mirage-crypto-rng 1.2.0 · OCaml Package

Entropy sources and collection

type source

Entropy sources.

val sources : unit -> source list

sources () returns the list of available sources.

val pp_source : Format.formatter -> source -> unit

pp_source ppf source pretty-prints the entropy source on ppf.

val register_source : string -> source

register_source name registers name as entropy source.

Bootstrap

val whirlwind_bootstrap : int -> string

whirlwind_bootstrap id exploits CPU-level data races which lead to execution-time variability. It returns 200 bytes random data prefixed by id.

See http://www.ieee-security.org/TC/SP2014/papers/Not-So-RandomNumbersinVirtualizedLinuxandtheWhirlwindRNG.pdf for further details.

val cpu_rng_bootstrap : (int -> string, [ `Not_supported ]) Result.t

cpu_rng_bootstrap id returns 8 bytes of random data using the CPU RNG (rdseed). On 32bit platforms, only 4 bytes are filled. The id is used as prefix. If only rdrand is available, the return value is the concatenation of 512 calls to rdrand.

raises Failure
if rdrand fails 512 times, or if rdseed fails and rdrand is not available.

val bootstrap : int -> string

bootstrap id is either cpu_rng_bootstrap, if the CPU supports it, or whirlwind_bootstrap if not.

Timer source

val interrupt_hook : unit -> string

interrupt_hook collects lower bytes from the cycle counter, to be used for entropy collection in the event loop.

val timer_accumulator : g option -> unit -> unit

timer_accumulator g is the accumulator for the timer source, applying interrupt_hook on each call.

Periodic pulled sources

val feed_pools : 
  g option ->
  source ->
  (unit -> (string, [ `No_random_available ]) result) ->
  unit

feed_pools g source f feeds all pools of g using source by executing f for each pool.

val cpu_rng : (g option -> unit -> unit, [ `Not_supported ]) Result.t

cpu_rng g uses the CPU RNG (rdrand or rdseed) to feed all pools of g. It uses feed_pools internally. If neither rdrand nor rdseed are available, `Not_supported is returned.

val rdrand_calls : unit -> int

rdrand_calls () returns the number of rdrand calls.

val rdrand_failures : unit -> int

rdrand_failures () returns the number of rdrand failures.

val rdseed_calls : unit -> int

rdseed_calls () returns the number of rdseed calls.

val rdseed_failures : unit -> int

rdseed_failures () returns the number of rdseed failures.

package mirage-crypto-rng

Bootstrap

Timer source

Periodic pulled sources