orlandos-nl / cyphertextkit Goto Github PK

• Invite
• Accept Invite
• Decline Invite
• Leave Group
• Kick form Group
• Send Magic Packets when changing the Group Config
• Send a magic packet to inform other users

Synchronisation Strategy:

• Synchronise using the framework from #29
• Most Recent
• Last Known

• Last Message Date

Requires #8

• Too many messages being received may block the app's queue from functioning
• Likewise, too much data in the database will fill up the phone's storage

Track a conversation ID in messages during transport. Messages from old conversation IDs (before a rekey occurred) can then be ignored, not triggering a new rekey.

The conversation ID could then also be used as the 'public information' when generating an initial key using HDKF

The cache is shared between copies of a decrypted model, but multiple locations are decrypting the same model, leading to duplicate caches.

• Tested

• Edit Message
• Delete Message
• Poll (for Group Chats)
• Share Location

Add support for tuple messages. When multiple messages are to be sent to the same device, we can bundle them together in a single packet.

This helps reduce metadata in the on-device storage.

Friendship

• Block Users
• Add as Friend
• Remove as Friend
• Block & Unblock
• Can Ignore group communication by blocked users
• Can prevent sending disallowed messages

Block

• Client-Side Support
• Server-Side Support
• Disable Push by non-Friends (Server)
• Client-Side Transport Hook (notify Server)

Tests

Test 1

When FriendshipRuleset.ignoreWhenUndecided == true, block all plugins down the line from communication.

1. Create chat
2. Don't add friends
3. Send message(s)
4. Neither Side sees the message, sender fails to send

Test 2

When FriendshipRuleset.blockAffectsGroupChats == true, doesn't block normal group communication

1. Create group chat
2. Start chatting
3. Both parties can chat normally in the group

Test 3

FriendshipRuleset.blockAffectsGroupChats == true blocks blocked users

1. Create group chat
2. Start chatting
3. Both parties can chat normally in the group
4. Either party blocks the other
5. New group messages don't arrive

Test 4

With FriendshipRuleset.ignoreWhenUndecided == true

1. Create chat
2. Add friends
3. Chatting works
4. User A blocks user B
5. Can't chat
6. User B blocks User A
7. Can't chat still
8. Both parties unblock each other (don't explicitly reclaim friendship)
9. Parties resume chatting normally

Test 5

With FriendshipRuleset.canIgnoreMagicPackets == true and custom plugin

1. Create chat
2. Add friends
3. A sends Magic packet using custom plugin
4. B's plugin receives message
5. A blocks B
6. A sends Magic packet using custom plugin
7. B's plugin doesn't receive it

Test 5

With FriendshipRuleset.canIgnoreMagicPackets == false and custom plugin

1. Create chat
2. Add friends
3. A sends Magic packet using custom plugin
4. B's plugin receives message
5. A blocks B
6. A sends Magic packet using custom plugin
7. B's plugin receives message

This can be used for plausible deniability, custom models among other features.

Provide hooks that can signal the server to send a notification

https://eprint.iacr.org/2019/1416.pdf

• Try to train the ML algorithm to recognise packet types
• Try to train ML so that it reduces application 'health'
• Measure application 'health'

This should ignore successive receives

• Preferences & Settings
• Contact metadata
• Chat metadata
• Changes are timestamped

Data is synchronised with the master device, which relays the latest state onto other devices.

Test 1

1. Master is offline
2. Non-Master Client Changes State
3. Other Non-Master Changes State
4. Devices are out-of-sync
5. Master comes online
6. Devices are all in sync

Test 2

1. Master is online
2. Non-Master Client Changes State
3. Other Non-Master Changes State
4. Devices are all using the most recent state

Test 3

1. All devices are offline
2. Non-Master Client (A) Changes State
3. Other Non-Master (B) Changes State
4. B comes online and synchronises state with Master
5. A comes online and synchronises state with Master
6. B's state remains in place, as it's most recent

Collaborate with launching customer project

• Support lack of sendMultiRecipientMessage in group chats
• Support duplicating messages to each member of a virtual group chat

• Configurable
• Tests

Negotiated on initial connection