PAC_PRIVSVR_CHECKSUM
ret = k5_insert_checksum(context, pac, PAC_PRIVSVR_CHECKSUM,
ret = k5_pac_locate_buffer(context, pac, PAC_PRIVSVR_CHECKSUM, &privsvr_cksum);
assert(type == PAC_SERVER_CHECKSUM || type == PAC_PRIVSVR_CHECKSUM);
ret = k5_pac_zero_signature(context, pac, PAC_PRIVSVR_CHECKSUM, &pac_data);
ret = k5_pac_locate_buffer(context, pac, PAC_PRIVSVR_CHECKSUM, &privsvr_checksum);