Do the wife and suckling daughters of the father become unlawful to him through fosterage, and is it permissible for him to shake hands with them?

"What is forbidden by lineage is also forbidden by fosterage. Thus, the foster son's wife is considered a mahram to his foster father, and his daughters are also his mahrams. Therefore, it is permissible for the foster father to shake hands with them, be alone with them, and see what a man is permitted to see of his mahram relatives."