The villain with long white hair and beard is a fairly common one in classic kungfu cinema, so much so that Gordon Liu was asked to play Bak Mei (White Eyebrow) in the Tarantino movie Kill Bill. There was also Hwang Jang Lee in The Secret Rivals 1 and 2, and many more.
The movie you're describing sounds familiar, but I'm wondering you're thinking of the One Armed Boxer from 1971 with Jimmy Wang Yu?
You might find your white haired villain here: there is a twof-fingered punch by a guy with a metal glove at 7.00. Is your film Shaolin Prince?