[Freeipa-devel] [PATCH] Add option to disable setkeytab extended operations

[Petr Spacek]

On 1.12.2015 09:47, Alexander Bokovoy wrote:
> On Tue, 01 Dec 2015, Petr Spacek wrote:
>> On 1.12.2015 09:21, Alexander Bokovoy wrote:
>>> On Tue, 01 Dec 2015, Petr Spacek wrote:
>>>> On 24.11.2015 20:42, Simo Sorce wrote:
>>>>> Since some time we use the getkeytab operation to fetch keytabs on newer
>>>>> clients. According to bug #232 setkeytab can be used to circumvent
>>>>> password quality controls so it needs to be slowly retired.
>>>>>
>>>>> The attached patches implement #5485 in 2 parts.
>>>>>
>>>>> The first introduces the option DisableSetKeytab which globally disables
>>>>> the setkeytab extended operation. This is set to false by default for
>>>>> backwards compatibility.
>>>>>
>>>>> The second introduces an option called DisableUserSetKeytab, which is
>>>>> active by default in new installs (but not in upgraded ones), and only
>>>>> disables the use of setkeytab for ipa suers, but not for hosts/services.
>>>>> This is because user's are the ones that may abuse the interface to
>>>>> escape password policies and users also normally do not acquire keytabs,
>>>>> so it is a safe bet to disable just them by default in new installs.
>>>>
>>>> On a related note, how this works with plain kadmin & kpasswd protocols?
>>> It is unrelated. We don't support principal manipulation via kadmin
>>> protocol.
>>
>> Sure, I know that, but I'm trying to find out if we re-invented the wheel or
>> if our wheel has some additional features which cannot be incorporated to the
>> original wheel :-)
> There is no need to incorporate something specific into kadmin protocol,
> the problem is with the fact that we don't have access controls within
> our KDC driver. It always connects to LDAP server over ldapi as root and
> thus maps to cn=Directory Manager which bypasses LDAP ACIs. As such,
> this means we'll need to have some access control added to KDC DAL
> driver before we can allow kadmin operations on principals.
> 
> Adding those access controls is not an easy feat.

Hmm, why is that? We could use LDAP Proxy control (RFC 4370) and let DS to
evaluate ACIs as usual. The change in kadmin would be adding LDAP Proxy
control with proper DN (i.e. mapping from principal name to DN) to the LDAP
requests.

-- 
Petr^2 Spacek