OWIN OpenIdConnect Middleware IDX10311 nonce cannot be validated

Question

I have an application using the OWIN middleware for OpenIdConnect. The startup.cs file uses the standard implementation of app.UseOpenIdConnectAuthentication. The cookie is set to the browser, but it errors with:

IDX10311: RequireNonce is 'true' (default) but validationContext.Nonce is null. A nonce cannot be validated. If you don't need to check the nonce, set OpenIdConnectProtocolValidator.RequireNonce to 'false'.

I've found that when running fiddler as I do for most debug projects this behavior happens. The error is returned, but if I go back to the site everything is working and my user is authenticated. Has anyone seen this behavior when running fiddler?

With fiddler:

• SecurityTokenValidated notification in OpenIdConnect is executed twice.
• After the second pass through the IDX10311 error is thrown
• Browser contains the valid cookie, going back to the page I can view the valid User.Identity data.

Running without fiddler:

• SecurityTokenValidated executes once in OpenIdConnect
• No error thrown, proceeds to load up controller action for post authentication redirect Uri
• Cookie also valid and User.Identity data correct.

Ideas? I can get around it without running fiddler, but when debugging it would be nice to also run fiddler to inspect traffic.

Answer 1

Maybe is this the cause?

Hello there, I think I found the root cause of this issue.

I'm summing up my discoveries:

1. The problem is in the OpenIdConnect.nonce.OpenIdConnect cookie

2. This cookie is set from the app (let's call this "ID Client") as soon as the OpenID Middleware init an authentication session

3. The cookie should be sent back from the browser to the "ID Client" as soon as the authentication has been completed. My assumption is that this cookie is needed to have a double check from the ID client point of view (i.e. did I really started an OpenID Connect authorization flow?)

4. A lot of confusion in me was caused by the "Nonce" term, used both in this cookie and in the OpenID Connect flow from the ID server.

5. The exception, in my case, was caused by the missing cookie (not the nonce of the ID Server), simply because it wasn't sent by the browser back to the "ID client"

So the main root, in my case, was this: OpenIdConnect.nonce.OpenIdConnect cookie was not sent back to the ID Client by the browser. In some cases (i.e. Chrome, Firefox and Edge) cookie was sent correctly, while in others (IE11, Safari) it wasn't.

After a lot of research, I discovered that the problem was on the Cookie restriction policy, defined on the browser. In my case, the "ID client" is embedded in an <iframe>. This cause the "ID Client" to be seen as a "third-party client", because the user didn't navigate to that URL directly in the main window. Because this is a third-party, for some browsers, it's cookies have to be blocked. Indeed the same effect may be obtained on Chrome, by setting "Block third-party cookies".

So, I have to conclude that:

a) If iframe is a must (as in my case, because "ID Clients" are apps that must run inside the graphic content of the our main platform app), I think the only solution is to intercept the error, and handle it with a page, asking the user to enable third party cookies.

b) If iframe is not a must, it should suffice opening the "ID Client" in a new window.

Hope this helps somebody, because I got crazy!

Marco

Answer 2

I had the same problem but switching back the Microsoft.Owin.Security.OpenIdConnect to version 3.0.1 solved the issue

Answer 3

For anyone else who gets here in 2021, you'll likely get this issue if:

• You're redirecting http -> https
• Or you've changed your app's host domain.

Both of these aren't an issue with the middleware or your app, but it's about the combination of two issues:

• The fact that your app is still hosted on the old old domain or protocol. You want to prevent browsers hitting that by implementing a redirect on the web server.
• The redirect URI (sometimes know as reply URL) in Azure or whichever OpenIdConnect authorization server you're authenticating with. You want to get this updated to the new protocol or domain.

Our example: We had https://old.example.com/app/ that was now also hosted at https://new.example.com/app/. We wanted users' previous bookmarks to still work.

Our solution:

1. We updated the redirect URI (reply url) to point to the new domain for the app (https://new.example.com/app/signin-endpoint). Ideally, make sure there is only one URI listed for your app and that it's https.
2. We added the new domain binding to the site in IIS (we're old school, but do the same for your hosting of choice 😊)
3. We added an IIS redirect to the new domain (new.example.com) so that users' bookmarks still work. Again if you're not on IIS, implement a permanent redirect in the web server of your choice.

Until we had the final step above, we were seeing the error in the OP's post. It's the same process if you're forcing http -> https.

Here is the IIS re-write for those who are also "old school":

<rewrite>
  <rules>
    <rule name="Redirect old.example.com to new.example.com" enabled="true" patternSyntax="Wildcard" stopProcessing="true">
      <match url="*" />
      <conditions>
        <add input="{HTTP_HOST}" pattern="old.example.com" />
      </conditions>
      <action type="Redirect" url="https://new.example.com{REQUEST_URI}" />
    </rule>
  </rules>
</rewrite>

It goes in the <system.webServer> section of your web.config file. Enjoy!

Answer 4

For me changing reply url in Azure active directory works.

This happens when you enable SSL because it changes only the sign on URL to the HTTPS URL while the reply URL remains the same HTTP URL.

When you try to access your app using the https URL, it sets a cookie with a unique number(nonce) in your browser and hits Azure AD for authentication. After authentication, the browser has to give access to that cookie. But since the sign on URL and reply URL are different the browser does not recognize your app and does not give access to that cookie and hence the application throws this error.