Question

我已将WebApp和WebAPI注册到同一Azure AD。

我正在尝试从WebApp调用WebAPI。

我已经在Azure AD Applcaition中将服务WebAPI添加到了我的WebApp中。像下面-

运行WebAPI时，登录成功后将显示登录屏幕，我可以访问WebAPI方法。这是正常现象。

当我运行WebApp时，它将起到相同的登录屏幕的作用，成功登录后，我可以看到WebApp。

现在，我想从WebApp调用WebAPI方法，但是我不希望WebAPI登录屏幕，因为当我运行WebApp时，我将获得登录屏幕登录后，我希望通过使用同一用户，我应该能够访问WebAPI而无需再次执行登录操作，因为我有令牌，该令牌将对两者均适用 WebApp和WebAPI。

WebAPI代码-

Startup.Auth.cs

public partial class Startup
    {
        private static string clientId = ConfigurationManager.AppSettings["ida:ClientId"];
        private static string appKey = ConfigurationManager.AppSettings["ida:ClientSecret"];
        private static string aadInstance = EnsureTrailingSlash(ConfigurationManager.AppSettings["ida:AADInstance"]);
        private static string tenantId = ConfigurationManager.AppSettings["ida:TenantId"];
        private static string postLogoutRedirectUri = ConfigurationManager.AppSettings["ida:PostLogoutRedirectUri"];

        public static readonly string Authority = aadInstance + tenantId;

        // This is the resource ID of the AAD Graph API.  We'll need this to request a token to call the Graph API.
        string graphResourceId = "https://graph.windows.net";

        public void ConfigureAuth(IAppBuilder app)
        {
            ApplicationDbContext db = new ApplicationDbContext();

            app.SetDefaultSignInAsAuthenticationType(CookieAuthenticationDefaults.AuthenticationType);

            app.UseCookieAuthentication(new CookieAuthenticationOptions());

            app.UseOpenIdConnectAuthentication(
                new OpenIdConnectAuthenticationOptions
                {
                    ClientId = clientId,
                    Authority = Authority,
                    PostLogoutRedirectUri = postLogoutRedirectUri,

                    Notifications = new OpenIdConnectAuthenticationNotifications()
                    {
                        // If there is a code in the OpenID Connect response, redeem it for an access token and refresh token, and store those away.
                       AuthorizationCodeReceived = (context) => 
                       {
                           var code = context.Code;
                           ClientCredential credential = new ClientCredential(clientId, appKey);
                           string signedInUserID = context.AuthenticationTicket.Identity.FindFirst(ClaimTypes.NameIdentifier).Value;
                           AuthenticationContext authContext = new AuthenticationContext(Authority, new ADALTokenCache(signedInUserID));
                           AuthenticationResult result = authContext.AcquireTokenByAuthorizationCodeAsync(
                               code, new Uri(HttpContext.Current.Request.Url.GetLeftPart(UriPartial.Path)), credential, graphResourceId).Result;

                           return Task.FromResult(0);
                       }
                    }
                });
        }

        private static string EnsureTrailingSlash(string value)
        {
            if (value == null)
            {
                value = string.Empty;
            }

            if (!value.EndsWith("/", StringComparison.Ordinal))
            {
                return value + "/";
            }

            return value;
        }
    }

TestController.cs

[Authorize]
    public class TestController : ApiController
    {
        [HttpGet]
        [Route("api/getdata")]
        public IEnumerable<string> GetData()
        {
            return new string[] { "value1", "value2" };
        }
    }

WebApp代码-

Startup.Auth.cs

 public partial class Startup
    {
        private static string clientId = ConfigurationManager.AppSettings["ida:ClientId"];
        private static string appKey = ConfigurationManager.AppSettings["ida:ClientSecret"];
        private static string aadInstance = EnsureTrailingSlash(ConfigurationManager.AppSettings["ida:AADInstance"]);
        private static string tenantId = ConfigurationManager.AppSettings["ida:TenantId"];
        private static string postLogoutRedirectUri = ConfigurationManager.AppSettings["ida:PostLogoutRedirectUri"];

        public static readonly string Authority = aadInstance + tenantId;

        // This is the resource ID of the AAD Graph API.  We'll need this to request a token to call the Graph API.
        string graphResourceId = "https://graph.windows.net";

        public void ConfigureAuth(IAppBuilder app)
        {
            ApplicationDbContext db = new ApplicationDbContext();

            app.SetDefaultSignInAsAuthenticationType(CookieAuthenticationDefaults.AuthenticationType);

            app.UseCookieAuthentication(new CookieAuthenticationOptions());

            app.UseOpenIdConnectAuthentication(
                new OpenIdConnectAuthenticationOptions
                {
                    ClientId = clientId,
                    Authority = Authority,
                    PostLogoutRedirectUri = postLogoutRedirectUri,

                    Notifications = new OpenIdConnectAuthenticationNotifications()
                    {
                        // If there is a code in the OpenID Connect response, redeem it for an access token and refresh token, and store those away.
                       AuthorizationCodeReceived = (context) => 
                       {
                           var code = context.Code;
                           ClientCredential credential = new ClientCredential(clientId, appKey);
                           string signedInUserID = context.AuthenticationTicket.Identity.FindFirst(ClaimTypes.NameIdentifier).Value;
                           AuthenticationContext authContext = new AuthenticationContext(Authority, new ADALTokenCache(signedInUserID));
                           AuthenticationResult result = authContext.AcquireTokenByAuthorizationCodeAsync(
                               code, new Uri(HttpContext.Current.Request.Url.GetLeftPart(UriPartial.Path)), credential, graphResourceId).Result;

                           return Task.FromResult(0);
                       }
                    }
                });
        }

        private static string EnsureTrailingSlash(string value)
        {
            if (value == null)
            {
                value = string.Empty;
            }

            if (!value.EndsWith("/", StringComparison.Ordinal))
            {
                return value + "/";
            }

            return value;
        }
    }

HomeController.cs

[Authorize]
    public class HomeController : Controller
    {
        private static string clientIdWebApp = ConfigurationManager.AppSettings["ida:clientIdWebApp"];
        private static string clientIdWebApi = ConfigurationManager.AppSettings["ida:clientIdWebApi"];
        private static string clientSecretWebApp = ConfigurationManager.AppSettings["ida:clientSecretWebApp"];
        private static string aadInstance = (ConfigurationManager.AppSettings["ida:AADInstance"]);
        private static string tenantId = ConfigurationManager.AppSettings["ida:TenantId"];
        private static string PostLogoutRedirectUri = ConfigurationManager.AppSettings["ida:PostLogoutRedirectUri"];
        Uri redirectUri = new Uri(PostLogoutRedirectUri);
        public static readonly string Authority = aadInstance + tenantId;

        public ActionResult Index()
        {          
                return View();
        }

        public async System.Threading.Tasks.Task<ActionResult> About()
        {
            ViewBag.Message = "Your application description page.";
            try
            {
                AuthenticationResult result = null;

                string userObjectID = ClaimsPrincipal.Current.FindFirst("http://schemas.xmlsoap.org/ws/2005/05/identity/claims/nameidentifier").Value;
                AuthenticationContext authContext = new AuthenticationContext(Startup.Authority, new ADALTokenCache(userObjectID));
                ClientCredential credential = new ClientCredential(clientIdWebApp, clientSecretWebApp);
                //AcquireTokenSilentAsync should have to work as i'm accessing WebAPI using same user I logged in to WebApp 
                result = authContext.AcquireTokenSilentAsync(clientIdWebApi,credential, new UserIdentifier(userObjectID, UserIdentifierType.UniqueId)).Result;
                // gettign exception {"Failed to acquire token silently as no token was found in the cache. Call method AcquireToken"} but I got match id into cache. 
        // and if use AcquireToken instead then it works but api response is login html //page instead of api output 
                HttpClient client = new HttpClient();
                HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, "https://MYWEBAPI/api/getdata");
                request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", result.AccessToken);
                HttpResponseMessage response = await client.SendAsync(request);

                // Return the user's profile in the view.
                if (response.IsSuccessStatusCode)
                {
                    string responseString = await response.Content.ReadAsStringAsync();
                }
            }
            catch (AdalException ex)
            {
            }
            return View();
        }
    }

AdalTokenCache.cs-WebApp和WebAPI均相同

 public class ADALTokenCache : TokenCache
    {
        private ApplicationDbContext db = new ApplicationDbContext();
        private string userId;
        private UserTokenCache Cache;

        public ADALTokenCache(string signedInUserId)
        {
            // associate the cache to the current user of the web app
            userId = signedInUserId;
            this.AfterAccess = AfterAccessNotification;
            this.BeforeAccess = BeforeAccessNotification;
            this.BeforeWrite = BeforeWriteNotification;
            // look up the entry in the database
            Cache = db.UserTokenCacheList.FirstOrDefault(c => c.webUserUniqueId == userId);
            // place the entry in memory
            this.Deserialize((Cache == null) ? null : MachineKey.Unprotect(Cache.cacheBits,"ADALCache"));
        }

        // clean up the database
        public override void Clear()
        {
            base.Clear();
            var cacheEntry = db.UserTokenCacheList.FirstOrDefault(c => c.webUserUniqueId == userId);
            db.UserTokenCacheList.Remove(cacheEntry);
            db.SaveChanges();
        }

        // Notification raised before ADAL accesses the cache.
        // This is your chance to update the in-memory copy from the DB, if the in-memory version is stale
        void BeforeAccessNotification(TokenCacheNotificationArgs args)
        {
            if (Cache == null)
            {
                // first time access
                Cache = db.UserTokenCacheList.FirstOrDefault(c => c.webUserUniqueId == userId);
            }
            else
            { 
                // retrieve last write from the DB
                var status = from e in db.UserTokenCacheList
                             where (e.webUserUniqueId == userId)
                select new
                {
                    LastWrite = e.LastWrite
                };

                // if the in-memory copy is older than the persistent copy
                if (status.First().LastWrite > Cache.LastWrite)
                {
                    // read from from storage, update in-memory copy
                    Cache = db.UserTokenCacheList.FirstOrDefault(c => c.webUserUniqueId == userId);
                }
            }
            this.Deserialize((Cache == null) ? null : MachineKey.Unprotect(Cache.cacheBits, "ADALCache"));
        }

        // Notification raised after ADAL accessed the cache.
        // If the HasStateChanged flag is set, ADAL changed the content of the cache
        void AfterAccessNotification(TokenCacheNotificationArgs args)
        {
            // if state changed
            if (this.HasStateChanged)
            {
                if (Cache == null)
                {
                    Cache = new UserTokenCache
                    {
                        webUserUniqueId = userId
                    };
                }

                Cache.cacheBits = MachineKey.Protect(this.Serialize(), "ADALCache");
                Cache.LastWrite = DateTime.Now;

                // update the DB and the lastwrite 
                db.Entry(Cache).State = Cache.UserTokenCacheId == 0 ? EntityState.Added : EntityState.Modified;
                db.SaveChanges();
                this.HasStateChanged = false;
            }
        }

        void BeforeWriteNotification(TokenCacheNotificationArgs args)
        {
            // if you want to ensure that no concurrent write take place, use this notification to place a lock on the entry
        }

        public override void DeleteItem(TokenCacheItem item)
        {
            base.DeleteItem(item);
        }
    }

最重要的是，我发现webapi也具有AccountController，其下面的代码与webapp一样用于登录。在这种情况下应该怎么办？

 public class AccountController : BaseMvcController
    {
        public void SignIn()
        {
            // Send an OpenID Connect sign-in request.
            if (!Request.IsAuthenticated)
            {
                HttpContext.GetOwinContext().Authentication.Challenge(new AuthenticationProperties { RedirectUri = "/" },
                    OpenIdConnectAuthenticationDefaults.AuthenticationType);
            }
        }

        public void SignOut()
        {
            string callbackUrl = Url.Action("SignOutCallback", "Account", routeValues: null, protocol: Request.Url.Scheme);

            HttpContext.GetOwinContext().Authentication.SignOut(
                new AuthenticationProperties { RedirectUri = callbackUrl },
                OpenIdConnectAuthenticationDefaults.AuthenticationType, CookieAuthenticationDefaults.AuthenticationType);
        }

        public ActionResult SignOutCallback()
        {
            if (Request.IsAuthenticated)
            {
                // Redirect to home page if the user is authenticated.
                return RedirectToAction("Index", "Home");
            }

            return View();
        }
    }

Answer 1

AcquireTokenSilentAsync方法只有在您的应用程序至少已经为目标资源至少获取一次目标资源的有效令牌（在您的情况下为后端Web API）并且已将该令牌缓存以供后续使用时，才能为您提供帮助。 / p>

您可能会收到此错误，因为甚至一次都没有真正向Web API进行身份验证（即，为Web API获取了一个有效的令牌，并且甚至一次传递了该令牌），因此缓存中没有可用的东西。

简单地说，您将无法使用AcquireTokenSilentAsync进行首次身份验证。

为进一步理解，请查看您作为问题本身一部分共享的GitHub示例。 Secure a backend web API

该示例代码首先使用授权代码流获取Web API的有效令牌。
只有第一个有效的令牌在那里后，它才会被缓存，随后的调用可以由authContext.AcquireTokenSilentAsync处理。样本文档中也明确指出了这一点。

资源ID。您在Azure AD中注册Web API时创建的Web API的App ID URI



令牌缓存。缓存访问令牌的对象。请参阅令牌缓存。



如果AcquireTokenByAuthorizationCodeAsync成功，则ADAL缓存   令牌。以后，您可以通过调用从缓存中获取令牌   AcquireTokenSilentAsync

示例代码

要使用授权码流首次获取有效令牌

/// OpenID Connect中间件在获得授权代码时发送此事件。

public override async Task AuthorizationCodeReceived(AuthorizationCodeReceivedContext context)
{
    string authorizationCode = context.ProtocolMessage.Code;
    string authority = "https://login.microsoftonline.com/" + tenantID
    string resourceID = "https://tailspin.onmicrosoft.com/surveys.webapi" // App ID URI
    ClientCredential credential = new ClientCredential(clientId, clientSecret);

    AuthenticationContext authContext = new AuthenticationContext(authority, tokenCache);
    AuthenticationResult authResult = await authContext.AcquireTokenByAuthorizationCodeAsync(
    authorizationCode, new Uri(redirectUri), credential, resourceID);

    // If successful, the token is in authResult.AccessToken
}

稍后，您可以通过调用AcquireTokenSilentAsync从缓存中获取令牌：

AuthenticationContext authContext = new AuthenticationContext(authority, tokenCache);
var result = await authContext.AcquireTokenSilentAsync(resourceID, credential, new UserIdentifier(userId, UserIdentifierType.UniqueId));

使用Azure AD登录后无法使用WebApp静默获取令牌吗？

1 个答案: