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Re: search request not blocked by ACLs

Le lun. 9 sept. 2019 à 18:25, Quanah Gibson-Mount <quanah@symas.com> a écrit :

--On Thursday, September 5, 2019 10:35 AM +0200 Manuela Mandache
<manuela3mandache@gmail.com> wrote:

> Le mer. 4 sept. 2019 à 16:00, Quanah Gibson-Mount <quanah@symas.com> a
> écrit :
> --On Wednesday, September 4, 2019 1:56 PM +0200 Manuela Mandache
> <manuela3mandache@gmail.com> wrote:
>> olcAccess: {0}to * by dn.base="cn=admin,cn=config" manage by
>> dn.base="cn=adm
>>  in,dc=example,dc=com" manage by * break
>> olcAccess: {1}to dn.base="" by * read
>> olcAccess: {2}to dn.base=cn=Subschema by * read
>> olcAccess: {3}to dn.subtree="dc=example,dc=com" attrs=userPassword by *
>> auth
>> olcAccess: {4}to dn.subtree="dc=example,dc=com" attrs=entry by * read
>> olcAccess: {5}to dn.subtree="dc=example,dc=com" attrs=cn,mail by * read
>> olcAccess: {6}to * by anonymous none by * read
> On what cn=config entry have you set these ACLs?
> They're on
> olcDatabase={2}mdb,cn=config
> This is the DB containing the actual data of the directory, with
> olcSuffix: dc=example,dc=com

Given that, I would make the following notes:

a) rootDNs are never subject to ACLs, so the access for cn=admin,cn=config
manage in {0} is suspect, as I would infer that is a rootdn.

b) ACL {1} is invalid for this database.  It should be set in the dn:
olcDatabase={-1}frontend,cn=config database

c) ACL {2} is invalid for this database.  See solution listed in (b)

d) ACL {3} should only give auth access to anonymous, not *

e) ACLs 3-5 should be rewritten to drop the dn.subtree="dc=example,dc=com"
bit entirely.  You're already only setting ACLs for that database, no need
to list that restriction.  You can also combine ACLs 4 & 5.

olcAccess: {3} to attrs=userPassword by anonymous auth
olcAccess: {4} to attrs=entry,cn,mail by * read
olcAccess: {5} to * by anonymous none by * read

Hello Quanah,

Thank you for the detailed analysis of the ACLs - I wrote them based on very old inherited ones, but this is no excuse.
Although I (believed I had) thoroughly RTFM, I feel like I only begin to really understand the way they must be defined. Well, back to the drawing board.
Do poorly written ACLs have a strong impact on performance?
As for your question in general, I don't think you understand how ACLs work
in relation to incoming search requests.  The server did exactly what your
ACLs said it should do: It provided no information when someone tried to
search for data using an attribute that access is not granted to, and
correctly returned 0 entries.  It sounds as though you expected the
connection to be dropped when the search was initiated because it was
filtering off of sn. 

No, I didn't think the connection would be dropped, but I thought no data which are never to be returned would be searched.
- there are three branches in the directory, ou=people,dc=example,dc=com, ou=dogs,dc=... and ou=carpets,...;
- a user has read rights on ou=dogs and none on the two other branches;
- this user makes a search with -b dc=example,dc=com and no filter.
As far as I understand, the whole content is recovered, then the people and the carpets are dropped and only the dogs are returned.
I expected the request to be parsed against the ACLs before performing the actual search in the directory, and so this search to be done only on ou=dogs.

Maybe this example is completely different from the one in my first post: It's true that I do not know how requests-and-ACLs actually work. Is there some documentation I could read on the topic?

Best regards,

That is now how things work.



Quanah Gibson-Mount
Product Architect
Symas Corporation
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