Fixed TypeError and added documentation

1 files changed, 10 insertions, 4 deletions

diff --git a/cryptography/hazmat/primitives/cmac.py b/cryptography/hazmat/primitives/cmac.py
index 7e7f65ab..cc8e8f2c 100644
--- a/cryptography/hazmat/primitives/cmac.py
+++ b/cryptography/hazmat/primitives/cmac.py
@@ -47,8 +47,11 @@ class CMAC(object):
     def update(self, data):
         if self._ctx is None:
             raise AlreadyFinalized("Context was already finalized")
-        if isinstance(data, six.text_type):
-            raise TypeError("Unicode-objects must be encoded before hashing")
+        if not isinstance(data, six.binary_type):
+            raise TypeError(
+                "data must be binary type. This is str in Python 2 and bytes "
+                "in Python 3"
+            )
         self._ctx.update(data)
 
     def finalize(self):
@@ -59,8 +62,11 @@ class CMAC(object):
         return digest
 
     def verify(self, signature):
-        if isinstance(signature, six.text_type):
-            raise TypeError("Unicode-objects must be encoded before verifying")
+        if not isinstance(signature, six.binary_type):
+            raise TypeError(
+                "signature must be binary type. This is str in Python 2 and "
+                "bytes in Python 3"
+            )
         digest = self.finalize()
         if not constant_time.bytes_eq(digest, signature):
             raise InvalidSignature("Signature did not match digest.")