JavaScript Encrypted Data Vault Client _(@digitalbazaar/edv-client)_

> A JavaScript library for Web and node.js apps for interfacing with a remote
> Encrypted Data Vault server

Table of Contents

- Background
- Install
- Usage
- API
- Contribute
- License

Background

This library provides a client that Web and node.js apps can use to interface
with remote Encrypted Data Vault (EDV) servers.

It consists of one main class:

* EdvClient - instances provide a CRUD (+ find) interface to a specific
configured Encrypted Data Vault server and ensure appropriate database
indexes are set up. Static methods allow for the creation of EDVs with a
remote storage service, e.g.
Encrypted Data Vault storage servers.

#### Encrypted Data Vault storage servers:
* MongoDB-based - https://github.com/digitalbazaar/bedrock-edv-storage
* PouchDB-based - https://github.com/digitalbazaar/bedrock-web-pouch-edv

Install

- Browsers and Node.js 18+ are supported.
- [Streams API][] required. Older browsers must use a polyfill.
- [Web Crypto API][] required. Older browsers must use a polyfill.

To install from NPM:

``sh
npm install @digitalbazaar/edv-client
`

To install locally (for development):

`sh
git clone https://github.com/digitalbazaar/edv-client.git
cd edv-client
npm install
`

Usage

$3

First, create a key agreement key and an HMAC (hash-based message authentication
code) key for encrypting your documents and blinding any indexed attributes in
them. This requires creating some cryptographic key material which can be done
locally or via a KMS system. The current example shows using a KMS system
(TODO: show a simpler local example):

`js
import {CapabilityAgent, KeystoreAgent, KmsClient} from 'webkms-client';
import {EdvClient} from 'edv-client';
`
Although Encrypted Data Vaults are not bound to any particular key management
system, we recommend that you set up a Key Management Service using an
implementation such as
webkms-switch
which you can connect to using
webkms-client.

Optional:

`js
// create a CapabilityAgent (for invoking zcaps)
const capabilityAgent = await CapabilityAgent.fromSecret({secret, handle});

// create a keystore and an agent for working with it
// the baseUrl can be set to a dev API or production API
const kmsBaseUrl = ${config.server.baseUri}/kms;
const keystore = KmsClient.createKeystore({
// the url for the keystore is configurable
url: ${kmsBaseUrl}/keystores,
config: {
// on init the sequence must be 0
sequence: 0,
controller: capabilityAgent.id,
invoker: capabilityAgent.id,
// this allows the capabilityAgent to delegate zCaps
delegator: capabilityAgent.id
},
/**
* optional httpsAgent,
* usually not applicable for front-end (you may use axios),
* for back-end use cases a nodejs https.Agent
* may be used to allow the use of self signed certificates using
* the rejectUnauthorized: false flag in the contructor.
*/
httpsAgent
});
const keystoreAgent = new KeystoreAgent({keystore, capabilityAgent});

// use the keystore agent to create key agreement and HMAC keys
const keyAgreementKey = await keystoreAgent.generateKey({type: 'keyAgreement'});
const hmac = await keystoreAgent.generateKey({type: 'hmac'});
`

Now you can create and register a new EDV configuration:

`js
// TODO: explain EDV service must be able to authenticate user
const controller = 'account id goes here';

const config = {
// on init the sequence must be 0 and is required
sequence: 0,
controller,
// TODO: Explain what 'referenceId' is
referenceId: 'primary',
keyAgreementKey: {id: keyAgreementKey.id, type: keyAgreementKey.type},
hmac: {id: hmac.id, type: hmac.type}
};

// sends a POST request to the remote service to create an EDV
const remoteConfig = await EdvClient.createEdv({config});

// connect to the new EDV via a EdvClient
const client = new EdvClient({id: remoteConfig.id, keyAgreementKey, hmac});
// to only use fips-compliant key agreement and encryption algorithms:
const client = new EdvClient(
{id: remoteConfig.id, keyAgreementKey, hmac, cipherVersion: 'fips'});
`

You can specify a url when you create and register a new EDV configuration:

`js
// TODO: explain EDV service must be able to authenticate user
const controller = 'account id (or DID if using zcaps) goes here';

const config = {
// on init the sequence must be 0 and is required
sequence: 0,
controller,
// TODO: Explain what 'referenceId' is
referenceId: 'primary',
keyAgreementKey: {id: keyAgreementKey.id, type: keyAgreementKey.type},
hmac: {id: hmac.id, type: hmac.type}
};

// sends a POST request to the remote service to create an EDV
const remoteConfig = await EdvClient.createEdv({
url: 'https://server.example/edvs',
config,
// must pass invocationSigner and optional capability if controller
// is a DID
/ invocationSigner, capability /
});

// connect to the new EDV via a EdvClient
const client = new EdvClient({id: remoteConfig.id, keyAgreementKey, hmac});
`

$3

If you have previously registered an EDV config (via createEdv()),
and you know its id, you can fetch its config via get():

`js
// registered config
const {id} = await EdvClient.createEdv({config});

// later, it can be fetched via the id
const remoteConfig = await EdvClient.getConfig({id});

// connect to the existing EDV via an EdvClient instance
const client = new EdvClient({id: remoteConfig.id, keyAgreementKey, hmac});
`

If you know a controller/accountId but do not know a specific EDV id, you
can create a client for an EDV by a controller-scoped custom referenceId:

`js
// get the account's 'primary' EDV config to connect to the EDV
// note that a referenceId can be any string but must be unique per controller
const config = await EdvClient.findConfig(
{controller: accountId, referenceId: 'primary'});
const client = new EdvClient({id: config.id, keyAgreementKey, hmac});
`

$3

See the API section below.

API

$3

#### constructor

#### insert

#### get

#### update

#### delete

#### find

#### ensureIndex

#### updateIndex`

Contribute

Please follow the existing code style.

PRs accepted.

If editing the Readme, please conform to the
standard-readme specification.

License

BSD-3-Clause Copyright 2019-2025 Digital Bazaar, Inc.

Commercial support is available by contacting
Digital Bazaar .

[Streams API]: https://developer.mozilla.org/en-US/docs/Web/API/Streams_API
[Web Crypto API]: https://developer.mozilla.org/en-US/docs/Web/API/Web_Crypto_API