init ratchets

src/public/chat.js

@@ -5,6 +5,31 @@ import { keccakKDF } from "./kdf.js";
 const socket = io();
 let secret = null;
 let sharedsecret = {};
+let dh_ratchets = {};
+let sending_ratchets = {};
+let receiving_ratchets = {};
+
+function init_ratchets(order, user_pubkey) {
+    let dh_ratchet = new keccakKDF()
+    let key_1 =  dh_ratchet.init(sharedsecret[user_pubkey], new Uint8Array(0));
+    let key_2 = dh_ratchet.next(new Uint8Array(0));
+    dh_ratchets[user_pubkey] = dh_ratchet;
+    let sending_ratchet = new keccakKDF();
+    let receiving_ratchet = new keccakKDF();
+    switch (order) {
+        case 0:
+            sending_ratchet.init(key_1, new Uint8Array(0));
+            receiving_ratchet.init(key_2, new Uint8Array(0));
+            break;
+        case 1:
+            sending_ratchet.init(key_2, new Uint8Array(0));
+            receiving_ratchet.init(key_1, new Uint8Array(0));
+            break;
+    }
+    sending_ratchets[user_pubkey] = sending_ratchet;
+    receiving_ratchets[user_pubkey] = receiving_ratchet;
+
+}
 
 socket.on('chat message', (msg, room) => {
     console.log(`received: ${msg}`);
@@ -30,10 +55,12 @@ socket.on('key exchange', (user_pubkey, pubkey, part) => {
             sharedsecret[user_pubkey] = sharedKey(secret, fromHexString(pubkey));
             socket.emit('key exchange', user_pubkey, toHexString(keys.pubkey), 2);
             console.log(`shared secret: ${toHexString(sharedsecret[user_pubkey])}`);
+            init_ratchets(0, user_pubkey)
             break;
         case 2:
             sharedsecret[user_pubkey] = sharedKey(secret, fromHexString(pubkey));
             console.log(`shared secret: ${toHexString(sharedsecret[user_pubkey])}`);
+            init_ratchets(1, user_pubkey)
             break;
     }
 });