Re: Search access does not return any result

On Mon, Nov 14, 2011 at 4:45 PM, Howard Chu <hyc@symas.com> wrote:

sim123 wrote:

On Mon, Nov 14, 2011 at 1:37 PM, sim123 <Sim3159@gmail.com
<mailto:Sim3159@gmail.com>> wrote:

Hi All,

I am playing with access controls on openldap 2.4.26, I have a user with
search access on everything

access to *
by anonymous auth
by dn="uid=102,ou=system,dc=example,dc=com" search

And when I perform search I get nothing

ldapsearch -H "ldap://testldap:389" -D
"uid=102,ou=system,dc=example,dc=com" -b "ou=users,dc=example,dc=com" -x
-W '(uid=1)' mail cn dn

Enter LDAP Password:
# extended LDIF
#
# LDAPv3
# base <ou=users,dc=example,dc=com> with scope subtree
# filter: (uid=1)
# requesting: mail cn dn
#

# search result
search: 2
result: 0 Success

# numResponses: 1

so I get a success but no value, is it a valid response?

Yes, it's a valid response. You haven't given Read access to anything, so no values can be returned. But the search base existed and you had search access to it, so the search request succeeded.

I want to control
access so that the "uid=102" user can do lookup from given attributes but
can not do (objectClass=*) to get a list of every entry in the ldap.

Thanks for the help

Other way of stating my problem is I want to control query filters on the
server side so the user with "uid=102" can only do query using filter (uid=.+)
, all other filters should be restricted. I tried this regular _expression_ but
getting no such object error.

It seems to me that what you want cannot be done. You need Read access in order to retrieve any values. Read access includes Search access. So if you are able to read the value of an attribute, you are allowed to Search for it as well.

Thanks for the response, just wondering how can one prevent ldap injections from the server side?

In my scenario there will be different systems talking to server and how can I prevent them from getting list of users by doing simple query? I am using uid as login id and this uid is not part of DN (because it can change and I need the DN in different ldap groups), so for normal authentication these systems need to know respective DN from given uid. Thats why I give read privilege to a system account, all anonymous users have auth privilege only. Am I missing something here?

Thanks again for the help and support.

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