def random_bytes

bend-collections-laws-crypto@1.0.0.0 · src/crypto/password.bend:90

import Base

90# n bytes from the operating system's generator.
91def random_bytes(n: Nat) -> IO(List<&2, U32>):
92  match n:
93    case 0n:
94      IO.pure(List<&2, U32>, Nil{})
95    case 1n+k:
96      do IO<List<&2, U32>>:
97        w : U32 <- IO.try(U32, IO.random_u32())
98        rest : List<&2, U32> <- random_bytes(k)
99        return U32.and(w, 255) <> rest