Crypto for WASI

While optimizing compilers could allow efficient implementation of cryptographic features in WebAssembly, there are several occasions as below where a host implementation is more desirable. WASI-crypto aims to fill those gaps by defining a standard interface as a set of APIs. Current not support android.

Prerequisites

For installation with the installer, you can follow the commands:

curl -sSf https://raw.githubusercontent.com/WasmEdge/WasmEdge/master/utils/install.sh | bash -s -- -v 0.12.1 --plugins wasi_crypto

You can also build WasmEdge with WASI-Crypto plug-in from source.

Write WebAssembly Using WASI-Crypto

(Optional) Rust Installation

For importing WASI-Crypto in rust, you should use the wasi-crypto binding in your cargo.toml

[dependencies]
wasi-crypto = "0.1.5"

High Level Operations

Hash Function

#![allow(unused)]
fn main() {
// hash "test" by SHA-256
let hash : Vec<u8> = Hash::hash("SHA-256", b"test", 32, None)?;
assert_eq!(hash.len(), 32);
}

Message Authentications function

#![allow(unused)]
fn main() {
// generate key
let key = AuthKey::generate("HMAC/SHA-512")?;
// generate tag
let tag = Auth::auth("test", &key)?;
// verify
Auth::auth_verify("test", &key, tag)?;
}

Key Driven function

Example:

#![allow(unused)]
fn main() {
let key = HkdfKey::generate("HKDF-EXTRACT/SHA-512")?;
let prk = Hkdf::new("HKDF-EXPAND/SHA-512", &key, Some(b"salt"))?;
let derived_key = prk.expand("info", 100)?;
assert_eq!(derived_key.len(), 100);
}

Signatures Operation

Example:

#![allow(unused)]
fn main() {
let pk = SignaturePublicKey::from_raw("Ed25519", &[0; 32])?;

let kp = SignatureKeyPair::generate("Ed25519")?;
let signature = kp.sign("hello")?;

kp.publickey()?.signature_verify("hello", &signature)?;
}