angularjsasp.net-web-apiasp.net-identityowin-middlewarehttp-token-authentication

TokenEndPoint not found while authenticating user from SPA to Web API using OWIN


I am facing difficulty while authenticating users using token mechanism from Angular JS SPA Page to WEB API.

I do not want to use ASP.NET Identity default tables to add or authenticate user. I have my own database and a table called "EmployeeAccess" table which contains EmployeeNumber as User Id and Password. I want to authenticate the users against the values in this table and then want to grant token so that they gets authorized for subsequent call. I have used all required OWIN and ASP.NET References to achieve the result.

Please see the relevant code below:-

Startup.cs

[assembly: OwinStartup(typeof(Application.WebAPI.Startup))]

namespace Application.WebAPI
{
    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=316888
            app.UseCors(Microsoft.Owin.Cors.CorsOptions.AllowAll);
            var myProvider = new AuthorizationServerProvider();
            OAuthAuthorizationServerOptions options = new OAuthAuthorizationServerOptions
            {
                AllowInsecureHttp = true,
                TokenEndpointPath = new PathString("/Token"),
                AccessTokenExpireTimeSpan = TimeSpan.FromDays(1),
                Provider = myProvider
            };
            app.UseOAuthAuthorizationServer(options);
        }
    }
}

AuthorizationServerProvider.cs

public class AuthorizationServerProvider : OAuthAuthorizationServerProvider
    {
        public override async Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
        {
            context.Validated(); // 
        }

        public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
        {
            context.OwinContext.Response.Headers.Add("Access-Control-Allow-Origin", new[] { "*" });
            string userId = context.UserName;
            string password = context.Password;

            EmployeeAccessBLL chkEmpAccessBLL = new EmployeeAccessBLL();
            EmployeeAccessViewModel vmEmployeeAccess = chkEmpAccessBLL.CheckEmployeeAccess(Convert.ToInt32(userId), password);

            if(vmEmployeeAccess != null)
            {
                var identity = new ClaimsIdentity(context.Options.AuthenticationType);
                identity.AddClaim(new Claim("username", vmEmployeeAccess.EmpName));
                context.Validated(identity);
            }

            else
            {
                context.SetError("invalid_grant", "Provided username and password is incorrect");
                return;
            }
        }
    }

WebApiConfig.cs

public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {            
            // Web API routes
            config.MapHttpAttributeRoutes();

            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );

            config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/html"));
            config.Formatters.Remove(config.Formatters.XmlFormatter);

            var cors = new EnableCorsAttribute("*", "*", "*");
            config.EnableCors(cors);
        }
    }

Login.html

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.0/angular.min.js"></script>
    <script src="../Scripts/AngularControllers/LoginController.js"></script>
    <script src="../Scripts/AngularServices/ApiCallService.js"></script>
</head>
<body ng-app="appHome">
    <div ng-controller="ctrlLogin">
        <label>Employee Number</label>
        <input type="text" id="txtEmpNumber" ng-model="md_empnumber" />
        <br/>
        <br/>
        <label>Password</label>
        <input type="text" id="txtEmpNumber" ng-model="md_password"  />

        <button id="btnAdd" type="submit" ng-click="Login()">Login</button>
    </div>
</body>
</html>

LoginController.js

var myApp = angular.module('appHome', []);
myApp.controller("ctrlLogin", ['$scope', 'MetadataOrgFactory', '$location', function ($scope, MetadataOrgFactory, $location) {
    $scope.Login = function () {
        var objLogin = {
            'username' : $scope.md_empnumber,
            'password' : $scope.md_password,
            'grant_type' : 'password'
        };

        MetadataOrgFactory.postLoginCall('Token', objLogin, function (dataSuccess) {
            alert("Welcome " + dataSuccess);           
        }, function (dataError) {
        });
    }
}]);

ApiCallService.js

var appService = angular.module('appHome');

appService.factory('MetadataOrgFactory', ['$http', function ($http) {

    var url = 'http://localhost:60544';

    var dataFactory = {};

    dataFactory.postLoginCall = function (controllerName, objData, callbackSuccess, callbackError) {

        $http.post(url + '/' + controllerName, objData).then
            (function success(response) {
                alert("Success");
                callbackSuccess(response.data);
            }, function error(response) {
                callbackError(response.status);
            });
    };
    return dataFactory;
}])

I am getting the below two errors when click on Login Button:-

OPTIONS http://localhost:60544/Token 404 (Not Found)

XMLHttpRequest cannot load http://localhost:60544/Token. Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:60512' is therefore not allowed access. The response had HTTP status code 404.

I searched many posts but none of the post is meeting my criteria so thought of posting my query. Please help me on that.


Solution

  • The error is the result of the OPTIONS call.

    The HTTP OPTIONS method is used to describe the communication options for the target resource. The client can specify a specific URL for the OPTIONS method, or an asterisk (*) to refer to the entire server.

    Since you do not handle these, you'll see 404 (not found). You can read about CORS here: https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS

    One way to implement this is to add in Global.asax the following code:

    public class WebApiApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
            GlobalConfiguration.Configure(WebApiConfig.Register);
        }
    
        protected void Application_BeginRequest()
        {
            if (HttpContext.Current.Request.HttpMethod == "OPTIONS")
            {
                // Cache the options request.
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", HttpContext.Current.Request.Headers["Origin"]);
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Methods", "GET, PUT, DELETE, POST, OPTIONS");
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Headers", "Content-Type, Accept, Authorization");
                HttpContext.Current.Response.AddHeader("Access-Control-Max-Age", "1728000");
                HttpContext.Current.Response.End();
            }
        }
    }