On 04.06.14 15:14, Charles Bueche wrote:
On 03.06.14 16:52, Pierangelo Masarati wrote:
On 06/03/2014 04:23 PM, Charles Bueche wrote:
Hi,
I'm running the latest openldap stable 2.4.39 on Ubuntu.
My openldap server is configured as a LDAP proxy to MS-AD using
back-meta. It works nicely, as long as I don't use OID in filters.
Specifically, I need LDAP_MATCHING_RULE_IN_CHAIN
(http://msdn.microsoft.com/en-us/library/aa746475(v=vs.85).aspx) to
search recursive groups in MS-AD.
If I use that special filter directly against AD, I get my group
list.
filter='(memberOf:1.2.840.113556.1.4.1941:=cn=ls-msp-app1,OU=App,DC=ad,DC=stuff,DC=ch)'
Or if I use a "normal" filter across my proxy, I get my group list as
well.
filter='(memberOf=cn=gs-msp-report,OU=Customers,DC=ad,DC=stuff,DC=ch)'
BROKEN: If I use the special filter across my LDAP proxy's
back-meta, I
get no results and filter="(?=undefined)" in my debug log.
filter='(memberOf:1.2.840.113556.1.4.1941:=cn=ls-msp-app1,OU=App,DC=ad,DC=stuff,DC=ch)'
So my guess is that my filter syntax with OID is not accepted by
back-meta.
When using -d -1, I see this:
...
538dd110 begin get_filter
538dd110 EXTENSIBLE
...
538dd110 end get_filter 0
538dd110 filter: (?=undefined)
...
I have looked at the code of
openldap-2.4.39/servers/slapd/filter.c but
I don't really see what's wrong.
Without looking at the code, I think OpenLDAP's slapd doesn't like
filters with unknown OIDs, that's it. The request doesn't even get to
back-meta.
On a side note, since the filter is supposed to be passed through to
the remote server, slapd should not worry about it; however, AFAIK
there's no way, so far, to disable such check. The easiest way is to
define a module that registers a dummy matching rule with that OID,
although it won't likely be that straightforward.
p.
Hi Pierangelo and list,
thanks for your answer, I'm very unsure now how to continue. I studied
the code of get_filter() and get_mra() without really understanding at
what time my filter is classified as invalid.
The ideas is to implement a workaround in form of a list of
white-listed
OID's (only 4 are needed from
http://msdn.microsoft.com/en-us/library/cc223367.aspx), where should I
put this in the code ?
I do compile my own openldap package anyway, so I can well put some
#ifdef around this, at least to be able to continue my project. I'm now
stopped by this problem and as usual I do have to deliver rsn.
On the other side, what do you mean with "define a module that
registers
a dummy matching rule with that OID" ?
Is this a module like back_meta, rwn and friends ? Do you have any
pointer like a dummy module to show where to begin ?
As you see, I'm pretty much at the beginning of the learning curve
and I
am very happy to get your help.
Regards,
Charles
ok, it did cost me a lot of brain power, but I do have a workaround. I
mention it here because I'm quite sure someone else will hit the same
problem one day.
1. the recursive search filter passed to the proxy should use a filter
supported by the proxy, eg
filter='(RecursiveMemberOf=cn=ls-msp-app2,OU=App,DC=extra,DC=proxy,DC=stuff,DC=ch)'
2. the proxy gasp it, accept it, and pass it to the rewrite module
3. use a rewrite rule to massage the filter:
rewriteRule
"RecursiveMemberOf=cn=(.*),dc=extra,dc=proxy,dc=stuff,dc=ch"
"memberOf:1.2.840.113556.1.4.1941:=cn=%1,dc=ad,dc=stuff,dc=ch"
":"
back_meta then pass the rewritten filter to the back-end AD.
To the developers: as mentioned by Pierangelo above, it should be
possible to disable the filter sanity check when it is passed to a LDAP
back-end. If the filter is insane, the back-end will complain soon
enough.