ASP.NET and OWIN Cookies Azure Open ID is not working - asp.net

Question

I have try to use OpenID to connect with Azure AD, and I use the exact code from the tutorial https://learn.microsoft.com/en-us/azure/active-directory/develop/tutorial-v2-asp-webapp with no luck.
My Startup:
public class Startup
{
string clientId = System.Configuration.ConfigurationManager.AppSettings["ClientId"];
string redirectUri = System.Configuration.ConfigurationManager.AppSettings["RedirectUri"];
static string tenant = System.Configuration.ConfigurationManager.AppSettings["Tenant"];
string authority = String.Format(System.Globalization.CultureInfo.InvariantCulture,
System.Configuration.ConfigurationManager.AppSettings["Authority"], tenant);
/// <summary>
/// Configure OWIN to use OpenIdConnect
/// </summary>
/// <param name="app"></param>
public void Configuration(IAppBuilder app)
{
app.SetDefaultSignInAsAuthenticationType(CookieAuthenticationDefaults.AuthenticationType);
app.UseCookieAuthentication(new CookieAuthenticationOptions());
app.UseOpenIdConnectAuthentication(
new OpenIdConnectAuthenticationOptions
{
ClientId = clientId,
Authority = authority,
RedirectUri = redirectUri,
PostLogoutRedirectUri = redirectUri,
Scope = OpenIdConnectScope.OpenIdProfile,
ResponseType = OpenIdConnectResponseType.IdToken,
TokenValidationParameters = new TokenValidationParameters()
{
ValidateIssuer = true
},
Notifications = new OpenIdConnectAuthenticationNotifications
{
AuthenticationFailed = OnAuthenticationFailed
}
}
);
}
/// <summary>
/// Handle failed authentication requests by redirecting the user to the home page with an error in the query string
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
private Task OnAuthenticationFailed(AuthenticationFailedNotification<OpenIdConnectMessage, OpenIdConnectAuthenticationOptions> context)
{
context.HandleResponse();
context.Response.Redirect("/?errormessage=" + context.Exception.Message);
return Task.FromResult(0);
}
My Login Page Code:
protected void Page_Load(object sender, EventArgs e)
{
try
{
if (!IsPostBack)
{
if (!Request.IsAuthenticated)
{
HttpContext.Current.GetOwinContext().Authentication.Challenge(
new AuthenticationProperties { RedirectUri = "/AMS/Dashboard" },
OpenIdConnectAuthenticationDefaults.AuthenticationType);
}
else
{
var userClaims = User.Identity as System.Security.Claims.ClaimsIdentity;
lblErrorMessage.InnerHtml = userClaims?.FindFirst("preferred_username")?.Value;
//check user info, and create session then redirect to Dashboard
}
}
}
catch (Exception ex)
{
//handle error
}
}
My Website structure is a little bit complicated as follow:
I have a website on the server x: mydomain.com
and I have a subdomain in server y: subdomain.mydomain.com
and I have my website AMS on server z with a redirect to subdomain.mydomain.com/AMS
now to solve cross-site cookie I use the following in web config
<outboundRules>
<rule name="Ensure httpOnly Cookies" preCondition="Missing httpOnly cookie">
<match serverVariable="RESPONSE_Set_Cookie" pattern="^(.*; path=/)" negate="false" />
<action type="Rewrite" value="{R:1}AMS; SameSite=none; secure; HttpOnly" />
</rule>
<preConditions>
<preCondition name="Missing httpOnly cookie">
<!-- Don't remove the first line! -->
<add input="{RESPONSE_Set_Cookie}" pattern="." />
<add input="{RESPONSE_Set_Cookie}" pattern="; SameSite=none; secure; HttpOnly" negate="true" />
</preCondition>
</preConditions>
</outboundRules>
My Problem is Request.IsAuthenticated is always false, so the page keep redirect to the Microsoft login page
Any ideas?
Thanks in advance

Answer 1

Instead of the rewrite rule try this:
app.SetDefaultSignInAsAuthenticationType(CookieAuthenticationDefaults.AuthenticationType);
app.UseCookieAuthentication(new CookieAuthenticationOptions
{
CookieSameSite = Microsoft.Owin.SameSiteMode.None,
CookieSecure = CookieSecureOption.Always
});
Also ensure the secure attribute is set as well
From https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie/SameSite
SameSite NONE - Cookies will be sent in all contexts, i.e in responses to both first-party and cross-origin requests. If SameSite=None is set, the cookie Secure attribute must also be set (or the cookie will be blocked).