The crypto module provides basic cryptographic helpers for Goja runtimes. It exposes UUID generation, random byte generation, and Node-style createHash digest objects.

The module is aliased as both crypto and node:crypto. It is intentionally a lightweight subset, not a full Node.js crypto polyfill.

JavaScript usage

const crypto = require("crypto");

const id = crypto.randomUUID();
// e.g. "550e8400-e29b-41d4-a716-446655440000"

const buf = crypto.randomBytes(16);
// Buffer with 16 random bytes

const hash = crypto.createHash("sha256")
  .update("hello")
  .digest("hex");
// "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824"

Module API

randomUUID()

Generates a version-4 UUID string.

randomBytes(size)

Generates a Buffer containing size cryptographically secure random bytes. Throws a type error when size is negative.

createHash(algorithm)

Creates a hash object for the named algorithm. Supported algorithms:

• sha256
• sha512
• sha1
• md5

Returns a Go-backed object with two methods:

• update(data) — appends data to the hash state and returns the same object for chaining.
• digest(encoding?) — finalizes the hash and returns the digest.
  • Without an encoding, returns a Buffer.
  • With "hex", returns a hex string.
  • With "base64", returns a Base64 string.
  • Any other encoding throws a type error.

Security notes

This module exists primarily for Node.js compatibility and convenience helpers such as request signatures and content hashing. SHA-1 and MD5 are provided because callers may need to match existing third-party interfaces. For new designs requiring collision resistance, prefer sha256.

Troubleshooting