lib.rs

// Copyright © 2021 Łukasz Kurowski. All rights reserved.
// SPDX-License-Identifier: BSD-3-Clause
#![feature(in_band_lifetimes)]

use ocaml::bigarray::Array1;
use zeroize::Zeroize;

struct Keypair(schnorrkel::Keypair);

ocaml::custom!(Keypair);

#[ocaml::func]
pub fn generate_keypair() -> ocaml::Pointer<Keypair> {
    let keypair = schnorrkel::Keypair::generate();
    ocaml::Pointer::alloc_custom(Keypair(keypair))
}

#[ocaml::func]
pub unsafe fn keypair_to_bytes(keypair: ocaml::Pointer<Keypair>) -> Array1<u8> {
    let mut bytes = keypair.as_ref().0.to_bytes();
    // copy bytes to bigarray, they are zeroized on ocaml side
    let res = Array1::from_slice(bytes);
    // zeroize the keypair bytes
    bytes.zeroize();
    res
}

struct PublicKey(schnorrkel::PublicKey);

ocaml::custom!(PublicKey);

#[ocaml::func]
pub unsafe fn public_key_bytes(keypair: ocaml::Pointer<Keypair>) -> Array1<u8> {
    let mut bytes = keypair.as_ref().0.public.to_bytes();
    // copy bytes to bigarray, they are zeroized on ocaml side
    let res = Array1::from_slice(bytes);
    // zeroize the public key bytes
    bytes.zeroize();
    res
}

struct Signature(schnorrkel::Signature);

ocaml::custom!(Signature);

#[ocaml::func]
pub unsafe fn keypair_sign(
    keypair: ocaml::Raw,
    //ctx: Vec<u8>,
    //bytes: Vec<u8>,
    ctx: &'a [u8],
    bytes: &[u8],
) -> ocaml::Pointer<'a, Signature> {
    let keypair = keypair.as_pointer::<Keypair>();
    //let ctx = schnorrkel::signing_context(&ctx);
    //let signature = keypair.as_ref().0.sign(ctx.bytes(&bytes));
    let ctx = schnorrkel::signing_context(ctx);
    let signature = keypair.as_ref().0.sign(ctx.bytes(bytes));
    ocaml::Pointer::alloc_custom(Signature(signature))
}