Download session keys with packet captures

You can download a keylog file that includes all captured SSL session keys for SSL packet captures. Then, you can download and open the associated packet capture file with a packet analysis tool like Wireshark that can display the decrypted payload.

Before you begin

  • You must have a configured ExtraHop Trace appliance before you can download packets and session keys from a Discover or Command appliance. See our deployment guides to get started.
  • The Discover appliance must be licensed for SSL Shared Secrets.
  • The SSL Session Key Storage setting must be enabled on the Discover appliance.
  • Users must have either unlimited privileges or limited privileges with packets and session keys access to download the keylog file.
  1. Log into the Web UI on the Discover or Command appliance.
  2. From the top menu, click Packets.
  3. Optional: Apply filters to refine the packet query.
  4. When the query completes, click Download PCAP.
  5. Click Download Session Keys.
    The keylog file is automatically downloaded to your computer and the session key download operation is recorded in the audit log.

    If there are no session keys available for the downloaded packet capture, the Download Session Keys button does not appear.

Configure Wireshark to view the decrypted payload

  1. Start the Wireshark application.
  2. Open the Wireshark Preferences pane, expand the Protocols section, and then click SSL.
  3. Optional: Click the Browse... button next to the SSL debug file field to create a log file.
  4. Click the Browse… button next to the (Pre)-Master-Secret log filename field, select the *.pcap.keylog.txt file you downloaded above, and then click Open.
  5. Click OK to close the Preferences window.
  6. Open the downloaded packet capture file in Wireshark.

When an SSL-encrypted frame is selected, the Decrypted SSL tab appears at the bottom of the Wireshark window. Click the tab to see the decrypted information in the packet capture as plain text.

Published 2018-11-09 13:57