# Constantine
# Copyright (c) 2018-2019    Status Research & Development GmbH
# Copyright (c) 2020-Present Mamy André-Ratsimbazafy
# Licensed and distributed under either of
#   * MIT license (license terms in the root directory or at http://opensource.org/licenses/MIT).
#   * Apache v2 license (license terms in the root directory or at http://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.

import
  std/unittest,
  ../constantine/csprngs/sysrand

suite "[CSPRNG] sysrand":
  test "Non-nil initialization":
    # Initializing to full 0 has a chance of 2^-256
    proc checkNonNil() =
      var buf: array[32, byte] # zero-init

      doAssert sysrand(buf)

      var nonNil = false
      for b in buf:
        nonNil = nonNil or (b != byte 0)

      doAssert nonNil

    checkNonNil()

  # TODO:
  # - Hamming weight average 50%
  # - statistics/hypothesis tests