単純なサーバー時間のチート対策

• ゲーム内アイテムは、特定の日付に失効するオークションからのみ購入できます。
• RTS ゲームの世界では、クールダウンに達するまで建物を建築できません。
• ノンプレイヤーキャラクター (NPC) は、ゲームの開始から数日後にのみ表示されます。

基本的な例

/* * Return the current UNIX timestamp of the server and its UTC string representation */module.exports = async () => {    // Get the current server timestamp    const unixTimestamp = Date.now();    // Convert the timestamp to a JavaScript Date object    const currentDate = new Date(unixTimestamp);    // Create a Universal Coordinate Time (UTC) string    const utcString = currentDate.toUTCString();    // Return both the timestamp and the formatted string back to the game client    return {        timestamp: unixTimestamp,        formattedDate: utcString,    };};

Cloud Save の活用

/* * Set the cooldown for a building with id "MUSEUM_BUILDING" in Cloud Save */const { DataApi } = require('@unity-services/cloud-save-1.4');// The Cloud Save key for the buildingconst MUSEUM_KEY = 'MUSEUM_BUILDING';// The cooldown before the "MUSEUM_BUILDING" is allowed to be built again.const MUSEUM_COOLDOWN = 30;module.exports = async ({ context, logger }) => {    // Initialize a Cloud Save API client using the player credentials    const { projectId, playerId } = context;    const cloudSaveApi = new DataApi(context);    // Get the current server timestamp and calculate when the cooldown is finished (in milliseconds)    const currentTimestamp = Date.now();    const expiresAt = currentTimestamp + MUSEUM_COOLDOWN * 1000;    // Save the data in Cloud Save    try {        await cloudSaveApi.setItem(projectId, playerId, { key: MUSEUM_KEY, value: expiresAt });    } catch (error) {        let errorMessage;        if (error.response) {            // If the error is from the Cloud Save server            errorMessage = JSON.stringify({                response: error.response.data,                status: error.response.status,                headers: error.response.headers,            });        } else {            // If the error is from the script            errorMessage = JSON.stringify(error.message);        }        logger.error(            `Could not save the key ${MUSEUM_KEY} in Cloud Save. Got error ${errorMessage}`        );        // Return an error to the game client        throw Error(`An error occurred when setting the cooldown of the ${MUSEUM_KEY}`);    }    // Return the current server time and when the cooldown expires    return {        serverTimestamp: currentTimestamp,        cooldown: {            durationSeconds: MUSEUM_COOLDOWN,            expiresAt: expiresAt,        },    };};

/* * Validate that the cooldown for a building with id "MUSEUM_BUILDING" in Cloud Save has expired */const { DataApi } = require('@unity-services/cloud-save-1.4');// The Cloud Save key for the buildingconst MUSEUM_KEY = 'MUSEUM_BUILDING';module.exports = async ({ context, logger }) => {    // Initialize a Cloud Save API client using the player credentials    const { projectId, playerId } = context;    const cloudSaveApi = new DataApi(context);    const currentTimestamp = Date.now();    let cooldown;    // Get the data from Cloud Save    try {        let { data: response } = await cloudSaveApi.getItems(projectId, playerId, [MUSEUM_KEY]);        cooldown = response?.results?.[0]?.value ?? 0;    } catch (error) {        let errorMessage;        if (error.response) {            // If the error is from the Cloud Save server            errorMessage = JSON.stringify({                response: error.response.data,                status: error.response.status,                headers: error.response.headers,            });        } else {            // If the error is from the script            errorMessage = JSON.stringify(error.message);        }        logger.error(            `Could not get the key ${MUSEUM_KEY} in Cloud Save. Got error ${errorMessage}`        );        // Return an error to the game client        throw Error(`An error occurred when getting the cooldown of the ${MUSEUM_KEY}`);    }    // Return a response to the client which indicates if the building can be built and if not, how long is left on the cooldown    const timeRemaining = (cooldown - currentTimestamp) / 1000;    const hasExpired = timeRemaining < 0 ? true : false;    return {        serverTimestamp: currentTimestamp,        cooldown: {            hasExpired: hasExpired,            timeRemaining: hasExpired ? 0 : timeRemaining,        },    };};

スクリプトのパラメーター化と Remote Config の追加

${BUILDING_ID}_COOLDOWN

/* * Use a script parameter "builidngId" for fetching the cooldown settings for a building from Remote Config. * Calculate when the cooldown for a building will expire and set the timestamp in Cloud Save. * Note: The Remote Config settings need to be saved before they become available to a Cloud Code script. */const { DataApi } = require('@unity-services/cloud-save-1.4');const { SettingsApi } = require('@unity-services/remote-config-1.1');const _ = require('lodash-4.17');module.exports = async ({ params, context, logger }) => {    // Initialize Cloud Save and RemoteConfig API clients using the player credentials    const { projectId, playerId, environmentId } = context;    const cloudSaveApi = new DataApi(context);    const remoteConfig = new SettingsApi(context);    const currentTimestamp = Date.now();    let configuredCooldown;    let expiresAt;    try {        // Get the cooldown value for the "buildingId" from RemoteConfig        const remoteConfigCooldownId = `${params.buildingId}_COOLDOWN`;        const remoteConfigResponse = await remoteConfig.assignSettingsGet(            projectId,            environmentId,            'settings',            [remoteConfigCooldownId]        );        // Validate the value from RemoteConfig, for example "MUSEUM_BUILDING_COOLDOWN"        configuredCooldown =            remoteConfigResponse?.data?.configs?.settings?.[remoteConfigCooldownId];        if (!configuredCooldown || !_.isNumber(configuredCooldown)) {            throw Error(`Invalid value for ${remoteConfigCooldownId}`);        }        // Calculate when the cooldown expires for the "buildingId"        expiresAt = currentTimestamp + configuredCooldown * 1000;        // Save the data in Cloud Save        await cloudSaveApi.setItem(projectId, playerId, {            key: params.buildingId,            value: expiresAt,        });    } catch (error) {        let errorMessage;        if (error.response) {            // If the error is from one of the API clients            errorMessage = JSON.stringify({                response: error.response.data,                status: error.response.status,                headers: error.response.headers,            });        } else {            // If the error is from the script            errorMessage = JSON.stringify(error.message);        }        logger.error(            `An error occurred when trying to set the cooldown for building id ${params.buildingId}. Got error: ${errorMessage}`        );        // Return an error to the game client        throw Error(`An error occurred when setting the cooldown of the ${params.buildingId}`);    }    // Return the current server time and when the cooldown expires    return {        serverTimestamp: currentTimestamp,        cooldown: {            durationSeconds: configuredCooldown,            expiresAt: expiresAt,        },    };};

/* * Validate that the cooldown for a building with id passed as a Script parameter "buildingId" in Cloud Save has expired */const { DataApi } = require('@unity-services/cloud-save-1.4');module.exports = async ({ params, context, logger }) => {    // Initialize a Cloud Save API client using the player credentials    const { projectId, playerId } = context;    const cloudSaveApi = new DataApi(context);    const currentTimestamp = Date.now();    let cooldown;    // Get the data from Cloud Save    try {        let { data: response } = await cloudSaveApi.getItems(projectId, playerId, [            params.buildingId,        ]);        cooldown = response?.results?.[0]?.value ?? 0;    } catch (error) {        let errorMessage;        if (error.response) {            // If the error is from the Cloud Save server            errorMessage = JSON.stringify({                response: error.response.data,                status: error.response.status,                headers: error.response.headers,            });        } else {            // If the error is from the script            errorMessage = JSON.stringify(error.message);        }        logger.error(            `Could not get the key ${params.buildingId} in Cloud Save. Got error ${errorMessage}`        );        // Return an error to the game client        throw Error(`An error occurred when getting the cooldown of the ${params.buildingId}`);    }    // Return a response to the client which indicates if the building can be built and if not, how long is left on the cooldown    const timeRemaining = (cooldown - currentTimestamp) / 1000;    const hasExpired = timeRemaining < 0 ? true : false;    return {        serverTimestamp: currentTimestamp,        cooldown: {            hasExpired: hasExpired,            timeRemaining: hasExpired ? 0 : timeRemaining,        },    };};