I am currently migrating a users database to an OpenLDAP solution. I
have to deal with some constraints for this project, namely password
policy and/or password syntax checking.
Fortunately the ppolicy overlay already implements the
draft-behera-ldap-password-policy, and offers the possibility to use
pwdCheckModule to check password via external modules.
Unfortunately, I did not find any module meeting all my requirements:
The check_password() function, as defined in ppolicy, provides
to the underlying module two parameters:
- The entry being modified
- The new password.
Now to support per user settings, which is one of these requirements,
I have to either store extra attributes among each entry, or the module
has to perform a ldapsearch against the db.
An option is to modify the check_password() function so it sends the
ppolicy object itself:
int check_password (char *pPasswd, char **ppErrStr, Entry *pEntry,
This way people using external modules would just need to store their
settings attributes in it.
As I don't want to break existing modules implementation, I have
developed a simple overlay which enforces password syntax
checking on a per user or per database basis. The overlay implements
also the check_password() function so it can be used in conjunction
I believe the code is clean enough to be contributed and
I will be glad to upload it if you think it can be of any interest.
However, I have some questions first.
The overlay allows me to define a default password constraints
object at a database level, or a subentry in the user entry, in a similar way
as the ppolicy_default setting and the pwdPolicySubentry attributes.
This is so similar that I think it would be more relevant to extend
the ppolicy overlay so it could support basic syntax checking. I
understand the need to have the pwdCheckModule functionality, for
those in need of exotics or platform dependent checks, but counting
the characters belonging to a class is not harder than checking the
min/max length of the password.
So to summarize:
- Could the check_password function be modified?
Yes, but we would not release this change until OpenLDAP 2.5.
- Could basic syntax checking be integrated in ppolicy?
Maybe; please give more details on how you propose to specify the nature of
And If none of these options are acceptable, should I upload the
overlay I developed?
You're always free to submit code to the ITS.
Of course I'm willing to help on the first two points.
-- Howard Chu
CTO, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc/
Chief Architect, OpenLDAP http://www.openldap.org/project/