为什么我的应用程序总是以调用 Program.PublicClientApp.AcquireTokenAsync 结束？

Question

这是我的 authenticate 代码，用于将 Microsoft Graph 与 Outlook 结合使用：

public async Task AquireToken()
{
    try
    {
        if (_AuthResult == null)
        {
            _AuthResult = await Program.PublicClientApp.AcquireTokenSilentAsync(
                _scopes, Program.PublicClientApp.Users.FirstOrDefault());
        }
    }
    catch (MsalUiRequiredException ex)
    {
        // A MsalUiRequiredException happened on AcquireTokenSilentAsync. 
        // This indicates you need to call AcquireTokenAsync to acquire a token.
        System.Diagnostics.Debug.WriteLine($"MsalUiRequiredException: {ex.Message}");

        try
        {
            _AuthResult = await Program.PublicClientApp.AcquireTokenAsync(_scopes);
        }
        catch (MsalException msalex)
        {
            _ResultsText = $"Error Acquiring Token:{System.Environment.NewLine}{msalex}";
        }
    }
    catch (Exception ex)
    {
        _ResultsText = $"Error Acquiring Token Silently:{System.Environment.NewLine}{ex}";
    }

    if (_AuthResult != null)
    {
        _ResultsText = await GetHttpContentWithToken(_graphAPIEndpoint, _AuthResult.AccessToken);
    }
}

它基于微软提供的samples。在控制台输出中显示：

Token Expires: 04/09/2017 14:18:06 +01:00

该代码显示自：

$"Token Expires: {_AuthResult.ExpiresOn.ToLocalTime()}" + Environment.NewLine;

因此，这意味着令牌的有效期为一小时。因此，如果我再次运行我的实用程序，我希望它使用相同的令牌，直到它需要一个新的令牌。但事实并非如此。它总是显示提示。

我错过了哪一步？

异常

根据评论中的要求，这是异常的详细信息：

MsalUiRequiredException: Null user was passed in AcquiretokenSilent API. Pass in a user object or call acquireToken authenticate.

这可能有帮助

我需要查看提供的答案：

you need to implement a token cache and use AcquireTokenSilentAsync. https://docs.microsoft.com/en-us/outlook/rest/dotnet-tutorial has a web app example.

Answer 1

桌面上的 MSAL .NET 不提供持久缓存，因为它没有明显的开箱即用存储（而 MSAL 在 UWP、Xamarin iOS 和 Android，其中应用程序隔离存储可用）。开箱即用，桌面上的 MSAL .NET 使用内存缓存，该缓存将在进程结束后立即消失。请参阅 https://azure.microsoft.com/en-us/resources/samples/active-directory-dotnet-desktop-msgraph-v2/ 示例，该示例演示了如何提供一个简单的基于文件的缓存，该缓存将在执行过程中保留令牌。

Answer 2

我使用了注册表。成功登录后保存令牌，然后在每次需要使用 GraphServiceClient 时调用令牌。如果令牌已过期或出现错误，您可以调用登录过程并保存新令牌。

 public static async Task<GraphServiceClient> GetAuthenticatedClientAsync()
    {
        GraphServiceClient graphClient = new GraphServiceClient(
            new DelegateAuthenticationProvider(
                async (requestMessage) =>
                {
                    string appID = ConfigurationManager.AppSettings["ida:AppId"];

                    PublicClientApplication PublicClientApp = new PublicClientApplication(appID);
                    string[] _scopes = new string[] { "Calendars.read", "Calendars.readwrite", "Mail.read", "User.read" };

                    AuthenticationResult authResult = null;

                    string keyName = @"Software\xxx\Security";
                    string valueName = "Status";
                    string token = "";

                    RegistryKey regKey = Registry.CurrentUser.OpenSubKey(keyName, false);
                    if (regKey != null)
                    {
                        token = (string)regKey.GetValue(valueName);
                    }

                    if (regKey == null || string.IsNullOrEmpty(token))
                    {
                        authResult = await PublicClientApp.AcquireTokenAsync(_scopes); //Opens Microsoft Login Screen
                        //code if key Not Exist
                        RegistryKey key;
                        key = Registry.CurrentUser.CreateSubKey(@"Software\xxx\Security");
                        key.OpenSubKey(@"Software\xxx\Security", true);
                        key.SetValue("Status", authResult.AccessToken);
                        key.SetValue("Expire", authResult.ExpiresOn.ToString());
                        key.Close();
                        // Append the access token to the request.
                        requestMessage.Headers.Authorization = new AuthenticationHeaderValue("bearer", token);
                    }
                    else
                    {
                        //code if key Exists
                        RegistryKey reg = Registry.CurrentUser.OpenSubKey(@"Software\xxx\Login", true);
                        // set value of "abc" to "efd"
                        token = (string)regKey.GetValue(valueName);
                        // Append the access token to the request.
                        requestMessage.Headers.Authorization = new AuthenticationHeaderValue("bearer", token);
                    }
                }));
        try
        {      
            Microsoft.Graph.User me = await graphClient.Me.Request().GetAsync();

        }
        catch(Exception e)
        {
            if (e.ToString().Contains("Access token validation failure") || e.ToString().Contains("Access token has expired"))
            {
                string keyName = @"Software\xxx\Security";
                using (RegistryKey key = Registry.CurrentUser.OpenSubKey(keyName, true))
                {
                    if (key != null)
                    {
                        key.DeleteValue("Status");
                        key.DeleteValue("Expire");
                    }
                    else
                    {
                        MessageBox.Show("Error! Something went wrong. Please contact your administrator.", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    }
                }
                await GetAuthenticatedClientAsync();
            }
        }

        return graphClient;
    }

为什么我的应用程序总是以调用 Program.PublicClientApp.AcquireTokenAsync 结束？

Why does my application always end up calling Program.PublicClientApp.AcquireTokenAsync?

c#

oauth

azure-active-directory

microsoft-graph-api

msal

异常

这可能有帮助