We have all heard of blacksmiths, the village blacksmith in olden days, etc. I must admit that whitesmith was not a term I have ever heard.
A whitesmith works with light-colored or “white” metals. These include tin and pewter. A whitesmith usually does not work with hot metals, like a blacksmith does. They work with unheated metal but may heat it occasionally to shape it the way they desire.
Items that might be produced by a whitesmith include (tin or pewter) cups, pitchers, silverware and candle holders to name a few.
The word origin is Middle English from the period 1275 to 1325.