Hi Ted, Peter, On 10/09/2013 06:07 PM, H. Peter Anvin wrote: > On 10/09/2013 07:46 AM, Stanimir Varbanov wrote: >> >> No, there is no public documentation for the block. Here is the driver >> documentation which I used as a base [1]. >> >> My guess was that - if it is PRNG (got from hardware description link >> above) than according to wiki [2] it is also known as a deterministic >> random bit generator (DRBG). The recommendation for RNG using DRBG is >> NIST 800-90. >> >> Of course I could be wrong, so I can add a comment that this is just a >> guess and we shouldn't over-reliance on this. >> > > There needs to be an architecturally guaranteed lower bound on the > entropic content for this to be at all useful. However, the hwrandom > interface is currently expecting fully entropic output (which is almost > certainly bogus... consider the PowerPC random number generator[1]) and > so using it for a PRNG output is directly wrong. This is part of why > RDRAND support is implemented directly in rngd so that we can do the > required cryptographic data reduction to produce fully entropic output. I ran the rngtest with following command line: # cat /dev/hw_random | rngtest -c 100000 Copyright (c) 2004 by Henrique de Moraes Holschuh This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. rngtest: starting FIPS tests... rngtest: bits received from input: 2000000032 rngtest: FIPS 140-2 successes: 99925 rngtest: FIPS 140-2 failures: 75 rngtest: FIPS 140-2(2001-10-10) Monobit: 10 rngtest: FIPS 140-2(2001-10-10) Poker: 9 rngtest: FIPS 140-2(2001-10-10) Runs: 20 rngtest: FIPS 140-2(2001-10-10) Long run: 38 rngtest: FIPS 140-2(2001-10-10) Continuous run: 0 rngtest: input channel speed: (min=1.267; avg=53.222; max=2384.186)Mibits/s rngtest: FIPS tests speed: (min=3.016; avg=48.847; max=49.931)Mibits/s rngtest: Program run time: 75191914 microseconds Could you guys comment those results? regards, Stan -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
