feat(android): back up the personal profile only

A copy of the application inside a work profile offers no backup, and no
source reads another profile.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

4 files changed, 90 insertions, 41 deletions

diff --git a/packages/meshbay-android/app/src/main/assets/bridge/meshbay-bridge.js b/packages/meshbay-android/app/src/main/assets/bridge/meshbay-bridge.js
index fb613a3..fc7231c 100644
--- a/packages/meshbay-android/app/src/main/assets/bridge/meshbay-bridge.js
+++ b/packages/meshbay-android/app/src/main/assets/bridge/meshbay-bridge.js
@@ -15,11 +15,12 @@
  * that refuses: `platform.js` decides what to show from whether an object
  * exists (`platform.node.available`, `platform.folder.available`, …).
  *
- * `HUB_BASE`, `BINARY`, `CAST` and `MESSAGES` are prepended by the shell when
- * it injects this file: the interface asks for the hub while its modules load, before
- * anything can await; BINARY says whether the WebView carries ArrayBuffer
- * messages; CAST whether this device can cast at all; MESSAGES whether this
- * build backs text messages up (not the Play build).
+ * `HUB_BASE`, `BINARY`, `CAST`, `BACKUP` and `MESSAGES` are prepended by the
+ * shell when it injects this file: the interface asks for the hub while its
+ * modules load, before anything can await; BINARY says whether the WebView carries ArrayBuffer
+ * messages; CAST whether this device can cast at all; BACKUP whether this is
+ * the personal profile, the only one backed up; MESSAGES whether this build
+ * backs text messages up (not the Play build).
  */
 (function () {
   'use strict';
@@ -198,41 +199,45 @@
         call('push:remember', subscription, account, secret, since),
     },
 
-    // Photo backup (§9.12): the phone lists its photos, keeps what was sent,
-    // and hands each photo's bytes over at /photosync/<token> on this origin.
-    // The page decides when and does the sending. Phone-only, like `push`.
-    photoSync: {
-      status: () => call('photosync:status'),
-      permit: () => call('photosync:permit'),
-      albums: () => call('photosync:albums'),
-      configure: (settings) => call('photosync:configure', settings || null),
-      estimate: (settings) => call('photosync:estimate', settings),
-      plan: () => call('photosync:plan'),
-      sent: (token, dir, name) => call('photosync:sent', token, dir, name),
-      completed: () => call('photosync:completed'),
-      failed: (code, text) => call('photosync:failed', code, text),
-      keepAlive: (on, text) => call('photosync:keep-alive', on === true, text || ''),
-    },
+    // Backups (§9.12, §9.13), of the personal profile only: a copy of the
+    // application inside a work profile has none of these (Profiles.kt).
+    ...(BACKUP ? {
+      // Photo backup (§9.12): the phone lists its photos, keeps what was sent,
+      // and hands each photo's bytes over at /photosync/<token> on this origin.
+      // The page decides when and does the sending. Phone-only, like `push`.
+      photoSync: {
+        status: () => call('photosync:status'),
+        permit: () => call('photosync:permit'),
+        albums: () => call('photosync:albums'),
+        configure: (settings) => call('photosync:configure', settings || null),
+        estimate: (settings) => call('photosync:estimate', settings),
+        plan: () => call('photosync:plan'),
+        sent: (token, dir, name) => call('photosync:sent', token, dir, name),
+        completed: () => call('photosync:completed'),
+        failed: (code, text) => call('photosync:failed', code, text),
+        keepAlive: (on, text) => call('photosync:keep-alive', on === true, text || ''),
+      },
 
-    // Where every backup goes (§9.12): one folder of one group the account
-    // owns and is alone in. Each kind goes into `<account>-<kind>` under it.
-    phoneSync: {
-      destination: () => call('phonesync:destination'),
-      setDestination: (d) => call('phonesync:set-destination', d || null),
-    },
+      // Where every backup goes (§9.12): one folder of one group the account
+      // owns and is alone in. Each kind goes into `<account>-<kind>` under it.
+      phoneSync: {
+        destination: () => call('phonesync:destination'),
+        setDestination: (d) => call('phonesync:set-destination', d || null),
+      },
 
-    // Contacts backup (§9.13): the phone writes the address book into one
-    // file, served at /phonesync/<token> on this origin, when it changed since
-    // the last one sent. The page decides when and does the sending.
-    contactSync: {
-      status: () => call('contactsync:status'),
-      permit: () => call('contactsync:permit'),
-      configure: (settings) => call('contactsync:configure', settings || null),
-      plan: () => call('contactsync:plan'),
-      sent: (token, dir, name) => call('contactsync:sent', token, dir, name),
-      completed: () => call('contactsync:completed'),
-      failed: (code, text) => call('contactsync:failed', code, text),
-    },
+      // Contacts backup (§9.13): the phone writes the address book into one
+      // file, served at /phonesync/<token> on this origin, when it changed since
+      // the last one sent. The page decides when and does the sending.
+      contactSync: {
+        status: () => call('contactsync:status'),
+        permit: () => call('contactsync:permit'),
+        configure: (settings) => call('contactsync:configure', settings || null),
+        plan: () => call('contactsync:plan'),
+        sent: (token, dir, name) => call('contactsync:sent', token, dir, name),
+        completed: () => call('contactsync:completed'),
+        failed: (code, text) => call('contactsync:failed', code, text),
+      },
+    } : {}),
 
     // Messages backup (§9.13), the same way as contacts: the messages added
     // since the last file the node took. Only in a build that may read them.
diff --git a/packages/meshbay-android/app/src/main/kotlin/org/meshbay/client/MainActivity.kt b/packages/meshbay-android/app/src/main/kotlin/org/meshbay/client/MainActivity.kt
index 0545ead..09cef0e 100644
--- a/packages/meshbay-android/app/src/main/kotlin/org/meshbay/client/MainActivity.kt
+++ b/packages/meshbay-android/app/src/main/kotlin/org/meshbay/client/MainActivity.kt
@@ -40,6 +40,7 @@ import org.meshbay.client.phonesync.ContactSource
 import org.meshbay.client.phonesync.DestinationChannels
 import org.meshbay.client.phonesync.DocChannels
 import org.meshbay.client.phonesync.Flavor
+import org.meshbay.client.phonesync.Profiles
 import org.meshbay.client.photos.PhotoChannels
 import org.meshbay.client.save.SaveSinks
 import org.meshbay.client.shell.Pickers
@@ -64,6 +65,8 @@ class MainActivity : Activity() {
     private lateinit var channels: Channels
     private lateinit var photos: PhotoChannels
     private var docs: List<DocChannels> = emptyList()
+    /** Backups exist in the personal profile only (Profiles.kt). */
+    private var backups = false
     private var network: android.net.ConnectivityManager.NetworkCallback? = null
     private val pickers = Pickers(this)
     private val text = NativeText { code ->
@@ -101,11 +104,12 @@ class MainActivity : Activity() {
         Thread { saves.cleanUpAfterAKilledProcess() }.start()
         cast = CastChannels(this, onCasting = { on -> runOnUiThread { casting = on; keepAlive() } },
                             tell = { m -> runOnUiThread { android.widget.Toast.makeText(this, m, android.widget.Toast.LENGTH_LONG).show() } })
+        backups = Profiles.isPersonal(this)
         val destinations = DestinationChannels(getSharedPreferences(DestinationChannels.PREFS, Context.MODE_PRIVATE))
         photos = PhotoChannels(this, getSharedPreferences(PhotoChannels.PREFS, Context.MODE_PRIVATE), destinations,
                                java.io.File(filesDir, "photosync"),
                                onKeepAlive = { on, line -> runOnUiThread { backup(on, line) } })
-        docs = listOf(
+        docs = if (!backups) emptyList() else listOf(
             DocChannels("contactsync", this, getSharedPreferences("contactsync", Context.MODE_PRIVATE), destinations,
                         java.io.File(cacheDir, "contactsync"), ContactSource(this),
                         notifyId = 10, permissionRequest = 4209),
@@ -121,7 +125,8 @@ class MainActivity : Activity() {
                                 channelNames = { mapOf(
                                     Notifier.CHANNEL_CHAT to text.get("push.channel_chat", channels.locale),
                                     Notifier.CHANNEL_OTHER to text.get("push.channel_other", channels.locale)) }),
-                            photos = photos, destinations = destinations, docs = docs)
+                            photos = photos.takeIf { backups }, destinations = destinations.takeIf { backups },
+                            docs = docs)
         WebViewCompat.addWebMessageListener(web, Bridge.PORT, setOf(UiAssets.ORIGIN), Bridge(channels))
         cast.control.warmUp()
         installShim()
@@ -167,7 +172,7 @@ class MainActivity : Activity() {
             override fun shouldInterceptRequest(view: WebView, request: WebResourceRequest): WebResourceResponse? {
                 val url = request.url
                 if (url.host == UiAssets.HOST && url.path?.startsWith(PhotoChannels.PATH) == true) {
-                    return photos.serve(url.path ?: "") ?: refused()
+                    return photos.takeIf { backups }?.serve(url.path ?: "") ?: refused()
                 }
                 if (url.host == UiAssets.HOST && url.path?.startsWith(DocChannels.PATH) == true) {
                     val path = url.path ?: ""
@@ -253,6 +258,7 @@ class MainActivity : Activity() {
         val binary = WebViewFeature.isFeatureSupported(WebViewFeature.WEB_MESSAGE_ARRAY_BUFFER)
         val prelude = "const HUB_BASE = ${JSONObject.quote(hub.base)};\nconst BINARY = $binary;\n" +
             "const CAST = ${cast.control.available()};\n" +
+            "const BACKUP = $backups;\n" +
             "const MESSAGES = ${docs.any { it.handles("messagesync:") }};\n"
         shim = WebViewCompat.addDocumentStartJavaScript(web, "(function(){$prelude$source\n})();", setOf(UiAssets.ORIGIN))
     }
diff --git a/packages/meshbay-android/app/src/main/kotlin/org/meshbay/client/phonesync/Profiles.kt b/packages/meshbay-android/app/src/main/kotlin/org/meshbay/client/phonesync/Profiles.kt
new file mode 100644
index 0000000..660cfaa
--- /dev/null
+++ b/packages/meshbay-android/app/src/main/kotlin/org/meshbay/client/phonesync/Profiles.kt
@@ -0,0 +1,24 @@
+package org.meshbay.client.phonesync
+
+import android.content.Context
+import android.os.Build
+import android.os.UserManager
+
+/**
+ * Backups are of the personal profile only, never of a work profile: a copy
+ * of the application installed inside a work profile offers none of them.
+ *
+ * In the personal profile, every source reads that profile alone: MediaStore,
+ * ContactsContract, the SMS and calendar providers answer for the profile
+ * they are asked from, and none of the cross-profile (`ENTERPRISE_*`) URIs
+ * is used (`test_android_shell.py` checks for them).
+ */
+object Profiles {
+    fun isPersonal(context: Context): Boolean {
+        val users = context.getSystemService(UserManager::class.java)
+        // Before Android 11 an application cannot ask whether its own profile
+        // is managed; a work profile is never the system user, so that is
+        // the test there (a secondary user on a shared tablet loses backups).
+        return if (Build.VERSION.SDK_INT >= 30) !users.isManagedProfile else users.isSystemUser
+    }
+}
diff --git a/packages/meshbay-hub/tests/test_android_shell.py b/packages/meshbay-hub/tests/test_android_shell.py
index 7b2e79f..2990e9b 100644
--- a/packages/meshbay-hub/tests/test_android_shell.py
+++ b/packages/meshbay-hub/tests/test_android_shell.py
@@ -260,6 +260,20 @@ def test_a_release_is_signed_with_the_release_key_or_not_built():
     assert not re.search(r'storePassword = "', build)
 
 
+def test_only_the_personal_profile_is_backed_up():
+    """A copy of the application inside a work profile offers no backup, and
+    nothing reads another profile's data through a cross-profile URI."""
+    activity = _read(SRC / "MainActivity.kt")
+    assert "Profiles.isPersonal(this)" in activity and "const BACKUP = $backups;" in activity
+    shim = _strip_js_comments(_read(SHIM))
+    gated = shim.split("...(BACKUP ? {", 1)[1].split("} : {}),", 1)[0]
+    for name in ("photoSync:", "phoneSync:", "contactSync:"):
+        assert name in gated, name
+    for path in [*(SRC / "phonesync").rglob("*.kt"), *(SRC / "photos").rglob("*.kt"),
+                 *(APP / "src" / "full").rglob("*.kt")]:
+        assert not re.search(r"\.ENTERPRISE_\w+", _read(path)), path.name
+
+
 def test_the_play_build_cannot_read_text_messages():
     """Play's policy keeps READ_SMS for the default SMS application: the Play
     build has neither the permission nor the code that reads messages."""