Legally Trump can give specifics. The President can do almost anything legally. But then there will be the CIA leaking that he gave away secrets. He exposed methods and abilities. And then there will be some investigation that he will have interfered with. So Trump can do it. But he needs to understand how the press will attack back.
And bring Snowden back to be in front of a dozen hearings across the CSPAN channels. Get America glued to what zero has been doing to them for 8 years.