Getting Data In

Why do I receive SSL alert number 40 with selfsigned certificates?

ortiz
Explorer

Dear all,

We are on process of ingesting Check Point EDR logs in our Splunk Cloud Platform. This should be done through a Heavy Forwarder. Checkpoint sends encrypted data to HFW.

For that purpose, we used the following guide provided by CheckPoint for generating and configure the certificates which contains specific instructions for Splunk:
https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solut...

As summary, there are two certificates that needs to be configured on the Splunk side: 

- splunk.pem It is a combination of SyslogServer.crt + SyslogServer.key + RootCa.pem configured in /opt/splunk/etc/apps/CheckPointAPP/local/inputs.conf
- ca.pem configured in /opt/splunk/etc/system/local/server.conf

This configuration is not working because the certificate splunk.pem is giving a handshake error "SSL alert number 40".


The following setting in server.conf as the CheckPoint guide specifies, returns an error in Splunk: "Invalid key in stanza [SSL]".

 

 

[SSL]
cipherSuite = TLSv1+HIGH:TLSv1.2+HIGH:@STRENGTH

 


We also have tried with this configuration with the same result:

 

 

[SSL] cipherSuite = ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA:AES256-SHA:DHE-RSA-AES128-SHA:AES128-SHA:AES256-SHA:AES128-SHA 

 

 

In Splunk internal wereceive the following error:

 

Received fatal SSL3 alert. ssl_state='SSLv3 read client certificate A', alert_description='unknown CA'.

 



Do you know which could be the point of failure? Why the certificate is returning an error 40 or if the configuration should be set in a different way?

Best regards

Tags (1)
0 Karma
Got questions? Get answers!

Join the Splunk Community Slack to learn, troubleshoot, and make connections with fellow Splunk practitioners in real time!

Meet up IRL or virtually!

Join Splunk User Groups to connect and learn in-person by region or remotely by topic or industry.

Get Updates on the Splunk Community!

Monitoring AI Agents with Splunk Observability Cloud

Let’s say I’m running a travel planning AI app in production. A user asks for three concise hotel options in ...

[Puzzles] Solve, Learn, Repeat: Tiling

This puzzle (first published here) is based on finding groups of tessellated tiles (inspired by floor tiles I ...

SOK it to Me: Top 3 Benefits of Using Splunk Operator on Kubernetes that’ll Make ...

    Thursday, July 9, 2026  |  11:00AM–12:00PM PDT Duration: 1 hour (includes Q&A) Managing can feel like a ...