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Re: (ITS#6083) ppolicy should also support invocation of an external password checker

Guillaume.Rousse@inria.fr wrote:
> Full_Name: Guillaume Rousse
> Version: 2.4.16
> OS: Linux
> URL: ftp://ftp.openldap.org/incoming/
> Submission from: (NULL) (
> Current implementation of ppolicy only accept an internal plugin as password
> checker. However, writing native code is more difficult for many sysadmins than
> using script languages. Moreover, it's also less safe, as any crash will
> endanger the whole slapd process. Allowing to run an external process for
> checking password would be desirable.

If you're talking about writing a checker feature that fork/execs an external 
script interpreter, then I'll say up front that this is not a good idea, and 
we've already been deprecating anything else that operates this way (like 
back-shell). fork()/system()/spawn() whatever don't mix well with pthreads and 
will most likely corrupt something.

As for isolation/crash vulnerability - this is a *password checker* - it is 
already a sensitive piece of code. If you're deploying a custom module without 
adequate testing or code review, you're already in trouble.

You could of course take a similar approach as back-sock - open a socket to 
some other daemon that performs your checks for you. You then have to decide 
how to behave when the external process isn't answering...

Ultimately, what you do inside your checker module is your own business. I see 
no action needed on our part; this ITS will be closed.

   -- Howard Chu
   CTO, Symas Corp.           http://www.symas.com
   Director, Highland Sun     http://highlandsun.com/hyc/
   Chief Architect, OpenLDAP  http://www.openldap.org/project/