Re: DRBG parallel requests

2015-04-16 Thread Stephan Mueller
Am Donnerstag, 16. April 2015, 23:30:38 schrieb Herbert Xu: Hi Herbert, >On Thu, Apr 16, 2015 at 05:13:50PM +0200, Stephan Mueller wrote: >> Surely, the shadow approach scales better than a global lock. But its >> drawback is the (almost) identical state. > >The drawback is that your DRBG is no l

Re: DRBG parallel requests

2015-04-16 Thread Herbert Xu
On Thu, Apr 16, 2015 at 05:13:50PM +0200, Stephan Mueller wrote: > > Surely, the shadow approach scales better than a global lock. But its > drawback > is the (almost) identical state. The drawback is that your DRBG is no longer anything like that specified by the standard. You've completely ch

Re: DRBG parallel requests

2015-04-16 Thread Stephan Mueller
Am Donnerstag, 16. April 2015, 22:44:55 schrieb Herbert Xu: Hi Herbert, Rafael, >Hi Stephan: > >Currently you can have two users of DRBG issuing requests in >parallel and end up using the same internal state. The only >difference between them is the cycle counter that you inject >into the DRBG.

DRBG parallel requests

2015-04-16 Thread Herbert Xu
Hi Stephan: Currently you can have two users of DRBG issuing requests in parallel and end up using the same internal state. The only difference between them is the cycle counter that you inject into the DRBG. I can't see how this is safe as the cycle counter contains minimal entropy. The whole