@rcompat/crypto

Cryptographic functions for JavaScript runtimes.

What is @rcompat/rypto?

A cross-runtime module providing cryptographic utilities including hashing and access to the Web Crypto API. Works consistently across Node, Deno, and Bun, using native implementations where available.

Installation

npm install @rcompat/crypto

pnpm add @rcompat/crypto

yarn add @rcompat/crypto

bun add @rcompat/crypto

Usage

hash

Generate a short hash from data. Useful for cache busting, fingerprinting, or generating unique identifiers.

import hash from "@rcompat/crypto/hash";

// Hash a string
const h1 = await hash("hello world");
console.log(h1);  // "b94d27b9934d3e08a52n"

// Hash with different algorithm
const h2 = await hash("hello world", "SHA-512");

// Hash binary data
const buffer = new TextEncoder().encode("hello world");
const h3 = await hash(buffer);

// Hash an ArrayBuffer
const arrayBuffer = new ArrayBuffer(16);
const h4 = await hash(arrayBuffer);

The hash function returns a 21-character string: 20 hex characters followed by "n" (for "numeric hash").

API Reference

hash(data, algorithm?)

import type { TypedArray } from "@rcompat/type";
type Algorithm = "SHA-256" | "SHA-384" | "SHA-512";

declare function hash(
  data: string | ArrayBuffer | TypedArray,
  algorithm?: Algorithm
): Promise<string>;

Generates a short hash from the input data.

| Parameter | Type | Default | Description | |-------------|---------------------------------------|--------------|-----------------------| | data | string \| ArrayBuffer \| TypedArray | — | Data to hash | | algorithm | string | "SHA-256" | Hash algorithm |

Returns: A promise that resolves to a 21-character hash string.

Supported algorithms:

• "SHA-256" (default)
• "SHA-384"
• "SHA-512"

Examples

Cache busting for assets

import hash from "@rcompat/crypto/hash";

async function getAssetUrl(content) {
  const fingerprint = await hash(content);
  return `/assets/bundle.${fingerprint}.js`;
}

const url = await getAssetUrl(bundleContents);
// "/assets/bundle.b94d27b9934d3e08a52n.js"

Content-based deduplication

import hash from "@rcompat/crypto/hash";

const seen = new Set();

async function processUnique(content) {
  const contentHash = await hash(content);

  if (seen.has(contentHash)) {
    return null;  // Already processed
  }

  seen.add(contentHash);
  return process(content);
}

Cross-Runtime Compatibility

| Runtime | Supported | |---------|-----------| | Node.js | ✓ | | Deno | ✓ | | Bun | ✓ |

No configuration required — just import and use.

License

MIT

Contributing

See CONTRIBUTING.md in the repository root.