access_token issue by webapi service1 is accepted by other webapi service

Question

I am implementing the token based authentication in web api service by referring this link https://www.codeproject.com/Articles/1187872/Token-Based-Authentication-for-Web-API-where-Legac

For testing purpose I have created two webapi service with same authentication code as given below. By using 'Postman' tool issued the access_token from webapi service 1 http://localhost:53396/token and copied it.

Opened a new tab in Postman tool to access the controller method of webapi service 2 http://localhost:49489/api/values, added the Authorization header and passed the copied token issued by webapi service 1 bearer Ihqbo6s16BOtKOMqIPYIKbv_N616MAg2X5exa9eLDQPtaTxa5Ucy7lB_oOkyutaWpBFSpIdomhza2pB3ca6gxY3QgOANG7rhPBnxA74EcQYsLGpHJVqXusmTmJ_CpXj9k00e_vngobyBMU3Dqpoxm35lD7vgL27JG6WXhUZ-qo8u6IzzaXliP2A25-pTVv1mRjQGCGGumisDssii0GUZ4K0RsAoq852x8UFawUOZUg8

then clicked on "Send" button, webapi service 2 accepting the token and return the result! that I was supposed not to accept by the service 2 as this is not issued by this service (service 2).

API call Result

[
    "value1",
    "value2"
]

Please let me correct what I am doing wrong here, as if this happens then any one can generate a token from their service and use the same token to access the others web api service.

Following is the authentication related code in my webapi service.

Startup.cs

using System;
using Microsoft.Owin;
using Microsoft.Owin.Security.OAuth;
using Owin;
using System.Collections.Generic;
using System.Linq;
using System.Web.Http;

namespace SampleWebApi
{
    public partial class Startup
    {
        public static void Register(HttpConfiguration config)
        {
            // Web API configuration and services

            config.SuppressDefaultHostAuthentication();
            config.Filters.Add(new HostAuthenticationFilter(OAuthDefaults.AuthenticationType));

            // Web API routes
            config.MapHttpAttributeRoutes();

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


        }

        public static OAuthAuthorizationServerOptions OAuthOptions { get; private set; }

        public static string PublicClientId { get; private set; }

        // For more information on configuring authentication, 
        // please visit http://go.microsoft.com/fwlink/?LinkId=301864
        public void ConfigureAuth(IAppBuilder app)
        {
            // Configure the application for OAuth based flow
            PublicClientId = "self";
            OAuthOptions = new OAuthAuthorizationServerOptions
            { 
                TokenEndpointPath = new PathString("/Token"),
                Provider = new ApplicationOAuthProvider(PublicClientId),
                AuthorizeEndpointPath = new PathString("/api/Account/ExternalLogin"),
                AccessTokenExpireTimeSpan = TimeSpan.FromMinutes(15),
                // In production mode set AllowInsecureHttp = false
                AllowInsecureHttp = true
            };

            // Enable the application to use bearer tokens to authenticate users
            app.UseOAuthBearerTokens(OAuthOptions);
        }
    }
}

WebApiConfig.cs

using Microsoft.Owin.Security.OAuth;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Http;

namespace SampleWebApi
{
    public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
            // Web API configuration and services

            config.SuppressDefaultHostAuthentication();
            config.Filters.Add(new HostAuthenticationFilter(OAuthDefaults.AuthenticationType));

            // Web API routes
            config.MapHttpAttributeRoutes();

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


        }
    }
}

ApplicationOAuthProvider.cs

using Microsoft.Owin.Security;
using Microsoft.Owin.Security.OAuth;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Claims;
using System.Threading.Tasks;
using System.Web;
using IE.BU.Common;
using IE.Entities.Common;

namespace SampleWebApi
{
    public class ApplicationOAuthProvider : OAuthAuthorizationServerProvider
    {
        private readonly string _publicClientId;

        public ApplicationOAuthProvider(string publicClientId)
        {
            if (publicClientId == null)
            {
                throw new ArgumentNullException("publicClientId");
            }

            _publicClientId = publicClientId;
        }

        public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
        {
            UserLogin ul;
            byte[] pwd;
            ul = new UserLogin();
            //var user = _context.Users.SingleOrDefault(x => x.Username == username);

            pwd = PCSPwdEncrypt.HashEncryption.PasswordEncrypt(context.Password);

            User user = ul.ValidateUser(context.UserName, pwd, true);

            if (user == null)
            {
                context.SetError("invalid_grant", "The user name or password is incorrect.");
                return;
            }

            ClaimsIdentity oAuthIdentity = new ClaimsIdentity(context.Options.AuthenticationType);
            ClaimsIdentity cookiesIdentity = new ClaimsIdentity(context.Options.AuthenticationType);

            AuthenticationProperties properties = CreateProperties(context.UserName);
            AuthenticationTicket ticket = new AuthenticationTicket(oAuthIdentity, properties);
            context.Validated(ticket);
            context.Request.Context.Authentication.SignIn(cookiesIdentity);

        }

        public override Task TokenEndpoint(OAuthTokenEndpointContext context)
        {
            foreach (KeyValuePair<string,
            string> property in context.Properties.Dictionary)
            {
                context.AdditionalResponseParameters.Add(property.Key, property.Value);
            }

            return Task.FromResult<object>(null);
        }

        public override Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
        {
            // Resource owner password credentials does not provide a client ID.
            if (context.ClientId == null)
            {
                context.Validated();
            }

            return Task.FromResult<object>(null);
        }

        public override Task ValidateClientRedirectUri
        (OAuthValidateClientRedirectUriContext context)
        {
            if (context.ClientId == _publicClientId)
            {
                Uri expectedRootUri = new Uri(context.Request.Uri, "/");

                if (expectedRootUri.AbsoluteUri == context.RedirectUri)
                {
                    context.Validated();
                }
            }

            return Task.FromResult<object>(null);
        }

        public static AuthenticationProperties CreateProperties(string userName)
        {
            IDictionary<string, string>
            data = new Dictionary<string, string>
            {
                { "userName", userName }
            };
            return new AuthenticationProperties(data);
        }
    }
}

ValuesController.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;

namespace MVCWebAPISample.Controllers
{
    [Authorize]
    public class ValuesController : ApiController
    {
        // GET api/values
        public IEnumerable<string> Get()
        {
            return new string[] { "value1", "value2" };
        }

        // GET api/values/5
        public string Get(int id)
        {
            return "value";
        }

        // POST api/values
        public void Post([FromBody]string value)
        {
        }

        // PUT api/values/5
        public void Put(int id, [FromBody]string value)
        {
        }

        // DELETE api/values/5
        public void Delete(int id)
        {
        }
    }
}

Web.config

<?xml version="1.0" encoding="utf-8"?>
<!--
  For more information on how to configure your ASP.NET application, please visit
  https://go.microsoft.com/fwlink/?LinkId=301879
  -->
<configuration>
  <appSettings>

  </appSettings>
  <connectionStrings>
    <add name="SQLConnectionString" connectionString="Data Source=xxxxx;Initial Catalog=xxxxx;Persist Security Info=True;User ID=xxxx;Password=xxxxx;Connection Timeout=60" providerName="System.Data.SqlClient" />
  </connectionStrings>
  <system.web>
    <compilation debug="true" targetFramework="4.6.1" />
    <httpRuntime targetFramework="4.6.1" />
  </system.web>

  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-5.2.3.0" newVersion="5.2.3.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Http" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-5.2.4.0" newVersion="5.2.4.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Net.Http.Formatting" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-5.2.4.0" newVersion="5.2.4.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-4.0.0.0" newVersion="4.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin.Security" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-4.0.0.0" newVersion="4.0.0.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
  <system.codedom>
    <compilers>
      <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.8.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:default /nowarn:1659;1699;1701" />
      <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.8.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:default /nowarn:41008 /define:_MYTYPE=\&quot;Web\&quot; /optionInfer+" />
    </compilers>
  </system.codedom>
<system.webServer>
    <handlers>
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <remove name="OPTIONSVerbHandler" />
      <remove name="TRACEVerbHandler" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers>
  </system.webServer></configuration>