be very explicit about signedness, don't rely on char as it's different on arm
be very explicit about signedness, don't rely on char as it's different on arm

ukscone/telehash-c,telehash/telehash-c,telehash/telehash-c,ukscone/telehash-c,ukscone/telehash-c,telehash/telehash-c,telehash/telehash-c,ukscone/telehash-c