On what basis does the Catholic Church teach that women cannot be ordained?

The Catholic Church maintains that it does not have the authority to ordain women. I.e., the Church *can't* ordain women. It's assumed then that God set a precedent or gave a mandate to ordain *only men*. According to the Church, in what way, how, and when was this mandate or precedent given? What [sound] theology and Patristic writing supports the Church's interpretation of that mandate and/or precedent? --- To clarify: I'm looking for the justification the Catholic Church does/might give, which I expect is supported by Patristic writings, theology, and scripture.