Set Up Inbound Decryption on Cloud NGFW for AWS
Table of Contents
Set Up Inbound Decryption on Cloud NGFW for AWS
Cloud NGFW uses SSL Inbound Decryption to
inspect and decrypt inbound SSL/TLS traffic from a client to a targeted
network server (any server you have the certificate for and can
import onto the firewall) and block suspicious sessions. The firewall
acts as a proxy between the external client and the internal server
and generates a new session key for each secure session. The firewall
creates a secure session between the client and the firewall and
another secure session between the firewall and the server to decrypt
and inspect the traffic. However, Cloud NGFW keeps your traffic
packet headers and payload intact, providing complete visibility
of the source’s identity to your applications in your VPCs.
Your certificate and session
key are stored on the AWS secrets manager to
perform SSL inbound inspection. The firewall validates that the
certificate sent by the targeted server during the SSL/TLS handshake
matches a certificate in your decryption policy rule. If there is
a match, the firewall forwards the server's certificate to the client
requesting server access and establishes a secure connection.
- Select Rulestacks and select a previously-created rulestack which to apply the certificate.Select Rules, then Create a new Security Rule for decryption.Provide the following details under General.
- Name—Name of the rule.
- Description—A description for the rule.
- Rule Priority—A unique priority for the rule.
- Enabled—Enable the field to associate the rulestack with the rule. This field is enabled by default.
Define matching criteria for the Source and Destination IP address fields.Configure Granular Controls.- Specify the Applications(App-ID™) you want the rule to allow or
block.You can create TLS decryption rules with Applications(App-ID™)—Any or SSL—Match only.
- Specify a URL Category as match criteria for the rule.
- Specify the Protocol and Ports you want the rule to allow or block.
Specify the Action you want the firewall to take when the traffic matches one of the rules you created.- Allow—Allow traffic.
- Deny—Block traffic and enforce the default Deny Action defined for the application that is being denied.
- Reset Server—Sends the TCP reset to the server-side device.
- Reset Both—Sends a TCP reset to both client and server-side devices.
Under TLS Decryption, select Inbound and select an Inbound Inspection Certificate.Create a certificate if you have not done so already. The Amazon Resource Name (ARN) of the secret must be used in the certificate ARN when creating the certificate object.The certificate and private key are stored in the AWS Secrets Manager (ASM), and the Application Load Balancer (ALB) uses these information to decrypt the traffic. The certificate need not be a CA certificate. If the certificate is a chain, use the leaf certificate and key.PKCS8 is the supported certificate format.Inbound decryption does not support self-signed certificates.The decryption profile for TLS decryption is set to Best Practice Security Policy. See decrypt traffic for full visibility and threat inspection for more information.Click Enabled to enable logging.Click Save.Click to save the rule to the running configuration the firewall.