Frank Denis jedisct1

How to embed C/C++ code in a Rust project targeting WebAssembly

When targeting WebAssembly, C/C++ code can be compiled as a library, and then get statically linked to a Rust project.

Step 1

Install the Zig toolchain in order to compile C and C++ code to WebAssembly.

zig cc is available for many platforms including Windows, and makes it easy to switch back and forth between native and wasm targets. WebAssembly is a Tier-1 target, and it was successfully used to port libraries such as ffmpeg, zlib, openssl, boringssl and libsodium.

std.crypto changes

New features

Salsa20: round-reduced variants can now be used.
The POLYVAL universal hash function was added.
AEGIS: support for 256-bit tags was added.
A MAC API was added to AEGIS (std.crypto.auth.aegis) - AEGIS can be used as a high-performance MAC on systems with hardware AES support. Note that this is not a hash function; a secret key is absolutely required in order to authenticate untrusted messages.
Edwards25519: a rejectLowOrder() function was added to quickly reject low-order points.
HKDF: with extractInit(), a PRK can now be initialized with only a salt, the keying material being added later, possibly as multiple chunks.

	#! /bin/sh

	IPV4_RANGES=(
	"23.235.32.0/20"
	"43.249.72.0/22"
	"103.244.50.0/24"
	"103.245.222.0/23"
	"103.245.224.0/24"
	"104.156.80.0/20"
	"140.248.64.0/18"

	#!/usr/bin/env python3

	import argparse
	import base64
	import hashlib
	import json
	import os
	import secrets
	import sys
	import time

	// Create a key pair for the app and a CSR:
	// $ openssl ecparam -genkey -name prime256v1 -out application.key
	// $ openssl req -new -sha256 -key application.key -out request.csr

	package main

	import (
	"crypto/ecdsa"
	"crypto/elliptic"
	"crypto/rand"

	package main

	import (
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"
	"encoding/pem"
	"fmt"
	"log"
	"os"

	// Cargo.toml:
	// [dependencies]
	// boring = { package = "superboring", version = "0.1.2" }

	fn main() -> Result<(), Box<dyn std::error::Error>> {
	// Ciphertext
	let ciphertext = include_bytes!("signed_message.bin");

	// Unencrypted RSA private key in PEM format
	let rsa_pem = include_str!("sessionprivatekey.pem");

	// Cargo.toml:
	// [dependencies]
	// rsa = "0.9.6"
	// rand = "0.8.5"

	fn main() -> Result<(), Box<dyn std::error::Error>> {
	use rsa::pkcs8::DecodePrivateKey as _;

	// Ciphertext
	let ciphertext = include_bytes!("signed_message.bin");

	use flate2::Compression;
	use std::io::prelude::*;

	use benchmark_simple::*;

	fn memusage() -> usize {
	#[cfg(target_arch = "wasm32")]
	let z = core::arch::wasm32::memory_grow(0, 0);

	#[cfg(not(target_arch = "wasm32"))]

	package main

	import (
	"crypto/aes"
	"net"
	)

	func EncryptIp(key []byte, ip net.IP) net.IP {
	cipher, err := aes.NewCipher(key)
	if err != nil {