Simo Sorce wrote:
On Fri, 2012-06-22 at 14:25 +0200, Martin Kosek wrote:
On 06/22/2012 02:23 PM, Simo Sorce wrote:
On Fri, 2012-06-22 at 12:20 +0200, Martin Kosek wrote:
On 06/18/2012 05:37 PM, Rob Crittenden wrote:
Martin Kosek wrote:
On Fri, 2012-06-15 at 10:15 -0400, Simo Sorce wrote:
On Fri, 2012-06-15 at 15:22 +0200, Martin Kosek wrote:
Hello all,
In a scope of ticket 2511 I would like to implement an ability to
delegate a DNS update permissions to chosen user (or host) without
having to give the user full "Update DNS Entries" privileges, i.e.
allow
him to modify any DNS zone or record.
So far, this is what I would like to do (comments welcome):
1) Create new objectclass "idnsManagedZone" with "managedBy" attribute
in MAY list
2) Create new DNS commands:
a] dnszone-add-managedby [--users=USERS] [--hosts=HOSTS]
b] dnszone-remove-managedby [--users=USERS] [--hosts=HOSTS]
- these commands would add/remove chosen user/host DN to managedBy
attribute in chosen DNS zone
3) Add new generic ACIs to cn=dns,$SUFFIX:
aci: (target = "ldap:///idnsname=*,cn=dns,$SUFFIX";)(version 3.0;acl
"Users and hosts can add DNS entries";allow (add) userattr =
"parent[1].managedby#USERDN";)
... add similar ACIs for UPDATE, REMOVE access
With these steps done, all that an administrator would need to do to
delegate a management of a DNS zone "example.com" is to run this
command:
$ ipa dnszone-add-managedby example.com --users=fbar
The only downside I found so far is that the user would already need to
have "Read DNS Entries" permission assigned, otherwise he would not be
able to actually read DNS entries (allow rules can't take precedence
over deny rule we implemented to deny public access to DNS tree).
An admin could of course create a special privilege and role with just
"Read DNS Entries" permission and then assign it to relevant
users/groups, but this looks awkward. Any idea to make this simpler?
Maybe creating a group "dns readers" by default which would allow such
access?
Change the deny rule to deny to everyone except the user in
"parent[1].managedby#USERDN" ?
Simo.
Good idea, I will do that. I will just use
"parent[0,1].managedby#USERDN" so that user can also read the zone
record. This way, a selected user will have read/write access to the
chosen zone only, which is exactly what we want to achieve.
Yes, this sounds workable to me too.
rob
There were some second thoughts about the proposed design, which I would
like to discuss so that we can eventually accept another (better)
solution for this feature.
The main concern here was that proposed solution (based on user list in
managedBy attribute in DNS zone) is not in line with the rest of
permission&privilege architecture in IPA.
Here is another idea how to address the feature (I tested it and it
would work):
1) Get rid of the deny rule on cn=dns,$SUFFIX by modifying global access
rule (a working patch attached) to avoid current and future issues with
extending ACIs (deny rules are evil).
2) Add new Managed Entry Definition and Template to automatically add
"Manage DNS zone $idsname" permission. These could be used with standard
IPA privileges, roles and thus could be assigned to users, groups,
hosts, hostgroups...
3) New DNS zone managedBy attribute won't be manageable by user, but it
will hold a DN of the managed Permission entry
4) Add the following ACIs to cn=dns,$SUFFIX:
aci: (targetattr = "*")
(version 3.0; acl "Read DNS entries"; allow (read,search,compare)
userattr = "parent[0,1].managedby#GROUPDN";)
aci: (target = "ldap:///idnsname=*,cn=dns,$SUFFIX";)
(version 3.0;acl "Add dns entries";allow (add)
userattr = "parent[1].managedby#GROUPDN";)
aci: (target = "ldap:///idnsname=*,cn=dns,$SUFFIX";)
(version 3.0;acl "Remove DNS entries";allow (delete)
userattr = "parent[1].managedby#GROUPDN";)
aci: (targetattr = "idnsname || cn || idnsallowdynupdate || dnsttl ||
dnsclass || arecord || aaaarecord || a6record || nsrecord || cnamerecord
|| ptrrecord || srvrecord || txtrecord || mxrecord || mdrecord ||
hinforecord || minforecord || afsdbrecord || sigrecord || keyrecord ||
locrecord || nxtrecord || naptrrecord || kxrecord || certrecord ||
dnamerecord || dsrecord || sshfprecord || rrsigrecord || nsecrecord ||
idnsname || idnszoneactive || idnssoamname || idnssoarname ||
idnssoaserial || idnssoarefresh || idnssoaretry || idnssoaexpire ||
idnssoaminimum || idnsupdatepolicy || idnsallowquery ||
idnsallowtransfer || idnsallowsyncptr || idnsforwardpolicy ||
idnsforwarders")
(target = "ldap:///idnsname=*,cn=dns,$SUFFIX";)(version 3.0;acl "Update
DNS Entries";allow (write) userattr = "parent[0,1].managedby#GROUPDN";)
I needed to add permission DN to the managedBy attribute so that I could
create just one set of generic ACIs without having to create a set of
ACIs for every new zone and thus let users with "Update DNS entries"
permission have a write access to the "aci" attribute.
Would this design be better than the previous one? Comments welcome.
Removing Deny ACIs would be great.
But don't we need a second set of ACIs to allow uber admins to still
control all zones ? or is that part of current ACIs not going to
change ?
Simo.
Thanks to the removal of the deny rule, this would be already allowed by
this existing ACI:
aci: (targetattr != "userPassword || krbPrincipalKey || sambaLMPassword
|| sambaNTPassword || passwordHistory || krbMKey || krbPrincipalName ||
krbCanonicalName || krbUPEnabled || krbTicketPolicyReference ||
krbPrincipalExpiration || krbPasswordExpiration || krbPwdPolicyReference
|| krbPrincipalType || krbPwdHistory || krbLastPwdChange ||
krbPrincipalAliases || krbExtraData || krbLastSuccessfulAuth ||
krbLastFailedAuth || krbLoginFailedCount || krbTicketFlags ||
ipaUniqueId || memberOf || serverHostName || enrolledBy")(version 3.0;
acl "Admin can manage any entry"; allow (all) groupdn =
"ldap:///cn=admins,cn=groups,cn=accounts,$SUFFIX";;)
Oh right!
I like it even more then :-)
Simo.
Yes, this looks like it will work and eliminating a deny rule is a
definite plus.
rob
_______________________________________________
Freeipa-devel mailing list
[email protected]
https://www.redhat.com/mailman/listinfo/freeipa-devel
