Some applications can’t be decrypted for technical reasons
and some traffic can’t be decrypted for business, compliance, or
regulatory reasons. Make decryption exceptions only when you must.
You can exclude two types of traffic from decryption:
Traffic that breaks decryption for
such as using a pinned certificate, an incomplete certificate chain,
unsupported ciphers, or mutual authentication (decrypting blocks
the traffic). Palo Alto Networks provides a predefined SSL Decryption
Exclusion list (
SSL Decryption Exclusion
that excludes hosts with applications and services that are known
to break decryption technically from SSL Decryption by default.
If you encounter sites that break decryption technically and are
not on the SSL Decryption Exclusion list, you can add them to list
manually by server hostname. The firewall blocks sites whose applications
and services break decryption technically unless you add them to
the SSL Decryption Exclusion list.
Traffic that you
not to decrypt because of business,
regulatory, personal, or other reasons, such as financial-services,
health-and-medicine, or government traffic. You can choose to exclude
traffic based on source, destination, URL category, and service.
You can use asterisks (*) as wildcards to create decryption exclusions
for multiple hostnames associated with a domain. Asterisks behave
the same way that carets (^) behave for URL category exceptions—each
asterisk controls one variable subdomain (label) in the hostname.
This enables you to create both very specific and very general exclusions.
mail.*.com matches mail.company.com but does not match mail.company.sso.com.
*.company.com matches tools.company.com but does not match eng.tools.company.com.
*.*.company.com matches eng.tools.company.com but does not match
*.*.*.company.com matches corp.exec.mail.company.com, but
does not match corp.mail.company.com.
mail.google.* matches mail.google.com, but does not match mail.google.uk.com.
mail.google.*.* matches mail.google.co.uk, but does not match mail.google.com.
For example, to use wildcards to exclude video-stats.video.google.com
from decryption but not to exclude video.google.com from decryption,
Regardless of the number of asterisk wildcards that precede
a hostname (without a non-wildcard label preceding the hostname),
the hostname matches the entry. For example, *.google.com, *.*.google.com,
and *.*.*.google.com all match google.com. However, *.dev.*.google.com
does not match google.com because one label (dev) is not a wildcard.
To increase visibility into traffic and reduce the attack surface
as much as possible, don’t make decryption exceptions unless you