Cloud NGFW for Azure
Set Up Outbound Decryption on Cloud NGFW for Azure
Table of Contents
Set Up Outbound Decryption on Cloud NGFW for Azure
Learn how to set up outbound decryption on Cloud NGFW for Azure.
| Where Can I Use This? | What Do I Need? |
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With Outbound decryption, Cloud NGFW behaves like an SSL Forward Proxy, and uses its associated
certificates to establish itself as a trusted third party (meddler in the middle
(MitM)) for the client-server session. However, Cloud NGFW keeps your traffic packet
headers and payload intact, providing complete visibility of the source’s identity
to your destinations.
Use PAN-OS version 11.0.x when
using Azure key vault for outbound decryption.
Outbound decryption uses two certificate objects - Trust and Untrust. The NGFW
presents the trust certificate to clients during SSL decryption if the client is
attempting to connect to a server that has a certificate signed by a trusted
certificate authority (CA). Alternatively, the NGFW presents the untrust certificate
to the client attempting to connect to a server that has a certificate signed by a
CA that the NGFW does not trust.
You can configure the NGFW resource to decrypt the SSL traffic leaving your VNet or
subnet. You can then enforce App-ID and security settings on the plaintext traffic,
including Antivirus, Vulnerability, antispyware, URL Filtering, and file blocking
profiles. After decrypting and inspecting traffic, the firewall reencrypts the
plaintext traffic as it exits the firewall to ensure privacy and security.
This procedure only defines the certificates that the firewall uses for Outbound TLS
decryption. Enable Outbound TLS decryption during rules creation.
- Select Rulestacks and select a previously created rulestack that to apply the certificate.Select .Select a certificate.
- Select an Untrust Certificate.
- Select a Trust Certificate.
Add a Certificate to Cloud NGFW for Azure if you have not done so already.The certificate and private key are stored in the Azure key vault, and the workload uses this information to decrypt the traffic.The certificate must be a CA certificate. Set the CA value in the Basic Constraints to TRUE. The following is an example private CA certificate.Certificate: Data: Version: 3 (0x2) Serial Number: 4121 (0x1019) Signature Algorithm: sha256WithRSAEncryption Issuer: C=US, ST=Washington, L=Seattle, O=Example Company Root CA, OU=Corp, CN=www.example.com/emailAddress=corp@www.example.com Validity Not Before: Feb 26 20:27:56 2018 GMT Not After : Feb 24 20:27:56 2028 GMT Subject: C=US, ST=WA, L=Seattle, O=Examples Company Subordinate CA, OU=Corporate Office, CN=www.example.com Subject Public Key Info: Public Key Algorithm: rsaEncryption Public-Key: (2048 bit) Modulus: 00:c0: ... a3:4a:51 Exponent: 65537 (0x10001) X509v3 extensions: X509v3 Subject Key Identifier: F8:84:EE:37:21:F2:5E:0B:6C:40:C2:9D:C6:FE:7E:49:53:67:34:D9 X509v3 Authority Key Identifier: keyid:0D:CE:76:F2:E3:3B:93:2D:36:05:41:41:16:36:C8:82:BC:CB:F8:A0 X509v3 Basic Constraints: critical CA:TRUE X509v3 Key Usage: critical Digital Signature, CRL Sign Signature Algorithm: sha256WithRSAEncryption 6:bb:94: ... 80:d8If you're using an End-Entity certificate for decrypting traffic, only the End Entity Cert with public and private key is stored in the Azure key vault.PKCS8 is the supported certificate format.Trust certificates can’t be self-signed, but the untrust certificate can be self-signed or ca-signed.Navigate to the previously created Rulestack and go to the Managed Identity page.From the Enable MI dropdown menu, select the managed identity that was associated with the key vault.Click Save.
