Photon custom authentication done in PlayFab in a special way to make use of Data and AuthCookie features but also allow/block list AppVersions.

PlayFabCloudScript.js

// custom auth endpoint: https://{PlayFabTitleId}.playfablogic.com/webhook/1/prod/{PhotonSecretKey}/CustomAuth
// you can replace CustomAuth handler name and also in the URL
// C# client snippet:
// AuthenticationValues authValues = new AuthenticationValues();
// authValues.AuthType = CustomAuthenticationType.Custom;
// Dictionary<string, object> data = new Dictionary<string, object>(6);
// data["UserId"] = userId; // PlayFabId
// data["AppId"] = appId; // Photon AppId
// data["AppVersion"] = appVersion  // Photon AppVersion
// data["Ticket"] = ticket; // PlayFab auth session ticket
// data["Token"] = token; // Photon auth token obtained from PlayFab via client API call GetPhotonAuthenticationToken
// data["Nickname"] = nickanem; // optional
// authValues.SetAuthPostData(data);
handlers.CustomAuth = function (args, context)
{
	try {
		var debug = true; // set to true to debug
		if (debug === true) {
			server.WriteTitleEvent(
				{
					EventName: "photon_custom_auth",
					Timestamp: new Date(),
					Body: { args: args, context: context, currentPlayerId: currentPlayerId }
				}
			);
		}
		// PlayFab already checks AppId and UserId
		var appId = args.AppId;
		var userId = args.UserId;
		
		var appVersion = args.AppVersion;
		if (appVersion === undefined) {
			return { ResultCode: 2, Message: 'AppVersion is undefined' };
		}
		var token = args.Token;
		if (token === undefined) {
			return { ResultCode: 3, Message: 'Token is undefined' };
		}
		var ticket = args.Ticket;
		if (ticket === undefined) {
			return { ResultCode: 4, Message: 'Ticket is undefined' };
		}
		var nickname = args.Nickname;
		var titleId = script.titleId;
		//http.request(url, method, content, contentType, headers, logRequestAndResponse);
		//script.revision;
		//script.titleId;
		//var result = server.AuthenticateUserTicket(request);
		//log.info(msg, data);
		//log.debug(msg, data);
		//log.error(msg, data);
		var request = { SessionTicket: ticket };
		var result = server.AuthenticateSessionTicket(request);
		//var result = server.GetUserAccountInfo(request);
		if (debug === true) {
			server.WriteTitleEvent(
				{
					EventName: "AuthenticateSessionTicket",
					Timestamp: new Date(),
					Body: { req: request, res: result }
				}
			);
		}
		var userInfo = result.UserInfo;
		if (userInfo !== undefined) {
			if (userId !== userInfo.PlayFabId)
			{
				return { ResultCode: 5, Message: 'UserId and SessionTicket mismatch' };
			}
			if (userInfo.TitleInfo !== undefined) {
				var userTitleInfo = userInfo.TitleInfo;
				if (userTitleInfo.isBanned === true) {
					return { ResultCode: 6, Message: 'User is banned' };
				}
				if (nickname === undefined) {
					nickname = userTitleInfo.DisplayName;
				}
			}
			if (nickname === undefined) {
				nickname = userInfo.Username;
			}		
		}	
		var url = "https://" + titleId + ".playfabapi.com/photon/authenticate?username=" + userId + "&token=" + token;
		var httpMethod = "get";
		var response = http.request(url, httpMethod);
		var authRes = JSON.parse(response);
		if (debug === true) {
			server.WriteTitleEvent(
				{
					EventName: "PhotonAuthenticate",
					Timestamp: new Date(),
					Body: { url: url, httpMethod: httpMethod, response: response }
				}
			);
		}
		if (authRes.ResultCode === undefined) {
			authRes.ResultCode = authRes.resultCode;
		}		
		if (authRes.ResultCode !== 1) {
			if (authRes.ResultCode === undefined)
			{
				authRes.ResultCode = 252;
			}
			return authRes;
		}
		if (nickname === undefined || nickname === null)
		{
			if (authRes.Nickname === undefined) {
				if (authRes.nickname !== undefined && authRes.nickname !== null)
				{
					nickname = authRes.nickname;
				}
			}
			else if (authRes.Nickname !== null) {
				nickname = authRes.Nickname;
			}
		}		
		var keys = ["photon_appversion_allowlist", "photon_appversion_blocklist"];
		var titleData = server.GetTitleData({
			Keys: keys
		});
		if (debug === true)
		{
			server.WriteTitleEvent(
				{
					EventName: "GetTitleData",
					Timestamp: new Date(),
					Body: { Keys: keys, titleData: titleData }
				}
			);	
		}		
		var list = titleData.Data["photon_appversion_allowlist"]
		if (list !== undefined) {
			var array = list.split(',');
			if (array.indexOf(appVersion) === -1) {
				return { ResultCode: 7, Message: 'AppVersion not allowed' };
			}
		} else {		
			list = titleData.Data["photon_appversion_blocklist"]
			if (list !== undefined) {
				var array = list.split(',');
				if (array.indexOf(appVersion) !== -1) {
					return { ResultCode: 8, Message: 'AppVersion not allowed' };
				}
			}
		}
		// todo: transform userInfo into a flat one level JSON object (Dictionary) and return in Data.
		var secret = { s: "secret" };
		// todo: inject JSON object (flat one level) AuthCookie
		var data = { k: "value" };
		return { ResultCode: 1, UserId: userId, Nickname: nickname, Data: data, AuthCookie: secret };	
	} catch (e) {
		if (e.cloudScriptErrorCode !== undefined) {
			return { ResultCode: 254, Message: e.cloudScriptErrorCode + ': ' + e.stack };
		}
		if (e.name !== undefined && e.message !== undefined)
		{
			return { ResultCode: 255, Message: e.name + ': ' + e.message };
		}
		return { ResultCode: 253, Message: 'error:' + e };
	}
};