Error toast on computeSecret error.

client/src/builtin/E2EE.js

@@ -201,11 +201,15 @@ export default new class E2EE extends BuiltinModule {
     }
 
     computeSecret(userID, otherKey) {
+        try {
             const secret = this.ecdh[userID].computeSecret(otherKey, 'base64', 'base64');
             delete this.ecdh[userID];
             const hash = crypto.createHash('sha256');
             hash.update(secret);
             return hash.digest('base64');
+        } catch (e) {
+            throw e;
+        }
     }
 
     handleChannelTextAreaSubmit(component, args, retVal) {

client/src/builtin/E2EEComponent.vue

@@ -60,7 +60,8 @@
           chatInput[Object.keys(chatInput).find(k => k.startsWith('__reactEventHandlers'))].onChange.call(chatInput, evt);
           Toasts.success("Encryption key has been set for this DM channel.");
         } catch (e) {
-          throw e;
+          Toasts.error("Invalid public key. Please set up a new key exchange.");
+          console.error(e);
         }
     }