mod x25519;

use self::x25519::x25519_shared_key;

use crate::Key;
use rand::RngCore;

#[inline]
pub fn generate_psk(rng: &mut impl RngCore) -> Key {
    let mut key: Key = [0; 32];
    rng.fill_bytes(&mut key);
    key
}

#[inline]
pub fn generate_privkey(rng: &mut impl RngCore) -> Key {
    let mut k = generate_psk(rng);

    // curve25519_clamp_secret
    k[0] &= 0xF8;
    k[31] = (k[31] & 127) | 64;
    k
}

#[inline]
pub fn get_pubkey(private_key: &Key) -> Key {
    let u = [
        9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0,
    ];

    x25519_shared_key(&u, private_key)
}