'Verifies data and its signature.  If verification fails, an sspi.error
will be raised.'

def verify(self, data, sig):

    sigbuf = win32security.PySecBufferDescType()
    sigbuf.append(win32security.PySecBufferType(len(data), sspicon.SECBUFFER_DATA))
    sigbuf.append(win32security.PySecBufferType(len(sig), sspicon.SECBUFFER_TOKEN))
    sigbuf[0].Buffer = data
    sigbuf[1].Buffer = sig
    self.ctxt.VerifySignature(sigbuf, self._get_next_seq_num())
