[syslog-ng] Message parameter substitution

[Balazs Scheidler]

On Wed, 2011-12-21 at 14:31 +0530, Anup Shetty wrote:
> I am new to syslog-ng and would like some help on the pattern matching
> and the substitution option. Currently the requirement is to
> substitute a parameter in the message with a random value in order to
> anonymize it.
> 
> For example:
> 
> Dec 31 23:13:25 servername sshd[25218]: Failed
> keyboard-interactive/pam for user1 from 10.x.x.x port 47325 ssh2
> 
> 
> If I create a pattern database for this message and pick out the
> username using the string and substitute it user1 to say anon1, will I
> be able to store the original-substituted value pair for this user and
> use it repeatedly?
> Would I be able to do it for all the subsequent logs?
> 
> 
> To be more clear, an example substitution process that must happen as
> the logs arrive and the patterns are matched.
> log with user1 arrives and is substituted by anon1
> log with user2 arrives and is substituted by anon2
> again log with user1 arrives and is again substituted by anon1
> log with user3 arrives and is substituted by anon3
> again log with user2 arrives and is again substituted by anon2
> .
> .
> .
> .
> This is required so that once the usernames are substituted for
> attaining anonymity, there must be a way to reverse them for audit
> purposes.

you want to do that on-the-fly or during postprocessing?

Right now it is not possible to do with patterndb only as it only
extracts information from messages and never changes them, but
anonimization has always been a hidden agenda of patterndb, which never
materialized.

-- 
Bazsi