Reset enc/dec on set_key failure

Author: JeremiahM37

wolfcrypt/ciphers.py

@@ -191,6 +191,7 @@ def encrypt(self, string):
             self._enc = _ffi.new(self._native_type)
             ret = self._set_key(_ENCRYPTION)
             if ret < 0:  # pragma: no cover
+                self._enc = None
                 raise WolfCryptError("Invalid key error (%d)" % ret)
 
         result = _ffi.new("byte[%d]" % len(string))
@@ -224,6 +225,7 @@ def decrypt(self, string):
             self._dec = _ffi.new(self._native_type)
             ret = self._set_key(_DECRYPTION)
             if ret < 0:  # pragma: no cover
+                self._dec = None
                 raise WolfCryptError("Invalid key error (%d)" % ret)
 
         result = _ffi.new("byte[%d]" % len(string))