Foster, 26, will arrive from Scunthorpe after helping them to the League One title and a place in the Championship.

The 31-year-old White is to leave Notts County with the pair set to complete their moves on 1 July when their current deals come to an end.

Darlington boss by Dave Penney managed Foster at Doncaster and said: "It has been no secret one of my priorities was to strengthen the back four."