5.2 KiB
Synchronising
General
Andromeda is an Express, CouchDB & PouchDB web-app.
PouchDB handles the storing and synchronising of user data. Server side CouchDB handles accounts, syncing sessions, and storing user data. While Express gets used for account creation, updating and more.
Account
An account of the viewer is a CouchDB-account. To create, update, delete and password reset, the methods in account.js must get used.
An account name is always an UUID. The login-name is an email-address.
The email get stored in an email field.
To get the UUID/name a GET request gets made to /api/session/account with a basic login. The result contains the account infos. With them the client can login to CouchDB.
The account data will get stored in _local/account.
It is a local doc that isn't synchronised.
Password
The users password gets hashed on the client. First with PBKDF2 and then with HKDF.
Using them the password gets hashed into 64 byte. The first 32 bytes are the server password,
while the last 32 bytes are the encryption password.
The encryption password and users password will never leave the client!
Store
All synchronising data, must get stored in a local PouchDB database. hoodie-plugin-store-crypto must get used to encrypt the users data!
PouchDB and CouchDB are NoSQL databases. Documents (doc) are the data unit of CouchDB. A doc is a JSON-Object. No Array as base!
Every doc has an ID-string (_id key) that is unique for a database. It is the primary way to find a doc.
Every user has their own database.
Encryption
Andromeda uses hoodie-plugin-store-crypto to encrypt and decrypt user data.
It uses pbkdf2 with sha256 to generate a key and AES-GCM for data encryption.
The salt gets synced, but the encryption password and key are not synchronised!
Because the _id can't get encrypted, most data uses some random generated UUIDs in their names.
Store Layout
Docs get organised using prefixes on their IDs, separated with /. View it as folders with JSON-files in it.
Data from an avatar (chats) have dataSaveId as prefix. This is a random generated UUID unique to that avatar!
Avatars
Avatars get saved under avatars/, appended by an UUID.
The doc stores:
| key | description |
|---|---|
_id |
avatars/[random generated UUID] |
dataSaveId |
A random generated UUID, that is used as a prefix for all data of this avatar. |
avatarIdentifier |
The avatar-identifier consist out of the full avatar name. Then an @. Followed by an grid name. Where the first and last name are separated by a space. Used to differentiate the avatars. Tester Resident@OS Grid. |
name |
Full name of the avatar. Will be displayed on login screen. |
grid |
Name of the grid this avatar belongs to. |
Future version may save avatar specific settings (like default login position or RLV).
Grids
Grids get saved under grids/ appended by an UUID.
The doc stores:
| key | description |
|---|---|
_id |
grids/[random generated UUID]. |
name |
Display name and identifier in the avatar docs. |
loginURL |
URL of the login endpoint. |
Data of an Avatar
Every saved avatar saves its data under [dataSaveId]/. Where dataSaveId is the random generated UUID that get stored in the avatar doc.
Data that gets saved and synced:
- local-chat messages
- IM chats and messages
Local Chat
Local chat messages get saved by messages. Their ID has the structure of [dataSaveId]/localchat/[JSON-Time]. Where JSON-Time is the result of new Date().toJSON() (a ISO date/time string 2017-10-27T22:21:01.865Z).
The local chat doc contains every required data for its chat type. See in the wiki under ChatFromSimulator and ChatFromViewer.
IM Chat
IMs get saved by message. There are two types of docs for IMs.
| Key | Id | Info |
|---|---|---|
| Chat info | [dataSaveId]/imChatsInfos/[random generated UUID] |
Stores all relevant data and infos about the chat (chat type, target, ...). |
| IM message | [dataSaveId]/imChats/[chat-data-save-UUID]/[JSON-Time], where JSON-Time is the result of new Date().toJSON() (a ISO date/time string 2017-10-27T22:21:01.865Z). |
Stores data of a single message in the chat. |
Chat info docs contains:
| Key | Type | What is it |
|---|---|---|
chatType |
String | Type of the IM Chat. personal, group or conference. |
chatUUID |
String(UUID) | UUID of the IM Chat. Used in ID of the package. |
target |
String(UUID) | UUID of the target. This could be the other avatar-id, group-id or session-id. |
name |
String | Name of the target(s). |
saveId |
String(UUID) | Random generated UUID that is used in the _id of a message. |
The local chat doc contains every required data for its dialog type.