RE: Question about ACI

["Clowser, Jeff (Contractor)" <jeff_clowser@xxxxxxxxxxxxx>]

Couple things here.  First, avoid deny rules if at all possible - deny rules always take precedence, so you can *never* override a deny rule with something to allow access that has been denied elsewhere.

 

Second, I think you are misunderstanding how ldap:///self works.  ldap:///self basically says "These permissions are granted on the targetted entry if I bind to the server as that target entry".  In your case, what your deny rule is saying is that if I bind as user1, I can't read, write, or even search for the user1 entry, and as a deny rule, you can't create any other rule to ever allow user1 to see his own entry. 

 

So, you've created a rule that says anyone can read/write/search to anything under ou=serviceaccounts, *except* user1 can't read/write/search on his own entry.

 

BTW, this seems like a really bad idea.  Forget about ACI's and implementation for the moment - conceptually, what are you trying to do?  Who should be able to do what?  Are you saying you want anyone except user1 to be able to have full access to anything under ou=serviceaccounts? 

 

To define your access controls, you should really figure out who you want to do what, then define aci's for each thing you want to allow, such that they only *allow* just what you need, so you don't need any kind of deny rules.

 

If you want to, for example, allow any user to edit any part of just their own record, put something like the following on the ou=serviceaccounts entry:

 

aci:
 (targetattr = "*")
 (version 3.0;
 acl "default aci for service accounts";
 allow (all)
 (userdn=ldap:///self)
 ;)

This says that if I bind as a user under ou=serviceaccounts, I have full read/write/search access to the entry I bound as (i.e. my account).

However, I'd recommend making even that more restrictive (for example, if all they really need to write to is their password, create one aci to allow them to read/search all attributes except the userpassword, and one to allow write to the userpassword with userdn of ldap:///self), etc.  If you want all users to read other users entries, create another aci that allows search/read access to ldap:///anyone (and at least make it targetattr!="userpassword"), and so on..

 

 - Jeff

 

 

---

From: fedora-directory-users-bounces@xxxxxxxxxx [mailto:fedora-directory-users-bounces@xxxxxxxxxx] On Behalf Of Chun Tat David Chu
Sent: Monday, December 10, 2007 11:37 AM
To: fedora-directory-users@xxxxxxxxxx
Subject: Re: Question about ACI

Hi guys,

Please see below for my original question.

I 
spend a little more time reading "Chapter 6 - Managing Access Control" from the 
RH Administrator Guide.  At first, I thought it was my placement of ACI 
that was wrong, but it seems like that's not the case from what I read.  
The book stated that "The precedence rule that applies is that ACIs that deny 
access take precedence over ACIs that allow access."  If my root allows 
everything and then my leaf denies everything then I don't see why the add 
operation that I mentioned below should work. 

Let me clear up a little 
more in case there's any confusion.  The ou=serviceaccounts and cn=user1 
entry is created by the "cn=Directory Manager" user.  In my test, the root 
(ou=serviceaccounts), I specified an ACI that allows all user to do 
anything.  In my leaf (cn=user1), I specified an ACI that denies everything 
for user1 by defining the bind rule as (ldap:///self). 

When I logged in 
as user1, I'm able to add entry in the cn=user1 context.  I am not sure why 
because I thought that user1 shouldn't have any privilege to do anything due to 
my specified ACI.

Any idea?  Am I missing some obvious? 

Thanks!

David

On Dec 7, 2007 6:28 PM, Chun Tat David Chu <beyonddc.storage@xxxxxxxxx> wrote:

Hi guys,

I am trying to create an organizational unit and an user with ACI, but it looks like my ACI is not defined correctly.
Below is my ldif.

dn: ou=serviceaccounts,dc=test,dc=example,dc=com
changetype: add
objectclass: top
objectclass: organizationalunit
aci:
 (targetattr = "*")
 (version 3.0;
 acl "default aci for service accounts";
 allow (all)
 (userdn="ldap:///anyone")
 ;)

dn: cn=user1,ou=serviceaccounts,dc=test,dc=example,dc=com
changetype: add
objectclass: top
objectclass: person
sn: tscei.obs
userPassword: testing123
description: This is a test
aci:
 (targetattr = "*")
 (version 3.0;
 acl "user1";
 deny (all)
 (userdn="ldap:///self")
 ;)

I create an organizational unit that allows all users to modify it, then I create user1 that denies everything.
I then use the below LDIF to perform a LDAP add operation.

dn: cn=testing123,cn=user1,ou=serviceaccounts,dc=test,dc=example,dc=com
changetype: add
objectclass: top
objectclass: room

I use this ldapmodify command to perform the add operation
ldapmodify -h hostname -p 1389 -D "cn=user1,ou=serviceaccounts,dc=test,dc=example,dc=com" -w testing123 -f my_test.ldif -x

The add operation succeeded unexpectedly.  The result that I'm looking for should be not enough privilege to perform add operation.

Anyone knows what's wrong with my ACI setup?

Thanks!

David

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