ASP.NET Identity and Claim-based

Question

How to use claims? For example, I want to set access to each page (resource) for each user. I understand, I can do it using roles, but as I understand, claim-based is more effectively. But when I try to create a claim, I see the following method:

        userIdentity.AddClaim(new Claim(ClaimTypes.Role, "test role"));

first parameter of constructor of Claim class get ClaimTypes enum, which has many "strange" members like Email, Phone etc. I want to set that this claim and then check this claim to have access to certain resource. I'm on wrong way? How to do it?

Answer 1

From the code above, I am assuming you have already added the claim in startup class on authenticated of your provider as below.

context.Identity.AddClaim(new Claim("urn:google:name", context.Identity.FindFirstValue(ClaimTypes.Name))); // added claim for reading google name
context.Identity.AddClaim(new Claim("urn:google:email", context.Identity.FindFirstValue(ClaimTypes.Email))); // and email too

Once you have added the claims in startup, when the request is actually processed check if its a callback and if yes, read the claims as below(in IHttpHandler).

public void ProcessRequest(HttpContext context)
    {
        IAuthenticationManager authManager = context.GetOwinContext().Authentication;
        if (string.IsNullOrEmpty(context.Request.QueryString[CallBackKey]))
        {
            string providerName = context.Request.QueryString["provider"] ?? "Google";//I have multiple providers so checking if its google
            RedirectToProvider(context, authManager, providerName);
        }
        else
        {
            ExternalLoginCallback(context, authManager);
        }
    }

If its 1st call redirect to provider

private static void RedirectToProvider(HttpContext context, IAuthenticationManager authManager, string providerName)
    {
        var loginProviders = authManager.GetExternalAuthenticationTypes();

        var LoginProvider = loginProviders.Single(x => x.Caption == providerName);

        var properties = new AuthenticationProperties()
        {
            RedirectUri = String.Format("{0}&{1}=true", context.Request.Url, CallBackKey)
        };

        //string[] authTypes = { LoginProvider.AuthenticationType, DefaultAuthenticationTypes.ExternalCookie };
        authManager.Challenge(properties, LoginProvider.AuthenticationType);

        //without this it redirect to forms login page
        context.Response.SuppressFormsAuthenticationRedirect = true;
    }

And finally read the claims you get back

public void ExternalLoginCallback(HttpContext context, IAuthenticationManager authManager)
    {
        var loginInfo = authManager.GetExternalLoginInfo();
        if (loginInfo == null)
        {
            throw new System.Security.SecurityException("Failed to login");
        }

        var LoginProvider = loginInfo.Login.LoginProvider;
        var ExternalLoginConfirmation = loginInfo.DefaultUserName;

        var externalIdentity = authManager.GetExternalIdentityAsync(DefaultAuthenticationTypes.ExternalCookie);
        var emailClaim = externalIdentity.Result.Claims.FirstOrDefault(c => c.Type == ClaimTypes.Email);
        var email = emailClaim.Value;

        var pictureClaim = externalIdentity.Result.Claims.FirstOrDefault(c => c.Type.Equals("picture"));
        var pictureUrl = pictureClaim.Value;

        LogInByEmail(context, email, LoginProvider); //redirects to my method of adding claimed user as logged in, you will use yours.
    }