entropy status / benchmarks [was test an iso]

[coderman]

On 3/16/06, coderman <coderman at gmail.com> wrote:
> ...
> - does entropy mgmt on VIA hardware work? (c5test/c5keys/c5net)

for those with VIA/Intel/AMD hw entropy device support and a running
mtrngd you can get current status via '/etc/rc.d/rcS.mtrngd status'. 
logs are in /var/log/mtrngd/.

i'd be interesting in knowing run times for large amounts of entropy
gathered and mixed to /dev/random (gigabytes if it remains stable for
that long).  particularly for the Intel and AMD hw devices which i do
not currently have at my disposal for testing.

status output is similar to the following; sizes are in Bytes,
times/stats are in microseconds (not milli):

[Fri Mar 24 08:46:14-459926] Current MTRNGD Status:
  bad fips blocks ......: 13080
   monobit failures ___: 3359
   poker run failures _: 542707
   bit run failures  __: 1104377
   long run failures __: 9687
   cont run failures __: 35
  good fips blocks .....: 41614750
  hwrng read bytes .....: 104069575000
 entropy add bytes ....: 104036872320
  random writeable cnt .: 541858710
  hw entropy read stats ....:    min: 2479       avg:  3359      max:
22788      total: 139833561751
  rng fips check stats .....:    min: 904        avg:  919       max:
6464       total: 38267989605
  random recv starve stats .:    min: 3416       avg:  4305      max:
24018      total: 179159453561


you can stress /dev/random via 'bench-rng /dev/random 1024 1000000' or
simply 'cat /dev/random > /dev/null'.

uptime would be helpful.  note that i accidentally left "forgiving
fips check" set in the rcS.mtrngd script; this can be turned off for a
better real world test.  the forgiving option does not fail blocks
with poker or bit runs.  monobit, long, and continuous runs are always
critical and the block is discarded.

the FIPS check block size is 1500 bytes.  see
http://csrc.nist.gov/fips/fips1401.htm for more info.

by default entropy density is at 80% so take that into consideration
when calculating available /dev/random throughput.  ex:

entropy add bytes ....: 104036872320  x  0.80 == 83,229,497,856 Bytes
of actual entropy added to /dev/random pool.