cipher.update()

cipher.update(data[, input_encoding][, output_encoding])

Updates the cipher with data. If the input_encoding argument is given, it's value must be one of 'utf8', 'ascii', or 'binary' and the data argument is a string using the specified encoding. If the input_encoding argument is not given, data must be a Buffer. If data is a Buffer then input_encoding is ignored.

The output_encoding specifies the output format of the enciphered data, and can be 'binary', 'base64' or 'hex'. If the output_encoding is specified, a string using the specified encoding is returned. If no output_encoding is provided, a Buffer is returned.

The cipher.update() method can be called multiple times with new data until cipher.final() is called. Calling cipher.update() after cipher.final() will result in an error being thrown.