added KeyContainer for storing RSA keys

src/TokenAuthExampleWebApplication/KeyContainer.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Security.Cryptography;
+using System.Threading.Tasks;
+
+namespace TokenAuthExampleWebApplication
+{
+    public class KeyContainer
+    {
+        public static RSAParameters GetKeyFromContainer(string containerName)
+        {        
+            CspParameters cp = new CspParameters { KeyContainerName = containerName,  };
+            RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(2048, cp);
+            RSAParameters rsaKeyInfo = rsa.ExportParameters(true);
+            return rsaKeyInfo;
+
+        }
+    }
+}

src/TokenAuthExampleWebApplication/Startup.cs

@@ -25,25 +25,18 @@ public Startup(IHostingEnvironment env)
 
         public void ConfigureServices(IServiceCollection services)
         {
-            // *** CHANGE THIS FOR PRODUCTION USE ***
-            // Here, we're generating a random key to sign tokens - obviously this means
-            // that each time the app is started the key will change, and multiple servers 
-            // all have different keys. This should be changed to load a key from a file 
-            // securely delivered to your application, controlled by configuration.
-            //
-            // See the RSAKeyUtils.GetKeyParameters method for an examle of loading from
-            // a JSON file.
-            RSAParameters keyParams = RSAKeyUtils.GetRandomKey();
+            // Fetching key from KeyContainer, if the key does not exist, we create it.
+            var keyFromContainer = KeyContainer.GetKeyFromContainer("TokenAuthExample");
 
             // Create the key, and a set of token options to record signing credentials 
             // using that key, along with the other parameters we will need in the 
             // token controlller.
-            key = new RsaSecurityKey(keyParams);
+
             tokenOptions = new TokenAuthOptions()
             {
                 Audience = TokenAudience,
                 Issuer = TokenIssuer,
-                SigningCredentials = new SigningCredentials(key, SecurityAlgorithms.RsaSha256Signature)
+                SigningCredentials = new SigningCredentials(keyFromContainer, SecurityAlgorithms.RsaSha256Signature)
             };
 
             // Save the token options into an instance so they're accessible to the 
@@ -54,7 +47,7 @@ public void ConfigureServices(IServiceCollection services)
             services.AddAuthorization(auth =>
             {
                 auth.AddPolicy("Bearer", new AuthorizationPolicyBuilder()
-                    .AddAuthenticationSchemes(JwtBearerDefaults.AuthenticationScheme‌​)
+                    .AddAuthenticationSchemes(JwtBearerDefaults.AuthenticationScheme)
                     .RequireAuthenticatedUser().Build());
             });