Splunk Search

Check to valid credit card number - mod10|Luhn algorithm

rafamss
Contributor

Hello everyone,

I'm using the SPL to get credit card numbers on search time (I would like to maintain this on search time) :

 

 

| rex field=_raw "(?<firstStep_CC>(?:\d[ -]*?){13,30})"
| eval secondStep_CC=replace(firstStep_CC, "\-|\s|\.", "")
| rex field=secondStep_CC "(?<creditcard>^4[0-9]{12}(?:[0-9]{3})?)|(^5[1-5][0-9]{14})|(^6(?:011|5[0-9][0-9])[0-9]{12})|(^3[47][0-9]{13})|(^3(?:0[0-5]|[68][0-9])[0-9]{11})|((?:2131|1800|35\d{3})\d{11})"

 

 

With this SPL I get possible credit card numbers, but invalid numbers as well. Do you need a way to get only valid numbers?

I thought to split each digit from creditcard and do a mod10 verification, but I don't know if it's efficient. I read a lot of posts like these:

https://community.splunk.com/t5/All-Apps-and-Add-ons/TA-luhn-How-to-use-the-luhn-command-and-how-to-...

https://wiki.splunk.com/Community:Credit_card_masking_regex

Tks!

Labels (4)
0 Karma
1 Solution

richgalloway
SplunkTrust
SplunkTrust

What constitutes a valid CC number?  If you need to verify the check digits then you'll probably need a custom command.

---
If this reply helps you, Karma would be appreciated.

View solution in original post

0 Karma

richgalloway
SplunkTrust
SplunkTrust

What constitutes a valid CC number?  If you need to verify the check digits then you'll probably need a custom command.

---
If this reply helps you, Karma would be appreciated.
0 Karma

rafamss
Contributor

I need to validate if the credit card number is valid on search time, but for what I've found, is necessary to use the Luhn algorithm (modulus10) to do this. So I think, that it won't be possible to do just using SPL.

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!

[Puzzles] Solve, Learn, Repeat: Matching cron expressions

This puzzle (first published here) is based on matching timestamps to cron expressions.All the timestamps ...

Design, Compete, Win: Submit Your Best Splunk Dashboards for a .conf26 Pass

Hello Splunkers,  We’re excited to kick off a Splunk Dashboard contest! We know that dashboards are a primary ...

May 2026 Splunk Expert Sessions: Security & Observability

Level Up Your Operations: May 2026 Splunk Expert Sessions Whether you are refining your security posture or ...