Maskodid

Simple in-browser DID identity wallet

Rationale

When working with DID you eventually need a thing called Identity Wallet to store a private key, make compliant signatures and decrypt messages. It requires installing (and oftentimes building) custom browser extension, phone application, or heavily relying on external cloud infrastructure, which turns development into a nightmare. Maskodid is a simple in-browser Identity Wallet perfectly suited for development and testing of web-based DID solutions. It eliminates external dependencies, making development process fast and pleasant.

Installation

npm install maskodid

Usage

Maskodid allows an application to have three DID-related functions:

• get user's DID,
• create JSON Web Signature,
• decrypt JSON Web Encryption message

Get user's DID

This would ask a user for permission to share her DID with the application. If there is no private key, the user is asked to create DID first.

import { Maskodid } from "maskodid";
const maskodid = new Maskodid();
// Get DID
const did = await maskodid.authenticate(); // did:key:z...

Create JSON Web Signature

The result is JWS in compact form. If passed DID does not match with the user's DID, the call throws an error.

import { Maskodid } from "maskodid";
const maskodid = new Maskodid();
// First, get DID
const did = await maskodid.authenticate();
// Then sign
const jws = await maskodid.sign({ aud: "*", hello: "world" }, did);
// You could also add protected headers to the resulting JWS
const jwt = await maskodid.sign({ aud: "*", hello: "world" }, did, {
  typ: "JWT",
});

Resulting JWS contains key identifier (kid) as DID URL which makes it clear which key to check the signature against.

Decrypt JSON Web Encryption message

Maskodid supports ECDH-ES+XC20PKW JWE algorithm with x25519 key exchange schema. To encrypt a payload to a DID you only have to know the recipient's public key. It is decryption that requires knowledge of the private key. So, if one gets an encrypted message jwe, decryption happens like this:

import { Maskodid } from "maskodid";
const maskodid = new Maskodid();
const cleartext = await maskodid.decrypt(jwe);

DID Provider and js-did

Maskodid also exposes js-did:

import { Maskodid } from "maskodid";
const maskodid = new Maskodid();
// Get js-did instance
const did = maskodid.did

License

Apache-2.0 or MIT