From 56d004d15745ad34291c85d8b7a6cfb3501e383e Mon Sep 17 00:00:00 2001
From: Quentin Gliech <quenting@element.io>
Date: Fri, 13 Sep 2024 15:39:36 +0200
Subject: [PATCH 1/2] Use MSC4190 to provision devices for E2EE

---
 src/appservice/Appservice.ts |  8 ++++++++
 src/appservice/Intent.ts     | 15 ++++++++++++---
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/src/appservice/Appservice.ts b/src/appservice/Appservice.ts
index 6f2d0ea2..8be8c53c 100644
--- a/src/appservice/Appservice.ts
+++ b/src/appservice/Appservice.ts
@@ -135,6 +135,14 @@ export interface IAppserviceRegistration {
      */
     "de.sorunome.msc2409.push_ephemeral"?: boolean;
 
+    /**
+     * ** Experimental **
+     *
+     * Should the AS use the new device management APIs. Optional.
+     * @see https://github.com/matrix-org/matrix-spec-proposals/pull/4190
+     */
+    "io.element.msc4190"?: boolean;
+
     // not interested in other options
 }
 
diff --git a/src/appservice/Intent.ts b/src/appservice/Intent.ts
index 9d1e719d..f274671c 100644
--- a/src/appservice/Intent.ts
+++ b/src/appservice/Intent.ts
@@ -13,6 +13,7 @@ import { Appservice, IAppserviceOptions } from "./Appservice";
 import { timedIntentFunctionCall } from "../metrics/decorators";
 import { UnstableAppserviceApis } from "./UnstableAppserviceApis";
 import { MatrixError } from "../models/MatrixError";
+import { randomUUID } from "crypto";
 
 /**
  * An Intent is an intelligent client that tracks things like the user's membership
@@ -162,9 +163,17 @@ export class Intent {
                     }
 
                     if (!prepared) {
-                        // XXX: We work around servers that don't support device_id impersonation
-                        const accessToken = await Promise.resolve(storage?.readValue("accessToken"));
-                        if (!accessToken) {
+                        let accessToken;
+                        if (this.options.registration["io.element.msc4190"]) {
+                            // Generate a random device ID and create it
+                            deviceId = randomUUID();
+                            // Make sure the device is registered
+                            await this.client.doRequest("PUT", `/_matrix/client/v3/devices/${deviceId}`, null, {});
+                            this.makeClient(true);
+                            this.client.impersonateUserId(this.userId, deviceId);
+                            prepared = true;
+                        } else if (!(accessToken = await Promise.resolve(storage?.readValue("accessToken")))) {
+                            // XXX: We work around servers that don't support device_id impersonation
                             const loginBody = {
                                 type: "m.login.application_service",
                                 identifier: {

From a9cdac455c456b416c338967462559d9ae80ae6e Mon Sep 17 00:00:00 2001
From: Quentin Gliech <quenting@element.io>
Date: Fri, 13 Sep 2024 15:56:57 +0200
Subject: [PATCH 2/2] Lint

---
 src/appservice/Intent.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/appservice/Intent.ts b/src/appservice/Intent.ts
index f274671c..d9aeb2d9 100644
--- a/src/appservice/Intent.ts
+++ b/src/appservice/Intent.ts
@@ -1,3 +1,5 @@
+import { randomUUID } from "crypto";
+
 import {
     DeviceKeyAlgorithm,
     extractRequestError,
@@ -13,7 +15,6 @@ import { Appservice, IAppserviceOptions } from "./Appservice";
 import { timedIntentFunctionCall } from "../metrics/decorators";
 import { UnstableAppserviceApis } from "./UnstableAppserviceApis";
 import { MatrixError } from "../models/MatrixError";
-import { randomUUID } from "crypto";
 
 /**
  * An Intent is an intelligent client that tracks things like the user's membership