使用外部 HTTP 服务认证

HTTP/1.1 200 OK
Headers: Content-Type: application/json
...
Body:
{  
        "result": "allow", // "allow" | "deny" | "ignore"
        "client_attrs": { 
            "role": "admin",
            "sn": "10c61f1a1f47"
        }
        "expire_at": 1654254601, // 可选，表示当前认证策略的过期时间
        "acl": // 可选，用于使用既有的HTTP认证服务支持简单的授权，授权策略将会被缓存到MQTT服务端，再次触发时更新
        [
            {
                "effect": "allow",
                "action": ["publish","subscribe","connect"],
                "topic": "topic/AA/#",
                "qos": [1]
            },
            {
                "effect": "deny",
                "action": ["publish","connect"],
                "topic": "topic/BB"
            }
        ]
}