Check wc_AesInit return value

Author: JeremiahM37

wolfcrypt/ciphers.py

@@ -408,7 +408,9 @@ def __init__(self, key, IV, tag_bytes=16):
                 raise ValueError("key must be %s in length, not %d" %
                                  (self._key_sizes, len(key)))
             self._native_object = _ffi.new(self._native_type)
-            _lib.wc_AesInit(self._native_object, _ffi.NULL, -2)
+            ret = _lib.wc_AesInit(self._native_object, _ffi.NULL, -2)
+            if ret < 0:
+                raise WolfCryptError("AES init error (%d)" % ret)
             ret = _lib.wc_AesGcmInit(self._native_object, key, len(key), IV, len(IV))
             if ret < 0:
                 raise WolfCryptError("Init error (%d)" % ret)