End-of-Life (EoL)

Configure SSL Forward Proxy

To enable the firewall to perform SSL Forward Proxy decryption, you must set up the certificates required to establish the firewall as a trusted third party to the session between the client and the server. The firewall can use self-signed certificates or certificates signed by an enterprise certificate authority (CA) as
forward trust certificates
to authenticate the SSL session with the client.
  • (Recommended)
    Enterprise CA-signed Certificates
    An enterprise CA can issue a signing certificate which the firewall can use to sign the certificates for sites requiring SSL decryption. When the firewall trusts the CA that signed the certificate of the destination server, the firewall can then send a copy of the destination server certificate to the client signed by the enterprise CA.
  • Self-signed Certificates
    When a client connects to a server with a certificate that is signed by a CA that the firewall trusts, the firewall can sign a copy of the server certificate to present to the client and establish the SSL session. You can use self-signed certificates for SSL Forward Proxy decryption if your organization does not have an enterprise CA or if you intend to only perform decryption for a limited number of clients.
Additionally, set up a
forward untrust
certificate
for the firewall to present to clients when the server certificate is signed by a CA that the firewall does not trust. This ensures that clients are prompted with a certificate warning when attempting to access sites with untrusted certificates.
After setting up the forward trust and forward untrust certificates required for SSL Forward Proxy decryption, add a decryption policy rule to define the traffic you want the firewall to decrypt. SSL tunneled traffic matched to the decryption policy rule is decrypted to clear text traffic. The clear text traffic is blocked and restricted based on the decryption profile attached to the policy and the firewall security policy. Traffic is re-encrypted as it exits the firewall.
  1. Ensure that the appropriate interfaces are configured as either virtual wire, Layer 2, or Layer 3 interfaces.
    View configured interfaces on the
    Network
    Interfaces
    Ethernet
    tab. The
    Interface Type
    column displays if an interface is configured to be a
    Virtual Wire
    or
    Layer 2
    , or
    Layer 3
    interface. You can select an interface to modify its configuration, including what type of interface it is.
  2. Configure the forward trust certificate for the firewall to present to clients when the server certificate is signed by a trusted CA:
    (Recommended)
    Use an enterprise CA-signed certificate as the forward trust certificate.
    1. Generate a Certificate Signing Request (CSR) for the enterprise CA to sign and validate:
      1. Select
        Device
        Certificate Management
        Certificates
        and click
        Generate
        .
      2. Enter a
        Certificate Name
        , such as my-fwd-proxy.
      3. In the
        Signed By
        drop-down, select
        External Authority (CSR)
        .
      4. (Optional)
        If your enterprise CA requires it, add
        Certificate Attributes
        to further identify the firewall details, such as Country or Department.
      5. Click
        OK
        to save the CSR. The pending certificate is now displayed on the
        Device Certificates
        tab.
    2. Export the CSR:
      1. Select the pending certificate displayed on the
        Device Certificates
        tab.
      2. Click
        Export
        to download and save the certificate file.
        Leave
        Export private key
        unselected in order to ensure that the private key remains securely on the firewall.
      3. Click
        OK
        .
    3. Provide the certificate file to your enterprise CA. When you receive the enterprise CA-signed certificate from your enterprise CA, save the enterprise CA-signed certificate for import onto the firewall.
    4. Import the enterprise CA-signed certificate onto the firewall:
      1. Select
        Device
        Certificate Management
        Certificates
        and click
        Import
        .
      2. Enter the pending
        Certificate Name
        exactly (in this case, my-fwd-trust). The
        Certificate Name
        that you enter must exactly match the pending certificate name in order for the pending certificate to be validated.
      3. Select the signed
        Certificate File
        that you received from your enterprise CA.
      4. Click
        OK
        . The certificate is displayed as valid with the Key and CA check boxes selected.
    5. Select the validated certificate, in this case, my-fwd-proxy, to enable it as a
      Forward Trust Certificate
      to be used for SSL Forward Proxy decryption.
    6. Click
      OK
      to save the enterprise CA-signed forward trust certificate.
    Use a self-signed certificate as the forward trust certificate.
    1. Generate a new certificate:
      1. Select
        Device
        Certificate Management
        Certificates
        .
      2. Click
        Generate
        at the bottom of the window.
      3. Enter a
        Certificate Name
        , such as
        my-fwd-trust
        .
      4. Enter a
        Common Name
        , such as 192.168.2.1. This should be the IP or FQDN that will appear in the certificate. In this case, we are using the IP of the trust interface. Avoid using spaces in this field.
      5. Leave the
        Signed By
        field blank.
      6. Click the
        Certificate Authority
        check box to enable the firewall to issue the certificate. Selecting this check box creates a certificate authority (CA) on the firewall that is imported to the client browsers, so clients trust the firewall as a CA.
      7. Generate
        the certificate.
    2. Click the new certificate
      my-fwd-trust
      to modify it and enable the certificate to be a
      Forward Trust Certificate
      .
    3. Click
      OK
      to save the self-signed forward trust certificate.
  3. Distribute the forward trust certificate to client system certificate stores.
    If you do not install the forward trust certificate on client systems, users will see certificate warnings for each SSL site they visit.
    If you are using an enterprise-CA signed certificate as the forward trust certificate for SSL Forward Proxy decryption, and the client systems already have the enterprise CA added to the local trusted root CA list, you can skip this step.
    On a firewall configured as a GlobalProtect portal:
    This option is supported with Windows and Mac client OS versions, and requires GlobalProtect agent 3.0.0 or later to be installed on the client systems.
    1. Select
      Network
      GlobalProtect
      Portals
      and then select an existing portal configuration or
      Add
      a new one.
    2. Select
      Agent
      and then select an existing agent configuration or
      Add
      a new one.
    3. Add
      the SSL Forward Proxy forward trust certificate to the Trusted Root CA section.
    4. Install in Local Root Certificate Store
      so that the GlobalProtect portal automatically distributes the certificate and installs it in the certificate store on GlobalProtect client systems.
    5. Click
      OK
      twice.
    Without GlobalProtect:
    Export the forward trust certificate for import into client systems by highlighting the certificate and clicking
    Export
    at the bottom of the window. Choose PEM format, and do not select the
    Export private key
    option. import it into the browser trusted root CA list on the client systems in order for the clients to trust it. When importing to the client browser, ensure the certificate is added to the Trusted Root Certification Authorities certificate store. On Windows systems, the default import location is the Personal certificate store. You can also simplify this process by using a centralized deployment, such as an Active Directory Group Policy Object (GPO).
  4. Configure the forward untrust certificate.
    1. Click
      Generate
      at the bottom of the certificates page.
    2. Enter a
      Certificate Name
      , such as my-fwd-untrust.
    3. Set the
      Common Name
      , for example 192.168.2.1. Leave
      Signed By
      blank.
    4. Click the
      Certificate Authority
      check box to enable the firewall to issue the certificate.
    5. Click
      Generate
      to generate the certificate.
    6. Click
      OK
      to save.
    7. Click the new my-ssl-fw-untrust certificate to modify it and enable the
      Forward Untrust Certificate
      option.
      Do not export the forward untrust certificate for import into client systems. If the forward untrust certificate is imported on client systems, the users will not see certificate warnings for SSL sites with untrusted certificates.
    8. Click
      OK
      to save.
  5. (Optional)
    Set the key size of the SSL Forward Proxy certificates that the firewall presents to clients. By default, the firewall determines the key size to use based on the key size of the destination server certificate.
  6. Create a Decryption Policy Rule to define traffic for the firewall to decrypt.
    1. Select
      Policies
      Decryption
      , Add or modify an existing rule, and define traffic to be decrypted.
    2. Select
      Options
      and:
      • Set the rule
        Action
        to
        Decrypt
        matching traffic.
      • Set the rule
        Type
        to
        SSL Forward Proxy
        .
      • (Optional)
        Select a
        Decryption Profile
        to block and control various aspects of the decrypted traffic (for example, Create a Decryption Profile to perform certificate checks and enforce strong cipher suites and protocol versions).
    3. Click
      OK
      to save.
  7. This option requires an active WildFire license and is a WildFire best practice.
  8. Commit
    the configuration.
  9. Choose your next step...

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