Multi-tenant Azure AD Authentication Permission Error

Question

I am new to Azure AD authentication. I have created a app in azure and made it multi-tenant and set its permissions as follow

• Sign in and read user profile

• Read directory data

Here is my Startup.Auth.cs code

public partial class Startup
    {
        private static string clientId = ConfigurationManager.AppSettings["ida:ClientId"];
        private string appKey = ConfigurationManager.AppSettings["ida:ClientSecret"];
        private string graphResourceID = "https://graph.windows.net";
        private static string aadInstance = ConfigurationManager.AppSettings["ida:AADInstance"];
        private string authority = aadInstance + "common";
        private ApplicationDbContext db = new ApplicationDbContext();

        public void ConfigureAuth(IAppBuilder app)
        {

            app.SetDefaultSignInAsAuthenticationType(CookieAuthenticationDefaults.AuthenticationType);

            app.UseCookieAuthentication(new CookieAuthenticationOptions { });

            app.UseOpenIdConnectAuthentication(
                new OpenIdConnectAuthenticationOptions
                {
                    ClientId = clientId,
                    Authority = authority,
                    TokenValidationParameters = new System.IdentityModel.Tokens.TokenValidationParameters
                    {
                        // instead of using the default validation (validating against a single issuer value, as we do in line of business apps), 
                        // we inject our own multitenant validation logic
                        ValidateIssuer = false,
                    },
                    Notifications = new OpenIdConnectAuthenticationNotifications()
                    {
                        SecurityTokenValidated = (context) => 
                        {
                            return Task.FromResult(0);
                        },
                        AuthorizationCodeReceived = (context) =>
                        {
                            var code = context.Code;

                            ClientCredential credential = new ClientCredential(clientId, appKey);
                            string tenantID = context.AuthenticationTicket.Identity.FindFirst("http://schemas.microsoft.com/identity/claims/tenantid").Value;
                            string signedInUserID = context.AuthenticationTicket.Identity.FindFirst(ClaimTypes.NameIdentifier).Value;

                            AuthenticationContext authContext = new AuthenticationContext(aadInstance + tenantID, new ADALTokenCache(signedInUserID));
                            AuthenticationResult result = authContext.AcquireTokenByAuthorizationCode(
                                code, new Uri(HttpContext.Current.Request.Url.GetLeftPart(UriPartial.Path)), credential, graphResourceID);

                            return Task.FromResult(0);
                        },
                        AuthenticationFailed = (context) =>
                        {
                            context.OwinContext.Response.Redirect("/Home/Error");
                            context.HandleResponse(); // Suppress the exception
                            return Task.FromResult(0);
                        }
                    }
                });

        }
    }

But when I try to run application and login then it gives me error

    You can't access this application 
    XXXXXXX needs permission to access resources in your organization that only an admin can grant. 
    Please ask an admin to grant permission to this app before you can use it.

    Have an admin account? Sign in with that account 
    Return to the application without granting consent 

Answer 1

An Admin has to Grant permissions first so that other users would be able to access the resources. Try following steps

1. Login to portal as Admin
2. Go to your App registration blade
3. Click Required Permissions
4. In the permissions blade on top click Grant Permissions link.
5. Read the confirmation message and click OK.

Now try to login with Non-Admin User.

Hope this article helps.