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Andreia's avatar
Andreia
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Jan 24, 2023

How to "Convert" NGINX to iRules?

Hi, We have an NGINX that works as a reverse proxy to do mTLS with clients and that is also validated (mTLS) by the API that receives requests from this reverse proxy. I need to create a Virtual Se...
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Andreia's avatar
Andreia
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Hi! Thanks for answering!
In fact, the mTLS part with the client I managed to do by making an iRule that validates the client's certificate data and configuring the SSL Profile Client to require the client's certificate. My problem is in these " proxy_set_header X-SSL-I-DN $ssl_client_i_dn;", for example, "add_header x-debug-client-cert-i-dn $ssl_client_i_dn always;, I have no idea how to implement this via iRule. A part that competes certificates and SSL Profile client is OK I believe.
But that "proxy_pass https://api-dev.acme.com;" what would it be? A redirect? And how do I make it so that, when BIG-IP does this redirect, the API validates the BIG-IP certificate? I thought of configuring this in the SSL Profile Server, but that would only make sense if I put the API address in a pool, which is not the case if the "proxy_pass" is indeed a redirect....so how does the API Would you validate the data from auth-test-dev.acme.com.br?
I believe it is not a complex thing, but the pressure is great to implement it. 😞

Nikoolayy1's avatar
Nikoolayy1
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Jan 25, 2023

I am in no way Nginx expert but proxy_pass is more like F5 Rewrite profile that changes the URI to the real one without redirection and the reply is changed in reverse " Local Traffic > Profiles > Services > Rewrite".

 

For the SSL you will need to extract the data and send it in HTTP header to the servers (maybe theX509::subject irule command gives the SSL distinguished name/DN you are looking for to send to the backend servers). See the links below:

https://clouddocs.f5.com/api/irules/HTTP__header.html

https://clouddocs.f5.com/api/irules/HTTP_RESPONSE.html

https://clouddocs.f5.com/api/irules/CLIENTSSL_CLIENTCERT.html

https://support.f5.com/csp/article/K41600007

 

Nice article with extra link articles about adding the SNI to a http header:

 

https://support.f5.com/csp/article/K41600007

https://support.f5.com/csp/article/K39408450

https://support.f5.com/csp/article/K14204621

 

Outside of that for F5 to be like Nginx an APM module with API protection profile is the best:

https://www.youtube.com/watch?v=-2ndGH9Dp1Q&t=308s

 

 

You will have to play arround and it will take time no matter what the IT boss that has no real tech knowedge is saying. Good luck!

 

 

    • Nikoolayy1's avatar
      Nikoolayy1
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      Jan 25, 2023

      Test it but I think Nginx by default also changes the URI before sending it to the backend servers (similar to F5 wit pool and rewrite profile or F5 APM API protection that I recommend for real API authentication and security) but I  can't be 100%.

       

      Also be carefull about F5 SNAT Automap and One connect as in Ngnix I can't renember if source ip translation is by default enabled or if multiplexing, connection pooling, connection reuse, or OneConnect is by default enabled.