cs_len = struct.calcsize(PREFIX)
version, seqnum, root_hash, IV = struct.unpack(PREFIX, checkstring[:cs_len])
if version != 0: # TODO: just ignore the share
raise UnknownVersionError("got mutable share version %d, but I only understand version 0" % version)
return (seqnum, root_hash, IV)
cs_len = struct.calcsize(PREFIX)
version, seqnum, root_hash, IV = struct.unpack(PREFIX, checkstring[:cs_len])
if version != 0: # TODO: just ignore the share
raise UnknownVersionError("got mutable share version %d, but I only understand version 0" % version)
return (seqnum, root_hash, IV)