Bob Woodward — in an eye-opening excerpt from his forthcoming memoir, "Secrets," that's previewed in the new issue of The New Yorker — reveals that one of his best friends, the late Richard Darman, was also one of his best sources during the Ronald Reagan and George H.W. Bush administrations."Darman was willing, even eager at times, to talk about the most sensitive intelligence matters, including N.S.A. intercepts and covert C.I.A. operations," Woodward writes in his book, out Nov.