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Mike12345's avatar
Mike12345
Icon for Nimbostratus rankNimbostratus
Jul 28, 2024

F5 LTM SSL Bridging - send decrypted traffic to clone pool

Hi, I'm trying to lab a scenario I was asked about at work. Whether it is possible to send decrypted TLS/SSL traffic to an IDS through the clone pool. I have seen an overview stating this is possibl...
security
  • Kevin_Stewart's avatar
    Kevin_Stewart
    Jul 31, 2024

    Very simply, in the proxy "HUD" chain, a clone pool sits at layer 2, whereas TLS decryption happens at layer 6. In other words, you're seeing encrypted traffic at the clone pool because decryption hasn't happened yet.

    To get decrypted traffic to a clone pool you have to get past layer 6. If you're not re-encrypting to the server, you can put the clone on the server side of the proxy. If you are re-encrypting to the backend, then you'd need a VIP-target solution:

    client-side VIP --> (vip target) --> server-side VIP

    The client-side VIP has a client SSL profile and an iRule that VIP targets to the server-side VIP that has the server SSL profile. You can then put your clone pool on the server side (inside) of the client-side VIP, or client side (inside) of the server-side VIP.

     

Kevin_Stewart's avatar
Kevin_Stewart
Icon for Employee rankEmployee
Jul 31, 2024

Very simply, in the proxy "HUD" chain, a clone pool sits at layer 2, whereas TLS decryption happens at layer 6. In other words, you're seeing encrypted traffic at the clone pool because decryption hasn't happened yet.

To get decrypted traffic to a clone pool you have to get past layer 6. If you're not re-encrypting to the server, you can put the clone on the server side of the proxy. If you are re-encrypting to the backend, then you'd need a VIP-target solution:

client-side VIP --> (vip target) --> server-side VIP

The client-side VIP has a client SSL profile and an iRule that VIP targets to the server-side VIP that has the server SSL profile. You can then put your clone pool on the server side (inside) of the client-side VIP, or client side (inside) of the server-side VIP.

 

  • Mike12345's avatar
    Mike12345
    Icon for Nimbostratus rankNimbostratus
    Jul 31, 2024

    So essentially the cloe ports pick up the traffic too early i the service process. eg prior to using i-rules for traffic manipulation.

    To use clone pools to view plain HTTP traffic two sets of services are needed
    two services "SSLO Offload" (decrypt) and "SSL Onload" (encrypt) and place the clone pool on the server side of the first service.



    • Kevin_Stewart's avatar
      Kevin_Stewart
      Icon for Employee rankEmployee
      Jul 31, 2024

      Yes, or client side of second VIP.

      I'd also comment that SSL Orchestrator will also do this for you automatically, and also enable a policy to dynamically control decryption and traffic steering.

      • Mike12345's avatar
        Mike12345
        Icon for Nimbostratus rankNimbostratus
        Aug 02, 2024

        Thanks for your steer in the right direction.

        I got this working in the lab using the VIP target solution. We have a POC, so hopefully will be in touch.

         

  • Mike12345's avatar
    Mike12345
    Icon for Nimbostratus rankNimbostratus
    Aug 02, 2024

    A short course on i-rules and I managed to get something working as a POC.
    Thanks for the pointers.

    I totally agree this is much easier if you have SSLO running on the appliance