Files
ALwrity/backend/services/token_crypto_service.py

70 lines
2.3 KiB
Python

"""Service for encrypting/decrypting integration tokens with key version metadata."""
import base64
import hashlib
import os
from typing import Optional, Tuple
from cryptography.fernet import Fernet, InvalidToken
from loguru import logger
class TokenCryptoService:
"""Token encryption/decryption service with key version support."""
ENV_KEY = "ALWRITY_TOKEN_ENCRYPTION_KEY"
ENV_KEY_VERSION = "ALWRITY_TOKEN_KEY_VERSION"
def __init__(self):
raw_key = os.getenv(self.ENV_KEY, "")
if raw_key:
self._fernet_key = self._normalize_key(raw_key)
else:
self._fernet_key = self._derive_dev_key()
self._fernet = Fernet(self._fernet_key)
self._key_version = os.getenv(self.ENV_KEY_VERSION, "v1")
self._key_reference = self._fingerprint(self._fernet_key)
@property
def key_version(self) -> str:
return self._key_version
@property
def key_reference(self) -> str:
return self._key_reference
def encrypt_token(self, token: Optional[str]) -> Optional[str]:
if token is None:
return None
return self._fernet.encrypt(token.encode("utf-8")).decode("utf-8")
def decrypt_token(self, encrypted_token: Optional[str]) -> Optional[str]:
if encrypted_token is None:
return None
try:
return self._fernet.decrypt(encrypted_token.encode("utf-8")).decode("utf-8")
except InvalidToken:
logger.error("Token decryption failed due to invalid token/key")
raise
def encrypt_pair(self, access_token: str, refresh_token: Optional[str]) -> Tuple[str, Optional[str]]:
return self.encrypt_token(access_token), self.encrypt_token(refresh_token)
@staticmethod
def _normalize_key(raw_key: str) -> bytes:
raw_key = raw_key.strip()
if len(raw_key) == 44 and raw_key.endswith("="):
return raw_key.encode("utf-8")
digest = hashlib.sha256(raw_key.encode("utf-8")).digest()
return base64.urlsafe_b64encode(digest)
@staticmethod
def _derive_dev_key() -> bytes:
seed = "alwrity-local-token-key"
digest = hashlib.sha256(seed.encode("utf-8")).digest()
return base64.urlsafe_b64encode(digest)
@staticmethod
def _fingerprint(key: bytes) -> str:
return hashlib.sha256(key).hexdigest()[:16]