[Freeipa-devel] [PATCH 0049] Add support for protected tokens
Nathaniel McCallum
npmccallum at redhat.com
Fri Jun 13 19:59:13 UTC 2014
On Wed, 2014-06-11 at 12:43 -0400, Nathaniel McCallum wrote:
> On Wed, 2014-06-11 at 12:12 +0200, Ludwig Krispenz wrote:
> > On 05/13/2014 04:33 PM, Jan Cholasta wrote:
> > > On 12.5.2014 21:02, Nathaniel McCallum wrote:
> > >> On Thu, 2014-05-08 at 13:51 -0400, Simo Sorce wrote:
> > >>> On Thu, 2014-05-08 at 12:26 -0400, Nathaniel McCallum wrote:
> > >>>> On Wed, 2014-05-07 at 11:17 -0400, Simo Sorce wrote:
> > >>>>> On Wed, 2014-05-07 at 09:54 -0400, Dmitri Pal wrote:
> > >>>>>> On 05/07/2014 09:05 AM, Nathaniel McCallum wrote:
> > >>>>>>> On Wed, 2014-05-07 at 11:42 +0200, Jan Cholasta wrote:
> > >>>>>>>> Hi,
> > >>>>>>>>
> > >>>>>>>> On 6.5.2014 17:08, Nathaniel McCallum wrote:
> > >>>>>>>>> On Tue, 2014-05-06 at 09:49 -0400, Nathaniel McCallum wrote:
> > >>>>>>>>>> On Mon, 2014-05-05 at 12:42 -0400, Nathaniel McCallum wrote:
> > >>>>>>>>>>> This also constitutes a rethinking of the token ACIs after the
> > >>>>>>>>>>> introduction of SELFDN support.
> > >>>>>>>>>>>
> > >>>>>>>>>>> Admins, as before, have full access to all token permissions.
> > >>>>>>>>>>>
> > >>>>>>>>>>> Normal users have read/search/compare access to all of the
> > >>>>>>>>>>> non-secret
> > >>>>>>>>>>> data for tokens assigned to them, whether protected or
> > >>>>>>>>>>> non-protected.
> > >>>>>>>>>>> Users can add or delete non-protected tokens and modify most
> > >>>>>>>>>>> of their
> > >>>>>>>>>>> metadata. However they cannot create, delete or modify
> > >>>>>>>>>>> protected tokens.
> > >>>>>>>>>>> Regardless of whether the token is protected or not, users
> > >>>>>>>>>>> cannot change
> > >>>>>>>>>>> a token's ownership or unique identity.
> > >>>>>>>>>>>
> > >>>>>>>>>>> In contrast, admins can create protected tokens. This
> > >>>>>>>>>>> protects the token
> > >>>>>>>>>>> from deletion or modification when assigned to users.
> > >>>>>>>>>>> Additionally, when
> > >>>>>>>>>>> a user account is deleted, the assigned non-protected tokens
> > >>>>>>>>>>> are deleted
> > >>>>>>>>>>> but the protected tokens are merely orphaned. This permits
> > >>>>>>>>>>> the token to
> > >>>>>>>>>>> be reassigned without having to recreate it. This last point is
> > >>>>>>>>>>> particularly useful in the case of hardware tokens.
> > >>>>>>>>>>>
> > >>>>>>>>>>> https://fedorahosted.org/freeipa/ticket/4228
> > >>>>>>>>>>>
> > >>>>>>>>>>> NOTE: This patch depends on my patch 0048.
> > >>>>>>>>>> This new version makes ipatokenDisabled visible for token
> > >>>>>>>>>> owners. It is
> > >>>>>>>>>> also writable if the token is non-protected. This
> > >>>>>>>>>> additionally fixes:
> > >>>>>>>>>>
> > >>>>>>>>>> https://fedorahosted.org/freeipa/ticket/4259
> > >>>>>>>>> This new version changes the way the default value of
> > >>>>>>>>> protected is setup
> > >>>>>>>>> in accordance with the changes made for the review of my patch
> > >>>>>>>>> 0048.2.
> > >>>>>>>>>
> > >>>>>>>>> Nathaniel
> > >>>>>>>> Is using the ipatokenprotected attribute the final design?
> > >>>>>>> No. Alternate designs are welcome. The code is easy enough to
> > >>>>>>> modify.
> > >>>>>>>
> > >>>>>>>> I did not dig too deep into this, but I think it might be
> > >>>>>>>> better to
> > >>>>>>>> instead use the managedby attribute on a token to limit who can
> > >>>>>>>> delete
> > >>>>>>>> (or administer in other way) the token. On otptoken-add,
> > >>>>>>>> managedby would
> > >>>>>>>> be set to the "whoami" user DN, unless run with --protected, in
> > >>>>>>>> which
> > >>>>>>>> case managedby would be left empty. Then, when deleting a user,
> > >>>>>>>> the
> > >>>>>>>> token would be deleted only if the user manages the token.
> > >>>>>>> It seems to me that the mechanics of this are roughly the same as
> > >>>>>>> protected, just with a different syntax. The cost of this is more
> > >>>>>>> complex ACIs. In particular, we'd have to use two userdn clauses
> > >>>>>>> (is
> > >>>>>>> this possible?) instead of a simple filter. If there is a clear
> > >>>>>>> benefit,
> > >>>>>>> we can justify the more obtuse syntax.
> > >>>>>>
> > >>>>>> We usually try not to create new attributes until it is fully
> > >>>>>> justified.
> > >>>>>> I would like Simo to chime in on this.
> > >>>>>
> > >>>>> I would also prefer to reuse existing attributes and mechanism if
> > >>>>> possible and if it will not preclude future work.
> > >>>>>
> > >>>>> In this case, it "sounds" like managed-by has the appropriate
> > >>>>> meaning:
> > >>>>> "who manages the token ?" -> myself, admin, other, none ?
> > >>>>>
> > >>>>> Nathaniel can you send 2 lines showing the difference in ACIs between
> > >>>>> using managed-by vs a new attribute ?
> > >>>>
> > >>>> These are the ACIs using the protected mechanism:
> > >>>>
> > >>>> aci: (targetfilter = "(objectClass=ipaToken)")(targetattrs =
> > >>>> "objectclass || description || ipatokenUniqueID || ipatokenDisabled ||
> > >>>> ipatokenNotBefore || ipatokenNotAfter || ipatokenVendor ||
> > >>>> ipatokenModel
> > >>>> || ipatokenSerial || ipatokenOwner || ipatokenProtected")(version 3.0;
> > >>>> acl "Users can read basic token info"; allow (read, search, compare)
> > >>>> userattr = "ipatokenOwner#USERDN";)
> > >>>>
> > >>>> aci: (targetfilter = "(objectClass=ipatokenTOTP)")(targetattrs =
> > >>>> "ipatokenOTPalgorithm || ipatokenOTPdigits ||
> > >>>> ipatokenTOTPtimeStep")(version 3.0; acl "Users can see TOTP details";
> > >>>> allow (read, search, compare) userattr = "ipatokenOwner#USERDN";)
> > >>>>
> > >>>> aci: (targetfilter = "(objectClass=ipatokenHOTP)")(targetattrs =
> > >>>> "ipatokenOTPalgorithm || ipatokenOTPdigits")(version 3.0; acl
> > >>>> "Users can
> > >>>> see HOTP details"; allow (read, search, compare) userattr =
> > >>>> "ipatokenOwner#USERDN";)
> > >>>>
> > >>>> aci: (targetfilter =
> > >>>> "(&(objectClass=ipaToken)(!(ipatokenProtected=TRUE)))")(targetattrs =
> > >>>> "description || ipatokenDisabled || ipatokenNotBefore ||
> > >>>> ipatokenNotAfter || ipatokenVendor || ipatokenModel ||
> > >>>> ipatokenSerial")(version 3.0; acl "Users can write basic token info";
> > >>>> allow (write) userattr = "ipatokenOwner#USERDN";)
> > >>>>
> > >>>> aci: (target =
> > >>>> "ldap:///ipatokenuniqueid=*,cn=otp,$SUFFIX")(targetfilter
> > >>>> = "(&(objectClass=ipaToken)(!(ipatokenProtected=TRUE))))")(version
> > >>>> 3.0;
> > >>>> acl "Users can create and delete tokens"; allow (add, delete)
> > >>>> userattr =
> > >>>> "ipatokenOwner#SELFDN";)
> > >>>>
> > >>>> This is what they look like using managedBy (I have not tested this):
> > >>>>
> > >>>> aci: (targetfilter = "(objectClass=ipaToken)")(targetattrs =
> > >>>> "objectclass || description || ipatokenUniqueID || ipatokenDisabled ||
> > >>>> ipatokenNotBefore || ipatokenNotAfter || ipatokenVendor ||
> > >>>> ipatokenModel
> > >>>> || ipatokenSerial || ipatokenOwner || ipatokenProtected")(version 3.0;
> > >>>> acl "Users can read basic token info"; allow (read, search, compare)
> > >>>> userattr = "ipatokenOwner#USERDN"; allow (read, search, compare)
> > >>>> userattr = "managedBy#USERDN";)
> > >>>>
> > >>>> aci: (targetfilter = "(objectClass=ipatokenTOTP)")(targetattrs =
> > >>>> "ipatokenOTPalgorithm || ipatokenOTPdigits ||
> > >>>> ipatokenTOTPtimeStep")(version 3.0; acl "Users can see TOTP details";
> > >>>> allow (read, search, compare) userattr = "ipatokenOwner#USERDN"; allow
> > >>>> (read, search, compare) userattr = "managedBy#USERDN";)
> > >>>>
> > >>>> aci: (targetfilter = "(objectClass=ipatokenHOTP)")(targetattrs =
> > >>>> "ipatokenOTPalgorithm || ipatokenOTPdigits")(version 3.0; acl
> > >>>> "Users can
> > >>>> see HOTP details"; allow (read, search, compare) userattr =
> > >>>> "ipatokenOwner#USERDN"; allow (read, search, compare) userattr =
> > >>>> "managedBy#USERDN";)
> > >>>>
> > >>>> aci: (targetfilter = "(objectClass=ipaToken)")(targetattrs =
> > >>>> "description || ipatokenDisabled || ipatokenNotBefore ||
> > >>>> ipatokenNotAfter || ipatokenVendor || ipatokenModel ||
> > >>>> ipatokenSerial")(version 3.0; acl "Managers can write basic token
> > >>>> info";
> > >>>> allow (write) userattr = "managedBy#USERDN";)
> > >>>>
> > >>>> aci: (targetfilter = "(objectClass=ipaToken)")(version 3.0; acl
> > >>>> "Managers can delete tokens"; allow (delete) userattr =
> > >>>> "managedBy#USERDN";)
> > >>>>
> > >>>> aci: (target =
> > >>>> "ldap:///ipatokenuniqueid=*,cn=otp,$SUFFIX")(targetfilter
> > >>>> = "(objectClass=ipaToken)")(version 3.0; acl "Users can create
> > >>>> self-managed tokens"; allow (add) userattr = "ipatokenOwner#SELFDN"
> > >>>> and
> > >>>> userattr = "managedBy#SELFDN";)
> > >>>>
> > >>>> In short:
> > >>>> 1. Owner and manager get read, search and compare.
> > >>>> 2. Manager gets write (to select attributes) and delete.
> > >>>> 3. Users can create self-managed tokens for themselves only.
> > >>>>
> > >>>> The otptoken-add command should gain the following defaults:
> > >>>> 1. The owner defaults to the user adding the token.
> > >>>> 2. If owner == user adding token, managedBy defaults to owner.
> > >>>> 3. Otherwise, managedBy defaults to None.
> > >>>>
> > >>>> This means that if neither owner nor managedBy are specified, the
> > >>>> default is a self-owned, self-managed token. Likewise, if a different
> > >>>> owner is specified, no manager is assumed.
> > >>>>
> > >>>> rcrit expresses worry that ipalib's ACI parser may not handle the
> > >>>> above
> > >>>> syntax. This will become clear during testing if we want this
> > >>>> approach.
> > >>>>
> > >>>> Does this look sane?
> > >>>
> > >>> I am not entirely sure your ACI syntax is always right for the second
> > >>> set. and perhaps we want to duplicate ACIs in some cases (once for
> > >>> owner
> > >>> once for manager).
> > >>>
> > >>> I think the read ACIs do not need to list managedby ? Do we plan to
> > >>> have
> > >>> a manager that is another regular user but not the owner nor an admin ?
> > >>>
> > >>> In any case I prefer the sytnax that uses managedby, as it has more
> > >>> potential.
> > >>
> > >> Attached is a new version of the patch which implements the feature
> > >> using managedBy instead of ipatokenProtected. One important thing needs
> > >> to be said about this patch. I am not exposing managedBy in either the
> > >> UI, the CLI or LDAP (ACI). Do we care about this? If yes, should I
> > >> expose this similar to owner or as a relationship?
> > >
> > > I would expose it, as a relationship. (Note that ipatokenowner should
> > > ideally be represented as a relationship too, but the framework does
> > > not support 1-to-many relationships ATM.)
> > >
> > >
> > > Just curious, why are the ACIs divided like this:
> > >
> > > aci: (targetfilter = "(objectClass=ipaToken)")(targetattrs =
> > > "objectclass || description || ipatokenUniqueID || ipatokenDisabled ||
> > > ipatokenNotBefore || ipatokenNotAfter || ipatokenVendor ||
> > > ipatokenModel || ipatokenSerial || ipatokenOwner")(version 3.0; acl
> > > "Users/managers can read basic token info"; allow (read, search,
> > > compare) userattr = "ipatokenOwner#USERDN" or userattr =
> > > "managedBy#USERDN";)
> > > aci: (targetfilter = "(objectClass=ipatokenTOTP)")(targetattrs =
> > > "ipatokenOTPalgorithm || ipatokenOTPdigits ||
> > > ipatokenTOTPtimeStep")(version 3.0; acl "Users/managers can see TOTP
> > > details"; allow (read, search, compare) userattr =
> > > "ipatokenOwner#USERDN" or userattr = "managedBy#USERDN";)
> > > aci: (targetfilter = "(objectClass=ipatokenHOTP)")(targetattrs =
> > > "ipatokenOTPalgorithm || ipatokenOTPdigits")(version 3.0; acl
> > > "Users/managers can see HOTP details"; allow (read, search, compare)
> > > userattr = "ipatokenOwner#USERDN" or userattr = "managedBy#USERDN";)
> > >
> > > IMHO you could make them less complex by dividing them like this:
> > >
> > > aci: (targetfilter = "(objectClass=ipaToken)")(targetattrs =
> > > "objectclass || description || ipatokenUniqueID || ipatokenDisabled ||
> > > ipatokenNotBefore || ipatokenNotAfter || ipatokenVendor ||
> > > ipatokenModel || ipatokenSerial || ipatokenOwner ||
> > > ipatokenOTPalgorithm || ipatokenOTPdigits ||
> > > ipatokenTOTPtimeStep")(version 3.0; acl "Owner can read token
> > > details"; allow (read, search, compare) userattr =
> > > "ipatokenOwner#USERDN";)
> > > aci: (targetfilter = "(objectClass=ipaToken)")(targetattrs =
> > > "objectclass || description || ipatokenUniqueID || ipatokenDisabled ||
> > > ipatokenNotBefore || ipatokenNotAfter || ipatokenVendor ||
> > > ipatokenModel || ipatokenSerial || ipatokenOwner ||
> > > ipatokenOTPalgorithm || ipatokenOTPdigits ||
> > > ipatokenTOTPtimeStep")(version 3.0; acl "Managers can read token
> > > details"; allow (read, search, compare) userattr = "managedBy#USERDN";)
> > do you mean aci: (targetfilter =
> > "(|(objectClass=ipaToken)(objectClass=ipatokenTOTP)(objectClass=ipatokenHOTP))")
> > or are the attrs like ipatokenOTPdigits also in the ipatoken objectclass ?
> > >
>
> Ludwig,
>
> objectClasses: (2.16.840.1.113730.3.8.16.2.1 NAME 'ipaToken' SUP top
> ABSTRACT DESC 'Abstract token class for tokens' MUST (ipatokenUniqueID)
> MAY (description $ ipatokenOwner $ ipatokenDisabled $ ipatokenNotBefore
> $ ipatokenNotAfter $ ipatokenVendor $ ipatokenModel $ ipatokenSerial)
> X-ORIGIN 'IPA OTP')
>
> objectClasses: (2.16.840.1.113730.3.8.16.2.2 NAME 'ipatokenTOTP' SUP
> ipaToken STRUCTURAL DESC 'TOTP Token Type' MUST (ipatokenOTPkey $
> ipatokenOTPalgorithm $ ipatokenOTPdigits $ ipatokenTOTPclockOffset $
> ipatokenTOTPtimeStep) X-ORIGIN 'IPA OTP')
>
> objectClasses: (2.16.840.1.113730.3.8.16.2.5 NAME 'ipatokenHOTP' SUP
> ipaToken STRUCTURAL DESC 'HOTP Token Type' MUST (ipatokenOTPkey $
> ipatokenOTPalgorithm $ ipatokenOTPdigits $ ipatokenHOTPcounter) X-ORIGIN
> 'IPA OTP')
Ludwig / Jan,
I'd like to propose that we move ahead and merge this patch since the
only outstanding item is the question of performance for the ACIs.
Nathaniel
More information about the Freeipa-devel
mailing list