Forum Discussion
Johan_Lång
Cirrus
CirrusCors preflight requests problem
I have two different web applications that make requests to domain names other than themselves. For example, x.domain.com makes a request to y.domain.com to retrieve certain data. The user is authenticated through APM, and we are using a multidomain sso.
The problem is that when the request is sent, BIG-IP will make an redirect to /my.policy and finally to /my.logout.php3?errorcode=19.
I've tried the workaround with this irule: https://devcentral.f5.com/s/articles/cors-implementation but it does not solve the issue.
The APM still not allow the request to reach its destination.
My only workaround is to let these requests go to a "public VIP", only with ASM as protection, but I want it to go through APM and the same VIP as the original site that is already authenticated.
Thanks!
Johan
AlexBCTCumulonimbus
Hi Johan,
Do I understand it correctly that the backend server of the first web application (the server hosting x.domain.com) needs to reach y.domain.com in order to gather some information it needs to complete a request for the client?
If so, do you need that backend server to log in to the APM policy, or do you just need it to be able to reach the backend system? If you just need the backend system to gain access to the application, you could put in an agent in the APM policy BEFORE it gets to the login page? This agent can then check if the request is coming from a specific IP, or some other way in which you can identify that it is this server. If so, you can then bypass the login page and go straight through to the "Allow".
Of course, do ensure there is no other way anyone could exploit that ;)
Hope this helps.
Johan_LångHmm, not quite, I think.
Isnt it the client who makes the acctual call to the backend server, y.domain.com?
x.domain.com responds with a 302 to the client with a new location header and the client trying to make a new request to the new location?
In your scenario, x.domain.com makes the acctual request to y.domain.com in the back, right?
But if there is way to accomplish that instead, im in! :) but im not sure how to do that really..
Best regards,
Johan
- AlexBCT
Ahyes, that's another way indeed - there are many ways in which you can get multiple components from different sources.
In that case, I think this is what you are looking for: https://techdocs.f5.com/en-us/bigip-14-0-0/big-ip-access-policy-manager-authentication-and-single-sign-on-14-0-0/single-sign-on-and-multi-domain-support.html You can configure the APM policy to be working for multiple domains, but only have a single login. Check under the heading "Configuring an access policy for SSO multi-domain support" for the exact instructions.
Basically you tell the policy to look out for requests for any of the following domains. In your case you configure the multi-domains as x.example.com and y.example.com, with probably x.example.com as your main authentication URL. You then attach the same APM policy to both virtual servers (x. and y.) and let the user go to either one. If the user is not logged in yet and goes to y., they will be redirected to the primary authentication URL (x. in the above example) for login, and then get redirected back to y. for the content. If the user first goes to x., they will log in first, then get redirected by the backend to y., which will check over the session details and allows it through without showing the login page again.
Hope this makes sense (..and works! ;)
- Johan_Lång
I can see now that my original question can be interpreted exactly as you did.
samstepCirrocumulus
if you are using ASM it might be the culprit, check this:
Bug ID 746394: With ASM CORS set to 'Disabled' it strips all CORS headers in response.
https://cdn.f5.com/product/bugtracker/ID746394.html
Also if y.domain.com where your request is landing has an ASM policy in blocking mode please do check that OPTIONS method is not blocked in ASM policy (it is blocked by default)
- Johan_Lång
Thanks for your reply, unfortunately we´re not using ASM together with APM.
/Johan