使用 oAuth2 重新连接 ews 流连接

Question

我正在重写使用 EWS 流连接监控邮箱的后端服务，我正在将其从基本身份验证更改为 oAuth2。

一切正常，在服务启动时我订阅了邮箱，它创建了一个交换服务，检索一个身份验证令牌，然后监视邮箱 30 分钟，直到流连接到期。我有一个事件处理程序附加到订阅的 OnDisconnect 事件以自动重新连接。这也有效。但是，oAuth2 令牌的生命周期为 1 小时。所以第二次流连接尝试重新连接它失败并出现未经授权的错误代码。

当流连接超时时，如何强制它更新 oAuth 令牌并使用更新的令牌每 30 分钟重新连接一次？

这是我的代码：

获取身份验证令牌：

    Public Async Function getTokenAsync() As Task(Of String)

    Try
        Dim authority As String = ConfigurationManager.AppSettings("AuthorizationUri").Replace("common", "xxxxxxxxxxxxxxx")
        Dim authenticationContext As Microsoft.IdentityModel.Clients.ActiveDirectory.AuthenticationContext = New Microsoft.IdentityModel.Clients.ActiveDirectory.AuthenticationContext(authority, False)
        Dim certfile As String = "D:\DevRepos\Test apps\oAuth2 EWS test app\testCert.pfx"
        Dim cert As X509Certificate2 = New X509Certificate2(certfile, "xxxx", X509KeyStorageFlags.MachineKeySet)
        Dim cac As Microsoft.IdentityModel.Clients.ActiveDirectory.ClientAssertionCertificate = New Microsoft.IdentityModel.Clients.ActiveDirectory.ClientAssertionCertificate("xxxxxxxxxxxx", cert)
        Dim authenticationResult = Await authenticationContext.AcquireTokenAsync("https://outlook.office365.com", cac)

        Return authenticationResult.AccessToken

    Catch ex As Exception
        MsgBox(ex.ToString)
    End Try


    Return Nothing

End Function

创建 Exchange 服务：

    Public Async Function exchangeServiceconnection() As Task(Of ExchangeService)
    Dim test As Task(Of String)
    test = getTokenAsync()
    Dim result2 As String = Await test
    Dim ewsClient = New ExchangeService()

    Try
        ewsClient.Url = New Uri("https://outlook.office365.com/EWS/Exchange.asmx")
        ewsClient.Credentials = New OAuthCredentials(result2)
        ewsClient.ImpersonatedUserId = New ImpersonatedUserId(ConnectingIdType.SmtpAddress, "mailbox@testdomain.com")
        ewsClient.HttpHeaders.Add("X-AnchorMailbox", "mailbox@testdomain.com")

    Catch ex As MsalException
        MsgBox($"Error acquiring access token: {ex.ToString()}")
    Catch ex As Exception
        MsgBox($"Error: {ex.ToString()}")
    End Try

    Return ewsClient

End Function

订阅邮箱：

    Async Sub Subscribe()
    Dim service As ExchangeService
    service = Await exchangeServiceconnection()
    Dim locateMailbox = New Mailbox With {
        .Address = "mailbox@testdomain.com"
    }
    Dim folderId = New FolderId(WellKnownFolderName.Inbox, locateMailbox)
    Dim foldersToWatch = {folderId}
    Dim streamingSubscription As StreamingSubscription = service.SubscribeToStreamingNotifications(foldersToWatch, EventType.NewMail)
    Dim streamingConnection = New StreamingSubscriptionConnection(service, 30)
    streamingConnection.AddSubscription(streamingSubscription)
    AddHandler streamingConnection.OnSubscriptionError, AddressOf ResolveError
    AddHandler streamingConnection.OnDisconnect, AddressOf Reconnect
    AddHandler streamingConnection.OnNotificationEvent, AddressOf Form1.message
    streamingConnection.Open()
End Sub

重新连接处理程序：

    Public Sub Reconnect(ByVal sender As Object, ByVal disconnectEventArgs As SubscriptionErrorEventArgs)
    If Not CType(sender, StreamingSubscriptionConnection).IsOpen Then
        CType(sender, StreamingSubscriptionConnection).Open()
    End If
End Sub

出错时重新连接：

    Public Sub ResolveError(ByVal sender As Object, ByVal errorEventArgs As SubscriptionErrorEventArgs)
    Dim streamingSubscriptionConnection = CType(sender, StreamingSubscriptionConnection)
    If Not streamingSubscriptionConnection.IsOpen Then streamingSubscriptionConnection.Open()
End Sub

Answer 1

所以我在我的重新连接功能中执行了以下操作，公开了交换服务，在重新连接时请求新的身份验证令牌并使用新令牌更新服务凭据。

现在似乎工作正常，服务已经运行了一夜没有问题。

    Public Async Sub Reconnect(ByVal sender As Object, ByVal disconnectEventArgs As SubscriptionErrorEventArgs)
    If Not CType(sender, StreamingSubscriptionConnection).IsOpen Then
        Dim test As Task(Of String)
        test = getTokenAsync()
        result2 = Await test
        service.Credentials = New OAuthCredentials(result2)
        CType(sender, StreamingSubscriptionConnection).Open()
    End If
End Sub

这解决了我的问题，如果有更好的方法请评论

Answer 2

我已经设法摆脱了处理 HTTP 401 并返回 OAuth 以获取新令牌。