>
    Configure SSL Forward Proxy
    Focus
    Download PDF
    Focus
    1. Home
    2. Network Security
    4. Enable Decryption
    5. Configure SSL Forward Proxy
    Download PDF
    Network Security

    Configure SSL Forward Proxy

    Table of Contents

    Configure SSL Forward Proxy

    SSL Forward Proxy decryption enables a Next-Generation Firewall to see potential threats in outbound encrypted traffic and apply security protections against those threats.
    Where Can I Use This?What Do I Need?
    No separate license required for decryption when using NGFWs or Prisma Access.
    Note: The features and capabilities available to you in Strata Cloud Manager depend on your active license(s).
    To enable SSL Forward Proxy decryption, set up the certificates required to establish the Next-Generation Firewall (NGFW) as a trusted third party (proxy) to the session between the client and the server. You can use certificates signed by an enterprise certificate authority (CA) or self-signed certificates generated on the NGFW as Forward Trust certificates to authenticate the SSL/TLS session with the client.
    • (Best Practice) Enterprise CA-signed Certificates—An enterprise CA can issue a signing certificate that an NGFW uses to sign the certificates for sites requiring SSL/TLS decryption. When the NGFW trusts the CA that signed the certificate of the destination server, it can send a CA-signed copy of the destination server certificate to the client.
      This is a best practice because it streamlines the rollout process. Network devices typically trust the enterprise CA already (it is usually installed in the devices’ CA trust storage), so you don’t need to deploy the certificate on endpoints.
    • Self-signed Certificates—An NGFW can act as a CA and generate self-signed certificates that it uses to sign the certificates for sites requiring SSL/TLS decryption. The NGFW signs a copy of the server certificate to present to the client and establish an SSL session. This method requires installation of the self-signed certificates on all network devices, so that those devices recognize the self-signed certificates. Self-signed certificates are better for small deployments and proof of concept (PoC) trials because of the need to install certificates on all devices.
    Additionally, set up a Forward Untrust certificate for the NGFW to present to clients when the server certificate is signed by a CA that the NGFW doesn't trust. This ensures that clients receive a certificate warning when attempting to access sites with untrusted certificates.
    Generate separate subordinate Forward Trust CA certificates for each NGFW, regardless of if you use enterprise-CA signed or self-signed certificates. This practice offers several benefits:
    • Enables you to revoke one certificate when you decommission a device (or device pair) without affecting the rest of the deployment.
    • Reduces the impact in any situation requiring revocation of a certificate.
    • Improves troubleshooting because the CA error message the user sees includes information about the NGFW the traffic is traversing. If you use the same Forward Trust CA, you lose the granularity of that information.
    After setting up Forward Trust and Forward Untrust certificates, create a decryption policy rule to define the traffic you want to decrypt. Next, create a decryption profile to apply additional SSL/TLS controls and checks to the traffic defined in the decryption policy rule. Traffic that matches the rule is converted to cleartext. The NGFW blocks and restricts traffic based on the decryption profile and Security policy rules, then re-encrypts the traffic as it exits the NGFW.
    When you configure SSL Forward Proxy, the proxied traffic does not support DSCP code points or QoS.

    Configure SSL Forward Proxy (Strata Cloud Manager)

    1. Verify that the appropriate interfaces are configured as either virtual wire, Layer 2, or Layer 3 interfaces.
      To view the configured interfaces, select Manage Configuration NGFW and Prisma AccessDevice SettingsInterfaces.
    2. Configure the Forward Trust certificate that the NGFW presents to clients when a trusted CA has signed the server certificate.
      (Best Practice) 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 ManageConfiguration NGFW and Prisma Access Objects Certificate Management.
        2. Click Generate to add a custom certificate.
        3. Enter a Certificate Name. Use a unique name for each NGFW.
        4. For Signed By, select External Authority (CSR).
        5. For Certificate Use For, select Forward Trust Certificate.
        6. Specify Cryptographic Settings: Algorithm, Number of Bits, Digest, and Expiration.
        7. (Optional) If your enterprise CA requires it, add Certificate Attributes to further identify NGFW details, such as Country or Department.
        8. (Optional) Select an OCSP Responder.
        9. Save the CSR. The pending certificate displays under Custom Certificates.
      2. Export the CSR:
        1. Under Custom Certificates, select the pending certificate, and then click Export Certificate.
        2. Click Export to download and save the certificate file.
        3. Select a Format for the certificate, and Save the setting to download the certificate file.
        4. Provide the certificate file to your enterprise CA. When you receive the enterprise CA-signed certificate, save it onto your system.
      3. Import the enterprise CA-signed certificate onto Strata Cloud Manager. An Import Certificate dialog appears.
        1. Enter the pending Certificate Name exactly.
          The Certificate Name that you enter must exactly match the pending certificate name for the pending certificate to be validated.
        2. Select the signed Certificate File that you received from your enterprise CA.
        3. (Optional) Browse and select a Key File.
        4. (Optional) Enter a Passphrase, then Confirm Passphrase
        5. Click Save to import the signed certificate.
      4. Select the validated certificate and for Certificate Use For, select Forward Trust Certificate.
      5. Click Update to confirm your changes.
      Use a self-signed certificate as the Forward Trust certificate:
      1. Create a self-signed root CA certificate.
        1. Select Manage Configuration NGFW and Prisma Access Objects Custom Certificates.
        2. Generate a certificate.
        3. Enter a Certificate Name, such as GlobalProtect_CA.
        4. Generate a certificate.
        5. Enter a Common Name: the FQDN (recommended) or IP address of the interface where you will configure the service that will use this certificate.
        6. Leave Signed By blank.
        7. For Certificate Use For, select Forward Trust Certificate.
        8. Specify Cryptographic Settings: Algorithm, Number of Bits, Digest, and Expiration.
        9. Leave the OCSP Responder field blank. Revocation status verification doesn’t apply to root CA certificates.
        10. If your enterprise CA requires it, Add Certificate Attributes such as Country or Department to further identify the NGFW.
        11. Click Save to generate the certificate.
        1. Configure the certificate to be used as a trusted root CA.
          1. Click the certificate from the list of Custom Certificates (Manage ConfigurationNGFW and Prisma AccessObjectsCertificate Management). Certificate settings and details appear.
          2. For Certificate Use for, select Trusted Root CA.
          3. Save the certificate.
        1. Generate new subordinate CA certificates for each NGFW:
          1. Select Manage ConfigurationNGFW and Prisma AccessObjectsCertificate Management.
          2. Click Generate.
          3. Enter a Certificate Name
          4. Enter a Common Name. This should be the IP address or FQDN that appears in the certificate.
          5. For Signed By, select the self-signed root CA certificate that you created.
          6. For Certificate Use For, select Forward Trust Certificate.
          7. Select Certificate Authority to enable the NGFW to issue the certificate. This creates a certificate authority (CA) that is imported to client browsers, so clients trust the NGFW as a CA.
          8. Specify Cryptographic Settings: Algorithm, Number of Bits, Digest, and Expiration.
          9. Leave the OCSP Responder field blank; revocation status verification doesn’t apply to root CA certificates.
          10. If your enterprise CA requires it, Add Certificate Attributes such as Country or Department to further identify the NGFW.
          11. Save the certificate to generate.
          12. Repeat this procedure to generate a unique subordinate CA certificate on each NGFW.
    3. Distribute the Forward Trust certificate to client system certificate stores.
      Skip this step if you are using an enterprise-CA signed certificate as the Forward Trust certificate and the client systems already have the enterprise CA installed in the local trusted root CA list. (The client systems trust the subordinate CA certificates you generate on the NGFW because the enterprise trusted root CA has signed them.)
      If you do not install the Forward Trust certificate on client systems, users see certificate warnings for each SSL site they visit.
      On an NGFW 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 NetworkGlobalProtectPortals 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 self-signed trusted root CA certificate to the Trusted Root CA section. After GlobalProtect distributes the trusted root CA certificate to client systems, the client systems trust the NGFW's subordinate CA certificates because the clients trust the NGFW's root CA certificate.
      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 trusted root CA certificate so that you can import it into client systems. Highlight the certificate and click Export at the bottom of the window. Choose the PEM format.
      Don’t select Export private key. The private key should remain on the NGFW and not be exported to client systems.
      Import the trusted root CA certificate into the browser Trusted Root CA list on the client systems for the clients to trust it. When importing into the client browser, ensure that you add the certificate 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 option, such as an Active Directory Group Policy Object (GPO).
    4. Configure the Forward Untrust certificate (use the same Forward Untrust certificate for each NGFW).
      1. Select Manage Configuration NGFW and Prisma Access Objects Custom Certificates
      2. Generate a certificate.
      3. Enter a Certificate Name, such as my-ssl-fwd-untrust.
      4. Enter a Common Name, for example 192.168.2.1.
      5. Leave Signed By blank.
      6. For Certificate Use For, select Forward Untrust Certificate.
      7. Specify Cryptographic Settings: Algorithm, Number of Bits, Digest, and Expiration.
      8. (Optional) If your enterprise CA requires it, Add Certificate Attributes such as Country or Department to further identify the NGFW.
      9. (Optional) Select an OCSP Responder.
      10. Click Save.
        Don't export the Forward Untrust certificate to the certificate trust lists of your network devices. Don't install the Forward Untrust certificate on client systems. Installing the Untrust certificate in the Trust List results in devices trusting websites that the NGFW doesn't trust. In addition, users won’t see certificate warnings for untrusted sites, so they may access those sites, which could expose your network to threats.
    5. (Optional) Configure the key size for the SSL Forward Proxy server certificates that the NGFW presents to clients.
      By default, the NGFW determines the key size to use based on the key size of the destination server certificate.
    6. Create a decryption policy rule to define criteria that traffic must match for SSL Forward Proxy decryption.
      • In the Action and Advanced Inspection section, for Action, select Decrypt.
      • For decryption Type, select SSL Forward Proxy.
      • (Optional but a best practice) Configure or select a Decryption Profile to block and control various aspects of matching traffic.
        For example, create a decryption profile or select one that performs certificate checks and blocks weak cipher suites and protocols from allowing questionable traffic on your network.
      • Save the decryption policy rule.
    7. Push Config to start enforcing the rule.
    8. Choose your next step:

    Configure SSL Forward Proxy (PAN-OS)

    1. Verify that the appropriate interfaces are configured as either virtual wire, Layer 2, or Layer 3 interfaces.
      To view the configured interfaces, select NetworkInterfacesEthernet 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 that the NGFW presents to clients when a trusted CA has signed the server certificate.
      (Recommended Best Practice) 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 DeviceCertificate ManagementCertificates and click Generate.
        2. Enter a Certificate Name. Use a unique name for each NGFW.
        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 NGFW details, such as Country or Department.
        5. Click Generate to save the CSR. The pending certificate displays 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 to ensure that the private key remains securely on the NGFW.
        3. Click OK.
      3. Provide the certificate file to your enterprise CA. When you receive the enterprise CA-signed certificate, save it onto your system.
      4. Import the enterprise CA-signed certificate onto the NGFW:
        1. Select DeviceCertificate ManagementCertificates and click Import.
        2. Enter the pending Certificate Name exactly.
          The Certificate Name that you enter must exactly match the pending certificate name 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 checkboxes selected.
      5. Select the validated certificate to enable it as a Forward Trust Certificate.
      6. Click OK to save the enterprise CA-signed forward trust certificate.
      Use a self-signed certificate as the Forward Trust certificate:
      1. Create a self-signed root CA certificate.
      2. Click the self-signed root CA certificate (DeviceCertificate ManagementCertificatesDevice Certificates) to open Certificate information and then click the Trusted Root CA checkbox.
      3. Click OK.
      4. Generate new subordinate CA certificates for each NGFW:
        1. Select DeviceCertificate ManagementCertificates.
        2. Click Generate at the bottom of the window.
        3. Enter a Certificate Name.
        4. Enter a Common Name, such as 192.168.2.1. This should be the IP address or FQDN that will appear in the certificate. In this example, we are using the IP address of the trust interface. Avoid using spaces in this field.
        5. In the Signed By field, select the self-signed root CA certificate that you created.
        6. Select the Certificate Authority check box to enable the NGFW to issue the certificate. Selecting this check box creates a certificate authority (CA) on the NGFW that is imported to the client browsers, so clients trust the NGFW as a CA.
        7. Generate the certificate.
      5. Click the new certificate to modify it and click the Forward Trust Certificate checkbox to configure the certificate as the Forward Trust Certificate.
      6. Click OK to save the self-signed forward trust certificate.
      7. Repeat steps 2.d, 2.e, and 2.f for eachNGFW.
    3. Distribute the Forward Trust certificate to client system certificate stores.
      Skip this step 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 installed in the local trusted root CA list. (The client systems trust the subordinate CA certificates you generate on the NGFW because the enterprise trusted root CA has signed them.)
      If you do not install the Forward Trust certificate on client systems, users see certificate warnings for each SSL site they visit.
      On an NGFW 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 NetworkGlobalProtectPortals 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 self-signed trusted root CA certificate to the Trusted Root CA section. After GlobalProtect distributes the NGFW's trusted root CA certificate to client systems, the client systems trust the NGFW’s subordinate CA certificates because the clients trust the NGFW’s root CA certificate.
      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 NGFW trusted root CA certificate so that you can import it into client systems. Highlight the certificate and click Export at the bottom of the window. Choose the PEM format.
      Don’t select the Export private key checkbox. The private key should remain on the NGFW and not be exported to client systems.
      Import the NGFW’s trusted root CA certificate into the browser Trusted Root CA list on the client systems for the clients to trust it. When importing into the client browser, ensure that you add the certificate 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 option, such as an Active Directory Group Policy Object (GPO).
    4. Configure the Forward Untrust certificate (use the same Forward Untrust certificate for each NGFW).
      1. Click Generate at the bottom of the certificates page.
      2. Enter a Certificate Name, such as my-ssl-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 NGFW to issue the certificate.
      5. Generate the certificate.
      6. Click OK to save.
      7. Click the new certificate to modify it and enable the Forward Untrust Certificate option.
        Don’t export the Forward Untrust certificate to the certificate trust lists of your network devices. Don’t install the Forward Untrust certificate on client systems. This is critical because installing the Untrust certificate in the trust list results in devices trusting websites that the NGFW does not trust. In addition, users won’t see certificate warnings for untrusted sites, so they won’t know the sites are untrusted and may access those sites, which could expose your network to threats.
      8. Click OK to save.
    5. (Optional) Configure the key size for the SSL Forward Proxy server certificates that the NGFW presents to clients.
      By default, the NGFW determines the key size to use based on the key size of the destination server certificate.
    6. Create a decryption policy rule to define criteria that traffic must match for SSL Forward Proxy decryption.
      1. Select PoliciesDecryption, Add or modify an existing rule, and define traffic to be decrypted.
      2. Select Options and:
        • For the rule Action, select Decrypt.
        • For Type, select SSL Forward Proxy.
        • (Optional but a best practice) Configure or select an existing Decryption Profile to block and control various aspects of the decrypted traffic.
          For example, create a decryption profile or select one that performs certificate checks and blocks weak cipher suites and protocols from allowing questionable traffic on your network.
      3. Click OK to save.
    7. Commit your changes.
    8. Choose your next step:

    © 2025 Palo Alto Networks, Inc. All rights reserved.