Add the OpenIddict endpoints tests

src/OpenIddict.Core/Infrastructure/OpenIddictProvider.Authentication.cs

@@ -338,7 +338,8 @@ namespace OpenIddict.Infrastructure {
 
                 // Create a new authorization request containing only the request_id parameter.
                 var address = QueryHelpers.AddQueryString(
-                    uri: context.HttpContext.Request.PathBase + context.HttpContext.Request.Path,
+                    uri: context.HttpContext.Request.Scheme + "://" + context.HttpContext.Request.Host +
+                         context.HttpContext.Request.PathBase + context.HttpContext.Request.Path,
                     name: OpenIdConnectConstants.Parameters.RequestId, value: context.Request.RequestId);
 
                 context.HttpContext.Response.Redirect(address);

src/OpenIddict.Core/Infrastructure/OpenIddictProvider.Discovery.cs

@@ -8,6 +8,7 @@ using System.Threading.Tasks;
 using AspNet.Security.OpenIdConnect.Extensions;
 using AspNet.Security.OpenIdConnect.Server;
 using JetBrains.Annotations;
+using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace OpenIddict.Infrastructure {
@@ -20,7 +21,8 @@ namespace OpenIddict.Infrastructure {
             // OpenIddict disallows the use of the unsecure code_challenge_method=plain method,
             // which must be manually removed from the code_challenge_methods_supported property.
             // See https://tools.ietf.org/html/rfc7636#section-7.2 for more information.
-            context.CodeChallengeMethods.Remove(OpenIdConnectConstants.CodeChallengeMethods.Plain);
+            context.CodeChallengeMethods.Clear();
+            context.CodeChallengeMethods.Add(OpenIdConnectConstants.CodeChallengeMethods.Sha256);
 
             // Note: the OpenID Connect server middleware automatically populates grant_types_supported
             // by determining whether the authorization and token endpoints are enabled or not but
@@ -39,8 +41,9 @@ namespace OpenIddict.Infrastructure {
             context.Scopes.Add(OpenIdConnectConstants.Scopes.Phone);
             context.Scopes.Add(OpenIddictConstants.Scopes.Roles);
 
-            // Only add the "offline_access" scope if "refresh_token" is listed as a supported grant type.
-            if (context.GrantTypes.Contains(OpenIdConnectConstants.GrantTypes.RefreshToken)) {
+            // Only add the "offline_access" scope if the refresh
+            // token flow is enabled in the OpenIddict options.
+            if (services.Options.IsRefreshTokenFlowEnabled()) {
                 context.Scopes.Add(OpenIdConnectConstants.Scopes.OfflineAccess);
             }
 

src/OpenIddict.Core/Infrastructure/OpenIddictProvider.Introspection.cs

@@ -16,9 +16,7 @@ using Microsoft.Extensions.Logging;
 namespace OpenIddict.Infrastructure {
     public partial class OpenIddictProvider<TApplication, TAuthorization, TScope, TToken> : OpenIdConnectServerProvider
         where TApplication : class where TAuthorization : class where TScope : class where TToken : class {
-        public override async Task ValidateIntrospectionRequest([NotNull] ValidateIntrospectionRequestContext context) {
-            var services = context.HttpContext.RequestServices.GetRequiredService<OpenIddictServices<TApplication, TAuthorization, TScope, TToken>>();
-
+        public override Task ExtractIntrospectionRequest([NotNull] ExtractIntrospectionRequestContext context) {
             // Note: the OpenID Connect server middleware supports both GET and POST
             // introspection requests but OpenIddict only accepts POST requests.
             if (!string.Equals(context.HttpContext.Request.Method, "POST", StringComparison.OrdinalIgnoreCase)) {
@@ -26,9 +24,15 @@ namespace OpenIddict.Infrastructure {
                     error: OpenIdConnectConstants.Errors.InvalidRequest,
                     description: "Introspection requests must use HTTP POST.");
 
-                return;
+                return Task.FromResult(0);
             }
 
+            return Task.FromResult(0);
+        }
+
+        public override async Task ValidateIntrospectionRequest([NotNull] ValidateIntrospectionRequestContext context) {
+            var services = context.HttpContext.RequestServices.GetRequiredService<OpenIddictServices<TApplication, TAuthorization, TScope, TToken>>();
+
             // Note: the OpenID Connect server middleware supports unauthenticated introspection requests
             // but OpenIddict uses a stricter policy preventing unauthenticated/public applications
             // from using the introspection endpoint, as required by the specifications.

src/OpenIddict.Core/Infrastructure/OpenIddictProvider.Session.cs

@@ -116,7 +116,8 @@ namespace OpenIddict.Infrastructure {
 
                 // Create a new logout request containing only the request_id parameter.
                 var address = QueryHelpers.AddQueryString(
-                    uri: context.HttpContext.Request.PathBase + context.HttpContext.Request.Path,
+                    uri: context.HttpContext.Request.Scheme + "://" + context.HttpContext.Request.Host +
+                         context.HttpContext.Request.PathBase + context.HttpContext.Request.Path,
                     name: OpenIdConnectConstants.Parameters.RequestId, value: context.Request.RequestId);
 
                 context.HttpContext.Response.Redirect(address);

src/OpenIddict.Core/Managers/OpenIddictApplicationManager.cs

@@ -24,7 +24,7 @@ namespace OpenIddict {
             [NotNull] IServiceProvider services,
             [NotNull] IOpenIddictApplicationStore<TApplication> store,
             [NotNull] ILogger<OpenIddictApplicationManager<TApplication>> logger) {
-            Context = services?.GetRequiredService<IHttpContextAccessor>()?.HttpContext;
+            Context = services?.GetService<IHttpContextAccessor>()?.HttpContext;
             Store = store;
             Logger = logger;
         }

src/OpenIddict.Core/Managers/OpenIddictAuthorizationManager.cs

@@ -21,7 +21,7 @@ namespace OpenIddict {
             [NotNull] IServiceProvider services,
             [NotNull] IOpenIddictAuthorizationStore<TAuthorization> store,
             [NotNull] ILogger<OpenIddictAuthorizationManager<TAuthorization>> logger) {
-            Context = services?.GetRequiredService<IHttpContextAccessor>()?.HttpContext;
+            Context = services?.GetService<IHttpContextAccessor>()?.HttpContext;
             Logger = logger;
             Store = store;
         }

src/OpenIddict.Core/Managers/OpenIddictScopeManager.cs

@@ -21,7 +21,7 @@ namespace OpenIddict {
             [NotNull] IServiceProvider services,
             [NotNull] IOpenIddictScopeStore<TScope> store,
             [NotNull] ILogger<OpenIddictAuthorizationManager<TScope>> logger) {
-            Context = services?.GetRequiredService<IHttpContextAccessor>()?.HttpContext;
+            Context = services?.GetService<IHttpContextAccessor>()?.HttpContext;
             Logger = logger;
             Store = store;
         }

src/OpenIddict.Core/Managers/OpenIddictTokenManager.cs

@@ -22,7 +22,7 @@ namespace OpenIddict {
             [NotNull] IServiceProvider services,
             [NotNull] IOpenIddictTokenStore<TToken> store,
             [NotNull] ILogger<OpenIddictTokenManager<TToken>> logger) {
-            Context = services?.GetRequiredService<IHttpContextAccessor>()?.HttpContext;
+            Context = services?.GetService<IHttpContextAccessor>()?.HttpContext;
             Logger = logger;
             Store = store;
         }

test/OpenIddict.Core.Tests/Infrastructure/OpenIddictProviderTests.Authentication.cs

@@ -0,0 +1,563 @@
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using AspNet.Security.OpenIdConnect.Extensions;
+using Microsoft.Extensions.Caching.Distributed;
+using Microsoft.Extensions.DependencyInjection;
+using Moq;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Bson;
+using Xunit;
+
+namespace OpenIddict.Core.Tests.Infrastructure {
+    public partial class OpenIddictProviderTests {
+        [Fact]
+        public async Task ExtractAuthorizationRequest_UnsupportedRequestParameterIsRejected() {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                RedirectUri = "http://www.fabrikam.com/path",
+                Request = "eyJhbGciOiJub25lIn0.eyJpc3MiOiJodHRwOi8vd3d3LmZhYnJpa2FtLmNvbSIsImF1ZCI6Imh" +
+                          "0dHA6Ly93d3cuY29udG9zby5jb20iLCJyZXNwb25zZV90eXBlIjoiY29kZSIsImNsaWVudF9pZC" +
+                          "I6IkZhYnJpa2FtIiwicmVkaXJlY3RfdXJpIjoiaHR0cDovL3d3dy5mYWJyaWthbS5jb20vcGF0aCJ9.",
+                ResponseType = OpenIdConnectConstants.ResponseTypes.Code,
+                Scope = OpenIdConnectConstants.Scopes.OpenId
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.RequestNotSupported, response.Error);
+            Assert.Equal("The request parameter is not supported.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ExtractAuthorizationRequest_UnsupportedRequestUriParameterIsRejected() {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                RedirectUri = "http://www.fabrikam.com/path",
+                RequestUri = "http://www.fabrikam.com/request/GkurKxf5T0Y-mnPFCHqWOMiZi4VS138cQO_V7PZHAdM",
+                ResponseType = OpenIdConnectConstants.ResponseTypes.Code,
+                Scope = OpenIdConnectConstants.Scopes.OpenId
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.RequestUriNotSupported, response.Error);
+            Assert.Equal("The request_uri parameter is not supported.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ExtractAuthorizationRequest_InvalidRequestIdParameterIsRejected() {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                RedirectUri = "http://www.fabrikam.com/path",
+                RequestId = "EFAF3596-F868-497F-96BB-AA2AD1F8B7E7",
+                ResponseType = OpenIdConnectConstants.ResponseTypes.Code
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("Invalid request: timeout expired.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateAuthorizationRequest_UnknownResponseTypeParameterIsRejected() {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                RedirectUri = "http://www.fabrikam.com/path",
+                ResponseType = "unknown_response_type"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.UnsupportedResponseType, response.Error);
+            Assert.Equal("The specified response_type parameter is not supported.", response.ErrorDescription);
+        }
+
+        [Theory]
+        [InlineData(OpenIdConnectConstants.GrantTypes.AuthorizationCode, "code")]
+        [InlineData(OpenIdConnectConstants.GrantTypes.AuthorizationCode, "code id_token")]
+        [InlineData(OpenIdConnectConstants.GrantTypes.AuthorizationCode, "code id_token token")]
+        [InlineData(OpenIdConnectConstants.GrantTypes.AuthorizationCode, "code token")]
+        [InlineData(OpenIdConnectConstants.GrantTypes.Implicit, "code id_token")]
+        [InlineData(OpenIdConnectConstants.GrantTypes.Implicit, "code id_token token")]
+        [InlineData(OpenIdConnectConstants.GrantTypes.Implicit, "code token")]
+        [InlineData(OpenIdConnectConstants.GrantTypes.Implicit, "id_token")]
+        [InlineData(OpenIdConnectConstants.GrantTypes.Implicit, "id_token token")]
+        [InlineData(OpenIdConnectConstants.GrantTypes.Implicit, "token")]
+        public async Task ValidateAuthorizationRequest_RequestIsRejectedWhenCorrespondingFlowIsDisabled(string flow, string type) {
+            // Arrange
+            var server = CreateAuthorizationServer(builder => {
+                builder.Configure(options => options.GrantTypes.Remove(flow));
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                Nonce = "n-0S6_WzA2Mj",
+                RedirectUri = "http://www.fabrikam.com/path",
+                ResponseType = type,
+                Scope = OpenIdConnectConstants.Scopes.OpenId
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.UnsupportedResponseType, response.Error);
+            Assert.Equal("The specified response_type parameter is not allowed.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateAuthorizationRequest_RequestWithOfflineAccessScopeIsRejectedWhenRefreshTokenFlowIsDisabled() {
+            // Arrange
+            var server = CreateAuthorizationServer(builder => {
+                builder.Configure(options => options.GrantTypes.Remove(OpenIdConnectConstants.GrantTypes.RefreshToken));
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                RedirectUri = "http://www.fabrikam.com/path",
+                ResponseType = OpenIdConnectConstants.ResponseTypes.Code,
+                Scope = OpenIdConnectConstants.Scopes.OfflineAccess
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("The 'offline_access' scope is not allowed.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateAuthorizationRequest_UnknownResponseModeParameterIsRejected() {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                RedirectUri = "http://www.fabrikam.com/path",
+                ResponseMode = "unknown_response_mode",
+                ResponseType = OpenIdConnectConstants.ResponseTypes.Code
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("The specified response_mode parameter is not supported.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateAuthorizationRequest_RequestIsRejectedWhenRedirectUriIsMissing() {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                RedirectUri = null,
+                ResponseType = OpenIdConnectConstants.ResponseTypes.Code
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("The required redirect_uri parameter was missing.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateAuthorizationRequest_RequestIsRejectedWhenCodeChallengeMethodIsMissing() {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                CodeChallenge = "E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM",
+                CodeChallengeMethod = null,
+                RedirectUri = "http://www.fabrikam.com/path",
+                ResponseType = OpenIdConnectConstants.ResponseTypes.Code
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("The 'code_challenge_method' parameter must be specified.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateAuthorizationRequest_RequestIsRejectedWhenCodeChallengeMethodIsPlain() {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                CodeChallenge = "E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM",
+                CodeChallengeMethod = OpenIdConnectConstants.CodeChallengeMethods.Plain,
+                RedirectUri = "http://www.fabrikam.com/path",
+                ResponseType = OpenIdConnectConstants.ResponseTypes.Code
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("The specified response_type parameter is not allowed when using PKCE.", response.ErrorDescription);
+        }
+
+        [Theory]
+        [InlineData("code id_token token")]
+        [InlineData("code token")]
+        public async Task ValidateAuthorizationRequest_CodeChallengeRequestWithForbiddenResponseTypeIsRejected(string type) {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                CodeChallenge = "E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM",
+                CodeChallengeMethod = OpenIdConnectConstants.CodeChallengeMethods.Sha256,
+                Nonce = "n-0S6_WzA2Mj",
+                RedirectUri = "http://www.fabrikam.com/path",
+                ResponseType = type,
+                Scope = OpenIdConnectConstants.Scopes.OpenId
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("The specified response_type parameter is not allowed when using PKCE.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateAuthorizationRequest_RequestIsRejectedWhenClientCannotBeFound() {
+            // Arrange
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(null);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                RedirectUri = "http://www.fabrikam.com/path",
+                ResponseType = OpenIdConnectConstants.ResponseTypes.Code
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidClient, response.Error);
+            Assert.Equal("Application not found in the database: ensure that your client_id is correct.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+        }
+
+        [Fact]
+        public async Task ValidateAuthorizationRequest_RequestIsRejectedWhenRedirectUriIsInvalid() {
+            // Arrange
+            var application = Mock.Of<object>();
+
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(application);
+
+                instance.Setup(mock => mock.ValidateRedirectUriAsync(application, "http://www.fabrikam.com/path"))
+                    .ReturnsAsync(false);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                RedirectUri = "http://www.fabrikam.com/path",
+                ResponseType = OpenIdConnectConstants.ResponseTypes.Code
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidClient, response.Error);
+            Assert.Equal("Invalid redirect_uri.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.ValidateRedirectUriAsync(application, "http://www.fabrikam.com/path"), Times.Once());
+        }
+
+        [Theory]
+        [InlineData("code id_token token")]
+        [InlineData("code token")]
+        [InlineData("id_token token")]
+        [InlineData("token")]
+        public async Task ValidateAuthorizationRequest_ImplicitOrHybridRequestIsRejectedWhenClientIsConfidential(string type) {
+            // Arrange
+            var application = Mock.Of<object>();
+
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(application);
+
+                instance.Setup(mock => mock.ValidateRedirectUriAsync(application, "http://www.fabrikam.com/path"))
+                    .ReturnsAsync(true);
+
+                instance.Setup(mock => mock.GetClientTypeAsync(application))
+                    .ReturnsAsync(OpenIddictConstants.ClientTypes.Confidential);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                Nonce = "n-0S6_WzA2Mj",
+                RedirectUri = "http://www.fabrikam.com/path",
+                ResponseType = type,
+                Scope = OpenIdConnectConstants.Scopes.OpenId
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("Confidential clients are not allowed to retrieve " +
+                         "an access token from the authorization endpoint.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.ValidateRedirectUriAsync(application, "http://www.fabrikam.com/path"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.GetClientTypeAsync(application), Times.Once());
+        }
+
+        [Fact]
+        public async Task HandleAuthorizationRequest_RequestIsPersistedInDistributedCache() {
+            // Arrange
+            var cache = new Mock<IDistributedCache>();
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    var application = Mock.Of<object>();
+
+                    instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                        .ReturnsAsync(application);
+
+                    instance.Setup(mock => mock.ValidateRedirectUriAsync(application, "http://www.fabrikam.com/path"))
+                        .ReturnsAsync(true);
+
+                    instance.Setup(mock => mock.GetClientTypeAsync(application))
+                        .ReturnsAsync(OpenIddictConstants.ClientTypes.Public);
+                }));
+
+                builder.Services.AddSingleton(cache.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                RedirectUri = "http://www.fabrikam.com/path",
+                ResponseType = OpenIdConnectConstants.ResponseTypes.Token
+            });
+
+            var identifier = (string) response[OpenIdConnectConstants.Parameters.RequestId];
+
+            // Assert
+            Assert.Equal(1, response.Count());
+            Assert.NotNull(identifier);
+
+            cache.Verify(mock => mock.SetAsync(
+                OpenIddictConstants.Environment.AuthorizationRequest + identifier,
+                It.IsAny<byte[]>(),
+                It.IsAny<DistributedCacheEntryOptions>()), Times.Once());
+        }
+
+        [Theory]
+        [InlineData("code")]
+        [InlineData("code id_token")]
+        [InlineData("code id_token token")]
+        [InlineData("code token")]
+        [InlineData("id_token")]
+        [InlineData("id_token token")]
+        [InlineData("token")]
+        public async Task HandleAuthorizationRequest_RequestsAreNotHandledLocally(string type) {
+            // Arrange
+            var request = new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                Nonce = "n-0S6_WzA2Mj",
+                RedirectUri = "http://www.fabrikam.com/path",
+                ResponseType = type,
+                Scope = OpenIdConnectConstants.Scopes.OpenId
+            };
+
+            var stream = new MemoryStream();
+            using (var writer = new BsonWriter(stream)) {
+                writer.CloseOutput = false;
+
+                var serializer = JsonSerializer.CreateDefault();
+                serializer.Serialize(writer, request);
+            }
+
+            var cache = new Mock<IDistributedCache>();
+
+            cache.Setup(mock => mock.GetAsync(OpenIddictConstants.Environment.AuthorizationRequest +
+                                              "b2ee7815-5579-4ff7-86b0-ba671b939d96"))
+                .ReturnsAsync(stream.ToArray());
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    var application = Mock.Of<object>();
+
+                    instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                        .ReturnsAsync(application);
+
+                    instance.Setup(mock => mock.ValidateRedirectUriAsync(application, "http://www.fabrikam.com/path"))
+                        .ReturnsAsync(true);
+
+                    instance.Setup(mock => mock.GetClientTypeAsync(application))
+                        .ReturnsAsync(OpenIddictConstants.ClientTypes.Public);
+                }));
+
+                builder.Services.AddSingleton(CreateTokenManager(instance => {
+                    instance.Setup(mock => mock.CreateAsync(OpenIdConnectConstants.TokenTypeHints.AuthorizationCode))
+                        .ReturnsAsync("3E228451-1555-46F7-A471-951EFBA23A56");
+                }));
+
+                builder.Services.AddSingleton(cache.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                RequestId = "b2ee7815-5579-4ff7-86b0-ba671b939d96"
+            });
+
+            // Assert
+            Assert.True(!string.IsNullOrEmpty(response.AccessToken) ||
+                        !string.IsNullOrEmpty(response.Code) ||
+                        !string.IsNullOrEmpty(response.IdToken));
+        }
+
+        [Fact]
+        public async Task ApplyAuthorizationResponse_RequestIsRemovedFromDistributedCache() {
+            // Arrange
+            var request = new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                RedirectUri = "http://www.fabrikam.com/path",
+                ResponseType = OpenIdConnectConstants.ResponseTypes.Token
+            };
+
+            var stream = new MemoryStream();
+            using (var writer = new BsonWriter(stream)) {
+                writer.CloseOutput = false;
+
+                var serializer = JsonSerializer.CreateDefault();
+                serializer.Serialize(writer, request);
+            }
+
+            var cache = new Mock<IDistributedCache>();
+
+            cache.Setup(mock => mock.GetAsync(OpenIddictConstants.Environment.AuthorizationRequest +
+                                              "b2ee7815-5579-4ff7-86b0-ba671b939d96"))
+                .ReturnsAsync(stream.ToArray());
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    var application = Mock.Of<object>();
+
+                    instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                        .ReturnsAsync(application);
+
+                    instance.Setup(mock => mock.ValidateRedirectUriAsync(application, "http://www.fabrikam.com/path"))
+                        .ReturnsAsync(true);
+
+                    instance.Setup(mock => mock.GetClientTypeAsync(application))
+                        .ReturnsAsync(OpenIddictConstants.ClientTypes.Public);
+                }));
+
+                builder.Services.AddSingleton(cache.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                RequestId = "b2ee7815-5579-4ff7-86b0-ba671b939d96"
+            });
+
+            // Assert
+            Assert.NotNull(response.AccessToken);
+
+            cache.Verify(mock => mock.RemoveAsync(
+                OpenIddictConstants.Environment.AuthorizationRequest +
+                "b2ee7815-5579-4ff7-86b0-ba671b939d96"), Times.Once());
+        }
+
+        [Fact]
+        public async Task ApplyAuthorizationResponse_ErroredRequestIsNotHandledLocallyWhenStatusCodeMiddlewareIsEnabled() {
+            // Arrange
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    var application = Mock.Of<object>();
+
+                    instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                        .ReturnsAsync(application);
+
+                    instance.Setup(mock => mock.ValidateRedirectUriAsync(application, "http://www.fabrikam.com/path"))
+                        .ReturnsAsync(true);
+
+                    instance.Setup(mock => mock.GetClientTypeAsync(application))
+                        .ReturnsAsync(OpenIddictConstants.ClientTypes.Public);
+                }));
+
+                builder.EnableAuthorizationEndpoint("/authorize-status-code-middleware");
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync("/authorize-status-code-middleware", new OpenIdConnectRequest {
+                ClientId = null,
+                RedirectUri = null,
+                ResponseType = null
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, (string) response["error_custom"]);
+        }
+    }
+}

test/OpenIddict.Core.Tests/Infrastructure/OpenIddictProviderTests.Discovery.cs

@@ -0,0 +1,104 @@
+using System.Linq;
+using System.Threading.Tasks;
+using AspNet.Security.OpenIdConnect.Extensions;
+using Xunit;
+
+namespace OpenIddict.Core.Tests.Infrastructure {
+    public partial class OpenIddictProviderTests {
+        [Fact]
+        public async Task HandleConfigurationRequest_PlainCodeChallengeMethodIsNotReturned() {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.GetAsync(ConfigurationEndpoint);
+
+            // Assert
+            Assert.DoesNotContain(
+                OpenIdConnectConstants.CodeChallengeMethods.Plain,
+                response[OpenIdConnectConstants.Metadata.CodeChallengeMethodsSupported].Values<string>());
+        }
+
+        [Theory]
+        [InlineData(OpenIdConnectConstants.GrantTypes.AuthorizationCode)]
+        [InlineData(OpenIdConnectConstants.GrantTypes.ClientCredentials)]
+        [InlineData(OpenIdConnectConstants.GrantTypes.Implicit)]
+        [InlineData(OpenIdConnectConstants.GrantTypes.Password)]
+        [InlineData(OpenIdConnectConstants.GrantTypes.RefreshToken)]
+        public async Task HandleConfigurationRequest_EnabledFlowsAreReturned(string flow) {
+            // Arrange
+            var server = CreateAuthorizationServer(builder => {
+                builder.Configure(options => {
+                    options.GrantTypes.Clear();
+                    options.GrantTypes.Add(flow);
+                });
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.GetAsync(ConfigurationEndpoint);
+            var types = response[OpenIdConnectConstants.Metadata.GrantTypesSupported].Values<string>();
+
+            // Assert
+            Assert.Equal(1, types.Count());
+            Assert.Contains(flow, types);
+        }
+
+        [Theory]
+        [InlineData(OpenIdConnectConstants.Scopes.Profile)]
+        [InlineData(OpenIdConnectConstants.Scopes.Email)]
+        [InlineData(OpenIdConnectConstants.Scopes.Phone)]
+        [InlineData(OpenIddictConstants.Scopes.Roles)]
+        public async Task HandleConfigurationRequest_StandardScopesAreExposed(string scope) {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.GetAsync(ConfigurationEndpoint);
+
+            // Assert
+            Assert.Contains(scope, response[OpenIdConnectConstants.Metadata.ScopesSupported].Values<string>());
+        }
+
+        [Fact]
+        public async Task HandleConfigurationRequest_OfflineAccessScopeIsReturnedWhenRefreshTokenFlowIsEnabled() {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.GetAsync(ConfigurationEndpoint);
+
+            // Assert
+            Assert.Contains(OpenIdConnectConstants.Scopes.OfflineAccess,
+                response[OpenIdConnectConstants.Metadata.ScopesSupported].Values<string>());
+        }
+
+        [Fact]
+        public async Task HandleConfigurationRequest_OfflineAccessScopeIsReturnedWhenRefreshTokenFlowIsDisabled() {
+            // Arrange
+            var server = CreateAuthorizationServer(builder => {
+                builder.Configure(options => {
+                    // Note: at least one flow must be enabled.
+                    options.GrantTypes.Clear();
+                    options.GrantTypes.Add(OpenIdConnectConstants.GrantTypes.AuthorizationCode);
+                });
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.GetAsync(ConfigurationEndpoint);
+
+            // Assert
+            Assert.DoesNotContain(OpenIdConnectConstants.Scopes.OfflineAccess,
+                response[OpenIdConnectConstants.Metadata.ScopesSupported].Values<string>());
+        }
+    }
+}

test/OpenIddict.Core.Tests/Infrastructure/OpenIddictProviderTests.Exchange.cs

@@ -0,0 +1,552 @@
+using System.Security.Claims;
+using System.Threading.Tasks;
+using AspNet.Security.OpenIdConnect.Extensions;
+using AspNet.Security.OpenIdConnect.Server;
+using Microsoft.AspNetCore.Authentication;
+using Microsoft.AspNetCore.Http.Authentication;
+using Microsoft.Extensions.DependencyInjection;
+using Moq;
+using Xunit;
+
+namespace OpenIddict.Core.Tests.Infrastructure {
+    public partial class OpenIddictProviderTests {
+        [Theory]
+        [InlineData(OpenIdConnectConstants.GrantTypes.AuthorizationCode)]
+        [InlineData(OpenIdConnectConstants.GrantTypes.ClientCredentials)]
+        [InlineData(OpenIdConnectConstants.GrantTypes.Password)]
+        [InlineData(OpenIdConnectConstants.GrantTypes.RefreshToken)]
+        public async Task ValidateTokenRequest_RequestIsRejectedWhenFlowIsNotEnabled(string flow) {
+            // Arrange
+            var server = CreateAuthorizationServer(builder => {
+                builder.Configure(options => options.GrantTypes.Remove(flow));
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                Code = "SplxlOBeZQQYbYS6WxSbIA",
+                GrantType = flow,
+                Username = "johndoe",
+                Password = "A3ddj3w",
+                RefreshToken = "8xLOxBtZp8"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.UnsupportedGrantType, response.Error);
+            Assert.Equal("The specified grant_type is not supported by this authorization server.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateTokenRequest_RequestWithOfflineAccessScopeIsRejectedWhenRefreshTokenFlowIsDisabled() {
+            // Arrange
+            var server = CreateAuthorizationServer(builder => {
+                builder.Configure(options => options.GrantTypes.Remove(OpenIdConnectConstants.GrantTypes.RefreshToken));
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                GrantType = OpenIdConnectConstants.GrantTypes.Password,
+                Username = "johndoe",
+                Password = "A3ddj3w",
+                Scope = OpenIdConnectConstants.Scopes.OfflineAccess
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("The 'offline_access' scope is not allowed.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateTokenRequest_ClientCredentialsRequestWithOfflineAccessScopeIsRejected() {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                GrantType = OpenIdConnectConstants.GrantTypes.ClientCredentials,
+                Scope = OpenIdConnectConstants.Scopes.OfflineAccess
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("The 'offline_access' scope is not allowed when using grant_type=client_credentials.", response.ErrorDescription);
+        }
+
+        [Theory]
+        [InlineData("client_id", "")]
+        [InlineData("", "client_secret")]
+        public async Task ValidateTokenRequest_ClientCredentialsRequestIsRejectedWhenCredentialsAreMissing(string identifier, string secret) {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                ClientId = identifier,
+                ClientSecret = secret,
+                GrantType = OpenIdConnectConstants.GrantTypes.ClientCredentials
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("Client applications must be authenticated to use the client credentials grant.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateTokenRequest_RequestWithoutClientIdIsRejectedWhenClientIdentificationIsRequired() {
+            // Arrange
+            var server = CreateAuthorizationServer(builder => builder.RequireClientIdentification());
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                ClientId = null,
+                GrantType = OpenIdConnectConstants.GrantTypes.Password,
+                Username = "johndoe",
+                Password = "A3ddj3w"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("The mandatory 'client_id' parameter was missing.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateTokenRequest_RequestIsRejectedWhenClientCannotBeFound() {
+            // Arrange
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(null);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                GrantType = OpenIdConnectConstants.GrantTypes.Password,
+                Username = "johndoe",
+                Password = "A3ddj3w"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidClient, response.Error);
+            Assert.Equal("Application not found in the database: ensure that your client_id is correct.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+        }
+
+        [Fact]
+        public async Task ValidateTokenRequest_ClientCredentialsRequestFromPublicClientIsRejected() {
+            // Arrange
+            var application = Mock.Of<object>();
+
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(application);
+
+                instance.Setup(mock => mock.GetClientTypeAsync(application))
+                    .ReturnsAsync(OpenIddictConstants.ClientTypes.Public);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                ClientSecret = "7Fjfp0ZBr1KtDRbnfVdmIw",
+                GrantType = OpenIdConnectConstants.GrantTypes.ClientCredentials
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.UnauthorizedClient, response.Error);
+            Assert.Equal("Public clients are not allowed to use the client credentials grant.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.GetClientTypeAsync(application), Times.Once());
+        }
+
+        [Fact]
+        public async Task ValidateTokenRequest_ClientSecretCannotBeUsedByPublicClients() {
+            // Arrange
+            var application = Mock.Of<object>();
+
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(application);
+
+                instance.Setup(mock => mock.GetClientTypeAsync(application))
+                    .ReturnsAsync(OpenIddictConstants.ClientTypes.Public);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                ClientSecret = "7Fjfp0ZBr1KtDRbnfVdmIw",
+                GrantType = OpenIdConnectConstants.GrantTypes.Password,
+                Username = "johndoe",
+                Password = "A3ddj3w"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("Public clients are not allowed to send a client_secret.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.GetClientTypeAsync(application), Times.Once());
+        }
+
+        [Fact]
+        public async Task ValidateTokenRequest_ClientSecretIsRequiredForConfidentialClients() {
+            // Arrange
+            var application = Mock.Of<object>();
+
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(application);
+
+                instance.Setup(mock => mock.GetClientTypeAsync(application))
+                    .ReturnsAsync(OpenIddictConstants.ClientTypes.Confidential);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                ClientSecret = null,
+                GrantType = OpenIdConnectConstants.GrantTypes.Password,
+                Username = "johndoe",
+                Password = "A3ddj3w"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidClient, response.Error);
+            Assert.Equal("Missing credentials: ensure that you specified a client_secret.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.GetClientTypeAsync(application), Times.Once());
+        }
+
+        [Fact]
+        public async Task ValidateTokenRequest_RequestIsRejectedWhenClientCredentialsAreInvalid() {
+            // Arrange
+            var application = Mock.Of<object>();
+
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(application);
+
+                instance.Setup(mock => mock.GetClientTypeAsync(application))
+                    .ReturnsAsync(OpenIddictConstants.ClientTypes.Confidential);
+
+                instance.Setup(mock => mock.ValidateSecretAsync(application, "7Fjfp0ZBr1KtDRbnfVdmIw"))
+                    .ReturnsAsync(false);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                ClientSecret = "7Fjfp0ZBr1KtDRbnfVdmIw",
+                GrantType = OpenIdConnectConstants.GrantTypes.Password,
+                Username = "johndoe",
+                Password = "A3ddj3w"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidClient, response.Error);
+            Assert.Equal("Invalid credentials: ensure that you specified a correct client_secret.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.GetClientTypeAsync(application), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.ValidateSecretAsync(application, "7Fjfp0ZBr1KtDRbnfVdmIw"), Times.Once());
+        }
+
+        [Fact]
+        public async Task HandleTokenRequest_RequestIsRejectedWhenAuthorizationCodeIsExpired() {
+            // Arrange
+            var ticket = new AuthenticationTicket(
+                new ClaimsPrincipal(),
+                new AuthenticationProperties(),
+                OpenIdConnectServerDefaults.AuthenticationScheme);
+
+            ticket.SetPresenters("Fabrikam");
+            ticket.SetTicketId("3E228451-1555-46F7-A471-951EFBA23A56");
+            ticket.SetUsage(OpenIdConnectConstants.Usages.AuthorizationCode);
+
+            var format = new Mock<ISecureDataFormat<AuthenticationTicket>>();
+
+            format.Setup(mock => mock.Unprotect("SplxlOBeZQQYbYS6WxSbIA"))
+                .Returns(ticket);
+
+            var manager = CreateTokenManager(instance => {
+                instance.Setup(mock => mock.FindByIdAsync("3E228451-1555-46F7-A471-951EFBA23A56"))
+                    .ReturnsAsync(null);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    var application = Mock.Of<object>();
+
+                    instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                        .ReturnsAsync(application);
+
+                    instance.Setup(mock => mock.GetClientTypeAsync(application))
+                        .ReturnsAsync(OpenIddictConstants.ClientTypes.Public);
+                }));
+
+                builder.Services.AddSingleton(manager);
+
+                builder.Configure(options => options.AuthorizationCodeFormat = format.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                Code = "SplxlOBeZQQYbYS6WxSbIA",
+                GrantType = OpenIdConnectConstants.GrantTypes.AuthorizationCode
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidGrant, response.Error);
+            Assert.Equal("The authorization code is no longer valid.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByIdAsync("3E228451-1555-46F7-A471-951EFBA23A56"), Times.Once());
+        }
+
+        [Fact]
+        public async Task HandleTokenRequest_RequestIsRejectedWhenRefreshTokenIsExpired() {
+            // Arrange
+            var ticket = new AuthenticationTicket(
+                new ClaimsPrincipal(),
+                new AuthenticationProperties(),
+                OpenIdConnectServerDefaults.AuthenticationScheme);
+
+            ticket.SetTicketId("60FFF7EA-F98E-437B-937E-5073CC313103");
+            ticket.SetUsage(OpenIdConnectConstants.Usages.RefreshToken);
+
+            var format = new Mock<ISecureDataFormat<AuthenticationTicket>>();
+
+            format.Setup(mock => mock.Unprotect("8xLOxBtZp8"))
+                .Returns(ticket);
+
+            var manager = CreateTokenManager(instance => {
+                instance.Setup(mock => mock.FindByIdAsync("60FFF7EA-F98E-437B-937E-5073CC313103"))
+                    .ReturnsAsync(null);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    var application = Mock.Of<object>();
+
+                    instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                        .ReturnsAsync(application);
+
+                    instance.Setup(mock => mock.GetClientTypeAsync(application))
+                        .ReturnsAsync(OpenIddictConstants.ClientTypes.Public);
+                }));
+
+                builder.Services.AddSingleton(manager);
+
+                builder.Configure(options => options.RefreshTokenFormat = format.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                GrantType = OpenIdConnectConstants.GrantTypes.RefreshToken,
+                RefreshToken = "8xLOxBtZp8"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidGrant, response.Error);
+            Assert.Equal("The refresh token is no longer valid.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByIdAsync("60FFF7EA-F98E-437B-937E-5073CC313103"), Times.Once());
+        }
+
+        [Fact]
+        public async Task HandleTokenRequest_AuthorizationCodeIsAutomaticallyRevoked() {
+            // Arrange
+            var identity = new ClaimsIdentity(OpenIdConnectServerDefaults.AuthenticationScheme);
+            identity.AddClaim(ClaimTypes.NameIdentifier, "Bob le Bricoleur");
+
+            var ticket = new AuthenticationTicket(
+                new ClaimsPrincipal(identity),
+                new AuthenticationProperties(),
+                OpenIdConnectServerDefaults.AuthenticationScheme);
+
+            ticket.SetPresenters("Fabrikam");
+            ticket.SetTicketId("3E228451-1555-46F7-A471-951EFBA23A56");
+            ticket.SetUsage(OpenIdConnectConstants.Usages.AuthorizationCode);
+
+            var format = new Mock<ISecureDataFormat<AuthenticationTicket>>();
+
+            format.Setup(mock => mock.Unprotect("SplxlOBeZQQYbYS6WxSbIA"))
+                .Returns(ticket);
+
+            var token = Mock.Of<object>();
+
+            var manager = CreateTokenManager(instance => {
+                instance.Setup(mock => mock.FindByIdAsync("3E228451-1555-46F7-A471-951EFBA23A56"))
+                    .ReturnsAsync(token);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    var application = Mock.Of<object>();
+
+                    instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                        .ReturnsAsync(application);
+
+                    instance.Setup(mock => mock.GetClientTypeAsync(application))
+                        .ReturnsAsync(OpenIddictConstants.ClientTypes.Public);
+                }));
+
+                builder.Services.AddSingleton(manager);
+
+                builder.Configure(options => options.AuthorizationCodeFormat = format.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                Code = "SplxlOBeZQQYbYS6WxSbIA",
+                GrantType = OpenIdConnectConstants.GrantTypes.AuthorizationCode
+            });
+
+            // Assert
+            Mock.Get(manager).Verify(mock => mock.FindByIdAsync("3E228451-1555-46F7-A471-951EFBA23A56"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.RevokeAsync(token), Times.Once());
+        }
+
+        [Fact]
+        public async Task HandleTokenRequest_RefreshTokenIsAutomaticallyRevokedWhenSlidingExpirationIsEnabled() {
+            // Arrange
+            var identity = new ClaimsIdentity(OpenIdConnectServerDefaults.AuthenticationScheme);
+            identity.AddClaim(ClaimTypes.NameIdentifier, "Bob le Bricoleur");
+
+            var ticket = new AuthenticationTicket(
+                new ClaimsPrincipal(identity),
+                new AuthenticationProperties(),
+                OpenIdConnectServerDefaults.AuthenticationScheme);
+
+            ticket.SetTicketId("60FFF7EA-F98E-437B-937E-5073CC313103");
+            ticket.SetUsage(OpenIdConnectConstants.Usages.RefreshToken);
+
+            var format = new Mock<ISecureDataFormat<AuthenticationTicket>>();
+
+            format.Setup(mock => mock.Unprotect("8xLOxBtZp8"))
+                .Returns(ticket);
+
+            var token = Mock.Of<object>();
+
+            var manager = CreateTokenManager(instance => {
+                instance.Setup(mock => mock.FindByIdAsync("60FFF7EA-F98E-437B-937E-5073CC313103"))
+                    .ReturnsAsync(token);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    var application = Mock.Of<object>();
+
+                    instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                        .ReturnsAsync(application);
+
+                    instance.Setup(mock => mock.GetClientTypeAsync(application))
+                        .ReturnsAsync(OpenIddictConstants.ClientTypes.Public);
+                }));
+
+                builder.Services.AddSingleton(manager);
+
+                builder.Configure(options => options.RefreshTokenFormat = format.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                GrantType = OpenIdConnectConstants.GrantTypes.RefreshToken,
+                RefreshToken = "8xLOxBtZp8"
+            });
+
+            // Assert
+            Mock.Get(manager).Verify(mock => mock.FindByIdAsync("60FFF7EA-F98E-437B-937E-5073CC313103"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.RevokeAsync(token), Times.Once());
+        }
+
+        [Theory]
+        [InlineData(OpenIdConnectConstants.GrantTypes.ClientCredentials)]
+        [InlineData(OpenIdConnectConstants.GrantTypes.Password)]
+        [InlineData("urn:ietf:params:oauth:grant-type:custom_grant")]
+        public async Task HandleTokenRequest_RequestsAreNotHandledLocally(string flow) {
+            // Arrange
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    var application = Mock.Of<object>();
+
+                    instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                        .ReturnsAsync(application);
+
+                    instance.Setup(mock => mock.GetClientTypeAsync(application))
+                        .ReturnsAsync(OpenIddictConstants.ClientTypes.Confidential);
+
+                    instance.Setup(mock => mock.ValidateSecretAsync(application, "7Fjfp0ZBr1KtDRbnfVdmIw"))
+                        .ReturnsAsync(true);
+                }));
+
+                builder.AllowCustomFlow("urn:ietf:params:oauth:grant-type:custom_grant");
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                ClientSecret = "7Fjfp0ZBr1KtDRbnfVdmIw",
+                GrantType = flow,
+                Username = "johndoe",
+                Password = "A3ddj3w"
+            });
+
+            // Assert
+            Assert.NotNull(response.AccessToken);
+        }
+    }
+}

test/OpenIddict.Core.Tests/Infrastructure/OpenIddictProviderTests.Introspection.cs

@@ -0,0 +1,321 @@
+using System.Linq;
+using System.Security.Claims;
+using System.Threading.Tasks;
+using AspNet.Security.OpenIdConnect.Extensions;
+using AspNet.Security.OpenIdConnect.Server;
+using Microsoft.AspNetCore.Authentication;
+using Microsoft.AspNetCore.Http.Authentication;
+using Microsoft.Extensions.DependencyInjection;
+using Moq;
+using Xunit;
+
+namespace OpenIddict.Core.Tests.Infrastructure {
+    public partial class OpenIddictProviderTests {
+        [Fact]
+        public async Task ExtractIntrospectionRequest_GetRequestsAreRejected() {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.GetAsync(IntrospectionEndpoint, new OpenIdConnectRequest {
+                Token = "2YotnFZFEjr1zCsicMWpAA"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("Introspection requests must use HTTP POST.", response.ErrorDescription);
+        }
+
+        [Theory]
+        [InlineData("client_id", "")]
+        [InlineData("", "client_secret")]
+        public async Task ValidateIntrospectionRequest_ClientCredentialsRequestIsRejectedWhenCredentialsAreMissing(string identifier, string secret) {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(IntrospectionEndpoint, new OpenIdConnectRequest {
+                ClientId = identifier,
+                ClientSecret = secret,
+                Token = "2YotnFZFEjr1zCsicMWpAA"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("Clients must be authenticated to use the introspection endpoint.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateIntrospectionRequest_RequestIsRejectedWhenClientCannotBeFound() {
+            // Arrange
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(null);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(IntrospectionEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                ClientSecret = "7Fjfp0ZBr1KtDRbnfVdmIw",
+                Token = "2YotnFZFEjr1zCsicMWpAA"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidClient, response.Error);
+            Assert.Equal("Application not found in the database: ensure that your client_id is correct.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+        }
+
+        [Fact]
+        public async Task ValidateIntrospectionRequest_RequestsSentByPublicClientsAreRejected() {
+            // Arrange
+            var application = Mock.Of<object>();
+
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(application);
+
+                instance.Setup(mock => mock.GetClientTypeAsync(application))
+                    .ReturnsAsync(OpenIddictConstants.ClientTypes.Public);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(IntrospectionEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                ClientSecret = "7Fjfp0ZBr1KtDRbnfVdmIw",
+                Token = "2YotnFZFEjr1zCsicMWpAA"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidClient, response.Error);
+            Assert.Equal("Public applications are not allowed to use the introspection endpoint.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.GetClientTypeAsync(application), Times.Once());
+        }
+
+        [Fact]
+        public async Task ValidateIntrospectionRequest_RequestIsRejectedWhenClientCredentialsAreInvalid() {
+            // Arrange
+            var application = Mock.Of<object>();
+
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(application);
+
+                instance.Setup(mock => mock.GetClientTypeAsync(application))
+                    .ReturnsAsync(OpenIddictConstants.ClientTypes.Confidential);
+
+                instance.Setup(mock => mock.ValidateSecretAsync(application, "7Fjfp0ZBr1KtDRbnfVdmIw"))
+                    .ReturnsAsync(false);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(IntrospectionEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                ClientSecret = "7Fjfp0ZBr1KtDRbnfVdmIw",
+                Token = "2YotnFZFEjr1zCsicMWpAA"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidClient, response.Error);
+            Assert.Equal("Invalid credentials: ensure that you specified a correct client_secret.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.GetClientTypeAsync(application), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.ValidateSecretAsync(application, "7Fjfp0ZBr1KtDRbnfVdmIw"), Times.Once());
+        }
+
+        [Fact]
+        public async Task HandleIntrospectionRequest_RequestIsRejectedWhenClientIsNotAValidAudience() {
+            // Arrange
+            var identity = new ClaimsIdentity(OpenIdConnectServerDefaults.AuthenticationScheme);
+            identity.AddClaim(ClaimTypes.NameIdentifier, "Bob le Bricoleur");
+
+            var ticket = new AuthenticationTicket(
+                new ClaimsPrincipal(identity),
+                new AuthenticationProperties(),
+                OpenIdConnectServerDefaults.AuthenticationScheme);
+
+            ticket.SetAudiences("Contoso");
+            ticket.SetTicketId("3E228451-1555-46F7-A471-951EFBA23A56");
+            ticket.SetUsage(OpenIdConnectConstants.Usages.AccessToken);
+
+            var format = new Mock<ISecureDataFormat<AuthenticationTicket>>();
+
+            format.Setup(mock => mock.Unprotect("2YotnFZFEjr1zCsicMWpAA"))
+                .Returns(ticket);
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    var application = Mock.Of<object>();
+
+                    instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                        .ReturnsAsync(application);
+
+                    instance.Setup(mock => mock.GetClientTypeAsync(application))
+                        .ReturnsAsync(OpenIddictConstants.ClientTypes.Confidential);
+
+                    instance.Setup(mock => mock.ValidateSecretAsync(application, "7Fjfp0ZBr1KtDRbnfVdmIw"))
+                        .ReturnsAsync(true);
+                }));
+
+                builder.Configure(options => options.AccessTokenFormat = format.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(IntrospectionEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                ClientSecret = "7Fjfp0ZBr1KtDRbnfVdmIw",
+                Token = "2YotnFZFEjr1zCsicMWpAA"
+            });
+
+            // Assert
+            Assert.Equal(1, response.Count());
+            Assert.False((bool) response[OpenIdConnectConstants.Claims.Active]);
+        }
+
+        [Fact]
+        public async Task HandleIntrospectionRequest_RequestIsRejectedWhenAuthorizationCodeIsRevoked() {
+            // Arrange
+            var identity = new ClaimsIdentity(OpenIdConnectServerDefaults.AuthenticationScheme);
+            identity.AddClaim(ClaimTypes.NameIdentifier, "Bob le Bricoleur");
+
+            var ticket = new AuthenticationTicket(
+                new ClaimsPrincipal(identity),
+                new AuthenticationProperties(),
+                OpenIdConnectServerDefaults.AuthenticationScheme);
+
+            ticket.SetTicketId("3E228451-1555-46F7-A471-951EFBA23A56");
+            ticket.SetUsage(OpenIdConnectConstants.Usages.AuthorizationCode);
+
+            var format = new Mock<ISecureDataFormat<AuthenticationTicket>>();
+
+            format.Setup(mock => mock.Unprotect("2YotnFZFEjr1zCsicMWpAA"))
+                .Returns(ticket);
+
+            var manager = CreateTokenManager(instance => {
+                instance.Setup(mock => mock.FindByIdAsync("3E228451-1555-46F7-A471-951EFBA23A56"))
+                    .ReturnsAsync(null);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    var application = Mock.Of<object>();
+
+                    instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                        .ReturnsAsync(application);
+
+                    instance.Setup(mock => mock.GetClientTypeAsync(application))
+                        .ReturnsAsync(OpenIddictConstants.ClientTypes.Confidential);
+
+                    instance.Setup(mock => mock.ValidateSecretAsync(application, "7Fjfp0ZBr1KtDRbnfVdmIw"))
+                        .ReturnsAsync(true);
+                }));
+
+                builder.Services.AddSingleton(manager);
+
+                builder.Configure(options => options.AuthorizationCodeFormat = format.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(IntrospectionEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                ClientSecret = "7Fjfp0ZBr1KtDRbnfVdmIw",
+                Token = "2YotnFZFEjr1zCsicMWpAA"
+            });
+
+            // Assert
+            Assert.Equal(1, response.Count());
+            Assert.False((bool) response[OpenIdConnectConstants.Claims.Active]);
+
+            Mock.Get(manager).Verify(mock => mock.FindByIdAsync("3E228451-1555-46F7-A471-951EFBA23A56"), Times.Once());
+        }
+
+        [Fact]
+        public async Task HandleIntrospectionRequest_RequestIsRejectedWhenRefreshTokenIsRevoked() {
+            // Arrange
+            var identity = new ClaimsIdentity(OpenIdConnectServerDefaults.AuthenticationScheme);
+            identity.AddClaim(ClaimTypes.NameIdentifier, "Bob le Bricoleur");
+
+            var ticket = new AuthenticationTicket(
+                new ClaimsPrincipal(identity),
+                new AuthenticationProperties(),
+                OpenIdConnectServerDefaults.AuthenticationScheme);
+
+            ticket.SetTicketId("3E228451-1555-46F7-A471-951EFBA23A56");
+            ticket.SetUsage(OpenIdConnectConstants.Usages.RefreshToken);
+
+            var format = new Mock<ISecureDataFormat<AuthenticationTicket>>();
+
+            format.Setup(mock => mock.Unprotect("2YotnFZFEjr1zCsicMWpAA"))
+                .Returns(ticket);
+
+            var manager = CreateTokenManager(instance => {
+                instance.Setup(mock => mock.FindByIdAsync("3E228451-1555-46F7-A471-951EFBA23A56"))
+                    .ReturnsAsync(null);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    var application = Mock.Of<object>();
+
+                    instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                        .ReturnsAsync(application);
+
+                    instance.Setup(mock => mock.GetClientTypeAsync(application))
+                        .ReturnsAsync(OpenIddictConstants.ClientTypes.Confidential);
+
+                    instance.Setup(mock => mock.ValidateSecretAsync(application, "7Fjfp0ZBr1KtDRbnfVdmIw"))
+                        .ReturnsAsync(true);
+                }));
+
+                builder.Services.AddSingleton(manager);
+
+                builder.Configure(options => options.RefreshTokenFormat = format.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(IntrospectionEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                ClientSecret = "7Fjfp0ZBr1KtDRbnfVdmIw",
+                Token = "2YotnFZFEjr1zCsicMWpAA"
+            });
+
+            // Assert
+            Assert.Equal(1, response.Count());
+            Assert.False((bool) response[OpenIdConnectConstants.Claims.Active]);
+
+            Mock.Get(manager).Verify(mock => mock.FindByIdAsync("3E228451-1555-46F7-A471-951EFBA23A56"), Times.Once());
+        }
+    }
+}

test/OpenIddict.Core.Tests/Infrastructure/OpenIddictProviderTests.Revocation.cs

@@ -0,0 +1,352 @@
+using System;
+using System.IdentityModel.Tokens.Jwt;
+using System.Linq;
+using System.Security.Claims;
+using System.Threading.Tasks;
+using AspNet.Security.OpenIdConnect.Extensions;
+using AspNet.Security.OpenIdConnect.Server;
+using Microsoft.AspNetCore.Authentication;
+using Microsoft.AspNetCore.Http.Authentication;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.IdentityModel.Tokens;
+using Moq;
+using Xunit;
+
+namespace OpenIddict.Core.Tests.Infrastructure {
+    public partial class OpenIddictProviderTests {
+        [Theory]
+        [InlineData(OpenIdConnectConstants.TokenTypeHints.AccessToken)]
+        [InlineData(OpenIdConnectConstants.TokenTypeHints.IdToken)]
+        public async Task ValidateRevocationRequest_UnknownTokenTokenHintIsRejected(string hint) {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(RevocationEndpoint, new OpenIdConnectRequest {
+                Token = "SlAV32hkKG",
+                TokenTypeHint = hint
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.UnsupportedTokenType, response.Error);
+            Assert.Equal("Only authorization codes and refresh tokens can be revoked. When specifying a token_type_hint " +
+                         "parameter, its value must be equal to 'authorization_code' or 'refresh_token'.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateRevocationRequest_RequestWithoutClientIdIsRejectedWhenClientIdentificationIsRequired() {
+            // Arrange
+            var server = CreateAuthorizationServer(builder => builder.RequireClientIdentification());
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(RevocationEndpoint, new OpenIdConnectRequest {
+                Token = "SlAV32hkKG",
+                TokenTypeHint = OpenIdConnectConstants.TokenTypeHints.RefreshToken
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("The mandatory 'client_id' parameter was missing.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateRevocationRequest_RequestIsRejectedWhenClientCannotBeFound() {
+            // Arrange
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(null);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(RevocationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                Token = "SlAV32hkKG",
+                TokenTypeHint = OpenIdConnectConstants.TokenTypeHints.RefreshToken
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidClient, response.Error);
+            Assert.Equal("Application not found in the database: ensure that your client_id is correct.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+        }
+
+        [Fact]
+        public async Task ValidateRevocationRequest_ClientSecretCannotBeUsedByPublicClients() {
+            // Arrange
+            var application = Mock.Of<object>();
+
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(application);
+
+                instance.Setup(mock => mock.GetClientTypeAsync(application))
+                    .ReturnsAsync(OpenIddictConstants.ClientTypes.Public);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(RevocationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                ClientSecret = "7Fjfp0ZBr1KtDRbnfVdmIw",
+                Token = "SlAV32hkKG",
+                TokenTypeHint = OpenIdConnectConstants.TokenTypeHints.RefreshToken
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("Public clients are not allowed to send a client_secret.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.GetClientTypeAsync(application), Times.Once());
+        }
+
+        [Fact]
+        public async Task ValidateRevocationRequest_ClientSecretIsRequiredForConfidentialClients() {
+            // Arrange
+            var application = Mock.Of<object>();
+
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(application);
+
+                instance.Setup(mock => mock.GetClientTypeAsync(application))
+                    .ReturnsAsync(OpenIddictConstants.ClientTypes.Confidential);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(RevocationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                ClientSecret = null,
+                Token = "SlAV32hkKG",
+                TokenTypeHint = OpenIdConnectConstants.TokenTypeHints.RefreshToken
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidClient, response.Error);
+            Assert.Equal("Missing credentials: ensure that you specified a client_secret.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.GetClientTypeAsync(application), Times.Once());
+        }
+
+        [Fact]
+        public async Task ValidateRevocationRequest_RequestIsRejectedWhenClientCredentialsAreInvalid() {
+            // Arrange
+            var application = Mock.Of<object>();
+
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                    .ReturnsAsync(application);
+
+                instance.Setup(mock => mock.GetClientTypeAsync(application))
+                    .ReturnsAsync(OpenIddictConstants.ClientTypes.Confidential);
+
+                instance.Setup(mock => mock.ValidateSecretAsync(application, "7Fjfp0ZBr1KtDRbnfVdmIw"))
+                    .ReturnsAsync(false);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(RevocationEndpoint, new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                ClientSecret = "7Fjfp0ZBr1KtDRbnfVdmIw",
+                Token = "SlAV32hkKG",
+                TokenTypeHint = OpenIdConnectConstants.TokenTypeHints.RefreshToken
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidClient, response.Error);
+            Assert.Equal("Invalid credentials: ensure that you specified a correct client_secret.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByClientIdAsync("Fabrikam"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.GetClientTypeAsync(application), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.ValidateSecretAsync(application, "7Fjfp0ZBr1KtDRbnfVdmIw"), Times.Once());
+        }
+
+        [Fact]
+        public async Task HandleRevocationRequest_RequestIsRejectedWhenTokenIsAnAccessToken() {
+            // Arrange
+            var ticket = new AuthenticationTicket(
+                new ClaimsPrincipal(),
+                new AuthenticationProperties(),
+                OpenIdConnectServerDefaults.AuthenticationScheme);
+
+            ticket.SetTicketId("3E228451-1555-46F7-A471-951EFBA23A56");
+            ticket.SetUsage(OpenIdConnectConstants.Usages.AccessToken);
+
+            var format = new Mock<ISecureDataFormat<AuthenticationTicket>>();
+
+            format.Setup(mock => mock.Unprotect("SlAV32hkKG"))
+                .Returns(ticket);
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Configure(options => options.AccessTokenFormat = format.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(RevocationEndpoint, new OpenIdConnectRequest {
+                Token = "SlAV32hkKG"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.UnsupportedTokenType, response.Error);
+            Assert.Equal("Only authorization codes and refresh tokens can be revoked.", response.ErrorDescription);
+
+            format.Verify(mock => mock.Unprotect("SlAV32hkKG"), Times.Once());
+        }
+
+        [Fact]
+        public async Task HandleRevocationRequest_RequestIsNotRejectedWhenTokenIsAnIdentityToken() {
+            // Arrange
+            var token = Mock.Of<SecurityToken>(mock =>
+                mock.ValidFrom == DateTime.UtcNow.AddDays(-1) &&
+                mock.ValidTo == DateTime.UtcNow.AddDays(1));
+
+            var identity = new ClaimsIdentity(OpenIdConnectServerDefaults.AuthenticationScheme);
+            identity.AddClaim(OpenIdConnectConstants.Claims.Usage, OpenIdConnectConstants.Usages.IdentityToken);
+
+            var handler = new Mock<JwtSecurityTokenHandler>();
+
+            handler.Setup(mock => mock.CanReadToken("SlAV32hkKG"))
+                .Returns(true);
+
+            handler.As<ISecurityTokenValidator>()
+                .Setup(mock => mock.ValidateToken("SlAV32hkKG", It.IsAny<TokenValidationParameters>(), out token))
+                .Returns(new ClaimsPrincipal(identity));
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Configure(options => options.IdentityTokenHandler = handler.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(RevocationEndpoint, new OpenIdConnectRequest {
+                Token = "SlAV32hkKG"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.UnsupportedTokenType, response.Error);
+            Assert.Equal("Only authorization codes and refresh tokens can be revoked.", response.ErrorDescription);
+
+            handler.As<ISecurityTokenValidator>()
+                .Verify(mock => mock.CanReadToken("SlAV32hkKG"), Times.Once());
+
+            handler.As<ISecurityTokenValidator>()
+                .Verify(mock => mock.ValidateToken("SlAV32hkKG", It.IsAny<TokenValidationParameters>(), out token), Times.Once());
+        }
+
+        [Fact]
+        public async Task HandleRevocationRequest_TokenIsNotRevokedWhenItIsAlreadyInvalid() {
+            // Arrange
+            var ticket = new AuthenticationTicket(
+                new ClaimsPrincipal(),
+                new AuthenticationProperties(),
+                OpenIdConnectServerDefaults.AuthenticationScheme);
+
+            ticket.SetTicketId("3E228451-1555-46F7-A471-951EFBA23A56");
+            ticket.SetUsage(OpenIdConnectConstants.Usages.RefreshToken);
+
+            var format = new Mock<ISecureDataFormat<AuthenticationTicket>>();
+
+            format.Setup(mock => mock.Unprotect("SlAV32hkKG"))
+                .Returns(ticket);
+
+            var manager = CreateTokenManager(instance => {
+                instance.Setup(mock => mock.FindByIdAsync("3E228451-1555-46F7-A471-951EFBA23A56"))
+                    .ReturnsAsync(null);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+
+                builder.Configure(options => options.AccessTokenFormat = format.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(RevocationEndpoint, new OpenIdConnectRequest {
+                Token = "SlAV32hkKG"
+            });
+
+            // Assert
+            Assert.Equal(0, response.Count());
+
+            Mock.Get(manager).Verify(mock => mock.FindByIdAsync("3E228451-1555-46F7-A471-951EFBA23A56"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.RevokeAsync(It.IsAny<object>()), Times.Never());
+        }
+
+        [Fact]
+        public async Task HandleRevocationRequest_TokenIsSuccessfullyRevoked() {
+            // Arrange
+            var ticket = new AuthenticationTicket(
+                new ClaimsPrincipal(),
+                new AuthenticationProperties(),
+                OpenIdConnectServerDefaults.AuthenticationScheme);
+
+            ticket.SetTicketId("3E228451-1555-46F7-A471-951EFBA23A56");
+            ticket.SetUsage(OpenIdConnectConstants.Usages.RefreshToken);
+
+            var format = new Mock<ISecureDataFormat<AuthenticationTicket>>();
+
+            format.Setup(mock => mock.Unprotect("SlAV32hkKG"))
+                .Returns(ticket);
+
+            var token = Mock.Of<object>();
+
+            var manager = CreateTokenManager(instance => {
+                instance.Setup(mock => mock.FindByIdAsync("3E228451-1555-46F7-A471-951EFBA23A56"))
+                    .ReturnsAsync(token);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+
+                builder.Configure(options => options.AccessTokenFormat = format.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(RevocationEndpoint, new OpenIdConnectRequest {
+                Token = "SlAV32hkKG"
+            });
+
+            // Assert
+            Assert.Equal(0, response.Count());
+
+            Mock.Get(manager).Verify(mock => mock.FindByIdAsync("3E228451-1555-46F7-A471-951EFBA23A56"), Times.Once());
+            Mock.Get(manager).Verify(mock => mock.RevokeAsync(token), Times.Once());
+        }
+    }
+}

test/OpenIddict.Core.Tests/Infrastructure/OpenIddictProviderTests.Serialization.cs

@@ -0,0 +1,101 @@
+using System.IO;
+using System.Threading.Tasks;
+using AspNet.Security.OpenIdConnect.Extensions;
+using Microsoft.Extensions.Caching.Distributed;
+using Microsoft.Extensions.DependencyInjection;
+using Moq;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Bson;
+using Xunit;
+
+namespace OpenIddict.Core.Tests.Infrastructure {
+    public partial class OpenIddictProviderTests {
+        [Fact]
+        public async Task SerializeAuthorizationCode_AuthorizationCodeIsAutomaticallyPersisted() {
+            // Arrange
+            var request = new OpenIdConnectRequest {
+                ClientId = "Fabrikam",
+                RedirectUri = "http://www.fabrikam.com/path",
+                ResponseType = OpenIdConnectConstants.ResponseTypes.Code
+            };
+
+            var stream = new MemoryStream();
+            using (var writer = new BsonWriter(stream)) {
+                writer.CloseOutput = false;
+
+                var serializer = JsonSerializer.CreateDefault();
+                serializer.Serialize(writer, request);
+            }
+
+            var cache = new Mock<IDistributedCache>();
+
+            cache.Setup(mock => mock.GetAsync(OpenIddictConstants.Environment.AuthorizationRequest +
+                                              "b2ee7815-5579-4ff7-86b0-ba671b939d96"))
+                .ReturnsAsync(stream.ToArray());
+
+            var manager = CreateTokenManager(instance => {
+                instance.Setup(mock => mock.CreateAsync(OpenIdConnectConstants.TokenTypeHints.AuthorizationCode))
+                    .ReturnsAsync("3E228451-1555-46F7-A471-951EFBA23A56");
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    var application = Mock.Of<object>();
+
+                    instance.Setup(mock => mock.FindByClientIdAsync("Fabrikam"))
+                        .ReturnsAsync(application);
+
+                    instance.Setup(mock => mock.ValidateRedirectUriAsync(application, "http://www.fabrikam.com/path"))
+                        .ReturnsAsync(true);
+
+                    instance.Setup(mock => mock.GetClientTypeAsync(application))
+                        .ReturnsAsync(OpenIddictConstants.ClientTypes.Public);
+                }));
+
+                builder.Services.AddSingleton(manager);
+
+                builder.Services.AddSingleton(cache.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(AuthorizationEndpoint, new OpenIdConnectRequest {
+                RequestId = "b2ee7815-5579-4ff7-86b0-ba671b939d96"
+            });
+
+            // Assert
+            Assert.NotNull(response.Code);
+
+            Mock.Get(manager).Verify(mock => mock.CreateAsync(OpenIdConnectConstants.TokenTypeHints.AuthorizationCode), Times.Once());
+        }
+
+        [Fact]
+        public async Task SerializeRefreshToken_RefreshTokenIsAutomaticallyPersisted() {
+            // Arrange
+            var manager = CreateTokenManager(instance => {
+                instance.Setup(mock => mock.CreateAsync(OpenIdConnectConstants.TokenTypeHints.RefreshToken))
+                    .ReturnsAsync("3E228451-1555-46F7-A471-951EFBA23A56");
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(TokenEndpoint, new OpenIdConnectRequest {
+                GrantType = OpenIdConnectConstants.GrantTypes.Password,
+                Username = "johndoe",
+                Password = "A3ddj3w",
+                Scope = OpenIdConnectConstants.Scopes.OfflineAccess
+            });
+
+            // Assert
+            Assert.NotNull(response.RefreshToken);
+
+            Mock.Get(manager).Verify(mock => mock.CreateAsync(OpenIdConnectConstants.TokenTypeHints.RefreshToken), Times.Once());
+        }
+    }
+}

test/OpenIddict.Core.Tests/Infrastructure/OpenIddictProviderTests.Session.cs

@@ -0,0 +1,112 @@
+using System.Linq;
+using System.Threading.Tasks;
+using AspNet.Security.OpenIdConnect.Extensions;
+using Microsoft.Extensions.Caching.Distributed;
+using Microsoft.Extensions.DependencyInjection;
+using Moq;
+using Xunit;
+
+namespace OpenIddict.Core.Tests.Infrastructure {
+    public partial class OpenIddictProviderTests {
+        [Fact]
+        public async Task ExtractLogoutRequest_InvalidRequestIdParameterIsRejected() {
+            // Arrange
+            var server = CreateAuthorizationServer();
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(LogoutEndpoint, new OpenIdConnectRequest {
+                RequestId = "EFAF3596-F868-497F-96BB-AA2AD1F8B7E7"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, response.Error);
+            Assert.Equal("Invalid request: timeout expired.", response.ErrorDescription);
+        }
+
+        [Fact]
+        public async Task ValidateLogoutRequest_RequestIsRejectedWhenRedirectUriIsInvalid() {
+            // Arrange
+            var manager = CreateApplicationManager(instance => {
+                instance.Setup(mock => mock.FindByLogoutRedirectUri("http://www.fabrikam.com/path"))
+                    .ReturnsAsync(null);
+            });
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(manager);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(LogoutEndpoint, new OpenIdConnectRequest {
+                PostLogoutRedirectUri = "http://www.fabrikam.com/path"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidClient, response.Error);
+            Assert.Equal("Invalid post_logout_redirect_uri.", response.ErrorDescription);
+
+            Mock.Get(manager).Verify(mock => mock.FindByLogoutRedirectUri("http://www.fabrikam.com/path"), Times.Once());
+        }
+
+        [Fact]
+        public async Task HandleLogoutRequest_RequestIsPersistedInDistributedCache() {
+            // Arrange
+            var cache = new Mock<IDistributedCache>();
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    var application = Mock.Of<object>();
+
+                    instance.Setup(mock => mock.FindByLogoutRedirectUri("http://www.fabrikam.com/path"))
+                        .ReturnsAsync(application);
+                }));
+
+                builder.Services.AddSingleton(cache.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(LogoutEndpoint, new OpenIdConnectRequest {
+                PostLogoutRedirectUri = "http://www.fabrikam.com/path"
+            });
+
+            var identifier = (string) response[OpenIdConnectConstants.Parameters.RequestId];
+
+            // Assert
+            Assert.Equal(1, response.Count());
+            Assert.NotNull(identifier);
+
+            cache.Verify(mock => mock.SetAsync(
+                OpenIddictConstants.Environment.LogoutRequest + identifier,
+                It.IsAny<byte[]>(),
+                It.IsAny<DistributedCacheEntryOptions>()), Times.Once());
+        }
+
+        [Fact]
+        public async Task ApplyLogoutResponse_ErroredRequestIsNotHandledLocallyWhenStatusCodeMiddlewareIsEnabled() {
+            // Arrange
+            var server = CreateAuthorizationServer(builder => {
+                builder.Services.AddSingleton(CreateApplicationManager(instance => {
+                    instance.Setup(mock => mock.FindByLogoutRedirectUri("http://www.fabrikam.com/path"))
+                        .ReturnsAsync(null);
+                }));
+
+                builder.EnableAuthorizationEndpoint("/logout-status-code-middleware");
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync("/logout-status-code-middleware", new OpenIdConnectRequest {
+                PostLogoutRedirectUri = "http://www.fabrikam.com/path"
+            });
+
+            // Assert
+            Assert.Equal(OpenIdConnectConstants.Errors.InvalidRequest, (string) response["error_custom"]);
+        }
+    }
+}

test/OpenIddict.Core.Tests/Infrastructure/OpenIddictProviderTests.Userinfo.cs

@@ -0,0 +1,45 @@
+using System.Security.Claims;
+using System.Threading.Tasks;
+using AspNet.Security.OpenIdConnect.Extensions;
+using AspNet.Security.OpenIdConnect.Server;
+using Microsoft.AspNetCore.Authentication;
+using Microsoft.AspNetCore.Http.Authentication;
+using Moq;
+using Xunit;
+
+namespace OpenIddict.Core.Tests.Infrastructure {
+    public partial class OpenIddictProviderTests {
+        [Fact]
+        public async Task HandleUserinfoRequest_RequestIsHandledByUserCode() {
+            // Arrange
+            var identity = new ClaimsIdentity(OpenIdConnectServerDefaults.AuthenticationScheme);
+            identity.AddClaim(ClaimTypes.NameIdentifier, "Bob le Bricoleur");
+
+            var ticket = new AuthenticationTicket(
+                new ClaimsPrincipal(identity),
+                new AuthenticationProperties(),
+                OpenIdConnectServerDefaults.AuthenticationScheme);
+
+            var format = new Mock<ISecureDataFormat<AuthenticationTicket>>();
+
+            format.Setup(mock => mock.Unprotect("SlAV32hkKG"))
+                .Returns(ticket);
+
+            var server = CreateAuthorizationServer(builder => {
+                builder.Configure(options => options.AccessTokenFormat = format.Object);
+            });
+
+            var client = new OpenIdConnectClient(server.CreateClient());
+
+            // Act
+            var response = await client.PostAsync(UserinfoEndpoint, new OpenIdConnectRequest {
+                AccessToken = "SlAV32hkKG"
+            });
+
+            // Assert
+            Assert.Equal("Bob le Bricoleur", (string) response[OpenIdConnectConstants.Claims.Subject]);
+
+            format.Verify(mock => mock.Unprotect("SlAV32hkKG"), Times.Once());
+        }
+    }
+}

test/OpenIddict.Core.Tests/Infrastructure/OpenIddictProviderTests.cs

@@ -0,0 +1,150 @@
+using System;
+using System.Reflection;
+using System.Security.Claims;
+using System.Threading.Tasks;
+using AspNet.Security.OpenIdConnect.Extensions;
+using AspNet.Security.OpenIdConnect.Server;
+using Microsoft.AspNetCore.Authentication;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.DataProtection;
+using Microsoft.AspNetCore.Diagnostics;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Http.Authentication;
+using Microsoft.AspNetCore.TestHost;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Microsoft.Net.Http.Headers;
+using Moq;
+using Newtonsoft.Json;
+
+namespace OpenIddict.Core.Tests.Infrastructure {
+    public partial class OpenIddictProviderTests {
+        public const string AuthorizationEndpoint = "/connect/authorize";
+        public const string ConfigurationEndpoint = "/.well-known/openid-configuration";
+        public const string IntrospectionEndpoint = "/connect/introspect";
+        public const string LogoutEndpoint = "/connect/logout";
+        public const string RevocationEndpoint = "/connect/revoke";
+        public const string TokenEndpoint = "/connect/token";
+        public const string UserinfoEndpoint = "/connect/userinfo";
+
+        private static TestServer CreateAuthorizationServer(Action<OpenIddictBuilder> configuration = null) {
+            var builder = new WebHostBuilder();
+
+            builder.UseEnvironment("Testing");
+
+            builder.ConfigureLogging(options => options.AddDebug());
+
+            builder.ConfigureServices(services => {
+                var instance = services.AddOpenIddict<object, object, object, object>()
+                    // Disable the transport security requirement during testing.
+                    .DisableHttpsRequirement()
+
+                    // Enable the tested endpoints.
+                    .EnableAuthorizationEndpoint(AuthorizationEndpoint)
+                    .EnableIntrospectionEndpoint(IntrospectionEndpoint)
+                    .EnableLogoutEndpoint(LogoutEndpoint)
+                    .EnableRevocationEndpoint(RevocationEndpoint)
+                    .EnableTokenEndpoint(TokenEndpoint)
+                    .EnableUserinfoEndpoint(UserinfoEndpoint)
+
+                    // Enable the tested flows.
+                    .AllowAuthorizationCodeFlow()
+                    .AllowClientCredentialsFlow()
+                    .AllowImplicitFlow()
+                    .AllowPasswordFlow()
+                    .AllowRefreshTokenFlow()
+
+                    // Register the X.509 certificate used to sign the identity tokens.
+                    .AddSigningCertificate(
+                        assembly: typeof(OpenIddictProviderTests).GetTypeInfo().Assembly,
+                        resource: "OpenIddict.Core.Tests.Certificate.pfx",
+                        password: "OpenIddict")
+
+                    // Note: overriding the default data protection provider is not necessary for the tests to pass,
+                    // but is useful to ensure unnecessary keys are not persisted in testing environments, which also
+                    // helps make the unit tests run faster, as no registry or disk access is required in this case.
+                    .UseDataProtectionProvider(new EphemeralDataProtectionProvider());
+
+                // Run the configuration delegate
+                // registered by the unit tests.
+                configuration?.Invoke(instance);
+            });
+
+            builder.Configure(app => {
+                app.UseStatusCodePages(context => {
+                    context.HttpContext.Response.Headers[HeaderNames.ContentType] = "application/json";
+
+                    return context.HttpContext.Response.WriteAsync(JsonConvert.SerializeObject(new {
+                        error_custom = OpenIdConnectConstants.Errors.InvalidRequest
+                    }));
+                });
+
+                app.Use(next => context => {
+                    if (context.Request.Path != "/authorize-status-code-middleware" &&
+                        context.Request.Path != "/logout-status-code-middleware") {
+                        var feature = context.Features.Get<IStatusCodePagesFeature>();
+                        feature.Enabled = false;
+                    }
+
+                    return next(context);
+                });
+
+                app.UseOpenIddict();
+
+                app.Run(context => {
+                    if (context.Request.Path == AuthorizationEndpoint ||
+                        context.Request.Path == TokenEndpoint) {
+                        var request = context.GetOpenIdConnectRequest();
+
+                        var identity = new ClaimsIdentity(OpenIdConnectServerDefaults.AuthenticationScheme);
+                        identity.AddClaim(ClaimTypes.NameIdentifier, "Bob le Magnifique");
+
+                        var ticket = new AuthenticationTicket(
+                            new ClaimsPrincipal(identity),
+                            new AuthenticationProperties(),
+                            OpenIdConnectServerDefaults.AuthenticationScheme);
+
+                        ticket.SetScopes(request.GetScopes());
+
+                        return context.Authentication.SignInAsync(ticket.AuthenticationScheme, ticket.Principal, ticket.Properties);
+                    }
+
+                    else if (context.Request.Path == UserinfoEndpoint) {
+                        context.Response.Headers[HeaderNames.ContentType] = "application/json";
+
+                        return context.Response.WriteAsync(JsonConvert.SerializeObject(new {
+                            sub = "Bob le Bricoleur"
+                        }));
+                    }
+
+                    return Task.FromResult(0);
+                });
+            });
+
+            return new TestServer(builder);
+        }
+
+        private static OpenIddictApplicationManager<object> CreateApplicationManager(Action<Mock<OpenIddictApplicationManager<object>>> setup = null) {
+            var manager = new Mock<OpenIddictApplicationManager<object>>(
+                Mock.Of<IServiceProvider>(),
+                Mock.Of<IOpenIddictApplicationStore<object>>(),
+                Mock.Of<ILogger<OpenIddictApplicationManager<object>>>());
+
+            setup?.Invoke(manager);
+
+            return manager.Object;
+        }
+
+        private static OpenIddictTokenManager<object> CreateTokenManager(Action<Mock<OpenIddictTokenManager<object>>> setup = null) {
+            var manager = new Mock<OpenIddictTokenManager<object>>(
+                Mock.Of<IServiceProvider>(),
+                Mock.Of<IOpenIddictTokenStore<object>>(),
+                Mock.Of<ILogger<OpenIddictTokenManager<object>>>());
+
+            setup?.Invoke(manager);
+
+            return manager.Object;
+        }
+    }
+}

test/OpenIddict.Core.Tests/Placeholder.cs

@@ -1,3 +0,0 @@
-namespace OpenIddict.Core.Tests {
-    public class Placeholder { }
-}

test/OpenIddict.Core.Tests/project.json

@@ -1,10 +1,15 @@
 {
   "buildOptions": {
-    "warningsAsErrors": true
+    "warningsAsErrors": true,
+
+    "embed": {
+      "include": [ "Certificate.pfx" ]
+    }
   },
 
   "dependencies": {
     "dotnet-test-xunit": "2.2.0-preview2-build1029",
+    "Microsoft.AspNetCore.Diagnostics": "1.0.0",
     "Microsoft.AspNetCore.TestHost": "1.0.0",
     "Microsoft.Extensions.Caching.Memory": "1.0.0",
     "Microsoft.Extensions.Logging.Debug": "1.0.0",