ipsec_ranbits - generate random bits in ASCII form
ipsec ranbits [--quick] [--continuous] [--bytes] nbits
Ranbits obtains nbits (rounded up to the nearest byte) high-quality
random bits from random(4), and emits them on standard output as an
ASCII string. The default output format is datatot(3) h format:
lowercase hexadecimal with a 0x prefix and an underscore every 32 bits.
The --quick option produces quick-and-dirty random bits: instead of
using the high-quality random bits from /dev/random, which may take
some time to supply the necessary bits if nbits is large, ranbits uses
/dev/urandom, which yields prompt results but lower-quality randomness.
The --continuous option uses datatot(3) x output format, like h but
without the underscores.
The --bytes option causes nbits to be interpreted as a byte count
rather than a bit count.
Written for the Linux FreeS/WAN project <http://www.freeswan.org> by
There is an internal limit on nbits, currently 20000.
Without --quick, ranbits’s run time is difficult to predict. A request
for a large number of bits, at a time when the system’s entropy pool is
low on randomness, may take quite a while to satisfy.
Though not a bug of ranbits, the direct use of /dev/hw_random, the
Linux hardware random number generator is not supported because it can
produce very non-random data. To properly use /dev/hw_random, the rngd
daemon should be used to read from /dev/hw_random and write to
/dev/random, while performing a FIPS test on the hardware random read.
No changes to Openswan are required for this support - just a running