I notice a Catholic always uses a Nazi as a witness. Yet Hitler was a nominal Catholic himself. Based on the timeline, he could have easily learned his AS in the pews. Looks like it was prevalent at the highest levels of the church during that time. To say nothing of the Popes, made saints of not during earlier Catholic history.
Hitler was an adherent of Schönerer and the Los Von Rom movement.
Los Von Rom Bewegung ('Away from Rome') was an explicitly anti-Catholic, pro-Lutheran organisation.