//! The single place where we generate random material for our own use.

use alloc::vec;

use alloc::vec::Vec;

use crate::crypto::SecureRandom;

/// Make a [`Vec<u8>`] of the given size containing random material.

pub(crate) fn random_vec(

    secure_random: &dyn SecureRandom,

    len: usize,

) -> Result<Vec<u8>, GetRandomFailed> {

    let mut v = vec![0; len];

    secure_random.fill(&mut v)?;

    Ok(v)

}

/// Return a uniformly random [`u32`].

pub(crate) fn random_u32(secure_random: &dyn SecureRandom) -> Result<u32, GetRandomFailed> {

    let mut buf = [0u8; 4];

    secure_random.fill(&mut buf)?;

    Ok(u32::from_be_bytes(buf))

}

/// Return a uniformly random [`u16`].

pub(crate) fn random_u16(secure_random: &dyn SecureRandom) -> Result<u16, GetRandomFailed> {

    let mut buf = [0u8; 2];

    secure_random.fill(&mut buf)?;

    Ok(u16::from_be_bytes(buf))

}

/// Random material generation failed.

#[derive(Debug)]

pub struct GetRandomFailed;