class HexaPDF::Encryption::RubyAES

def initialize(key, iv, mode)

The mode must either be :encrypt or :decrypt.

Creates a new AES object using the given encryption key and initialization vector. 
def initialize(key, iv, mode)
  @key = key
  @expanded_key_blocks = expand_key(@key)
  @prev_block = iv.bytes
  @mode = mode
end