Java-缺少参数，解密时未初始化密码

Question

尝试使用AES解码消息时，出现java.security.InvalidKeyException: Parameters missing错误。这是我的密码初始化代码

Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, key);

密钥生成如下

MessageDigest sha = MessageDigest.getInstance("SHA-1");
byte[] bytes = passwordString.getBytes(StandardCharsets.UTF_8);
bytes = sha.digest(bytes);
bytes = Arrays.copyOf(bytes, 16);
SecretKeySpec key = new SecretKeySpec(bytes, "AES");

此错误仅在解密邮件时发生。加密工作正常。