Initial version of the HSWro party line

groupchatbot/bot.py

@@ -1,11 +1,81 @@
 from lxmfbot import LXMFBot
+from redis import Redis
+from time import monotonic
+from hashlib import sha256
+import json
+from functools import reduce
 
 bot = LXMFBot("HSWro Conference Bot")
+PASS = '34a77e61000b2ba1f56201332ef64d93f9cdc60e63ab48bc255102586ef7e592'
+WRONG_LOGIN_BAN_DURATION = 60
+
+
+def check_password(password: str) -> bool:
+    gotten = sha256(f"hswrosalt{password}".encode(
+        'utf-8'), usedforsecurity=True).hexdigest()
+    return PASS == gotten
+
+
+def ban_sender(r, userhash, until):
+    r.rpush("hswroconference:banned", str(json.dumps({
+        "hash": userhash,
+        "until": str(until),
+    })))
+
+
+def check_banned(r, userhash):
+    for raw in r.lrange("hswroconference:banned", 0, -1):
+        m = json.loads(raw.decode('utf-8'))
+        if m['hash'] == userhash:
+            if monotonic() > float(m['until']):
+                r.lrem("hswroconference:banned", 0, raw)
+                print(f"Ban expired for {userhash}, unbanning")
+                return False
+            return True
+
+
+def handle_login(msg, r, from_known_sender):
+    def login_usage():
+        msg.reply("Usage: `/login [NICK] [PASSWORD]`")
+    parts = msg.content.split()
+    if len(parts) != 3:
+        login_usage()
+        return
+    assert parts[0] == "/login"
+    if not check_password(parts[2]):
+        ban_sender(r, msg.sender, monotonic() + WRONG_LOGIN_BAN_DURATION)
+        return
+    r.rpush("hswroconference:users", str(json.dumps({
+        "hash": msg.sender,
+        "nick": parts[1],
+    })))
+    msg.reply(f"Logged in as {parts[1]}.")
 
 
 @bot.received
 def echo_msg(msg):
-    msg.reply(msg.content)
+    r = Redis(host='localhost', port=6379, db=0)
+    if check_banned(r, msg.sender):
+        print(f"Message from banned user: {msg.sender}")
+        return
+    known_senders = list(map(lambda x: json.loads(x.decode('utf-8')),
+                             r.lrange("hswroconference:users", 0, -1)))
+    sender_info = reduce(lambda x, y: y if (y["hash"] == msg.sender) else x,
+                         known_senders, None)
+    from_known_sender = sender_info is not None
+    assert isinstance(msg.content, str)
+    if msg.content.startswith("/login"):
+        handle_login(msg, r, from_known_sender)
+        return
+
+    if not from_known_sender:
+        msg.reply("Please identify with `/login [NICK] [PASSWORD]`")
+    else:
+        print(f"Forwarding message from {sender_info['nick']}")
+        for r in known_senders:
+            if r["hash"] == msg.sender:
+                continue
+            bot.send(r["hash"], f"<{sender_info['nick']}> {msg.content}")
 
 
 bot.run()

groupchatbot/requirements.txt

@@ -1,3 +1,4 @@
 appdirs==1.4.4
 lxmf==0.8
 rns==1.0
+redis==6.4.0