Simple Authentication Plugin

simple auth plugin is a simple MQTT authentication plugin that provides basic username/password authentication functionality.

Features

• Support multi-user configuration
• Simple username/password authentication mechanism
• Easy to configure and use

Configuration

Configure user account information in plugin.yaml, format as follows:

accounts:
  - username: admin
    password: admin

Usage Instructions

1. Install the plugin to the MQTT server
2. Configure user accounts in plugin.yaml
3. Restart the MQTT service for configuration to take effect

Notes

• Passwords are stored in plain text, please keep the configuration file secure
• Recommend using more secure authentication methods in production environments

Workflow Diagram

Authentication Swimlane Diagram

sequenceDiagram
    autonumber
    participant Client as MQTT Client
    participant Broker as MQTT Broker
    participant Plugin as Simple Auth Plugin
    participant Config as plugin.yaml Config

    Client->>Broker: 1. CONNECT packet<br/>(username + password)
    Broker->>Plugin: 2. Forward authentication request<br/>(extract credentials)
    Plugin->>Config: 3. Query account list
    Config-->>Plugin: 4. Return matching account
    
    alt Account exists and password matches
        Plugin-->>Broker: 5. Return authentication success
        Broker-->>Client: 6. CONNACK(return code 0)<br/>Connection successful
        Note over Client,Broker: Subsequent MQTT communication
    else Account doesn't exist or password incorrect
        Plugin-->>Broker: 5. Return authentication failure
        Broker-->>Client: 6. CONNACK(return code 4)<br/>Authentication failed
        Broker->>Client: 7. Disconnect TCP connection
    end

Flow Description

1. CONNECT Packet: Client sends connection request to Broker, carrying username and password
2. Account Lookup: Plugin looks up matching account from plugin.yaml configuration
3. Identity Verification: Compare username and password in request with configured account information
4. Result Processing:
   • Verification passed: Return connection successful, allow client subsequent communication
   • Verification failed: Reject connection and disconnect client