C# 使用owin中间件和IdentityServer v3刷新令牌

我最近安装了IdentityServer v3，它的运行就像做梦一样，但是我在OWIN中间件方面遇到了问题

我想使用混合流，这样我就可以在后端刷新令牌，而无需用户每5分钟重定向回IdentityServer以获取一个新的访问令牌（这也很奇怪，因为它在服务器上的生命周期设置为1小时）

我在startup中使用了下面的配置，我可以很好地获得令牌，但它似乎从来没有尝试在访问令牌过期后刷新它。我是否需要一些自定义逻辑来刷新我的令牌

        app.UseOpenIdConnectAuthentication(new OpenIdConnectAuthenticationOptions
        {
            ClientId = clientId,
            ClientSecret = clientSecret, //Not sure what this does?

            Authority = "https://auth.example.com",

            RedirectUri = "http://website.example.com",
            PostLogoutRedirectUri = "http://website.example.com",

            ResponseType = "code id_token token",
            Scope = "openid profile email write read offline_access",

            SignInAsAuthenticationType = "Cookies",

            Notifications = new OpenIdConnectAuthenticationNotifications
            {
                AuthorizationCodeReceived = async n =>
                {
                    // filter "protocol" claims
                    var claims = new List<Claim>(from c in n.AuthenticationTicket.Identity.Claims
                                                 where c.Type != "iss" &&
                                                       c.Type != "aud" &&
                                                       c.Type != "nbf" &&
                                                       c.Type != "exp" &&
                                                       c.Type != "iat" &&
                                                       c.Type != "nonce" &&
                                                       c.Type != "c_hash" &&
                                                       c.Type != "at_hash"
                                                 select c);

                    // get userinfo data
                    var userInfoClient = new UserInfoClient(
                        new Uri(n.Options.Authority + "/connect/userinfo"),
                        n.ProtocolMessage.AccessToken);

                    var userInfo = await userInfoClient.GetAsync();
                    userInfo.Claims.ToList().ForEach(ui => claims.Add(new Claim(ui.Item1, ui.Item2)));

                    // get access and refresh token
                    var tokenClient = new OAuth2Client(
                        new Uri(n.Options.Authority + "/connect/token"),
                        clientId,
                        clientSecret);

                    var response = await tokenClient.RequestAuthorizationCodeAsync(n.Code, n.RedirectUri);

                    claims.Add(new Claim("access_token", response.AccessToken));
                    claims.Add(new Claim("expires_at", DateTime.UtcNow.AddSeconds(response.ExpiresIn).ToLocalTime().ToString(CultureInfo.InvariantCulture)));
                    claims.Add(new Claim("refresh_token", response.RefreshToken));
                    claims.Add(new Claim("id_token", n.ProtocolMessage.IdToken));

                    //Does this help?
                    n.AuthenticationTicket.Properties.AllowRefresh = true;

                    n.AuthenticationTicket = new AuthenticationTicket(
                        new ClaimsIdentity(
                            claims.Distinct(new ClaimComparer()),
                            n.AuthenticationTicket.Identity.AuthenticationType),
                        n.AuthenticationTicket.Properties);
                },

                RedirectToIdentityProvider = async n =>
                {
                    // if signing out, add the id_token_hint
                    if (n.ProtocolMessage.RequestType == OpenIdConnectRequestType.LogoutRequest)
                    {
                        var id = n.OwinContext.Authentication.User.FindFirst("id_token");

                        if (id != null)
                        {
                            var idTokenHint = id.Value;
                            n.ProtocolMessage.IdTokenHint = idTokenHint;
                        }
                    }
                }
            }
        });

---

我能够获取刷新令牌，然后使用它获取新的访问令牌： 我按照和你一样的逻辑得到了一个代币。 我创建了以下方法，每次需要令牌时都会调用该方法：

private static async Task CheckAndPossiblyRefreshToken(ClaimsIdentity id)
    {
        var clientName = "Myhybridclient";
        // check if the access token hasn't expired.
        if (DateTime.Now.ToLocalTime() >=
             (DateTime.Parse(id.FindFirst("expires_at").Value)))
        {
            // expired.  Get a new one.
            var tokenEndpointClient = new OAuth2Client(
                new Uri(Constants.TokenEndpoint),
                clientName,
                "secret");

            var tokenEndpointResponse =
                await tokenEndpointClient
                .RequestRefreshTokenAsync(id.FindFirst("refresh_token").Value);

            if (!tokenEndpointResponse.IsError)
            {
                // replace the claims with the new values - this means creating a 
                // new identity!                              
                var result = from claim in id.Claims
                             where claim.Type != "access_token" && claim.Type != "refresh_token" &&
                                   claim.Type != "expires_at"
                             select claim;

                var claims = result.ToList();

                claims.Add(new Claim("access_token", tokenEndpointResponse.AccessToken));
                claims.Add(new Claim("expires_at",
                             DateTime.Now.AddSeconds(tokenEndpointResponse.ExpiresIn)
                             .ToLocalTime().ToString()));
                claims.Add(new Claim("refresh_token", tokenEndpointResponse.RefreshToken));

                var newIdentity = new ClaimsIdentity(claims, "Cookies");
                var wrapper = new HttpRequestWrapper(HttpContext.Current.Request);
                wrapper.GetOwinContext().Authentication.SignIn(newIdentity);
            }
            else
            {
                // log, ...
                throw new Exception("An error has occurred");
            }
        }
    } 

---

在我看来，等待本地时间大于或等于访问令牌到期时间不是最好的主意。设想一种情况，当这种情况将考虑Access在到期前只有几毫秒的有效性。如果您将此类AccessToken发送到其他服务，那么它可能会被拒绝，因为它在此期间已过期。当您添加声明“expires\u at”时，您还可以添加类似“refresh\u at”的声明，作为从现在到“expires\u at”值之间的一半时间间隔。这样的解决方案可以确保访问令牌不会在您能够使用它之前过期。我通常允许通过配置，用1分钟来检查令牌是否过期：例如，如果令牌在1分钟内过期，我将继续刷新它。

private static async Task CheckAndPossiblyRefreshToken(ClaimsIdentity id)
    {
        var clientName = "Myhybridclient";
        // check if the access token hasn't expired.
        if (DateTime.Now.ToLocalTime() >=
             (DateTime.Parse(id.FindFirst("expires_at").Value)))
        {
            // expired.  Get a new one.
            var tokenEndpointClient = new OAuth2Client(
                new Uri(Constants.TokenEndpoint),
                clientName,
                "secret");

            var tokenEndpointResponse =
                await tokenEndpointClient
                .RequestRefreshTokenAsync(id.FindFirst("refresh_token").Value);

            if (!tokenEndpointResponse.IsError)
            {
                // replace the claims with the new values - this means creating a 
                // new identity!                              
                var result = from claim in id.Claims
                             where claim.Type != "access_token" && claim.Type != "refresh_token" &&
                                   claim.Type != "expires_at"
                             select claim;

                var claims = result.ToList();

                claims.Add(new Claim("access_token", tokenEndpointResponse.AccessToken));
                claims.Add(new Claim("expires_at",
                             DateTime.Now.AddSeconds(tokenEndpointResponse.ExpiresIn)
                             .ToLocalTime().ToString()));
                claims.Add(new Claim("refresh_token", tokenEndpointResponse.RefreshToken));

                var newIdentity = new ClaimsIdentity(claims, "Cookies");
                var wrapper = new HttpRequestWrapper(HttpContext.Current.Request);
                wrapper.GetOwinContext().Authentication.SignIn(newIdentity);
            }
            else
            {
                // log, ...
                throw new Exception("An error has occurred");
            }
        }
    }