'Initialize the message-digest and set all fields to zero.'

def init(self):

    self.length = 0L
    self.input = []
    self.H0 = 839939668L
    self.H1 = 587294533L
    self.H2 = 3303440546L
    self.H3 = 3697776675L
    self.H4 = 3498408500L
