jsonwebkey-thumbprint

Variable-Length Integer Encoding defined by RFC 7638.

Tables of Content

• Features
• Usage
• Security Considerations
• License

Features

• JWK Thumbprint pre-compute
• JWK Thumbprint when passing a hash and encoding function
• TypeScript types

Usage

import { jwkThumbprint } from "jsonwebkey-thumbprint";

// A public key exported as a JWK
const keypair = await crypto.subtle.generateKey("Ed25519", true, [
  "sign",
  "verify",
]);
const jwk = await crypto.subtle.exportKey("jwk", keypair.publicKey);

// Using sha-256 as a hash function and base64url as encoding
const hash = (b: BufferSource) => crypto.subtle.digest("SHA-256", b);
const decode = (u: ArrayBuffer) =>
  b64ToB64URL(b64ToB64NoPadding(u8ToB64(new Uint8Array(u))));

// Compute the JWK Thumbprint for the public key
console.log(await jwkThumbprint(jwk));

// Helper functions
const u8ToB64 = (u: Uint8Array) => btoa(String.fromCharCode(...u));

const b64ToB64URL = (s: string) => s.replace(/\+/g, "-").replace(/\//g, "_");

const b64ToB64NoPadding = (s: string) => s.replace(/=/g, "");

Security Considerations

This software has not been audited. Please use at your sole discretion.

License

This project is under the Apache-2.0 license.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be Apache-2.0 licensed as above, without any additional terms or conditions.