(Notice that the law as quoted below encodes that it is the president who ultimately chooses who is authorized to share classifed information).
Quote: "The term “unauthorized person” means any person who, or agency which, is not authorized to receive information of the categories set forth in subsection (a) of this section, by the President, or by the head of a department or agency of the United States Government which is expressly designated by the President to engage in communication intelligence activities for the United States."