Files
PlexPlaylistSync/app/utils/auth.py
T
2025-12-18 06:46:27 +09:00

105 lines
3.2 KiB
Python

import base64
import hashlib
import hmac
import json
import os
import time
from dataclasses import dataclass
from app.utils.logger import logger
def _parse_bool(value: str | None, default: bool = False) -> bool:
if value is None:
return default
return value.strip().lower() in {"1", "true", "yes", "y", "on"}
def _b64url_encode(data: bytes) -> str:
return base64.urlsafe_b64encode(data).decode("utf-8").rstrip("=")
def _b64url_decode(data: str) -> bytes:
padding = "=" * (-len(data) % 4)
return base64.urlsafe_b64decode((data + padding).encode("utf-8"))
@dataclass(frozen=True)
class AuthConfig:
enabled: bool
username: str
password: str
token_secret: bytes
token_ttl_seconds: int
def load_auth_config() -> AuthConfig:
enabled = _parse_bool(os.environ.get("PLEXPLAYLISTSYNC_AUTH_ENABLED"), default=False)
username = os.environ.get("PLEXPLAYLISTSYNC_AUTH_USERNAME", "").strip()
password = os.environ.get("PLEXPLAYLISTSYNC_AUTH_PASSWORD", "")
ttl = int(os.environ.get("PLEXPLAYLISTSYNC_AUTH_TOKEN_TTL_SECONDS", "86400"))
ttl = max(60, ttl)
secret_env = os.environ.get("PLEXPLAYLISTSYNC_AUTH_TOKEN_SECRET", "").strip()
if secret_env:
token_secret = secret_env.encode("utf-8")
elif enabled:
# If auth is enabled but no explicit secret is set, fall back to an ephemeral secret.
# This means tokens become invalid after restart, which is acceptable for this project.
token_secret = os.urandom(32)
logger.warning(
"PLEXPLAYLISTSYNC_AUTH_TOKEN_SECRET not set; using ephemeral secret (tokens reset on restart)."
)
else:
token_secret = b""
if enabled:
if not username or not password:
raise RuntimeError(
"Auth enabled but missing credentials: please set PLEXPLAYLISTSYNC_AUTH_USERNAME and PLEXPLAYLISTSYNC_AUTH_PASSWORD."
)
return AuthConfig(
enabled=enabled,
username=username,
password=password,
token_secret=token_secret,
token_ttl_seconds=ttl,
)
def issue_token(config: AuthConfig, username: str) -> str:
now = int(time.time())
payload = {"u": username, "exp": now + config.token_ttl_seconds}
payload_bytes = json.dumps(payload, separators=(",", ":"), ensure_ascii=False).encode("utf-8")
payload_b64 = _b64url_encode(payload_bytes)
sig = hmac.new(config.token_secret, payload_b64.encode("utf-8"), hashlib.sha256).digest()
sig_b64 = _b64url_encode(sig)
return f"{payload_b64}.{sig_b64}"
def verify_token(config: AuthConfig, token: str) -> dict | None:
try:
payload_b64, sig_b64 = token.split(".", 1)
except ValueError:
return None
try:
expected_sig = hmac.new(
config.token_secret, payload_b64.encode("utf-8"), hashlib.sha256
).digest()
actual_sig = _b64url_decode(sig_b64)
if not hmac.compare_digest(expected_sig, actual_sig):
return None
payload = json.loads(_b64url_decode(payload_b64).decode("utf-8"))
exp = int(payload.get("exp", 0))
if exp <= int(time.time()):
return None
if not payload.get("u"):
return None
return payload
except Exception:
return None