Use SSL keys for decryption

You can use SSL private key to decrypt data captured by Splunk_TA_stream, provided that the data is encrypted using an RSA cipher that uses the same private key.

By default, some web servers can negotiate session ciphers that do not use RSA private keys. These ephemeral key exchange protocols (such as Diffie-Hellman) make it impossible for any passive observer to decrypt the traffic, and are therefore not supported by Stream.

To ensure that Stream can intercept all of your encrypted traffic, you might need to disable support for ephemeral ciphers on your web server. This does not make your web server less secure, because the web server uses equally effective alternative ciphers for the connection.

Add SSL Private Key

1. Confirm that your SSL key is a PEM private key file. For example:

   -----BEGIN ENCRYPTED PRIVATE KEY-----
   MIIFDjBABgkqhkiG9w0BBQ0wMzAbBgkqhkiG9w0BBQwwDgQIS2qgprFqPxECAggA
   MBQGCCqGSIb3DQMHBAgD1kGN4ZslJgSCBMi1xk9jhlPxP3FyaMIUq8QmckXCs3Sa
   9g73NQbtqZwI+9X5OhpSg/2ALxlCCjbqvzgSu8gfFZ4yo+Xd8VucZDmDSpzZGDod
   A .... MANY LINES LIKE THAT .... .... MANY LINES LIKE THAT .... 
   X0R+meOaudPTBxoSgCCM51poFgaqt4l6VlTN4FRpj+c/WZeoMM/BVXO+nayuIMyH
   blK948UAda/bWVmZjXfY4Tztah0CuqlAldOQBzu8TwE7WDwo5S7lo5u0EXEoqCCq
   H0ga/iLNvWYexG7FHLRiq5hTj0g9mUPEbeTXuPtOkTEb/0ckVE2iZH9l7g5edmUZ
   GEs=
   -----END ENCRYPTED PRIVATE KEY-----
   

2. Go to $SPLUNK_HOME/etc/apps/Splunk_TA_stream/linux_x86_64/bin.
3. Use the streamfwd --addsslkey command to add the PEM private key file:

    ./streamfwd --addsslkey <key_name> <pem_file> <password>
   

   This adds the new private key file to $SPLUNK_HOME/etc/apps/Splunk_TA_stream/local/keystore.db. keystore.db protects SSL keys using an AES-256 cipher.

4. Restart streamfwd:
   1. Go to Settings > Data Inputs.
   2. Click on Wire Data.
   3. Locate the streamfwd data input. Click Disable then click Enable.

Note: If you want to push your private key out to multiple forwarders, either copy your Splunk_TA_stream directory to your forwarders, or copy Splunk_TA_stream into $SPLUNK_HOME/etc/deployment-apps and use the deployment server to distribute the add-on.

Convert PFX files to PEM files

Windows servers often use .pfx files instead of .pem files. You can convert .pfx files to .pem files using this openSSL command:

openssl pkcs12 -in CUSTOMERSKEY.pfx -nocerts -out KEYFORSTREAM.pem -nodes</code>