diff options
Diffstat (limited to 'cryptography/hazmat/primitives/cmac.py')
| -rw-r--r-- | cryptography/hazmat/primitives/cmac.py | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/cryptography/hazmat/primitives/cmac.py b/cryptography/hazmat/primitives/cmac.py index 7ae5c118..d5e26a57 100644 --- a/cryptography/hazmat/primitives/cmac.py +++ b/cryptography/hazmat/primitives/cmac.py @@ -59,9 +59,11 @@ class CMAC(object): def verify(self, signature): if not isinstance(signature, bytes): raise TypeError("signature must be bytes.") - digest = self.finalize() - if not constant_time.bytes_eq(digest, signature): - raise InvalidSignature("Signature did not match digest.") + if self._ctx is None: + raise AlreadyFinalized("Context was already finalized.") + + ctx, self._ctx = self._ctx, None + ctx.verify(signature) def copy(self): if self._ctx is None: |