Very helpful, thanks a ton! This will give me something to bang around on for awhile and I should be able to get it to do everything we want it to. Ranner, Frank MR wrote:
-----Original Message----- From: freeradius-users-bounces@lists.freeradius.org [mailto:freeradius-users-bounces@lists.freeradius.org] On Behalf Of Kostas Kalevras Sent: Friday, 14 September 2007 04:18 To: FreeRadius users mailing list Subject: Re: OpenLDAP + FreeRADIUS Complete Solution
O/H Mitch McCracken έγραψε:
When organizations grow, there becomes more and more
systems that need
to be maintained, and each may have different
configurations and users
which have access to them. Individually editing local config files gets old pretty fast for hundred of devices, and developing
a unified
and central user authorization database system that spans
across all
types of information systems becomes necessary.
Enter: OpenLDAP. I think I've developed a solution to
maintain Linux
hosts which controls POSIX users/groups/sudo access/apache website access/etc. by using a central LDAP database that stores
policies of
what a user can do on any one of our PCs. The actual
configuration got
fairly ugly, though (PAM not allowing you to specify more than one LDAP Group to allow access to the machine, thus the posixGroup LDAP schema had to be used (since /etc/security/access.conf
allows you to
specify multiple posix group access) instead of groupOfNames, but groupOfNames is needed for apache's ldap auth module, so
both must be
used..), but I've only covered access management for our
websites and
Linux PCs, not all of the various routers, switches, or other RADIUS-aware equipment that exist within the organization.
We use radiuGroupName to assign users to groups. The attribute is stored with the User DN and you can have multiple instances. Apache mod_ldap is compatible with this approach.
Enter: FreeRADIUS. We do already have a FreeRADIUS
configuration that
is auto-generated by our internal MySQL-based access policies to control access to our networking equipment, although this is fairly ugly, and it would be much much nicer if it could use the LDAP database I'm currently developing to control access across
all devices
instead. To put it gently, I want FreeRADIUS to be configured *entirely* off of LDAP.
[snip]
users: All users which will have some sort of access to one of the clients. It appears users are able to be pulled from the LDAP directory by providing the correct DN users are located in. For me, users are all located in ou=people,dc=grnoc,dc=iu,dc=edu.
My personal
entry is something like:
dn: uid=mrmccrac,ou=people,dc=grnoc,dc=iu,dc=edu objectClass: inetOrgPerson objectClass: posixAccount objectClass: radiusprofile ... uid: mrmccrac
I still need to go back and look at the HOWTO perhaps, although I believe this setup can be used somehow/somewhere with FreeRADIUS to have it pull all of our users (specifically uids) from LDAP
instead of
a local file. This leads me to the next FreeRADIUS construct..
groups (group): this specifies groups of users, which can
then later
be used to define access levels (in huntgroups?). From what I read this too can be pulled from FreeRADIUS, that is, the groupOfNames object class can be interpreted if you supply the DN which
has all of
the groups. An example groupOfNames object I currently have
is as such:
dn: cn=dev,ou=ldapgroups,dc=grnoc,dc=iu,dc=edu cn: dev objectClass: groupOfNames objectClass: top member: uid=mrmccrac,ou-people,dc=grnoc,dc=iu,dc=edu
Thus I should be able to tell FreeRADIUS to look at dn: ou=ldapgroups,dc=grnoc,dc=iu,dc=edu, and it should know to
look at the
member attributes to determine which users DN are in each group it finds. Now, finally...
huntgroups: I believe this is the glue between users/groups
to RADIUS
clients. I think the level of access can be defined per
group (which
would be ideal), and then with huntgroups we say which
groups may get
their specified level of access (enable mode or not..) to which networking devices we specified in the clients. Again, like clients.conf, I don't want to have to edit the huntgroups
file anytime
a change is made, but instead make the change in the LDAP directory and have FreeRADIUS pull all huntgroups from there.
In raddb/hints
DEFAULT Hint = `%{ldap:ldap:///ou=hosts,dc=whatever?radiusHuntgroupName?one?ipHostNumber=%{NAS-IP-Address}}`
Is any/all of what I mentioned currently possible based upon my current setup and FreeRADIUS's capabilities? Or, will all
changes to
clients and huntgroups need to be made locally in a file on
the radius
server, but I can at least pull available users and the groups that exist/they belong in from LDAP?
In raddb/users
DEFAULT Hint == "", Huntgroup-Name !* Any,Auth-Type := Reject Reply-Message := "Unknown device, not present in any group."
DEFAULT LDAP-Group == "%{Hint:-%{Huntgroup-Name}}_munge" Reply-Message := "%u found in %{Hint}- We have a combined winner!", Fall-Through = no
DEFAULT Hint != "", LDAP-Group == "%{Hint}_qwerty" Reply-Message := "%u found in %{Hint}- We have a hinted winner!", Fall-Through = no
DEFAULT Huntgroup-Name =* Any, LDAP-Group == "%{Huntgroup-Name}_qwerty" Reply-Message := "%u found in %{Huntgroup-Name}- We have a hunted winner!", Fall-Through = no
# If you don't match any of the systems, deny access DEFAULT Auth-Type := Reject Reply-Message := "You are not in %{Hint:-%{Huntgroup-Name}}"
In addition to straight comparison, you can add suffixes to provide different authorisations. Typically we use _RO, _RW and _RWA to group users into read-only, read-write and read-write-admin groups.
Eg dn: uid=franner,ou=People,dc=whatever radiusGroupName: mss_systemadmin radiusGroupName: PSAX_RW radiusGroupName: Nortel_RO radiusGroupName: tivoli radiusGroupName: ciscoworks radiusGroupName: netscreen_RWA radiusGroupName: Region_ALL radiusGroupName: Netview radiusGroupName: NetviewNative radiusGroupName: config
This is checked like so:
DEFAULT Ldap-Group == `%{Huntgroup-Name}_RWA` Access-Level := RWA, NS-Admin-Privilege := Root-Admin, NS-NSM-User-Domain-Name = global, NS-NSM-User-Role-Mapping = "global:Domain Administrator", Service-Type = Administrative-User
DEFAULT Ldap-Group == `%{Huntgroup-Name}_RO` Access-Level := RO, NS-Admin-Privilege := Read-Only-Admin, NS-NSM-User-Domain-Name = global, NS-NSM-User-Role-Mapping = "global:Read-Only Domain Administrator", Service-Type = Nas-Prompt-User
DEFAULT Ldap-Group == `%{Huntgroup-Name}_10` Cisco-AVPair := "shell:priv-lvl=10"
Using radiusGroupName makes it easy to search for users using cli scripts. It also means, when a user is deleted all group memberships vanish as well. It does mean you cannot create group hierarchies by being in a group contained in another group.
We also use radiusGroupName to determine which servers a user can log into. Using a matching rule in the Ldap ACL we allow servers to only see people whose radiusGroupName matches the proxy cn of the server. In the above ldif record, the tivoli group allows login to tivoli servers. The 'config' group is referenced by apache2 to allow access to a internal web site, etc.
Hope this helps.
Regards Frank Ranner
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