxxxxxxx> Date: Thu, 8 Sep 2011 07:48:27 -0400 > On Thursday, September 08, 2011 04:44:20 AM Christoph Hellwig wrote: >> On Wed, Sep 07, 2011 at 11:27:12PM +0200, Stephan Mueller wrote: >> > And exactly that is the concern from organizations like BSI. Their >> > cryptographer's concern is that due to the volume of data that you can >> > extract from /dev/urandom, you may find cycles or patterns that increase >> > the probability to guess the next random value compared to brute force >> > attack. Note, it is all about probabilities. >> >> So don't use /dev/urandom if you don't like the behaviour. Breaking all >> existing application because of a certification is simply not an option. > > This patch does not _break_ all existing applications. If a system were under attack, > they might pause momentarily, but they do not break. Please, try the patch and use a > nice large number like 2000000 and see for yourself. Right now, everyone arguing about > this breaking things have not tried it to see if in fact things do break and how they > break if they do. If the application holds a critical resource other threads want when it blocks on /dev/urandom, then your change breaks things. I can come up with more examples if you like. Please get off this idea that you can just change the blocking behavior for a file descriptor and nothing of consequence will happen. When this happens in the networking due to a bug or similar, we know it does break things. -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
