Allow passing decryption keys to `WakuStore` instance

To avoid having to pass them at every `queryHistory` call.

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Examples (eth-pm): Encrypt Public Key Messages using symmetric encryption. 
 - 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.
 
 ### 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_store/index.spec.ts

@@ -236,9 +236,11 @@ describe('Waku Store', () => {
       storePeers = waku2.store.peers;
     }
 
+    waku2.store.addDecryptionKey(symKey);
+
     dbg('Retrieve messages from store');
     const messages = await waku2.store.queryHistory([], {
-      decryptionKeys: [privateKey, symKey],
+      decryptionKeys: [privateKey],
     });
 
     expect(messages?.length).eq(3);

src/lib/waku_store/index.ts

@@ -52,6 +52,7 @@ export interface QueryOptions {
  */
 export class WakuStore {
   pubSubTopic: string;
+  public decryptionKeys: Set<Uint8Array>;
 
   constructor(public libp2p: Libp2p, options?: CreateOptions) {
     if (options?.pubSubTopic) {
@@ -59,6 +60,8 @@ export class WakuStore {
     } else {
       this.pubSubTopic = DefaultPubSubTopic;
     }
+
+    this.decryptionKeys = new Set();
   }
 
   /**
@@ -115,7 +118,7 @@ export class WakuStore {
     const connection = this.libp2p.connectionManager.get(peer.id);
     if (!connection) throw 'Failed to get a connection to the peer';
 
-    const decryptionKeys: Uint8Array[] = [];
+    const decryptionKeys = Array.from(this.decryptionKeys.values());
     if (opts.decryptionKeys) {
       opts.decryptionKeys.forEach((key) => {
         decryptionKeys.push(hexToBuf(key));
@@ -198,6 +201,28 @@ export class WakuStore {
     }
   }
 
+  /**
+   * Register a decryption key to attempt decryption of messages received in any
+   * subsequent [[queryHistory]] call. This can either be a private key for
+   * asymmetric encryption or a symmetric key. [[WakuStore]] will attempt to
+   * decrypt messages using both methods.
+   *
+   * Strings must be in hex format.
+   */
+  addDecryptionKey(key: Uint8Array | string): void {
+    this.decryptionKeys.add(hexToBuf(key));
+  }
+
+  /**
+   * Delete a decryption key that was used to attempt decryption of messages
+   * received in subsequent [[queryHistory]] calls.
+   *
+   * Strings must be in hex format.
+   */
+  deleteDecryptionKey(key: Uint8Array | string): void {
+    this.decryptionKeys.delete(hexToBuf(key));
+  }
+
   /**
    * Returns known peers from the address book (`libp2p.peerStore`) that support
    * store protocol. Waku may or  may not be currently connected to these peers.