Module Mirage_crypto_rng_miou_unix

Pfortuna, a domain-safe CSPRNG proposed by Schneier.

Type of tasks seeding the RNG.

initialize ?g ?sleep (module Generator) will allow the RNG to operate in a returned task. This task periodically launches sub-tasks that seed the engine (using getrandom(), getentropy() or BCryptGenRandom() depending on the system). These sub-tasks must be cleaned periodically (in seconds) according to the sleep parameter given (defaults to 1 second).

The user must then kill the returned task at the end of the program to be sure to clean everything. Otherwise, Miou will complain with the exception Still_has_children.

We strongly recommend using Pfortuna as an RNG engine rather than Mirage_crypto_rng.Fortuna. The engine is launched in parallel with the other tasks if at least one domain is available. To ensure that there is no compromise in the values generated by a data-race, Pfortuna is an domain-safe implementation of Fortuna.

The user cannot make any subsequent calls to initialize. In other words, you can only initialise a single rng task. You must kill the returned rng if you want to re-initialise the RNG.

A basic usage of mirage-crypto-rng-miou-unix is:

let () = Miou_unix.run @@ fun () ->
  let rng = Mirage_crypto_rng_miou_unix.(initialize (module Pfortuna)) in
  let str = Mirage_crypto_rng.generate 16 in
  Format.printf "random: %S\n%!" str;
  Mirage_crypto_rng_miou_unix.kill rng

kill rng terminates the background task which seeds the RNG.