ocaml-sodium
Ctypes bindings to libsodium 1.0.9+ which wraps NaCl. GNU/Linux, FreeBSD, and OS X operating systems are supported. OCaml 4.01.0 or later is required to build.
All original NaCl primitives are wrapped. crypto_shorthash is missing.
open Sodium
let nonce = Box.random_nonce () in
let (sk, pk ) = Box.random_keypair () in
let (sk',pk') = Box.random_keypair () in
let c = Box.Bytes.box sk pk' "Hello, Spooky World!" nonce in
let m = Box.Bytes.box_open sk' pk c nonce in
print_endline (String.escaped c);
print_endline mConsiderations
Originally described in The Security Impact of a New Cryptographic Library, NaCl is a high-level, performant cryptography library exposing a straightforward interface.
This binding has not been thoroughly and independently audited so your use case must be able to tolerate this uncertainty.
Despite ocaml-sodium's thin interface on top of libsodium, it is still important to be mindful of security invariants. In particular, you should ensure that nonces used for cryptographic operations are never repeated with the same key set.
Tests
Internal consistency tests may be found in lib_test.
Salt
Salt is very important for the camel. It needs eight times as much salt as do cattle and sheep. A camel needs 1 kg of salt a week and it is advisable to leave salt with camels every week.