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

Protocol Core

• Protocol Core
  • Transport
  • Entity ID
  • BaseMessage
  • Errors
  • User devices
  • Account registration/login
    • Create account
    • 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.
• 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:

id (string) - message identifier (used to track the request-response chain)
type (string) - type of message (used to determine which extension this message belongs to)
from (EntityID) - from which entity this message is send
to (EntityID) - message recipient
ok (boolean) - operation success indicator (used to determine if the error happened while processing request)
payload (Map<K,V>) - message payload (used to store extra information in message, list of permissible fields in the payload depends on "type" field)

Errors

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

Payload:

• errCode: int - error code (defined in extensions, may be same per extensions)
• errText: String - explanation of error in human-readable view
• errPayload: Map<K,V> - advanced error information (fields defined in extensions)

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

Create account

Description: Create user account on a server
Type: profile:register
Payload:

• Request:
  • username: string - the username that the user wants to register
  • thirdPIDs: [] - array of user third party IDs (email and/or MSISDN). Array contains objects with following fields:
    • type: string - type of third party ID.
    • value: string - string contains third party ID. Examples: juliet@capulett.com, +1234567890.
  • password: string - password of new account
• Response:
  • userID: EntityID- ID of user (Username in priority. If we haven't username, then we put to this field one of user's third party IDs).

Errors:

• 0: limit exceed
• 1: username/third party ID already taken
• 2: registration isn't allowed on a server

Usecase:

Request:

{
    "id": "abcd",
    "type": "profile:register",
    "to": "cadmium.org",
    "payload": {
        "username": "juliet",
        "thirdPIDs": [
            {"type":"email", "value":"juliet@capulett.com"},
            {"type":"msisdn", "value":"+1234567890"},
        ],
        "password": "romeo1"
    }
}

Response:

{
    "id": "abcd",
    "type": "profile:register",
    "from": "cadmium.org",
    "ok": true,
    "payload": {
        "userID": "@juliet@cadmium.org"
    }
}

Error response:

{
    "id": "abcd",
    "type": "profile:register",
    "from": "cadmium.org",
    "ok": false,
    "payload": {
        "errCode": 1,
        "errText": "{Username/email/msisdn} already taken"
    }
}

Special business rules: none.

Login into account (by username)

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

• Request:
  • username: string - the username of account which user wants to login
  • password: string - password of new account
• Response:
  • authToken: string - authentication token which required for various user actions (UUID)
  • deviceID: string - identifier of new user device (created by this login action)

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.