SSL decryption( Some traffic is not decrypted)

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SSL decryption( Some traffic is not decrypted)

Dear All,

 

I have applied SSL forward decryption in my Paloalto, then i observed some traffic are decrypted and some traffic not decrypt.

Example:- I have applied the decryption in social-networking (Facebook traffic is decrypted but Snapchat traffic is not decrypted,however, both are falling under the social-networking category.)

 

Why it's strange behaviour.

Cyber Elite

Hello,

Unfortunately there is some traffic that cannot be decrypted or it will break the connection. Snapchat is one of these as it uses a pinned certificate.

OtakarKlier_0-1581107884919.png

To view the automatically bypassed domains, click the Device tab -> Certificate Management -> SSL Decryption Exclusion

https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClEzCAK

 

Hope that helps.

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@OtakarKlier 

Ok, thanks for the information. it means all the URL/Application which are already in exclusion, will not decrypt?

 

Apart from this if any traffic is not decrypted so what is the issue? 

Cyber Elite

@Jafar_Hussain,

Correct; if the domain is listed in the SSL Decryption Exclusion list, the firewall is going to let that through without going through the decryption process so that it doesn't break anything. 

 


@Jafar_Hussain wrote:

Apart from this if any traffic is not decrypted so what is the issue? 


 Can you provide one of the domains that you are running into an issue with that isn't covered by an exclusion? Keep in mind, depending on how you have things configured if the firewall detects that it isn't able to decrypt certain traffic without causing an issue, it will put that into a cache to skip decryption going forward so it doesn't continue to break the site for users. 

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@BPry  Thanks for the information.

 

I will keep is in observation. if i found something I will let you know.

Thanks once again.

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@BPry @OtakarKlier 

 

I am facing a problem with the certificate(When I enabled the decryption and tried to open the website in Mozilla and internet explorer it is working as expected means it is taking the same self-sign certificate which I have generated).

However, when I tried to access the website in chrome, the browser is not accepting the certificate which is generated by FW. it is taking its own google certificate.

 

Can you help me with this?

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 any one can give me reply........

Cyber Elite

@Jafar_Hussain,

Can you post the actual website so we can actually take a look at it. 

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@BPry 

 

Example:-  For testing, I have created a custom URL category only for (youtube+facebook+netflix). this is policy i mention in decryption rule with decrypt SSL forward proxy. and I have an import certificate already in my machine. when i try to open this URL in Mozilla and Internet explorer it is working as expected both browsers are taking a certificate which i have import however in chrome i can't see the same certificate this browser is taking its own google certificate why ?????

Cyber Elite

How do these connecrions look in the traffic log? Could it be possible that they use port 443/udp? 

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