WASHINGTON -- David J. Rush, the former CIA officer found last month with $40 million in gold bars in his home and now under FBI investigation, had powerful friends in government. It turns out that one of them, Stephen A. Feinberg, the deputy secretary of defense, even contacted the CIA this year asking to work more closely with him. Before the CIA fired Rush, he and Feinberg worked together on a highly classified program focused on spying on China, according to the current and former officials.