HTTPS Inspection

HTTPS Internet traffic uses the TLS (Transport Layer Security) protocol and is encrypted to give data privacy and integrity. However, HTTPS traffic has a possible security risk and can hide illegal user activity and malicious traffic. Security Gateways cannot inspect HTTPS traffic because it is encrypted. You can enable the HTTPS InspectionClosed Feature on a Security Gateway that inspects traffic encrypted by the Secure Sockets Layer (SSL) protocol for malware or suspicious patterns. Synonym: SSL Inspection. Acronyms: HTTPSI, HTTPSi. feature to let the Security Gateways create new TLS connections with the external site or server. The Security Gateways are then able to decrypt and inspect HTTPS traffic that uses the new TLS connections.

There are two types of HTTPS Inspection:

  • Outbound HTTPS Inspection - To protect against malicious traffic that is sent from an internal client to an external site or server.

  • Inbound HTTPS Inspection - To protect internal servers from malicious requests that arrive from the Internet or an external network.

The Security GatewayClosed Dedicated Check Point server that runs Check Point software to inspect traffic and enforce Security Policies for connected network resources. uses certificates and becomes an intermediary between the client computer and the secure web site. All data is kept private in HTTPS Inspection logs. Only administrators with HTTPS Inspection permissions can see all the fields in such a log.

Inspecting HTTPS Packets

Outbound Connections

Outbound connections are HTTPS connections that arrive from an internal client and connect to the Internet. The Security Gateway compares the HTTPS request to the rules in the HTTPS Inspection Rule BaseClosed All rules configured in a given Security Policy. Synonym: Rulebase.. If the request does not match any ruleClosed Set of traffic parameters and other conditions in a Rule Base (Security Policy) that cause specified actions to be taken for a communication session., the packet is not HTTPS inspected and not logged.

If the request matches an HTTPS Inspection rule, the Security Gateway validates the certificate from the server (on the Internet). The Security Gateway validates the certificate using the Online Certificate Status Protocol (OCSP) standard. OCSP is faster and uses much less memory than CRL Validation, which is used for certificate validation in releases lower than R80.10. For a new HTTPS connection to the server, the Security Gateway creates and uses a new certificate. There are two HTTPS connections, one to the internal client and one to the external server. It can then decrypt and inspect the packets according to the Security PolicyClosed Collection of rules that control network traffic and enforce organization guidelines for data protection and access to resources with packet inspection.. The packets are encrypted again and sent to the destination.

Inbound Connections

Inbound connections are HTTPS connections that arrive from an external client and connect to a server in the DMZ or the internal network. The Security Gateway compares the HTTPS request to the rules in the HTTPS Inspection Rule Base. If the request does not match any rule, the packet is not HTTPS inspected and not logged.

If the request matches an HTTPS Inspection rule, the Security Gateway uses the certificate for the internal server to create an HTTPS connection with the external client. The Security Gateway creates a new HTTPS connection with the internal server. Since the Security Gateway has a secure connection with the external client, it can decrypt the HTTPS traffic. The decrypted traffic is inspected according to the Security Policy.

Configuring Security Gateways to inspect outbound and inbound HTTPS traffic

This section gives an example of how to configure a Security Gateway to inspect outbound and inbound HTTPS traffic.

Enabling HTTPS Inspection

You must enable HTTPS Inspection on each Security Gateway.

The first time you enable HTTPS Inspection on one of the Security Gateways, you must create an outbound CA certificate for HTTPS Inspection or import a CA certificate already deployed in your organization. This outbound certificate is used by all Security Gateways managed on the Security Management ServerClosed Dedicated Check Point server that runs Check Point software to manage the objects and policies in a Check Point environment within a single management Domain. Synonym: Single-Domain Security Management Server..

Creating an Outbound CA Certificate

The outbound CA certificate is saved with a CER file extension and uses a password to encrypt the private key of the file. The Security Gateways use this password to sign certificates for the sites accessed. You must keep the password because it is also used by other Security Management Servers that import the CA certificate to decrypt the file.

After you create an outbound CA certificate, you must export it so it can be distributed to clients. If you do not deploy the generated outbound CA certificate on clients, users will receive TLS error messages in their browsers when connecting to HTTPS sites. You can configure a troubleshooting option that logs such connections.

After you create the outbound CA certificate, a certificate object named Outbound Certificate is created. Use this object in rules that inspect outbound HTTPS traffic in the HTTPS Inspection Rule Base.

Importing an Outbound CA Certificate

You can import a CA certificate that is already deployed in your organization or import a CA certificate created on one Security Management ServerClosed Check Point Single-Domain Security Management Server or a Multi-Domain Security Management Server. to another Security Management Server.

Best Practice - Use private CA Certificates.

For each Security Management Server that has Security Gateways enabled with HTTPS Inspection, you must:

  • Import the CA certificate.

  • Enter the password the Security Management Server uses to decrypt the CA certificate file and sign the certificates for users. Use this password only when you import the certificate to a new Security Management Server.

Exporting a Certificate from the Security Management Server

If you use more than one Security Management Server in your organization, you must first export the CA certificate with the export_https_cert CLI command from the Security Management Server on which it was created before you can import it to other Security Management Servers.

Exporting and Deploying the Generated CA

To prevent users from getting warnings about the generated CA certificates that HTTPS Inspection uses, install the generated CA certificate used by HTTPS Inspection as a trusted CA. You can distribute the CA with different distribution mechanisms such as Windows GPO. This adds the generated CA to the trusted root certificates repository on client computers.

When users run standard updates, the generated CA will be in the CA list and they will not receive browser certificate warnings.

Deploying Certificates by Using Group Policy

You can use this procedure to deploy a certificate to multiple client machines with Active Directory Domain Services and a Group Policy Object (GPO). A GPO can contain multiple configuration options, and is applied to all computers in the scope of the GPO.

Membership in the local Administrators group, or equivalent, is necessary to complete this procedure.

Configuring Inbound HTTPS Inspection

Configure the Security Gateway for inbound HTTPS Inspection.

The first time you enable HTTPS Inspection on one of the Security Gateways, you must create an outbound CA certificate for HTTPS Inspection or import a CA certificate already deployed in your organization. This outbound certificate is used by all Security Gateways managed on the Security Management Server.

Assigning a Server Certificate for Inbound HTTPS Inspection

Add the server certificates to the Security Gateway. This creates a server certificate object.

When a client from outside the organization initiates an HTTPS connection to an internal server, the Security Gateway intercepts the traffic. The Security Gateway inspects the inbound traffic and creates a new HTTPS connection from the gateway to the internal server. To allow HTTPS Inspection, the Security Gateway must use the original server certificate and private key. The Security Gateway uses this certificate and the private key for TLS connections to the internal servers.

After you import a server certificate (with a CER file extension) to the Security Gateway, add the object to the HTTPS Inspection Policy.

Do this procedure for all servers that receive connection requests from clients outside of the organization.

The Successful Import window opens the first time you import a server certificate. It shows you where to add the object in the HTTPS Inspection Rule Base. Click Don't show this again if you do not want to see the window each time you import a server certificate and Close.

HTTPS Inspection Policy

The HTTPS Inspection rules define how the Security Gateways inspect HTTPS traffic. The HTTPS Inspection rules can use the URL FilteringClosed Check Point Software Blade on a Security Gateway that allows granular control over which web sites can be accessed by a given group of users, computers or networks. Acronym: URLF. categories to identify traffic for different websites and applications. For example, to protect the privacy of your users, you can use a rule to ignore HTTPS traffic to banks and financial institutions.

The HTTPS Inspection rules are applied to all the Software Blades that have HTTPS Inspection enabled.

Starting from R81, the HTTPS Inspection policy is in SmartConsole > the Security Policies view > HTTPS Inspection. Starting from R80.40 you can create different HTTPS Inspection layers per different policy packages. When you create a new policy package, you can use the pre-defined HTTPS Inspection layer, or customize the HTTPS Inspection layer to fit your security needs.

You can share an HTTPS Inspection layer across multiple policy packages.

Note - Note - When you go to the Security Policies view > HTTPS Inspection > HTTPS Tools > Additional Settings > Open HTTPS Inspection Policy In SmartDashboard, SmartDashboard unexpectedly closes, if there are more than 100,000 network objects configured in the management database of the Management Server.

Configuring HTTPS Inspection Rules

Create different HTTPS Inspection rules for outbound and inbound traffic.

The outbound rules use the certificate that was generated for the Security Gateway.

The inbound rules use a different certificate for each internal server.

You can also create bypass rules for traffic that is sensitive and should not be inspected. Make sure that the bypass rules are at the top of the HTTPS Inspection Rule Base.

After creating the rules, install the Access Control Policy.

Bypassing HTTPS Inspection for Software Update Services

Check Point dynamically updates a list of approved domain names of services from which content is always allowed. This option makes sure that Check Point updates or other 3rd party software updates are not blocked. For example, updates from Microsoft, Java, and Adobe.

Managing Certificates by Gateway

The Gateways pane in the HTTPS Inspection tab in SmartDashboard lists the gateways with HTTPS Inspection enabled.

In the CA Certificate section, in the lower part of the Gateways pane, you can Renew the certificate validity date range if necessary and Export it for distribution to the organization client machines.

If the Security Management Server which manages the selected Security Gateway does not have a generated CA certificate installed on it, you can add it with Import certificate from file.

  • You can import a CA certificate already deployed in your organization.

  • You can import a CA certificate from another Security Management Server. Before you can import it, you must first export it from the Security Management Server on which it was created (see Exporting and Deploying the Generated CA).

Adding Trusted CAs for Outbound HTTPS Inspection

When a client initiates an HTTPS connection to a website server, the Security Gateway intercepts the connection. The Security Gateway inspects the traffic and creates a new HTTPS connection from the Security Gateway to the designated server.

When the Security Gateway establishes a secure connection (a TLS tunnel) to the designated website, it must validate the site server certificate.

HTTPS Inspection comes with a preconfigured list of trusted CAs. This list is updated by Check Point when necessary and is automatically downloaded to the Security Gateway. After you install the update, make sure to install the policy. You can select to disable the automatic update option and manually update the Trusted CA list.

If the Security Gateway receives a non-trusted server certificate from a site, by default the user gets a self-signed certificate and not the generated certificate. A page notifies the user that there is a problem with the website security certificate, but lets the user continue to the website.

You can change the default setting to block untrusted server certificates.

Saving a CA Certificate

You can save a selected certificate in the trusted CAs list to the local file system.

HTTPS Validation

To learn more about these options, see the Help. Click the ? symbol in the HTTPS Validation page.

Showing HTTPS Inspection Logs

The predefined log query for HTTPS Inspection shows all HTTPS traffic that matched the HTTPS Inspection policy, and was configured to be logged.

The Logs tab includes an HTTP Inspection Action field. The field value can be inspect or bypass. If HTTPS Inspection was not done on the traffic, this field does not show in the log.

SNI support for Site Categorization

Starting from R80.30, a new functionality allows the categorization of HTTPS sites before the HTTPS Inspection begins, and prevents connectivity failure if the inspection does not succeed.

SNI is an extension to the TLS protocol, which indicates the hostname at the start of the TLS handshaking process.

The categorization is performed by examining the SNI field in the client hello message at the beginning of the TLS handshaking process. To make sure that you reached the right site, the SNI is verified against the Subject Alternative Name of the host, which appears in the certificate.

After the identity of the host is known and verified, the site is categorized, and it is determined whether the connection should be inspected or not.

SNI support is enabled by default.

HTTPS Inspection on Non-Standard Ports

Applications that use HTTP normally send the HTTP traffic on TCP port 80. Some applications send HTTP traffic on other ports also. You can configure some Software Blades to only inspect HTTP traffic on port 80, or to also inspect HTTP traffic on non-standard ports.

The security policies inspect all HTTP traffic, even if it is sent using nonstandard ports. This option is selected by default. You can configure this option in the Manage & Settings view > Blades > Threat Prevention > Advanced Settings.

Configuring Security Gateways to Inspect TLS v1.3 Traffic

From R81, Check Point Security Gateway can inspect the Transport Layer Security (TLS) v1.3 traffic (see RFC 8446).