Code example for simple client/server communication with OSCORE #310
Description
Background
Thanks for the great library! I'm trying to implement a simple client/server communication demo with OSCORE, and have already read the docs here: https://aiocoap.readthedocs.io/en/latest/stateofoscore.html. However, the docs only include instructions on using the CLIs rather than code examples, which would be very helpful if added to the docs.
Attempts
So I tried to write the demo code for the client:
import asyncio
from aiocoap import *
import logging
logging.basicConfig(level=logging.INFO)
async def main():
client = await Context.create_client_context()
client.client_credentials.load_from_dict({
"coap://localhost/*": {"oscore": {"contextfile": "client1/for-fileserver/"}}
})
request1 = Message(
code=GET, uri='coap://localhost/sensor_data')
print(request1.remote)
response1 = await client.request(request1).response
print("Response from Sensor1: %s" % response1.payload)
if __name__ == '__main__':
asyncio.get_event_loop().run_until_complete(main())As well as the server:
import asyncio
from aiocoap.resource import Resource, Site
from aiocoap import *
import logging
logging.basicConfig(level=logging.DEBUG)
class SensorResource(Resource):
async def render_get(self, request):
response = Message(payload=b"Sensor 1 data")
return response
async def main():
resource = SensorResource()
site = Site()
site.add_resource(('sensor_data',), resource)
server = await Context.create_server_context(site, bind=('localhost', 5683))
server.server_credentials.load_from_dict({
":client1": {"oscore": {"contextfile": "server/from-client1/"}}
})
print("Sensor server is running...")
await asyncio.sleep(3600)
if __name__ == '__main__':
asyncio.get_event_loop().run_until_complete(main())The OSCORE context here is exactly the same with the docs, but I got an error No Object-Security option present. After some debugging, I believe the problem here is that the communication is using simple6 transport rather than the expected oscore transport.
I'm aware that simple6 is used for platforms like OSX so I switched to Linux, and it's still using udp6, not oscore. I've also tried setting request1.opt.object_security = b'', which resolves the above error but still using simple6 transport. In addition, I tried using the provided CLIs client and fileserver and got the same No Object-Security option present error with the same simple6 transport.
I wonder if there's anything wrong with the above code. I'll be happy to contribute a correct code example for simple client/server communication with OSCORE to the current docs.
Output of python3 -m aiocoap.cli.defaults
Python version: 3.8.9 (default, Feb 18 2022, 07:45:33)
[Clang 13.1.6 (clang-1316.0.21.2)]
aiocoap version: 0.4.7
Modules missing for subsystems:
dtls: everything there
oscore: everything there
linkheader: everything there
prettyprint: missing termcolor
Python platform: darwin
Default server transports: oscore:tinydtls:tcpserver:tcpclient:tlsserver:tlsclient:simple6:simplesocketserver
Selected server transports: oscore:tinydtls:tcpserver:tcpclient:tlsserver:tlsclient:simple6:simplesocketserver
Default client transports: oscore:tinydtls:tcpclient:tlsclient:simple6
Selected client transports: oscore:tinydtls:tcpclient:tlsclient:simple6
SO_REUSEPORT available (default, selected): True, True