What we know so far is that Susan Rice did receive unredacted intelligence reports in which US citizens names were revealed ("unmasked").
Rice admits this and adding that it was not illegal to do so and no political use was made of the information. She points out that "unmasking" is not leaking, which is illegal, and she asserts that she did not leak anyone's name.
Who leaked Michael Flynn's name to David Ignatius, who then wrote in the New York Times about Flynn's meetings with the Russian ambassador, remains unknown.
Since this information improperly identifying Flynn publicly was obtained through intelligence, it is a felony offense punishable by a prison sentence of up to ten years.
Presently, I have not seen a comprehensive non-partisan objective analysis of the situation. The alternative is piecing together a scenario using different sources.
This is complicated by Trump proponents and the Obama/Clinton proponents spinning the story oppositionally and sometime in a contradictory way. So it is difficult to tease out where the truth may lie in these narratives whose purpose is to dominate the news cycle.
It has been established, however, that the Obama administration had specific intelligence about the Trump team, which had previously not been established. What they did with it is so far unclear, as it the identity of the leaker(s).
How Obama’s National Security Advisor Landed at the Center of Trump’s Wiretapping Claims