From 13c8a0527b8ceb1f4c29b4e484788ec9eddc8de2 Mon Sep 17 00:00:00 2001
From: Franck Royer <franck@status.im>
Date: Thu, 15 Jul 2021 12:12:43 +1000
Subject: [PATCH] Test symmetric encryption with nim-waku using relay

---
 src/lib/waku_message/index.spec.ts | 54 ++++++++++++++++++++++++++++++
 src/lib/waku_message/version_1.ts  |  9 +++--
 src/lib/waku_relay/index.ts        |  4 ++-
 src/test_utils/nim_waku.ts         | 40 ++++++++++++++++++++++
 4 files changed, 104 insertions(+), 3 deletions(-)

diff --git a/src/lib/waku_message/index.spec.ts b/src/lib/waku_message/index.spec.ts
index a0f14c6ff4..a9f552ab81 100644
--- a/src/lib/waku_message/index.spec.ts
+++ b/src/lib/waku_message/index.spec.ts
@@ -105,5 +105,59 @@ describe('Waku Message: Node only', function () {
       expect(msgs[0].contentTopic).to.equal(message.contentTopic);
       expect(hexToBuf(msgs[0].payload).toString('utf-8')).to.equal(messageText);
     });
+
+    it('JS decrypts nim message [symmetric, no signature]', async function () {
+      this.timeout(10000);
+      await delay(200);
+
+      const messageText = 'Here is a message encrypted in a symmetric manner.';
+      const message: WakuRelayMessage = {
+        contentTopic: DefaultContentTopic,
+        payload: Buffer.from(messageText, 'utf-8').toString('hex'),
+      };
+
+      const symKey = generatePrivateKey();
+
+      waku.relay.addDecryptionPrivateKey(symKey);
+
+      const receivedMsgPromise: Promise<WakuMessage> = new Promise(
+        (resolve) => {
+          waku.relay.addObserver(resolve);
+        }
+      );
+
+      dbg('Post message');
+      await nimWaku.postSymmetricMessage(message, symKey);
+
+      const receivedMsg = await receivedMsgPromise;
+
+      expect(receivedMsg.contentTopic).to.eq(message.contentTopic);
+      expect(receivedMsg.version).to.eq(1);
+      expect(receivedMsg.payloadAsUtf8).to.eq(messageText);
+    });
+
+    it('Js encrypts message for nim [symmetric, no signature]', async function () {
+      this.timeout(5000);
+
+      const symKey = await nimWaku.getSymmetricKey();
+
+      const messageText =
+        'This is a message I am going to encrypt with a symmetric key';
+      const message = await WakuMessage.fromUtf8String(messageText, {
+        symKey: symKey,
+      });
+
+      await waku.relay.send(message);
+
+      let msgs: WakuRelayMessage[] = [];
+
+      while (msgs.length === 0) {
+        await delay(200);
+        msgs = await nimWaku.getSymmetricMessages(symKey);
+      }
+
+      expect(msgs[0].contentTopic).to.equal(message.contentTopic);
+      expect(hexToBuf(msgs[0].payload).toString('utf-8')).to.equal(messageText);
+    });
   });
 });
diff --git a/src/lib/waku_message/version_1.ts b/src/lib/waku_message/version_1.ts
index 7cdbdf68e8..19ae218ad0 100644
--- a/src/lib/waku_message/version_1.ts
+++ b/src/lib/waku_message/version_1.ts
@@ -172,14 +172,19 @@ export async function decryptSymmetric(
 }
 
 /**
- * Generate a new private key
+ * Generate a new key. Can be used as a private key for Asymmetric encryption
+ * or a key for symmetric encryption.
+ *
+ * If using Asymmetric encryption, use {@link getPublicKey} to get the
+ * corresponding Public Key.
  */
 export function generatePrivateKey(): Uint8Array {
   return randomBytes(32);
 }
 
 /**
- * Return the public key for the given private key
+ * Return the public key for the given private key, to be used for asymmetric
+ * encryption.
  */
 export function getPublicKey(privateKey: Uint8Array | Buffer): Uint8Array {
   return secp256k1.publicKeyCreate(privateKey, false);
diff --git a/src/lib/waku_relay/index.ts b/src/lib/waku_relay/index.ts
index 041a428e35..ac4fc342b5 100644
--- a/src/lib/waku_relay/index.ts
+++ b/src/lib/waku_relay/index.ts
@@ -125,7 +125,9 @@ export class WakuRelay extends Gossipsub {
 
   /**
    * Register a decryption private key to attempt decryption of messages of
-   * the given content topic.
+   * the given content topic. This can either be a private key for asymmetric
+   * encryption or a symmetric key. Waku relay will attempt to decrypt messages
+   * using both methods.
    */
   addDecryptionPrivateKey(privateKey: Uint8Array): void {
     this.decPrivateKeys.add(privateKey);
diff --git a/src/test_utils/nim_waku.ts b/src/test_utils/nim_waku.ts
index cef77d7c4c..8a9acc0745 100644
--- a/src/test_utils/nim_waku.ts
+++ b/src/test_utils/nim_waku.ts
@@ -12,6 +12,7 @@ import debug from 'debug';
 import { Multiaddr, multiaddr } from 'multiaddr';
 import PeerId from 'peer-id';
 
+import { hexToBuf } from '../lib/utils';
 import { WakuMessage } from '../lib/waku_message';
 import { DefaultPubsubTopic } from '../lib/waku_relay';
 import * as proto from '../proto/waku/v2/message';
@@ -251,6 +252,45 @@ export class NimWaku {
     );
   }
 
+  async getSymmetricKey(): Promise<Buffer> {
+    this.checkProcess();
+
+    return this.rpcCall<string>(
+      'get_waku_v2_private_v1_symmetric_key',
+      []
+    ).then(hexToBuf);
+  }
+
+  async postSymmetricMessage(
+    message: WakuRelayMessage,
+    symKey: Uint8Array,
+    pubsubTopic?: string
+  ): Promise<boolean> {
+    this.checkProcess();
+
+    if (!message.payload) {
+      throw 'Attempting to send empty message';
+    }
+
+    return this.rpcCall<boolean>('post_waku_v2_private_v1_symmetric_message', [
+      pubsubTopic ? pubsubTopic : DefaultPubsubTopic,
+      message,
+      '0x' + bufToHex(symKey),
+    ]);
+  }
+
+  async getSymmetricMessages(
+    symKey: Uint8Array,
+    pubsubTopic?: string
+  ): Promise<WakuRelayMessage[]> {
+    this.checkProcess();
+
+    return await this.rpcCall<WakuRelayMessage[]>(
+      'get_waku_v2_private_v1_symmetric_messages',
+      [pubsubTopic ? pubsubTopic : DefaultPubsubTopic, '0x' + bufToHex(symKey)]
+    );
+  }
+
   async getPeerId(): Promise<PeerId> {
     return await this.setPeerId().then((res) => res.peerId);
   }