diff options
| -rw-r--r-- | cryptography/fernet.py | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/cryptography/fernet.py b/cryptography/fernet.py index 9f4294f0..c19309d5 100644 --- a/cryptography/fernet.py +++ b/cryptography/fernet.py @@ -19,8 +19,9 @@ import time import six +from cryptography.exceptions import InvalidSignature from cryptography.hazmat.backends import default_backend -from cryptography.hazmat.primitives import padding, hashes, constant_time +from cryptography.hazmat.primitives import padding, hashes from cryptography.hazmat.primitives.hmac import HMAC from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes @@ -105,8 +106,9 @@ class Fernet(object): raise InvalidToken h = HMAC(self._signing_key, hashes.SHA256(), backend=self._backend) h.update(data[:-32]) - hmac = h.finalize() - if not constant_time.bytes_eq(hmac, data[-32:]): + try: + h.verify(data[-32:]) + except InvalidSignature: raise InvalidToken iv = data[9:25] |