How to enable TLS on a socket created with asyncio.start_server - ssl

Question

I created a server in python using asyncio.start_server but what I want is to enable TLS for this server after its creation. I know it's possible to enable TLS using the tls parameter when creating the server but I want to do it later in the code.
I saw How do I enable TLS on an already connected Python asyncio stream?, it doesn't help me understand what to do.
Thank you for your kind answer and your time reading this.
The code for the server :
# ..init some parameters for the server
async def start_tls_connection(client_reader: asyncio.StreamReader, client_writer: asyncio.StreamWriter):
global ID
global msgList
global onlineList
global socket_server
data = await PStream.read_from_stream(streamObject=client_reader, debugMessage='Got message from client :')
if data == None:
return -1 # Handshake failure
# before proceeding we must upgrade the socket of the server to one that enables tls :
context = get_context()
logging.debug('socket before = ' + str(socket_server.sockets[0]._sock))
logging.debug(str(context))
socket_server.sockets[0]._sock = context.wrap_socket(socket_server.sockets[0]._sock)
logging.debug('socket after = ' + str(ssl_sock))
# upgrade socket here
data = await PStream.write_from_stream(streamObject=client_writer,
msg='<proceed xmlns="urn:ietf:params:xml:ns:xmpp-tls"/>',
debugMessage='Answer sent from server :')
if data == '':
return -1 # Handshake failure
# waiting for client to send a new stream header
data = await PStream.read_from_stream(streamObject=client_reader, debugMessage='Got message from client :')
if data == None:
return -1 # Handshake failure
# ... others methods for handshake
async def on_connect_client(client_reader: asyncio.StreamReader, client_writer: asyncio.StreamWriter):
logging.debug("START OF HANDSHAKE\nFIRST STEP: STREAM SESSION")
res = await stream_init(client_reader, client_writer)
if res == -1:
return res
logging.debug("START OF TLS HANDSHAKE")
res = await start_tls_connection(client_reader, client_writer)
if res == -1:
return res
logging.debug("START OF AUTHENTIFICATION")
res = await handshake_auth(client_reader, client_writer)
if res == -1:
return res
logging.debug("START OF ROOSTER PRESENCE")
res = await handshake_rooster_presence(client_reader, client_writer)
if res == -1:
return res
logging.debug("Waiting for request...")
while True:
data = await PStream.read_from_stream(streamObject=client_reader, debugMessage='Got message from client :')
if data == None:
break
async def server_start():
global socket_server
socket_server = await asyncio.start_server(on_connect_client, IP, PORT) # tls=ssl_context not here yet
logging.debug("Server just started")
async with socket_server:
await asyncio.gather(socket_server.serve_forever())
if __name__ == '__main__':
try:
asyncio.run(server_start())
except Exception as e:
print("Exception: ", str(e))
The line where
socket_server.sockets[0]._sock = context.wrap_socket(socket_server.sockets[0]._sock)
is written is where I have a problem, I don't know how to enable TLS on an already existing asyncio.start_server object.
The get_context() methods works well so don't worry about it btw.