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Sebas_82058's avatar
Sebas_82058
Icon for Nimbostratus rankNimbostratus
Jun 18, 2014

Two-way SSL authentication with self-signed client certificate

Hi, we're trying to implement a two-way SSL authentication against one of our virtual servers.

 

We have a certificate for our virtual server, which is signed by a CA and is working just as expected.

 

However, we don't want to let anyone connect to this virtual server unless we are presented with a client side SSL certificate.

 

The challenge we're facing is that, this client side certificate is self-signed. So, when the client connects, the F5 cannot validate the certificate and our connection cannot be established.

 

Just to get some things out of the way:

 

  • We only have the certificate and we cannot get the key for the client side certificate.
  • We cannot upload or CA certificate or key to the other side where the connections are coming from.

I would like to know:

 

  • Is there any way to tell the F5 to trust this certificate? If so, how?
  • I read, somewhere, that we can just set the mode to request and then add an iRule to validate the certificate. Is that possible?

I would appreciate any help on this matter.

 

Thanks

 

application delivery
LTM
security

8 Replies

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  • Cory_50405's avatar
    Cory_50405
    Icon for Noctilucent rankNoctilucent
    Jun 18, 2014

    Is the certificate needed on the backend server for authentication? If so, then you could enable proxy SSL within the client and server SSL profiles assigned to your virtual server. This will enable the client certificate to be passed along to the web server. Since you mention this is two-way SSL, I suspect the server is still doing the authentication piece.

     

    http://support.f5.com/kb/en-us/solutions/public/13000/300/sol13385.html

     

  • Sebas_82058's avatar
    Sebas_82058
    Icon for Nimbostratus rankNimbostratus
    Jun 18, 2014

    No, the backend doesn't even need to know about this. We just need the load balancer to validate connections are coming only from the sources we trust.

     

    It's similar to this, however, the CA piece is the one I am having problems with:

     

    https://devcentral.f5.com/questions/2-way-ssl-implementation-25325

     

  • Sebas_82058's avatar
    Sebas_82058
    Icon for Nimbostratus rankNimbostratus
    Jun 19, 2014

    I finally implemented this via an iRule that will do the work. Not the most beautiful solution, but it serves the purpose given the limitations on the client side.

     

  • Neeraj_Jags_152's avatar
    Neeraj_Jags_152
    Icon for Cirrus rankCirrus
    Nov 05, 2014

    I configured as per two way auth in F5 LB LTM ver 11.x as per below: - Client side SSL configured Server side SSL configured with key & cert and same key and cert are exist on pool member server.

     

    Only server side SSL auth is working but Client auth is not working:- take this way. Client shared a open.ssl self signed certificate let say client_cert.cer I have imported client_cert.cer in F5. then When I configuring the SSL Client Profile, I selected the client_cert.cer in drop down box of Trusted Certificate Authorities :-- .. is this configuration TRUE, or will I need the different CA certificate from client

     

    • nitass's avatar
      nitass
      Icon for Employee rankEmployee
      Nov 05, 2014
      >I read, somewhere, that we can just set the mode to request and then add an iRule to validate the certificate. Is that possible? yes, i think so. for trusted certificate authorities setting, you can leave it none. Client Certificate CN Checking (The second example)   https://clouddocs.f5.com/api/irules/ClientCertificateCNChecking.html >When I configuring the SSL Client Profile, I selected the client_cert.cer in drop down box of Trusted Certificate Authorities :-- .. is this configuration TRUE i think it could work too but i think the codeshare is more flexible. hope this helps.
  • Neeraj_Jags_152's avatar
    Neeraj_Jags_152
    Icon for Cirrus rankCirrus
    Nov 09, 2014

    Hi Nitass, Thanks for the same.

     

    Let me explain you again. generally certificate is signed by CA like Verisign, etc. in that case do we require CA (Verisign ) certificate to install in F5-LB or we only require certificate which is signed by Verisign. because Client-SSL-Profiles required a field like "Trusted Certificate Authorities" which means it should be Verisign certificate ?