Commit 5eb80f9a authored by Kirill Smelkov's avatar Kirill Smelkov

amari: Conn: add support for password-based authentication

Sometimes Amarisoft services are setup to require custom
challenge/response authentication upon connecting to their WebSocket.
In 61ad9032 (amari: Add functionality to interoperate with an Amarisoft
LTE service via WebSocket) I've put TODO for that but now we start to
need it.

-> Implement corresponding support for password-based authentication.

In the next patch we will teach XLog to use it.

See https://tech-academy.amarisoft.com/lteenb.doc#Startup for details of
the authentication handshake protocol.

/reported-and-tested-by @lu.xu
/reviewed-on !6
parent 8e606c64
# -*- coding: utf-8 -*-
# Copyright (C) 2022-2023 Nexedi SA and Contributors.
# Copyright (C) 2022-2024 Nexedi SA and Contributors.
# Kirill Smelkov <kirr@nexedi.com>
#
# This program is free software: you can Use, Study, Modify and Redistribute
......@@ -26,7 +26,8 @@ from __future__ import print_function, division, absolute_import
import websocket
import json
from golang import chan, select, nilchan, func, defer, panic
import hmac
from golang import chan, select, nilchan, func, defer, panic, b
from golang import context, sync, time
......@@ -47,7 +48,9 @@ class ConnClosedError(ConnError):
# connect connects to a service via WebSocket.
def connect(ctx, wsuri): # -> Conn
#
# The password is used if the service requires authentication.
def connect(ctx, wsuri, password=None): # -> Conn
#websocket.enableTrace(True) # TODO on $XLTE_AMARI_WS_DEBUG=y ?
ws = websocket.WebSocket()
ws.settimeout(5) # reasonable default
......@@ -56,7 +59,7 @@ def connect(ctx, wsuri): # -> Conn
ws.connect(wsuri)
except Exception as ex:
raise ConnError("connect") from ex
return Conn(ws, wsuri)
return Conn(ws, wsuri, password)
# Conn represents WebSocket connection to a service.
#
......@@ -65,8 +68,8 @@ def connect(ctx, wsuri): # -> Conn
class Conn:
# .wsuri websocket uri of the service
# ._ws websocket connection to service
# .srv_ready_msg message we got for "ready"
# .t_srv_ready_msg timestamp of "ready" reception
# .srv_ready_msg message we got for "ready" or initial "authenticate"
# .t_srv_ready_msg timestamp of "ready" / initial "authenticate" reception
# ._mu sync.Mutex
# ._rxtab {} msgid -> (request, rx channel) | None
......@@ -76,13 +79,29 @@ class Conn:
# ._rx_wg sync.WorkGroup for spawned _serve_recv
# ._down_once sync.Once
def __init__(conn, ws, wsuri):
def __init__(conn, ws, wsuri, password):
# initial handshake - see https://tech-academy.amarisoft.com/lteenb.doc#Startup
try:
msg0_raw = ws.recv()
t_msg0 = time.now()
msg0 = json.loads(msg0_raw)
# TODO also support 'authenticate'
if msg0['message'] != 'ready':
if msg0['message'] == 'ready':
pass
elif msg0['message'] == 'authenticate':
if password is None:
raise ValueError("service requires authentication, but no password provided")
res = '%s:%s:%s' % (msg0['type'], password, msg0['name'])
res = hmac.new(b(res), b(msg0['challenge']), 'sha256')
res = res.hexdigest()
ws.send(json.dumps({'message': 'authenticate', 'res': res}))
auth_ack_raw = ws.recv()
auth_ack = json.loads(auth_ack_raw)
if auth_ack['message'] != 'authenticate':
raise ValueError("unexpected authenticate reply: %s" % auth_ack)
if auth_ack.get('ready') != True:
raise ValueError("authentication failure: %s" % auth_ack['error'])
else:
raise ValueError("unexpected welcome message: %s" % msg0)
except Exception as ex:
ws.close()
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment