Matrix
FluffyChat uses the Matrix protocol. This means that FluffyChat is just a client that can be connected to any compatible matrix server. The respective data protection agreement of the server selected by the user then applies.
For convenience, one or more servers are set as default that the FluffyChat developers consider trustworthy. The developers of FluffyChat do not guarantee their trustworthiness. Before the first communication, users are informed which server they are connecting to.
FluffyChat only communicates with the selected server and with OpenStreetMap to display maps.
More information is available at: https://matrix.org
Database
FluffyChat caches some data received from the server in a local sqflite database on the device of the user. On web indexedDB is used. FluffyChat always tries to encrypt the database by using SQLCipher and stores the encryption key in the Secure Storage of the device.
More information is available at: https://pub.dev/packages/sqflite and https://pub.dev/packages/sqlcipher_flutter_libs
Encryption
All communication of substantive content between Fluffychat and any server is done in secure way, using transport encryption to protect it.
FluffyChat also uses End-To-End-Encryption by using Vodozemac and enables it by default for private chats.
App Permissions
The permissions are the same on Android and iOS but may differ in the name. This are the Android Permissions:
Internet Access
FluffyChat needs to have internet access to communicate with the Matrix Server.
Vibrate
FluffyChat uses vibration for local notifications. More informations about this are at the used package: https://pub.dev/packages/flutter_local_notifications
Record Audio
FluffyChat can send voice messages in a chat and therefore needs to have the permission to record audio.
Write External Storage
The user is able to save received files and therefore app needs this permission.
Read External Storage
The user is able to send files from the device's file system.
Location
FluffyChat makes it possible to share the current location via the chat. When the user shares their location, FluffyChat uses the device location service and sends the geo-data via Matrix.
Push Notifications
FluffyChat uses the Firebase Cloud Messaging service for push notifications on Android and iOS. This takes place in the following steps:
- The matrix server sends the push notification to the FluffyChat Push Gateway
- The FluffyChat Push Gateway forwards the message in a different format to Firebase Cloud Messaging
- Firebase Cloud Messaging waits until the user's device is online again
- The device receives the push notification from Firebase Cloud Messaging and displays it as a notification
The source code of the push gateway can be viewed here: https://github.com/krille-chan/fluffygate
event_id_only is used as the format for the push notification. A typical push notification therefore only contains:
- Event ID
- Room ID
- Unread Count
- Information about the device that is to receive the message
A typical push notification could look like this:
{
"notification": {
"event_id": "$3957tyerfgewrf384",
"room_id": "!slw48wfj34rtnrf:example.com",
"counts": {
"unread": 2,
"missed_calls": 1
},
"devices": [
{
"app_id": "chat.fluffy.fluffychat",
"pushkey": "V2h5IG9uIGVhcnRoIGRpZCB5b3UgZGVjb2RlIHRoaXM/",
"pushkey_ts": 12345678,
"data": {
"client_name": "<random-identifier-for-the-client-in-case-of-multi-account-usage>"
},
"tweaks": {
"sound": "bing"
}
}
]
}
}FluffyChat sets the event_id_only flag at the Matrix Server. This server is then responsible to send the correct data.
FluffyChat also supports UnifiedPush. When UnifiedPush is used, the UnifiedPush provider acts as the push notification service. Learn more at unifiedpush.org.
Crash Reports
FluffyChat can optionally assist with reporting errors. This feature is opt-in and can be toggled in the security settings.
When an error occurs, FluffyChat queries the public GitHub API with an anonymous hash to check for an existing issue. If found, the issue is opened in the browser. Otherwise, a pre-filled GitHub new-issue form is opened. No data is sent automatically — the user must actively submit the form.
More information: https://github.com/krille-chan/fluffychat/issues
Explanation of FluffyChat's Compliance with Google Play Store's Safety Standards
FluffyChat is committed to promoting a safe and respectful environment for all users. As a Matrix client, FluffyChat connects users to various Matrix servers. Please note that FluffyChat does not host or manage any servers directly, and as such, we do not have the capability to enforce content moderation or deletion within the app itself.
To enhance user safety and help protect against the sexual abuse and exploitation of children, FluffyChat enables users to report inappropriate content directly to server administrators.
Reporting Content or Users:
- Mark a message in the chat: Tap and hold the message you wish to report.
- Report the message: Select the "Report" option.
- Provide a reason and score: Enter the reason for reporting and assign a score from 1-100 to indicate how offensive the content is.
- Notification to admin: The server administrator will be notified of the reported content.
In addition to reporting messages, users can also report other users following a similar process.
We encourage server administrators to adhere to strict safety standards and provide mechanisms for addressing and moderating inappropriate content. For more information on the Matrix protocol and its safety standards, please refer to the following link: https://matrix.org/docs/older/moderation/
Calls
FluffyChat supports Matrix RTC calls via LiveKit. These calls use LiveKit encryption with asymmetric keys shared via olm-encrypted to-device messaging.
The SFU used depends on the origin of the call. Each homeserver can define its preferred SFU in a static file, which is then downloaded by the client. When starting a new call, the client uses the SFU defined by the homeserver. When joining an existing call, the client instead uses the SFU with which the call was created, which may be a foreign SFU instance.
