Crypto

1 min read

Use these APIs for hashes, secure random bytes, and authenticated encryption. They produce byte arrays; use Encoding to display or store those bytes as text. Check the availability table before choosing encryption for a browser app.

Import: import system.crypto;

SHA-2 hashes, HMAC, a secure RNG, and AES-256-GCM. SHA-256, SHA-512, and HMAC-SHA256 give identical results on every target, including the browser. The secure RNG uses the operating system (native or Node) or Web Crypto in the browser. APIs return raw byte[] — format with encoding. Not TLS.

import system;
import system.crypto;
import system.encoding;

fun main() {
    let msg = Encoding.utf8_encode("hello");
    System.println(Encoding.hex_encode(Sha256.hash(msg)));
}

Runtime	Digests / CSPRNG	AES-GCM
Native / Node	yes	yes
Browser	Web Crypto	compile error (@native / @node only)

Call	Meaning
Sha256.hash(bytes)	32-byte digest
Sha512.hash(bytes)	64-byte digest
HmacSha256.sign(key, data)	HMAC
SecureRandom.bytes(n)	CSPRNG bytes
AesGcm / AesGcmKey	authenticated encryption (native/Node)

let key = AesGcmKey.generate().unwrap();
let nonce = AesGcm.generate_nonce().unwrap();
let plain = Encoding.utf8_encode("secret");
let aad = Encoding.utf8_encode("");
let cipher = (AesGcm.encrypt(key, nonce, plain, aad)).unwrap();
let back = (AesGcm.decrypt(key, nonce, cipher, aad)).unwrap();
System.println(Encoding.utf8_decode(back));

For games and tests, use Random instead of SecureRandom.