def generate_jwt(self, ttl=43200, algo="RS256"):
"""Generates a JSON Web Token (https://jwt.io/) using network time.
:param int jwt_ttl: When the JWT token expires, defaults to 43200 minutes (or 12 hours).
:param str algo: Algorithm used to create a JSON Web Token.
Example usage of generating and setting a JSON-Web-Token:
..code-block:: python
jwt = CloudCore.generate_jwt()
print("Generated JWT: ", jwt)
"""
if self.logger:
self.logger.debug("Generating JWT...")
ntp = NTP.NTP(self._esp)
ntp.set_time()
claims = {
# The time that the token was issued at
"iat": time.time(),
# The time the token expires.
"exp": time.time() + ttl,
# The audience field should always be set to the GCP project id.
"aud": self._proj_id,
}
jwt = JWT.generate(claims, self._private_key, algo)
return jwt
def __init__(self, mqtt_client):
# Check that provided object is a MiniMQTT client object
mqtt_client_type = str(type(mqtt_client))
if "MQTT" in mqtt_client_type:
self._client = mqtt_client
else:
raise TypeError(
"This class requires a MiniMQTT client object, please create one."
)
# Verify that the MiniMQTT client was setup correctly.
try:
self.user = self._client.user
except Exception as err:
raise TypeError(
"Google Cloud Core IoT MQTT API requires a username.") from err
# Validate provided JWT before connecting
try:
JWT.validate(self._client.password)
except Exception as err:
raise TypeError("Invalid JWT provided.") from err
# If client has KeepAlive =0 or if KeepAlive > 20min,
# set KeepAlive to 19 minutes to avoid disconnection
# due to Idle Time (https://cloud.google.com/iot/quotas).
if self._client.keep_alive == 0 or self._client.keep_alive >= 1200:
self._client.keep_alive = 1140
# User-defined MQTT callback methods must be init'd to None
self.on_connect = None
self.on_disconnect = None
self.on_message = None
self.on_subscribe = None
self.on_unsubscribe = None
# MQTT event callbacks
self._client.on_connect = self._on_connect_mqtt
self._client.on_disconnect = self._on_disconnect_mqtt
self._client.on_message = self._on_message_mqtt
self._client.on_subscribe = self._on_subscribe_mqtt
self._client.on_unsubscribe = self._on_unsubscribe_mqtt
self.logger = False
if self._client.logger is not None:
# Allow MQTT_API to utilize MiniMQTT Client's logger
self.logger = True
self._client.set_logger_level("DEBUG")
self._connected = False
# Set up a device identifier by splitting out the full CID
self.device_id = self._client.client_id.split("/")[7]