If a person is born of citizen parents outside of the United States, they are still a citizen at birth. Just like John McCain was born in Panama and is eligible or like Vice-President Charles Curtis was born in the Kansas Territory and was eligible to be President.
I don’t know if Hasan’s parents were citizens or not, but if so, he is eligible since he was a citizen at birth and was not naturalized.
The US State Department advises that the issue of constitutional eligibility to the presidency is an unsettled question of law, in those cases. They are correct, of course, as no court has ever decided that question.