[Freeipa-devel] [PATCH 0049] Add support for protected tokens

Mon Jun 16 07:17:09 UTC 2014

On 13.6.2014 21:59, Nathaniel McCallum wrote:
> 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
>

I'm fine with that.

-- 
Jan Cholasta