SRV_TO_CLI_COOKIE_EXCH
(CLI_TO_SRV_COOKIE_EXCH + SRV_TO_CLI_COOKIE_EXCH + CLI_TO_SRV_EPOCH_0_RECS + CLI_TO_SRV_EPOCH_1_RECS + SRV_TO_CLI_EPOCH_0_RECS + SRV_TO_CLI_EPOCH_1_RECS)
(CLI_TO_SRV_RESUME_COOKIE_EXCH + SRV_TO_CLI_COOKIE_EXCH + CLI_TO_SRV_RESUME_EPOCH_0_RECS + CLI_TO_SRV_RESUME_EPOCH_1_RECS + SRV_TO_CLI_RESUME_EPOCH_0_RECS + SRV_TO_CLI_RESUME_EPOCH_1_RECS)
if (idx >= SRV_TO_CLI_COOKIE_EXCH + srv_to_cli_epoch0) {
idx -= SRV_TO_CLI_COOKIE_EXCH + srv_to_cli_epoch0;