[bug] incompatibilities between e2ee "not set up" vs "setup, but disabled"

[holzgeist]

Hi there,

Describe the bug

My issue is around e2ee and a seamless update path when enabling it.
In the new (e2ee enabled) version, I synchronize e2ee usage via attributes. E2ee is only enabled when all participants in a room have a "supportsE2EE: true" attribute. E2EE enabling works via room.setE2EEEnabled

So far so good, but it looks like tracks that are sent without e2ee setup at all are treated differently than tracks that are sent with e2ee setup, but disabled.

To Reproduce

Run this fork of the example app in web:

• once with e2ee disabled from the ui
• once with e2ee enabled from the ui, with an arbitrary key (e2ee will be disabled in code after connecting via await room.setE2EEEnabled(false))

Expected behavior

See video from both participants on both interfaces

Actual behavior

No video is shown on the e2ee version (at least on chrome browsers)

Platform information

• Flutter version:

flutter doctor -v

[✓] Flutter (Channel stable, 3.41.2, on Arch Linux 6.18.13-arch1-1, locale en_US.UTF-8) [41ms] • Flutter version 3.41.2 on channel stable at /home/tobias/src/3rdparty/flutter • Upstream repository https://github.com/flutter/flutter • Framework revision 90673a4eef (13 days ago), 2026-02-18 13:54:59 -0800 • Engine revision 6c0baaebf7 • Dart version 3.11.0 • DevTools version 2.54.1 • Feature flags: enable-web, enable-linux-desktop, enable-macos-desktop, enable-windows-desktop, enable-android, enable-ios, cli-animations, enable-native-assets, omit-legacy-version-file, enable-lldb-debugging, enable-uiscene-migration

[✓] Android toolchain - develop for Android devices (Android SDK version 36.0.0) [1,756ms]
• Android SDK at /home/tobias/Android/Sdk
• Emulator version 36.3.10.0 (build_id 14472402) (CL:N/A)
• Platform android-36, build-tools 36.0.0
• ANDROID_HOME = /home/tobias/Android/Sdk
• Java binary at: /opt/android-studio/jbr/bin/java
This is the JDK bundled with the latest Android Studio installation on this machine.
To manually set the JDK path, use: flutter config --jdk-dir="path/to/jdk".
• Java version OpenJDK Runtime Environment (build 21.0.9+-14649483-b1163.86)
• All Android licenses accepted.

[✓] Chrome - develop for the web [7ms]
• Chrome at google-chrome

[✓] Linux toolchain - develop for Linux desktop [414ms]
• clang version 21.1.8
• cmake version 4.2.3
• ninja version 1.13.2
• pkg-config version 2.5.1
• OpenGL core renderer: AMD Radeon 740M Graphics (radeonsi, phoenix, ACO, DRM 3.64, 6.18.13-arch1-1)
• OpenGL core version: 4.6 (Core Profile) Mesa 26.0.1-arch1.1
• OpenGL core shading language version: 4.60
• OpenGL ES renderer: AMD Radeon 740M Graphics (radeonsi, phoenix, ACO, DRM 3.64, 6.18.13-arch1-1)
• OpenGL ES version: OpenGL ES 3.2 Mesa 26.0.1-arch1.1
• OpenGL ES shading language version: OpenGL ES GLSL ES 3.20
• GL_EXT_framebuffer_blit: yes
• GL_EXT_texture_format_BGRA8888: yes

[✓] Connected device (3 available) [176ms]
• SM A145R (mobile) • R8YW707S3KF • android-arm64 • Android 15 (API 35)
• Linux (desktop) • linux • linux-x64 • Arch Linux 6.18.13-arch1-1
• Chrome (web) • chrome • web-javascript • Chromium 145.0.7632.116 Arch Linux

[✓] Network resources [235ms]
• All expected network resources are available.

• No issues found!

• Plugin version: latest main (bef5a00)
• Flutter target OS: Arch Linux/Chromium
• Flutter target OS version: Chromium 145.0.7632.116

[holzgeist]

My suspicion is an interference between skipping creation of a framecryptor if incoming track is not encrypted here and enabling encodedInsertableStreams here

The insertable stream config is always set as soon as e2ee is set up locally. Unencrypted incoming tracks are independent of the local e2ee setup, but depend on remote e2ee setup.
So the browser expects a processed stream, but processing is disabled, so it doesn't show anything

Disabling either of those to code snippets makes the system work again