Hamas have said many times they will accept a peace proposal negotiated by the PA and approved in a referendum by Pal people. Also in a recent interview Mashal said he can live with 1967 borders (although principally wrong in his eyes). The strong retoric comes from the early days of Hamas. In the last decades they sought a political solution and (especially in the 2005-2007 years) came up with constructive proposal, totally neglected by Israel and the West.
Netanyahu condemns West Bank arson attack, calling it 'terror' (Haaretz)
from the article: It's time for Israel to talk to Hamas