Files
the-button/server.py
T
2026-10-21 11:53:47 -04:00

626 lines
25 KiB
Python

"""The Button - a single-file, dependency-free game server (Python 3.9+)."""
import csv
import hashlib
import hmac
import json
import os
import re
import secrets
import sqlite3
import threading
import time
from contextlib import contextmanager
from http import HTTPStatus
from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
from pathlib import Path
ROOT = Path(__file__).resolve().parent
STATIC_DIR = ROOT / "static"
DATA_FILE = Path(os.environ.get("BUTTON_DATA_FILE", ROOT / "data.json"))
DATABASE_FILE = Path(os.environ.get("BUTTON_DATABASE_FILE", DATA_FILE.with_suffix(".sqlite3")))
MAILING_LIST_FILE = Path(os.environ.get("BUTTON_MAILING_LIST_FILE", ROOT / "mailing_list.csv"))
MAILING_LIST_FIELDS = ["subscribed_at", "player", "first_name", "last_name", "email", "phone"]
EMAIL_RE = re.compile(r"^[^@\s]+@[^@\s]+\.[^@\s]+$")
PHONE_RE = re.compile(r"^\+?[0-9 ()\-.]{7,25}$")
HOST = os.environ.get("BUTTON_HOST", "127.0.0.1")
PORT = int(os.environ.get("BUTTON_PORT", "8000"))
DURATION_MS = int(float(os.environ.get("BUTTON_DURATION_SECONDS", 24 * 60 * 60)) * 1000)
MAX_BODY_BYTES = 1024
MAX_NAME_LEN = 24
MIN_PASSWORD_LEN = 8
MAX_PASSWORD_LEN = 128
PBKDF2_ITERATIONS = 600_000
MAX_SESSIONS_PER_PLAYER = 10
LOGIN_MAX_FAILURES = 5
LOGIN_LOCKOUT_MS = 15 * 60 * 1000
# Ordered from a freshly reset countdown to an almost-expired one.
# "share" is each zone's relative slice of the timer, so high-value zones are brief.
ZONES = [
{"name": "green", "points": 0, "share": 32},
{"name": "blue", "points": 2, "share": 16},
{"name": "yellow", "points": 4, "share": 8},
{"name": "red", "points": 8, "share": 4},
{"name": "black", "points": 16, "share": 2},
{"name": "white", "points": 32, "share": 1},
]
_total_share = sum(z["share"] for z in ZONES)
_upper = DURATION_MS
for _z in ZONES:
_z["remaining_from_ms"] = _upper
_upper = round(_upper - DURATION_MS * _z["share"] / _total_share)
_z["remaining_to_ms"] = max(_upper, 0)
ZONES[-1]["remaining_to_ms"] = 0
STATIC_FILES = {
"/": ("index.html", "text/html; charset=utf-8"),
"/index.html": ("index.html", "text/html; charset=utf-8"),
"/app.js": ("app.js", "text/javascript; charset=utf-8"),
"/style.css": ("style.css", "text/css; charset=utf-8"),
"/favicon.ico": ("favicon.ico", "image/x-icon"),
"/poster.png": ("poster.png", "image/png"),
}
lock = threading.Lock()
def now_ms():
return int(time.time() * 1000)
def hash_token(token):
return hashlib.sha256(token.encode("utf-8")).hexdigest()
def hash_password(password, salt=None, iterations=PBKDF2_ITERATIONS):
salt = salt or secrets.token_hex(16)
digest = hashlib.pbkdf2_hmac("sha256", password.encode("utf-8"), bytes.fromhex(salt), iterations).hex()
return f"pbkdf2_sha256${iterations}${salt}${digest}"
def verify_password(password, stored):
_, iterations, salt, _ = stored.split("$")
return hmac.compare_digest(hash_password(password, salt, int(iterations)), stored)
# Verified against when the name doesn't exist so response timing doesn't reveal valid names.
DUMMY_PASSWORD_HASH = hash_password(secrets.token_hex(16))
def zone_for_remaining(remaining_ms):
for zone in ZONES:
if remaining_ms > zone["remaining_to_ms"]:
return zone
return ZONES[-1]
def new_game():
t = now_ms()
return {
"duration_ms": DURATION_MS,
"started_at": t,
"deadline": t + DURATION_MS,
"ended": False,
"ended_at": None,
"players": {}, # id -> {name, password_hash, token_hashes, created_at}
"presses": [], # {player_id, at, remaining_ms, zone, points}
}
@contextmanager
def database():
"""Use a separate connection per operation, with atomic writes and FK checks."""
connection = sqlite3.connect(DATABASE_FILE)
connection.row_factory = sqlite3.Row
try:
connection.execute("PRAGMA foreign_keys = ON")
with connection:
yield connection
finally:
connection.close()
def write_state(connection, state):
"""Persist a complete snapshot inside the caller's transaction."""
connection.execute("DELETE FROM presses")
connection.execute("DELETE FROM sessions")
connection.execute("DELETE FROM players")
connection.executemany(
"INSERT INTO players (id, name, password_hash, created_at, subscribed) VALUES (?, ?, ?, ?, ?)",
[(pid, p["name"], p.get("password_hash"), p["created_at"], p.get("subscribed", False))
for pid, p in state["players"].items()],
)
connection.executemany(
"INSERT INTO sessions (player_id, position, token_hash) VALUES (?, ?, ?)",
[(pid, position, token_hash) for pid, p in state["players"].items()
for position, token_hash in enumerate(p["token_hashes"])],
)
connection.executemany(
"INSERT INTO presses (position, player_id, at, remaining_ms, zone, points) VALUES (?, ?, ?, ?, ?, ?)",
[(position, p["player_id"], p["at"], p["remaining_ms"], p["zone"], p["points"])
for position, p in enumerate(state["presses"])],
)
connection.execute(
"""INSERT INTO game (id, duration_ms, started_at, deadline, ended, ended_at)
VALUES (1, ?, ?, ?, ?, ?)
ON CONFLICT(id) DO UPDATE SET duration_ms = excluded.duration_ms,
started_at = excluded.started_at, deadline = excluded.deadline,
ended = excluded.ended, ended_at = excluded.ended_at""",
(state["duration_ms"], state["started_at"], state["deadline"], state["ended"], state["ended_at"]),
)
def load_state():
if DATABASE_FILE.resolve() == DATA_FILE.resolve():
raise ValueError("BUTTON_DATABASE_FILE must differ from the legacy BUTTON_DATA_FILE")
DATABASE_FILE.parent.mkdir(parents=True, exist_ok=True)
with database() as connection:
connection.executescript("""
CREATE TABLE IF NOT EXISTS game (
id INTEGER PRIMARY KEY CHECK (id = 1),
duration_ms INTEGER NOT NULL,
started_at INTEGER NOT NULL,
deadline INTEGER NOT NULL,
ended INTEGER NOT NULL CHECK (ended IN (0, 1)),
ended_at INTEGER
);
CREATE TABLE IF NOT EXISTS players (
id TEXT PRIMARY KEY,
name TEXT NOT NULL,
password_hash TEXT,
created_at INTEGER NOT NULL,
subscribed INTEGER NOT NULL CHECK (subscribed IN (0, 1))
);
CREATE TABLE IF NOT EXISTS sessions (
player_id TEXT NOT NULL REFERENCES players(id),
position INTEGER NOT NULL,
token_hash TEXT NOT NULL UNIQUE,
PRIMARY KEY (player_id, position)
);
CREATE TABLE IF NOT EXISTS presses (
position INTEGER PRIMARY KEY,
player_id TEXT NOT NULL REFERENCES players(id),
at INTEGER NOT NULL,
remaining_ms INTEGER NOT NULL,
zone TEXT NOT NULL,
points INTEGER NOT NULL
);
""")
# Serialize initialization. A committed game row is the migration marker,
# not merely the existence of a possibly empty or interrupted database.
connection.execute("BEGIN IMMEDIATE")
game = connection.execute("SELECT * FROM game WHERE id = 1").fetchone()
if game is None:
if DATA_FILE.exists():
with DATA_FILE.open("r", encoding="utf-8") as f:
loaded = json.load(f)
for player in loaded["players"].values():
if "token_hash" in player: # migrate pre-login data as well
player["token_hashes"] = [player.pop("token_hash")]
else:
loaded = new_game()
# Any read/validation/SQL failure aborts startup without consuming the
# JSON source or committing a partial game. The next start can retry.
write_state(connection, loaded)
return loaded
loaded = dict(game)
del loaded["id"]
loaded["ended"] = bool(loaded["ended"])
loaded["players"] = {}
for row in connection.execute("SELECT * FROM players ORDER BY rowid"):
player = dict(row)
pid = player.pop("id")
player["subscribed"] = bool(player["subscribed"])
player["token_hashes"] = []
loaded["players"][pid] = player
for row in connection.execute("SELECT * FROM sessions ORDER BY player_id, position"):
loaded["players"][row["player_id"]]["token_hashes"].append(row["token_hash"])
loaded["presses"] = []
for row in connection.execute("SELECT * FROM presses ORDER BY position"):
press = dict(row)
del press["position"]
loaded["presses"].append(press)
return loaded
def save_state(state):
with database() as connection:
write_state(connection, state)
state = load_state()
token_index = {th: pid for pid, p in state["players"].items() for th in p["token_hashes"]}
failed_logins = {} # lowercase name -> (failure count, first failure ms)
def find_player_by_name(name):
for pid, p in state["players"].items():
if p["name"].lower() == name.lower():
return pid
return None
def issue_token(pid):
"""Must be called with the lock held."""
token = secrets.token_urlsafe(32)
th = hash_token(token)
hashes = state["players"][pid]["token_hashes"]
hashes.append(th)
token_index[th] = pid
while len(hashes) > MAX_SESSIONS_PER_PLAYER:
token_index.pop(hashes.pop(0), None)
save_state(state)
return token
def validate_credentials(data):
"""Returns (name, password, error)."""
name, password = data.get("name"), data.get("password")
if not isinstance(name, str) or not (1 <= len(name.strip()) <= MAX_NAME_LEN):
return None, None, f"Name must be 1-{MAX_NAME_LEN} characters"
name = " ".join(name.split())
if not name.isprintable():
return None, None, "Name contains invalid characters"
if not isinstance(password, str) or not (MIN_PASSWORD_LEN <= len(password) <= MAX_PASSWORD_LEN):
return None, None, f"Password must be {MIN_PASSWORD_LEN}-{MAX_PASSWORD_LEN} characters"
return name, password, None
def check_ended():
"""Must be called with the lock held."""
if not state["ended"] and now_ms() >= state["deadline"]:
state["ended"] = True
state["ended_at"] = state["deadline"]
save_state(state)
def empty_zone_counts():
return {z["name"]: 0 for z in ZONES}
def player_summary(pid):
presses = [p for p in state["presses"] if p["player_id"] == pid]
counts = empty_zone_counts()
for p in presses:
counts[p["zone"]] += 1
return {
"name": state["players"][pid]["name"],
"subscribed": state["players"][pid].get("subscribed", False),
"total_players": len(state["players"]),
"total_presses": len(state["presses"]),
"total_points": sum(p["points"] for p in presses),
"press_count": len(presses),
"zone_counts": counts,
"best_remaining_ms": min((p["remaining_ms"] for p in presses), default=None),
"presses": [
{k: p[k] for k in ("at", "remaining_ms", "zone", "points")} for p in presses
],
}
def public_press(p):
return {
"name": state["players"][p["player_id"]]["name"],
"at": p["at"],
"remaining_ms": p["remaining_ms"],
"zone": p["zone"],
"points": p["points"],
}
def public_leaderboard():
"""Public score totals only; do not expose sessions or individual presses."""
scores = {
pid: {"name": player["name"], "total_points": 0, "press_count": 0}
for pid, player in state["players"].items()
}
for press in state["presses"]:
score = scores[press["player_id"]]
score["total_points"] += press["points"]
score["press_count"] += 1
return sorted(scores.values(), key=lambda p: (-p["total_points"], p["name"].lower()))
def global_stats():
counts = empty_zone_counts()
for p in state["presses"]:
counts[p["zone"]] += 1
leaderboard = []
for pid in state["players"]:
s = player_summary(pid)
del s["presses"], s["subscribed"]
leaderboard.append(s)
leaderboard.sort(key=lambda s: (-s["total_points"], s["name"].lower()))
presses = state["presses"]
lowest = min(presses, key=lambda p: p["remaining_ms"], default=None)
return {
"started_at": state["started_at"],
"ended_at": state["ended_at"],
"total_players": len(state["players"]),
"total_presses": len(presses),
"zone_counts": counts,
"leaderboard": leaderboard,
"last_press": public_press(presses[-1]) if presses else None,
"lowest_press": public_press(lowest) if lowest else None,
"presses": [public_press(p) for p in presses],
}
class Handler(BaseHTTPRequestHandler):
server_version = "TheButton/1.0"
def log_message(self, fmt, *args):
pass
def send_json(self, status, payload):
body = json.dumps(payload).encode("utf-8")
self.send_response(status)
self.send_header("Content-Type", "application/json; charset=utf-8")
self.send_header("Cache-Control", "no-store")
self.send_common_headers()
self.send_header("Content-Length", str(len(body)))
self.end_headers()
self.wfile.write(body)
def send_common_headers(self):
self.send_header("X-Content-Type-Options", "nosniff")
self.send_header("X-Frame-Options", "DENY")
self.send_header("Referrer-Policy", "no-referrer")
self.send_header(
"Content-Security-Policy",
"default-src 'self'; script-src 'self' https://js.stripe.com; "
"frame-src 'self' https://js.stripe.com; frame-ancestors 'none'; "
"base-uri 'none'; form-action 'self'",
)
def read_json(self):
length = int(self.headers.get("Content-Length") or 0)
if length > MAX_BODY_BYTES:
raise ValueError("Request body too large")
raw = self.rfile.read(length) if length else b"{}"
data = json.loads(raw.decode("utf-8"))
if not isinstance(data, dict):
raise ValueError("Expected a JSON object")
return data
def bearer_hash(self):
auth = self.headers.get("Authorization", "")
if not auth.startswith("Bearer "):
return None
return hash_token(auth[7:].strip())
def authed_player(self):
th = self.bearer_hash()
return token_index.get(th) if th else None
def do_GET(self):
path = self.path.split("?", 1)[0]
if path == "/api/state":
with lock:
check_ended()
return self.send_json(HTTPStatus.OK, {
"now": now_ms(),
"started_at": state["started_at"],
"deadline": state["deadline"],
"duration_ms": DURATION_MS,
"ended": state["ended"],
"total_players": len(state["players"]),
"total_presses": len(state["presses"]),
"zones": ZONES,
})
if path == "/api/leaderboard":
with lock:
return self.send_json(HTTPStatus.OK, {"leaderboard": public_leaderboard()})
if path == "/api/me":
with lock:
pid = self.authed_player()
if pid is None:
return self.send_json(HTTPStatus.UNAUTHORIZED, {"error": "Not registered"})
return self.send_json(HTTPStatus.OK, player_summary(pid))
if path == "/api/stats":
with lock:
check_ended()
if not state["ended"]:
return self.send_json(HTTPStatus.FORBIDDEN, {"error": "Stats are published when the game ends"})
return self.send_json(HTTPStatus.OK, global_stats())
if path in STATIC_FILES:
filename, ctype = STATIC_FILES[path]
body = (STATIC_DIR / filename).read_bytes()
self.send_response(HTTPStatus.OK)
self.send_header("Content-Type", ctype)
self.send_common_headers()
self.send_header("Content-Length", str(len(body)))
self.end_headers()
self.wfile.write(body)
return
self.send_json(HTTPStatus.NOT_FOUND, {"error": "Not found"})
def do_POST(self):
path = self.path.split("?", 1)[0]
try:
data = self.read_json()
except (ValueError, UnicodeDecodeError):
return self.send_json(HTTPStatus.BAD_REQUEST, {"error": "Invalid JSON body"})
if path == "/api/register":
name, password, error = validate_credentials(data)
if error:
return self.send_json(HTTPStatus.BAD_REQUEST, {"error": error})
password_hash = hash_password(password) # slow; done outside the lock
with lock:
check_ended()
if state["ended"]:
return self.send_json(HTTPStatus.CONFLICT, {"error": "The game is over"})
if find_player_by_name(name) is not None:
return self.send_json(HTTPStatus.CONFLICT, {"error": "Name already taken"})
pid = secrets.token_hex(8)
state["players"][pid] = {
"name": name,
"password_hash": password_hash,
"token_hashes": [],
"created_at": now_ms(),
}
token = issue_token(pid)
return self.send_json(HTTPStatus.CREATED, {"name": name, "token": token})
if path == "/api/login":
name, password = data.get("name"), data.get("password")
if not isinstance(name, str) or not isinstance(password, str) or len(password) > MAX_PASSWORD_LEN:
return self.send_json(HTTPStatus.BAD_REQUEST, {"error": "Name and password required"})
name = " ".join(name.split())
key = name.lower()
with lock:
count, first = failed_logins.get(key, (0, 0))
if count >= LOGIN_MAX_FAILURES and now_ms() - first < LOGIN_LOCKOUT_MS:
return self.send_json(HTTPStatus.TOO_MANY_REQUESTS, {"error": "Too many failed attempts; try again later"})
pid = find_player_by_name(name)
stored = state["players"][pid].get("password_hash") if pid else None
ok = verify_password(password, stored or DUMMY_PASSWORD_HASH) and stored is not None
with lock:
if not ok:
count, first = failed_logins.get(key, (0, 0))
if now_ms() - first >= LOGIN_LOCKOUT_MS:
count, first = 0, now_ms()
failed_logins[key] = (count + 1, first)
return self.send_json(HTTPStatus.UNAUTHORIZED, {"error": "Invalid name or password"})
failed_logins.pop(key, None)
token = issue_token(pid)
return self.send_json(HTTPStatus.OK, {"name": state["players"][pid]["name"], "token": token})
if path == "/api/logout":
with lock:
th = self.bearer_hash()
pid = token_index.pop(th, None) if th else None
if pid is not None:
state["players"][pid]["token_hashes"].remove(th)
save_state(state)
return self.send_json(HTTPStatus.OK, {"ok": True})
if path == "/api/subscribe":
with lock:
pid = self.authed_player()
player_name = state["players"][pid]["name"] if pid else None
already_subscribed = bool(pid and state["players"][pid].get("subscribed"))
if pid is None:
return self.send_json(HTTPStatus.UNAUTHORIZED, {"error": "Log in to join the mailing list"})
if already_subscribed:
return self.send_json(HTTPStatus.OK, {"ok": True})
entry, error = validate_subscription(data)
if error:
return self.send_json(HTTPStatus.BAD_REQUEST, {"error": error})
entry["player"] = player_name
with mailing_lock:
# Same response for repeat emails so the endpoint doesn't reveal who is subscribed.
if entry["email"].lower() not in subscribed_emails:
add_subscriber(entry)
with lock:
state["players"][pid]["subscribed"] = True
save_state(state)
return self.send_json(HTTPStatus.OK, {"ok": True})
if path == "/api/press":
with lock:
pid = self.authed_player()
if pid is None:
return self.send_json(HTTPStatus.UNAUTHORIZED, {"error": "Not registered"})
check_ended()
if state["ended"]:
return self.send_json(HTTPStatus.CONFLICT, {"error": "The game is over"})
t = now_ms()
remaining = state["deadline"] - t
zone = zone_for_remaining(remaining)
press = {
"player_id": pid,
"at": t,
"remaining_ms": remaining,
"zone": zone["name"],
"points": zone["points"],
}
state["presses"].append(press)
state["deadline"] = t + DURATION_MS
save_state(state)
return self.send_json(HTTPStatus.OK, {
"press": {k: press[k] for k in ("at", "remaining_ms", "zone", "points")},
"deadline": state["deadline"],
"now": t,
})
self.send_json(HTTPStatus.NOT_FOUND, {"error": "Not found"})
mailing_lock = threading.Lock()
def load_subscribed_emails():
if not MAILING_LIST_FILE.exists():
return set()
with MAILING_LIST_FILE.open("r", newline="", encoding="utf-8") as f:
return {row["email"].lower() for row in csv.DictReader(f)}
subscribed_emails = load_subscribed_emails()
def clean_text(value, max_len):
"""Returns a whitespace-normalized string, "" for missing values, or None if invalid."""
if value is None:
return ""
if not isinstance(value, str):
return None
value = " ".join(value.split())
if len(value) > max_len or not value.isprintable():
return None
return value
def validate_subscription(data):
first = clean_text(data.get("first_name"), 50)
last = clean_text(data.get("last_name"), 50)
email = clean_text(data.get("email"), 254)
phone = clean_text(data.get("phone"), 25)
if not first:
return None, "First name is required (max 50 characters)"
if last is None:
return None, "Last name must be at most 50 characters"
if not email or not EMAIL_RE.match(email):
return None, "A valid email address is required"
if phone is None or (phone and not PHONE_RE.match(phone)):
return None, "Phone number is invalid"
return {"first_name": first, "last_name": last, "email": email, "phone": phone}, None
def csv_safe(value):
# Stops spreadsheet apps from interpreting user input as a formula.
return "'" + value if value[:1] in ("=", "+", "-", "@") else value
def add_subscriber(entry):
"""Must be called with mailing_lock held."""
is_new_file = not MAILING_LIST_FILE.exists()
row = {k: csv_safe(v) for k, v in entry.items()}
row["subscribed_at"] = time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime())
with MAILING_LIST_FILE.open("a", newline="", encoding="utf-8") as f:
writer = csv.DictWriter(f, fieldnames=MAILING_LIST_FIELDS)
if is_new_file:
writer.writeheader()
writer.writerow(row)
subscribed_emails.add(entry["email"].lower())
def end_watcher():
while True:
with lock:
check_ended()
if state["ended"]:
return
wait = (state["deadline"] - now_ms()) / 1000
time.sleep(min(max(wait, 0.05), 60))
if __name__ == "__main__":
threading.Thread(target=end_watcher, daemon=True).start()
print(f"The Button running on http://{HOST}:{PORT} (timer: {DURATION_MS / 1000:.0f}s)")
ThreadingHTTPServer((HOST, PORT), Handler).serve_forever()