Fix SimpleTokenAuthenticationHandler for RC1

There were changes in failed authentication management, I have to test if my decisions were fine.

Author: andresmoschini

src/MakingSense.AspNet.Authentication.SimpleToken/SimpleTokenAppBuilderExtensions.cs

@@ -8,11 +8,11 @@ namespace Microsoft.AspNet.Builder
 {
 	public static class SimpleTokenAppBuilderExtensions
 	{
-		public static IApplicationBuilder UseSimpleTokenAuthentication([NotNull] this IApplicationBuilder app, Action<SimpleTokenAuthenticationOptions> configureOptions = null, string optionsName = "")
+		public static IApplicationBuilder UseSimpleTokenAuthentication([NotNull] this IApplicationBuilder app, Action<SimpleTokenAuthenticationOptions> configureOptions = null, string authenticationScheme = "Bearer")
 		{
 			var options = new SimpleTokenAuthenticationOptions()
 			{
-				AuthenticationScheme = optionsName
+				AuthenticationScheme = authenticationScheme
 			};
 
 			if (configureOptions != null)

src/MakingSense.AspNet.Authentication.SimpleToken/SimpleTokenAuthenticationHandler.cs

@@ -50,6 +50,7 @@ public static string ExtractToken(HttpRequest request)
 					}
 				}
 
+				// Not so nice, but AuthenticateResult.Fail does not allow us to show the error
 				throw new AuthenticationException("Authorization header exists but does not contains valid information.");
 			}
 
@@ -63,19 +64,24 @@ public static string ExtractToken(HttpRequest request)
 			return null;
 		}
 
+		static readonly Task DoneTask = Task.FromResult(0);
 
 		/// <summary>
 		/// Searches the 'Authorization' header for a 'Bearer' token. If the 'Bearer' token is found, it is validated using <see cref="TokenValidationParameters"/> set in the options.
 		/// </summary>
 		/// <returns></returns>
-		protected override Task<AuthenticationTicket> HandleAuthenticateAsync()
+		protected override async Task<AuthenticateResult> HandleAuthenticateAsync()
 		{
+			// Ugly patch to make this method should to be async in order to allow result caching by caller
+			await DoneTask;
+
 			string token = ExtractToken(Request);
 
 			// If no token found, no further work possible
 			if (string.IsNullOrEmpty(token))
 			{
-				return Task.FromResult<AuthenticationTicket>(null);
+				// Not so nice, but AuthenticateResult.Fail has the same behavior
+				return null;
 			}
 
 			var validationParameters = Options.TokenValidationParameters.Clone();
@@ -88,10 +94,11 @@ protected override Task<AuthenticationTicket> HandleAuthenticateAsync()
 				{
 					var principal = validator.ValidateToken(token, validationParameters, out validatedToken);
 					var ticket = new AuthenticationTicket(principal, new AuthenticationProperties(), Options.AuthenticationScheme);
-					return Task.FromResult(ticket);
+					return AuthenticateResult.Success(ticket);
 				}
 			}
 
+			// Not so nice, but AuthenticateResult.Fail does not allow us to show the error
 			throw new AuthenticationException("Authorization token has been detected but it cannot be read.");
 		}
 	}