WordNet sense 1 (not straightforward or candid; giving a false appearance of frankness):

disingenuous

WordNet sense 2 (cunning and sly):

pawky

WordNet sense 3 (concealing crafty designs for advancing your own interest):

designing

WordNet sense 4 (marked by skill in deception):

crafty, cunning, slick, sly, tricky, wily

WordNet sense 5 (skillful (or showing skill) in adapting means to ends):

adroit, clever, ingenious