cadmium-docs-legacy/protocol-spec/core.md

Protocol Core

• Protocol Core
  • Transport
  • Entity ID
  • BaseMessage
  • Errors
  • User devices
  • Account registration/login
    • Login into account (by username)

Transport

For starting we simply use JSON + Websockets.

Entity ID

• Room alias: #<roomAlias>@<serverpart>
• Username: @<username>@<serverpart>
• User ID with any 3PID: %<type>:<data>@<serverpart>
  • Currently supported only following types: email and msisdn.
• Raw User ID: @<UUID>@<serverpart>
• Message ID: &<uuid>@<serverpart (from which server the message was sent)>
• Room ID: !<roomID>@<serverpart>
• Single server-part: <serverpart>

Server-part:

• hostname: IPv4 / [IPv6] / dns-domain:<port (1-65535)> (for end-users use)
• server ID: static SHA256 hash string from 4096 characters (for internal protocol use)

Username/Room alias/RoomID - MUST NOT be empty, and MUST contain only the characters a-z, 0-9, ., _, =, -, and /.

Special business rules:

• RoomID SHOULD be UUID identifier.
• Servers MUST use server ID in internal purposes instead of normal server-part with hostname. Only end-users MUST use normal server-part with hostname. This is done for easy multi-domain serving.

BaseMessage

BaseMessage is a basic message model, basis of the whole protocol. It is used for a very easy protocol extension process.

BaseMessage scheme:

interface BaseMessage {
    /**
     * Message identifier (used to track the request-response chain)
     */
    id: string,

    /**
     * Type of message (used to determine which extension this message belongs to)
     */
    type: string,
    /**
     * From which entity this message is send
     */
    from: EntityID,

    /**
     * Message recipient
     */
    to: EntityID,

    /**
     * Operation success indicator (used to determine if the error happened while processing request)
     */
    ok: boolean,

    /**
     * Message payload (used to store extra information in message, list of permissible fields in the payload depends on "type" field)
     */
    payload: Map<K,V>
}

Errors

Mechanism of error processing included into protocol. Adds into type name :error postfix.

Payload:

interface ErrorPayload {
    /**
     * Error code (defined in extensions, may be same per extensions)
     */
    errCode: number,

    /**
     * Explanation of error in human-readable view
     */
    errText: string,

    /**
     * Advanced error information (fields defined in extensions)
     */
    errPayload: Map<K,V>
}

Usecase:

Request:

{
    "id": "abcd",
    "type": "incorrectMessageType",
    "from": "@juliet@cadmium.im",
    "to": "cadmium.im",
    "payload": {
        "test": "test"
    }
}

Response:

{
    "id": "abcd",
    "type": "incorrectMessageType:error",
    "from": "cadmium.im",
    "to": "@juliet@cadmium.im",
    "payload": {
        "errCode": 0,
        "errText": "Incorrect type of message (type isn't implemented in the server)",
        "errPayload": {}
    }
}

User devices

todo

Account registration/login

Login into account (by username)

Description: Login into user account on a server by username Type: profile:login
Payload:

• Request:

interface LoginRequestPayload {
    /**
     * The username of account which user wants to login
     */
    username: string,
    
    /**
     * Password of new account
     */
    password: string
}

• Response:

interface LoginResponsePayload {
    /**
     * Authentication token which required for various user actions (UUID)
     */
    authToken: string,
    
    /**
     * Identifier of new user device (created by this login action)
     */
    deviceID: string
}

Errors:

• 0: limit exceed
• 1: user ID/password isn't valid

Usecase:

Request:

{
    "id": "abcd",
    "type": "profile:login",
    "to": "cadmium.org",
    "payload": {
        "username": "juliet",
        "password": "romeo1"
    }
}

Response:

{
    "id": "abcd",
    "type": "profile:login",
    "from": "cadmium.org",
    "ok": true,
    "payload": {
        "authToken": "3b5135a5-aff5-4396-a629-a254f383e82f",
        "deviceID": "ABCDEFG"
    }
}

Error response:

{
    "id": "abcd",
    "type": "profile:login",
    "from": "cadmium.org",
    "ok": false,
    "payload": {
        "errCode": 1,
        "errText": "Username/password isn't valid"
    }
}

Special business rules: none.