How to access Facebook private information by using ASP.NET Identity (OWIN)?

Question

Create a new Microsoft.Owin.Security.Facebook.AuthenticationOptions object in Startup.ConfigureAuth (StartupAuth.cs), passing it the FacebookAppId, FacebookAppSecret, and a new AuthenticationProvider. You will use a lambda expression to pass the OnAuthenticated method some code to add Claims to the identity which contain the values you extract from context.Identity. This will include access_token by default. You must add email to the Scope. Other user properties are available from context.User (see link at bottom for example).

StartUp.Auth.cs

// Facebook : Create New App
// https://dev.twitter.com/apps
if (ConfigurationManager.AppSettings.Get("FacebookAppId").Length > 0)
{
    var facebookOptions = new Microsoft.Owin.Security.Facebook.FacebookAuthenticationOptions()
    {
        AppId = ConfigurationManager.AppSettings.Get("FacebookAppId"),
        AppSecret = ConfigurationManager.AppSettings.Get("FacebookAppSecret"),
        Provider = new Microsoft.Owin.Security.Facebook.FacebookAuthenticationProvider()
        {
            OnAuthenticated = (context) =>
                {
                    context.Identity.AddClaim(new System.Security.Claims.Claim("urn:facebook:access_token", context.AccessToken, XmlSchemaString, "Facebook"));
                    context.Identity.AddClaim(new System.Security.Claims.Claim("urn:facebook:email", context.Email, XmlSchemaString, "Facebook"));
                    return Task.FromResult(0);
                }
        }

    };
    facebookOptions.Scope.Add("email");
    app.UseFacebookAuthentication(facebookOptions);
}

In AccountController, I extract the ClaimsIdentity from the AuthenticationManager using the external cookie. I then add it to the identity created using the application cookie. I ignored any claims that starts with “…schemas.xmlsoap.org/ws/2005/05/identity/claims” since it seemed to break the login.

AccountController.cs

private async Task SignInAsync(CustomUser user, bool isPersistent)
{
    AuthenticationManager.SignOut(DefaultAuthenticationTypes.ExternalCookie);
    var identity = await UserManager.CreateIdentityAsync(user, DefaultAuthenticationTypes.ApplicationCookie);

// Extracted the part that has been changed in SignInAsync for clarity.
    await SetExternalProperties(identity);

    AuthenticationManager.SignIn(new AuthenticationProperties() { IsPersistent = isPersistent }, identity);
}

private async Task SetExternalProperties(ClaimsIdentity identity)
{
    // get external claims captured in Startup.ConfigureAuth
    ClaimsIdentity ext = await AuthenticationManager.GetExternalIdentityAsync(DefaultAuthenticationTypes.ExternalCookie);

    if (ext != null)
    {
        var ignoreClaim = "http://schemas.xmlsoap.org/ws/2005/05/identity/claims";
        // add external claims to identity
        foreach (var c in ext.Claims)
        {
            if (!c.Type.StartsWith(ignoreClaim))
                if (!identity.HasClaim(c.Type, c.Value))
                    identity.AddClaim(c);
        } 
    }
}

And finally, I want to display whatever values are not from the LOCAL AUTHORITY. I created a partial view _ExternalUserPropertiesListPartial that appears on the /Account/Manage page. I get the claims I previously stored from AuthenticationManager.User.Claims and then pass it to the view.

AccountController.cs

[ChildActionOnly]
public ActionResult ExternalUserPropertiesList()
{
    var extList = GetExternalProperties();
    return (ActionResult)PartialView("_ExternalUserPropertiesListPartial", extList);
}

private List<ExtPropertyViewModel> GetExternalProperties()
{
    var claimlist = from claims in AuthenticationManager.User.Claims
                    where claims.Issuer != "LOCAL AUTHORITY"
                    select new ExtPropertyViewModel
                    {
                        Issuer = claims.Issuer,
                        Type = claims.Type,
                        Value = claims.Value
                    };

    return claimlist.ToList<ExtPropertyViewModel>();
}

And just to be thorough, the view:

_ExternalUserPropertiesListPartial.cshtml

@model IEnumerable<MySample.Models.ExtPropertyViewModel>

@if (Model != null)
{
    <legend>External User Properties</legend>
    <table class="table">
        <tbody>
            @foreach (var claim in Model)
            {
                <tr>
                    <td>@claim.Issuer</td>
                    <td>@claim.Type</td>
                    <td>@claim.Value</td>
                </tr>
            }
        </tbody>
    </table>
}

The working example and complete code is on GitHub: https://github.com/johndpalm/IdentityUserPropertiesSample

And any feedback, corrections, or improvements would be appreciated.

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