Azure AD B2C never logs in on Xamarin Forms - azure

Question

I'm using Azure AD B2C with our Xamarin Forms mobile app. However, when testing it never actually logs me in. I sign up for a new account, enter the verification code and password when prompted. When I go enter my details and try to login, it just keeps taking me back to the signin page (where I need to enter my login details....again).
Here are my Azure AD B2C settings.
public const string Tenant = "mytenant.onmicrosoft.com";
public static string ClientId = "my-clientid-for-the-application";
public static string SignUpSignInPolicy = "B2C_1_IfmMobileApp";
public static string PolicyResetPassword = "B2C_1_IfmMobileAppReset ";
public static string[] Scopes = { "" };
public static readonly string CustomRedirectUrl = $"msal{ClientId}://auth";
public static string AuthorityBase = $"https://login.microsoftonline.com/tfp/{Tenant}/";
public static string Authority = $"{AuthorityBase}{SignUpSignInPolicy}";
public static string AuthorityPasswordReset = $"{AuthorityBase}{PolicyResetPassword}";
And here's my signin / signout code.
private async void OnSignInSignOut(object sender, EventArgs e)
{
try
{
IEnumerable<IAccount> accounts = await AuthenticationService.PCA().GetAccountsAsync();
if (btnSignInSignOut.Text == "Sign in")
{
var account = this.GetAccountByPolicy(accounts, ApplicationConstants.SignUpSignInPolicy);
AuthenticationResult ar =
await AuthenticationService.PCA().AcquireTokenAsync(ApplicationConstants.Scopes, account, App.UiParent);
UpdateUserInfo(ar);
UpdateSignInState(true);
}
else
{
foreach (var user in accounts)
{
await AuthenticationService.PCA().RemoveAsync(user);
}
UpdateSignInState(false);
}
}
catch (MsalClientException ex)
{
await DisplayAlert($"MSAL Exception:", ex.ToString(), "Dismiss");
}
catch (Exception ex)
{
// Checking the exception message
// should ONLY be done for B2C
// reset and not any other error.
if (ex.Message.Contains("AADB2C90118"))
{
OnPasswordReset();
}
else
{
await DisplayAlert($"Exception:", ex.ToString(), "Dismiss");
}
}
}
Update
Looking through the Android log I see this error each time I try to log in. I'm assuming that this error is related to my issue.

Answer 1

I needed to add the following code (as per this example)
For Android in the MainActivity.cs file In OnActivityResult you need to add
AuthenticationContinuationHelper.SetAuthenticationContinuationEventArgs(requestCode, resultCode, data);
For iOS in AppDelegate.cs you need to add
public override bool OpenUrl(UIApplication app, NSUrl url, NSDictionary options)
{
AuthenticationContinuationHelper.SetAuthenticationContinuationEventArgs(url);
return true;
}
These changes ensure that the control goes back to MSAL once the interactive portion of the authentication flow has ended.