cipher.final([outputEncoding])

• outputEncoding <string> 返回值的编码。
• 返回: <Buffer> | <string> 任何剩余的加密内容。 如果指定了 outputEncoding，则返回字符串。 如果未提供 outputEncoding，则返回 Buffer。

一旦调用了 cipher.final() 方法，则 Cipher 对象就不能再用于加密数据。 多次尝试调用 cipher.final() 将导致抛出错误。

• outputEncoding <string> The encoding of the return value.
• Returns: <Buffer> | <string> Any remaining enciphered contents. If outputEncoding is specified, a string is returned. If an outputEncoding is not provided, a Buffer is returned.

Once the cipher.final() method has been called, the Cipher object can no longer be used to encrypt data. Attempts to call cipher.final() more than once will result in an error being thrown.