C++ integration
Learn how to implement authentication using C++ in Unreal Engine.
Read time 6 minutesLast updated 3 months ago
The following section shows how to integrate with the Authentication SDK using Unreal Engine Subsystems. The Blueprint API provides the Authentication Subsystem to expose this functionality.
Add the Authentication SDK as a dependency
Before continuing, addAuthenticationAuthenticationInclude the plugin header files you wish to access in your own classes:PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "Authentication" });
#include "AuthenticationSubsystem.h"
Authentication Subsystem
The Authentication Subsystem contains the interface to communicate with Unity Authentication servers, hold player profile information, and load/unload player preferences from local storage. It’s responsible for handling the authentication lifecycle and storing important authentication information for your project. You can access the Authentication Subsystem by obtaining a reference from a UGameInstance.UWorld* GameWorld = GetWorld();UGameInstance* GameInstance = GameWorld->GetGameInstance();UAuthenticationSubsystem* AuthenticationSubsystem = GameInstance->GetSubsystem<UAuthenticationSubsystem>();
SignInAnonymously
Use the SignInAnonymously() method to anonymously authenticate. This is a quick way to authenticate without any user information, and requires no interaction with external providers. If successful, this populates the current player profile with the retrieved credentials returned from the Unity Authentication servers. SignInAnonymously() takes anFAuthenticationSignInOptionsFAuthenticationResponse// Create sign-in options bodyFAuthenticationSignInOptions SignInOptions;SignInOptions.bCreateAccount = true;SignInOptions.Nonce = TEXT("abc123");AuthenticationSubsystem->SignInAnonymously(SignInOptions, THandler<FAuthenticationResponse>::CreateLambda([this](FAuthenticationResponse Response){ // Your response logic here}));
GetUserInfo
Use the GetUserInfo() method to retrieve information about the currently authenticated user. This includes their user Id, authentication timestamps, and any external Identity providers that are linked to their session. The response from the SDK can be handled in a response handler which needs to take in anFAuthenticationUserResponseAuthenticationSubsystem->GetUserInfo(THandler<FAuthenticationUserResponse>::CreateLambda([this](FAuthenticationUserResponse Response){ // Your response logic here}));
DeleteUser
Use the DeleteUser() method to delete all information related to the currently authenticated player. This method also signs out the player, and deletes all player preferences and profiles connected to the player.Note
If DeleteUser() Is called while using the default profile, then the profile information is cleared and the profile stays intact.
booltruefalseAuthenticationSubsystem->DeleteUser(THandler<bool>::CreateLambda([this](bool bResponse){ // Your response logic here}));
RegisterStateChangedCallback
Use the RegisterStateChangedCallback() method to assign a callback function that invokes upon the state of the subsystem changing. For instance, the assigned function executes when a player has successfully authenticated and the subsystem state has changed toAuthorizedAuthenticationStateChangedResponseAuthenticationSubsystem->RegisterStateChangedCallback(THandler<AuthenticationStateChangedResponse>::CreateLambda([this](AuthenticationStateChangedResponse Response){ // Your response logic here}));
SignOut
Use the SignOut() method to sign-out of the currently authenticated player profile. This removes the current player profile and switches to the default profile. This method also has an optional parameter to remove any stored credentials associated with this player.Note
If SignOut() is called while using the default profile, then the profile information is cleared and the profile stays intact.
AuthenticationSubsystem->SignOut(true); // Clear player credentials
SwitchProfile
Use the SwitchProfile() method to switch to or create a player profile.Note
SwitchProfile() can only be called while signed-out. If a profile switch is invoked while authenticated, a warning is logged and nothing happens.
FString NewProfileName = FString(TEXT("new_profile_123"));AuthenticationSubsystem->SwitchProfile(NewProfileName);
ProfileExists
Use the ProfileExists() method to check if a given profile exists in the current session.Note
ProfileExists() cannot detect profiles from previous sessions that have not been re-created in the current session.
FString ProfileToCheckFor = FString(TEXT("new_profile_123"));bool bExists = AuthenticationSubsystem->ProfileExists(ProfileToCheckFor);
GetCurrentProfileName
Use the GetCurrentProfileName() method to retrieve the name of the current player profile.FString ProfileName = AuthenticationSubsystem->GetCurrentProfileName();
GetProfileNames
Use the GetCurrentProfileName() method to retrieve a list of all player profile names being used in the current session.TArray<FString> ProfileNames = AuthenticationSubsystem->GetProfileNames();
RegisterProfileChangedCallback
Use the RegisterProfileChangedCallback() method to assign a callback function that invokes upon the player profile changing. For instance, the assigned function executes when SwitchProfile has executed successfully. The response from the SDK can be handled in a response handler which needs to take in an AuthenticationPlayerProfileChangedResponse.AuthenticationSubsystem->RegisterPlayerProfileChangedCallback(THandler<AuthenticationPlayerProfileChangedResponse>::CreateLambda([this](AuthenticationPlayerProfileChangedResponse Response){ // Your response logic here}));
RegisterProfileDeletedCallback
Use the RegisterProfileChangedCallback() method to assign a callback function that invokes upon a player profile getting removed from the current session. For instance, the assigned function executes when SignOut has executed successfully. The response from the SDK can be handled in a response handler which needs to take in an AuthenticationPlayerProfileChangedResponse.AuthenticationSubsystem->RegisterPlayerProfileChangedCallback(THandler<AuthenticationPlayerProfileChangedResponse>::CreateLambda([this](AuthenticationPlayerProfileChangedResponse Response){ // Your response logic here}));
IsSignedIn
Use the IsSignedIn() method to check whether the current player profile is signed-in. Being “Signed-In” is defined as being either Authorized or Expired.bool bSignedIn = AuthenticationSubsystem->IsSignedIn();
IsAnonymous
Use the IsAnonymous() method to check whether the current player profile is signed-in anonymously. This should return true after executing SignInAnonymously successfully.bool bAnonymous = AuthenticationSubsystem->IsAnonymous();
IsAuthorized
Use the IsAuthorized() method to check whether the current player profile is signed-in and currently authorized. This should return true after executing any sign-in method successfully while the expiration time has not yet passed.bool bAuthorized = AuthenticationSubsystem->IsAuthorized();
IsExpired
Use the IsExpired() method to check whether the current player profile’s session has expired. This should return true when the expiry time returned from a successful sign-in response has passed.bool bExpired = AuthenticationSubsystem->IsExpired();
SessionTokenExists
Use the SessionTokenExists() method to check whether a session token exists in player preferences for the current player profile.bool bTokenExists = AuthenticationSubsystem->SessionTokenExists();
GetUnityProjectId
Use the GetUnityProjectId() method to retrieve the Unity Project Id associated with the current authentication session.FGuid ProjectId = AuthenticationSubsystem->GetUnityProjectId();
GetUnityEnvironmentName
Use the GetUnityEnvironmentName() method to retrieve the name of the Unity Environment Id associated with the current authentication session.FString EnvironmentId = AuthenticationSubsystem->GetUnityEnvironmentName();
GetAccessToken
Use the GetAccessToken() method to retrieve the access token for the current session. If none exists, this returns an empty string.FString AccessToken = AuthenticationSubsystem->GetAccessToken();
GetSessionToken
Use the GetSessionToken() method to retrieve the session token for the current session. If none exists, this returns an empty string.FString SessionToken = AuthenticationSubsystem->GetSessionToken();
GetUserId
Use the GetUserId() method to retrieve the user Id for the current session. If none exists, this returns an empty string.Note
This is different from the player profile name. The user Id is the unique user identifier returned from the Unity Authentication System.
FString UserId = AuthenticationSubsystem->GetUserId();
GetState
Use the GetState() method to retrieve the current state of the authentication session.EAuthenticationState UserId = AuthenticationSubsystem->GetUserId();
SetUnityProjectId
Use the SetUnityProjectId() method to set the Unity Project Id for the current authentication session. This overrides the Unity Project Id configured in Project Settings.FGuid NewProjectId = FGuid(TEXT("00000000-1234-1234-000000000000"));AuthenticationSubsystem->SetUnityProjectId(NewProjectId);
SetUnityEnvironmentName
Use the SetUnityEnvironmentName() method to set the Unity Environment name for the current authentication session. This overrides the Unity Environment name configured in Project Settings.FString NewEnvironmentName = FString(TEXT("testenv2"));AuthenticationSubsystem->SetUnityEnvironmentName(NewEnvironmentName );