On Tue, Aug 09, 2016 at 06:30:03AM +0000, Pan, Miaoqing wrote: > Agree with Jason's point, also understand Stephan's concern. The > date rate can be roughly estimated by 'cat /dev/random |rngtest -c > 1000', the average speed is 1111.294Kibits/s. I will sent the patch > to disable ath9k RNG by default. If the ATH9K is generating some random amount of data, but you don't know how random, and you're gathering it opportunistically --- for example, suppose a wireless driver gets the radio's signal strength through the normal course of its operation, and while there might not be that much randomness for someone who can observe the exact details of how the phone is positioned in the room --- but for which the analyst sitting in Fort Meade won't know whether or not the phone is on the desk, or in a knapsack under the table, the right interface to use is: void add_device_randomness(const void *buf, unsigned int size); This won't increase the entropy count, but if you have the bit of potential randomness "for free", you might as well contribute it to the entropy pool. If it turns out that the chip was manufactured in China, and the MSS has backdoored it out the wazoo, it won't do any harm --- where as using the hwrng framework would be disastrous. Cheerfs, - Ted -- 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
