sslprovide (--f5 ssl) does not generate CLIENT/SERVER_TRAFFIC_SECRET on server-side TLS traffic

When I enable the sslprovider and start a tcpdump on the server-side in order to decode TLSv1.3 traffic, only the CLIENT_HANDSHAKE_TRAFFIC_SECRET and SERVER_HANDSHAKE_TRAFFIC_SECRET ‘keys’ are stored in the packet capture file, but the CLIENT_TRAFFIC_SECRET and SERVER_TRAFFIC_SECRET ‘keys’ are missing. This prevents me to decode the application data in the packet capture:

# tmsh modify sys db tcpdump.sslprovider value enable<br># tcpdump -i <em><server-side-VLAN></em> -s0 -f5 ssl:v -vvv -w /var/tmp/output.cap <br><br><em><Generate traffic></em><br><br># tshark -r /var/tmp/output.cap -Y "f5ethtrailer.tls.keylog" -T fields -e f5ethtrailer.tls.keylog

On the client-side, this works as expected.

Is this a bug (tested with TMOS 17.5.1)? Am I doing something wrong?

I mean CLIENT_TRAFFIC_SECRET_0 and  SERVER_TRAFFIC_SECRET_0 are missing.

Hi @Frank_ten_Wolde  
You may want to check this KB

https://my.f5.com/manage/s/article/K36120659

Hi Momahdy,

Thanks for pointing me to this KB article. I am aware of the ‘iRule-way’ to get the PMS data.

The observed sslprovider behaviour (missing CLIENT_TRAFFIC_SECRET_0 and SERVER_TRAFFIC_SECRET_0 data) sort of defies the purpose of it, doesn’t it?

Should I report a bug with F5 TAC, or is this a known issue already?

I always use this script to grab and reinject the secrets: https://github.com/JuergenMang/f5-tls-decrypt

You can check it to see if the issue is within tshark.

Hi @Frank_ten_Wolde  
Got what you mean, I don’t see published IDs on this one,  If you may try couple of items and reach to TAC if the same behavior continues,

- Make sure to include the p option,
tcpdump -i <server-side-VLAN>:nnnp -s0 -f5 ssl:v -vvv -w /var/tmp/output.cap