Article 1, Section 8 of the US Constitution appropriately gives the Legislative Branch the power to make all the laws for the Congress and the Judiciary Branch and the Executive Branch and all US Government Departments and agents regarding the exercise of their vested powers.
The phrase, 'any department or officer thereof' does include the President of the United States and his agents.
One of several vested powers that the President has is being the Commander in Chief (CIC).
How the hell does anyone contrive that that particular vested power of the President is somehow outside Article 1, Section 8 of the Constitution?
When the Congress makes laws saying no torture, and use FISA for any warrantless wiretaps deemed necessary, that is the law of the land and even the President is not above the law of the land. Otherwise the Constitution and the law of the land are not worthy of being defended by a CIC.