Cryptbase tests

src/cryptbase/cryptbase.py

@@ -9,6 +9,10 @@ from cryptography.hazmat.primitives.ciphers import modes
 class AES256CTREncryptor:
 
     def __init__(self, key):
+        if not isinstance(key, bytes):
+            raise ValueError()
+        if not len(key) == 32:
+            raise ValueError()
         self.__key = key
 
     def encrypt(self, plaintext):
@@ -36,13 +40,13 @@ class CryptoContainer:
         elif 'ciphertext' in kwargs and 'iv' in kwargs:
             self.__ciphertext = kwargs['ciphertext']
             self.__iv = kwargs['iv']
-            self.__plaintext = kwargs['encryptor'].decrypt(self.__ciphertext, self.__iv)
+            self.__plaintext = kwargs['encryptor'].decrypt(self.__ciphertext, self.__iv).decode('utf-8')
         else:
             raise ValueError()
 
     @property
     def plaintext(self):
-        return self.__plaintext.decode('utf-8')
+        return self.__plaintext
 
     @property
     def ciphertext(self):