The gateway authorization/authentication method. This setting
determines how Cloud IoT Core authorizes/authenticate devices to
access the gateway.
Values:
GATEWAY_AUTH_METHOD_UNSPECIFIED (0):
No authentication/authorization method
specified. No devices are allowed to access the
gateway.
ASSOCIATION_ONLY (1):
The device is authenticated through the
gateway association only. Device credentials are
ignored even if provided.
DEVICE_AUTH_TOKEN_ONLY (2):
The device is authenticated through its own
credentials. Gateway association is not checked.
ASSOCIATION_AND_DEVICE_AUTH_TOKEN (3):
The device is authenticated through both
device credentials and gateway association. The
device must be bound to the gateway and must
provide its own credentials.
