Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-17 Thread Austin S Hemmelgarn
On 2014-03-16 18:56, H. Peter Anvin wrote: On 03/03/2014 03:51 PM, Kees Cook wrote: When bringing a new RNG source online, it seems like it would make sense to use some of its bytes to make the system entropy pool more random, as done with all sorts of other devices that contain per-device or

Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-16 Thread H. Peter Anvin
On 03/03/2014 03:51 PM, Kees Cook wrote: When bringing a new RNG source online, it seems like it would make sense to use some of its bytes to make the system entropy pool more random, as done with all sorts of other devices that contain per-device or per-boot differences. Signed-off-by:

Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-16 Thread H. Peter Anvin
On 03/04/2014 02:39 PM, Matt Mackall wrote: [temporarily coming out of retirement to provide a clue] The pool mixing function is intentionally _reversible_. This is a crucial security property. That means, if I have an initial secret pool state X, and hostile attacker controlled data Y,

Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-10 Thread Herbert Xu
On Thu, Mar 06, 2014 at 07:55:33AM -0500, Jason Cooper wrote: On Mon, Mar 03, 2014 at 03:51:48PM -0800, Kees Cook wrote: When bringing a new RNG source online, it seems like it would make sense to use some of its bytes to make the system entropy pool more random, as done with all sorts of

Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-06 Thread Jason Cooper
On Wed, Mar 05, 2014 at 06:52:27PM -0600, Matt Mackall wrote: On Wed, 2014-03-05 at 16:11 -0500, Jason Cooper wrote: In other words, if there are 4096 bits of unknownness in X to start with, and I can get those same 4096 bits of unknownness back by unmixing X' and Y, then there must

Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-06 Thread Jason Cooper
On Mon, Mar 03, 2014 at 03:51:48PM -0800, Kees Cook wrote: When bringing a new RNG source online, it seems like it would make sense to use some of its bytes to make the system entropy pool more random, as done with all sorts of other devices that contain per-device or per-boot differences.

Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-05 Thread Jason Cooper
Matt, Kees, On Tue, Mar 04, 2014 at 04:39:57PM -0600, Matt Mackall wrote: On Tue, 2014-03-04 at 11:59 -0800, Kees Cook wrote: On Tue, Mar 4, 2014 at 11:53 AM, Jason Cooper ja...@lakedaemon.net wrote: On Tue, Mar 04, 2014 at 11:01:49AM -0800, Kees Cook wrote: On Tue, Mar 4, 2014 at 7:38

Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-05 Thread Kees Cook
On Wed, Mar 5, 2014 at 1:11 PM, Jason Cooper ja...@lakedaemon.net wrote: Matt, Kees, On Tue, Mar 04, 2014 at 04:39:57PM -0600, Matt Mackall wrote: On Tue, 2014-03-04 at 11:59 -0800, Kees Cook wrote: On Tue, Mar 4, 2014 at 11:53 AM, Jason Cooper ja...@lakedaemon.net wrote: On Tue, Mar 04,

Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-05 Thread Matt Mackall
On Wed, 2014-03-05 at 16:11 -0500, Jason Cooper wrote: In other words, if there are 4096 bits of unknownness in X to start with, and I can get those same 4096 bits of unknownness back by unmixing X' and Y, then there must still be 4096 bits of unknownness in X'. If X' is 4096 bits long,

Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-05 Thread Kees Cook
On Wed, Mar 5, 2014 at 4:52 PM, Matt Mackall m...@selenic.com wrote: On Wed, 2014-03-05 at 16:11 -0500, Jason Cooper wrote: In other words, if there are 4096 bits of unknownness in X to start with, and I can get those same 4096 bits of unknownness back by unmixing X' and Y, then there must

Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-04 Thread Jason Cooper
Kees, Ted, On Mon, Mar 03, 2014 at 03:51:48PM -0800, Kees Cook wrote: When bringing a new RNG source online, it seems like it would make sense to use some of its bytes to make the system entropy pool more random, as done with all sorts of other devices that contain per-device or per-boot

Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-04 Thread Kees Cook
On Tue, Mar 4, 2014 at 7:38 AM, Jason Cooper ja...@lakedaemon.net wrote: Kees, Ted, On Mon, Mar 03, 2014 at 03:51:48PM -0800, Kees Cook wrote: When bringing a new RNG source online, it seems like it would make sense to use some of its bytes to make the system entropy pool more random, as

Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-04 Thread Jason Cooper
On Tue, Mar 04, 2014 at 11:01:49AM -0800, Kees Cook wrote: On Tue, Mar 4, 2014 at 7:38 AM, Jason Cooper ja...@lakedaemon.net wrote: Kees, Ted, On Mon, Mar 03, 2014 at 03:51:48PM -0800, Kees Cook wrote: When bringing a new RNG source online, it seems like it would make sense to use some

Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-04 Thread Kees Cook
On Tue, Mar 4, 2014 at 11:53 AM, Jason Cooper ja...@lakedaemon.net wrote: On Tue, Mar 04, 2014 at 11:01:49AM -0800, Kees Cook wrote: On Tue, Mar 4, 2014 at 7:38 AM, Jason Cooper ja...@lakedaemon.net wrote: Kees, Ted, On Mon, Mar 03, 2014 at 03:51:48PM -0800, Kees Cook wrote: When

Re: [PATCH][RESEND 3] hwrng: add randomness to system from rng sources

2014-03-04 Thread Matt Mackall
On Tue, 2014-03-04 at 11:59 -0800, Kees Cook wrote: On Tue, Mar 4, 2014 at 11:53 AM, Jason Cooper ja...@lakedaemon.net wrote: On Tue, Mar 04, 2014 at 11:01:49AM -0800, Kees Cook wrote: On Tue, Mar 4, 2014 at 7:38 AM, Jason Cooper ja...@lakedaemon.net wrote: Kees, Ted, On Mon, Mar 03,