Allow passing decryption keys to `Waku` instance

Keys can be set at creation or at run time.
They are passed to `WakuStore` and `WakuRelay` instances.

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Guides: Encrypt messages using Waku Message Version 1.
 - Allow passing decryption keys in hex string format.
 - Allow passing decryption keys to `WakuStore` instance to avoid having to pass them at every `queryHistory` call.
+- Allow passing decryption keys to `Waku` instance to avoid having to pass them to both `WakuRelay` and `WakuStore`.
 
 ### Changed
 - **Breaking**: Moved `startTime` and `endTime` for history queries to a `timeFilter` property as both or neither must be passed; passing only one parameter is not supported.

src/lib/waku.spec.ts

@@ -12,6 +12,10 @@ import {
 } from '../test_utils/';
 
 import { Waku } from './waku';
+import { WakuMessage } from './waku_message';
+import { generateSymmetricKey } from './waku_message/version_1';
+
+const TestContentTopic = '/test/1/waku/utf8';
 
 describe('Waku Dial', function () {
   let waku: Waku;
@@ -130,3 +134,76 @@ describe('Waku Dial', function () {
     });
   });
 });
+
+describe('Decryption Keys', () => {
+  afterEach(function () {
+    if (this.currentTest?.state === 'failed') {
+      console.log(`Test failed, log file name is ${makeLogFileName(this)}`);
+    }
+  });
+
+  let waku1: Waku;
+  let waku2: Waku;
+  beforeEach(async function () {
+    [waku1, waku2] = await Promise.all([
+      Waku.create({ staticNoiseKey: NOISE_KEY_1 }),
+      Waku.create({
+        staticNoiseKey: NOISE_KEY_2,
+        libp2p: { addresses: { listen: ['/ip4/0.0.0.0/tcp/0/ws'] } },
+      }),
+    ]);
+
+    waku1.addPeerToAddressBook(waku2.libp2p.peerId, waku2.libp2p.multiaddrs);
+
+    await Promise.all([
+      new Promise((resolve) =>
+        waku1.libp2p.pubsub.once('pubsub:subscription-change', () =>
+          resolve(null)
+        )
+      ),
+      new Promise((resolve) =>
+        waku2.libp2p.pubsub.once('pubsub:subscription-change', () =>
+          resolve(null)
+        )
+      ),
+    ]);
+  });
+
+  afterEach(async function () {
+    this.timeout(5000);
+    await waku1.stop();
+    await waku2.stop();
+  });
+
+  it('Used by Waku Relay', async function () {
+    this.timeout(10000);
+
+    const symKey = generateSymmetricKey();
+
+    waku2.addDecryptionKey(symKey);
+
+    const messageText = 'Message is encrypted';
+    const messageTimestamp = new Date('1995-12-17T03:24:00');
+    const message = await WakuMessage.fromUtf8String(
+      messageText,
+      TestContentTopic,
+      {
+        timestamp: messageTimestamp,
+        symKey,
+      }
+    );
+
+    const receivedMsgPromise: Promise<WakuMessage> = new Promise((resolve) => {
+      waku2.relay.addObserver(resolve);
+    });
+
+    await waku1.relay.send(message);
+
+    const receivedMsg = await receivedMsgPromise;
+
+    expect(receivedMsg.contentTopic).to.eq(message.contentTopic);
+    expect(receivedMsg.version).to.eq(message.version);
+    expect(receivedMsg.payloadAsUtf8).to.eq(messageText);
+    expect(receivedMsg.timestamp?.valueOf()).to.eq(messageTimestamp.valueOf());
+  });
+});

src/lib/waku.ts

@@ -93,6 +93,7 @@ export interface CreateOptions {
    * {@link CreateOptions.libp2p}.
    */
   bootstrap?: boolean | string[] | (() => string[] | Promise<string[]>);
+  decryptionKeys?: Array<Uint8Array | string>;
 }
 
 export class Waku {
@@ -133,6 +134,8 @@ export class Waku {
     libp2p.connectionManager.on('peer:disconnect', (connection: Connection) => {
       this.stopKeepAlive(connection.remotePeer);
     });
+
+    options?.decryptionKeys?.forEach(this.addDecryptionKey);
   }
 
   /**
@@ -270,6 +273,29 @@ export class Waku {
     return this.libp2p.stop();
   }
 
+  /**
+   * Register a decryption key to attempt decryption of messages received via
+   * [[WakuRelay]] and [[WakuStore]]. This can either be a private key for
+   * asymmetric encryption or a symmetric key.
+   *
+   * Strings must be in hex format.
+   */
+  addDecryptionKey(key: Uint8Array | string): void {
+    this.relay.addDecryptionKey(key);
+    this.store.addDecryptionKey(key);
+  }
+
+  /**
+   * Delete a decryption key that was used to attempt decryption of messages
+   * received via [[WakuRelay]] or [[WakuStore]].
+   *
+   * Strings must be in hex format.
+   */
+  deleteDecryptionKey(key: Uint8Array | string): void {
+    this.relay.deleteDecryptionKey(key);
+    this.store.deleteDecryptionKey(key);
+  }
+
   /**
    * Return the local multiaddr with peer id on which libp2p is listening.
    * @throws if libp2p is not listening on localhost