The SSLKEYLOGFILE environment variable enables logging of keys for decrypting SSL/TLS traffic. Wireshark can then utilize these keys to decrypt SSL/TLS traffic. By using SSLKEYLOGFILE, you can enhance the Forwarder’s MITM capabilities with Wireshark-based tools.

Prerequisites #

Wireshark must be installed on your machine.

Run Forwarder with SSLKEYLOGFILE #

To enable SSLKEYLOGFILE in Forwarder, set the environment variable SSLKEYLOGFILE to the path where the SSL keys should be logged. Alternatively, you can use the --http-tls-keylog-file flag.

To use SSLKEYLOGFILE in Forwarder, you also need to enable MITM, see MITM Proxy tutorial for more details on this topic. For the purpose of this tutorial, we will use the --mitm flag to enable MITM with self-signed certificates.

Example #

SSLKEYLOGFILE=/path/to/sslkeylog.log forwarder run --mitm 

Run Wireshark #

Open Wireshark, set Display filter to http and Capture filter to tcp port 443, and start capturing traffic on your network interface.


Go to Edit > Preferences > Protocols > TLS. Set the (Pre)-Master-Secret log filename to the same value as the SSLKEYLOGFILE environment variable.

Now if you run some traffic through the Forwarder, you should see decrypted traffic in Wireshark.

curl -k -x localhost:3128

Wireshark HTTP

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