I thought this was an interesting article especially when they asked Michael Hayden about unmasking as well as a former Bush NSC aide.  

I asked retired Lt. Gen. Michael Hayden, former director of the National Security Agency, whether it’s unlawful or even unusual for someone in Rice’s position to ask the NSA to unmask the names of Americans caught up in intercepts. He replied, in an email, “Absolutely lawful. Even somewhat routine.”

It’s hardly out of the ordinary for a White House official like Rice, with high security clearances, to request unmasking. In Tuesday’s Washington Post, Glenn Kessler quotes Michael Doran, a former NSC aide under President George W. Bush, as saying, “I did it a couple of times.”

http://www.slate.com/articles/news_and_politics/war_stories/2017/04/the_bogus_susan_rice_unmasking_story_shows_how_desperate_the_white_house.html