Re: [OAUTH-WG] A proposal for a new Internet Draft

[Warren Parad <[e-mail]>]

I think it would make sense if after CalDAV was updated to explicitly
include OAuth scopes relevant for it, that it could be considered to update
the official OAuth parameter scope list to include them. But I would like
to avoid doing this in reverse. I.e. Let's have the calendar experts decide
what OAuth scopes make sense, and then we can approve adding them to the
list. This makes sense rather than us trying to decide which scopes make
sense for calendar applications that we don't necessarily have expertise
in. I don't have any confidence in my ability (I'm not going to speak for
everyone) in knowing whether these are the right scopes, and getting this
wrong is very very hard to undo. While we can replace CalDAV specs, we
don't have any good strategy to remove official scopes. So before we add
them, we should be near 100% sure that they are the correct ones and will
never change.

On Sun, Apr 2, 2023 at 11:53 PM Clinton Bunch <[e-mail]> wrote:

> On 4/2/2023 4:44 PM, Warren Parad wrote:
>
> If CalDAV is that spec, then wouldn't it make sense to request updates to
> that spec to additionally define OAuth scopes? I don't think it makes sense
> for the OAuth WG to define scopes for other specs, and I also don't think
> updating the CalDAV spec is in the purview of this working group. Instead
> the expectation is for specs using OAuth to define their own scopes. In
> that light, might it make sense to review the current working groups to
> find one that could take on the addendum to the existing CalDAV spec?
>
> I considered posting this to calext or emailcore, but neither would be
> appropriate for all these scopes and Oauth would need to approve the IANA
> registration using this URI namespace.  So I tried here first.
>
>
> On Sun, Apr 2, 2023 at 11:24 PM Clinton Bunch <[e-mail]> wrote:
>
>> On 4/2/2023 4:06 PM, Warren Parad wrote:
>>
>> Why is this still hypothetical, is there a reason you don't want to share
>> a concrete use case?
>>
>> I run a small e-mail and calendar server for my own use.  Thunderbird
>> cannot provide Oauth authentication to my server without knowing what
>> scopes define email services or calendar services or contacts services.  It
>> is impractical to expect Thunderbird to map my specific scopes to those
>> services and do the same for thousands of other servers.  So having a
>> well-defined set of scopes with well-defined semantics allows Thunderbird
>> to use the discovery protocol to see that my AS supports some or all of
>> those scopes.
>>
>>
>> Sure, Thunderbird needs to understand the scopes mapped by email
>> providers, but having shared scope names, does not imply the implementation
>> of those scopes. So Thunderbird still has to maintain a map of "what it
>> wants" to "what scope provides that by that service in question". Having
>> standard scopes doesn't change that, it only hopefully convinces existing
>> email providers to actually change their scope names.
>>
>> Since most small providers don't currently have scopes defined because
>> the clients don't even try to support scopes except those defined by the
>> big players, this gives them a set of scopes that can be reasonably
>> supported by both the AS and the client without manual configuration.
>>
>>
>> Are existing email providers going to change their scope names? I can't
>> see Google Calendar doing that. The problem with defining arbitrary strings
>> that imply permissions, is that "what exactly those scopes means" is not
>> trivially obvious. That is, as David Waite put it, does *calendar:update
>> imply calendar:read*. Adding both to the oauth params still allows some
>> providers to say *yes* while others say *no*. Which means we aren't just
>> talking about adding scopes, we are talking about what those scopes imply.
>> Before we can add scopes, I think we would need to first point to a
>> globally accepted calendar service interface specification which we could
>> use to draw inspiration from. However if such spec already existed, then
>> the scopes would also exist.
>>
>> How is CalDAV  not that spec?
>>
>> Yes, there may be places where the semantics are not quite well-defined
>> enough, that would be the point of having a discussion.
>>
>>
>> That is to say, a spec needs to exist before creating scopes, and if the
>> spec did exist, the scopes would already be defined. For the that reason, I
>> don't believe this this the best working group for that.
>>
>>
>> On Sun, Apr 2, 2023 at 10:53 PM Clinton Bunch <[e-mail]>
>> wrote:
>>
>>> On 4/2/2023 3:13 PM, Warren Parad wrote:
>>>
>>> I'm looking for proof that anyone actually needs these. Introducing
>>> unnecessary scopes into the spec is both a waste of time and needlessly
>>> complicates the documentation. So we need there to be a real problem that
>>> is attempting to be solved in which additional scopes is the right
>>> solution.
>>>
>>> I'm going to start off the conversation by saying, I think this is a bad
>>> idea. Most services in the world do not have any of these, and when they do
>>> the relevant scopes are coupled to the relevant authorization server (AS).
>>> In other words, you only define the scopes you want after reviewing the
>>> documentation for the relevant AS. Defining new standard scopes helps for
>>> interoperability, but there is zero interoperability with scopes (the AS
>>> defines them, the Dev picks them, and the User reviews them. Scopes don't
>>> carry additional meaning cross platforms). So this seems like just a really
>>> bad idea to me.
>>>
>>> Scopes do help with permissions and visibility in the created id_token
>>> (or access_token), for instance let's say a service wanted to link a user's
>>> access to their ethereum wallet. In that case, a new scope like
>>> eth_wallet_id might make sense, so that the wallet public key would show up
>>> in the id_token to be directly used.
>>>
>>> But the scopes that have been proposed don't expose data in the tokens,
>>> they define access. User contact information is already available via *profile,
>>> email, address, and phone*. That means not only are we talking about
>>> creating additional scopes, we are also talking about expanding scopes in a
>>> way that currently isn't used. Which brings us back to, what problem are
>>> you trying to solve?
>>>
>>>
>>> Right now an email (or calendar or contact) client (such as Thunderbird)
>>> is in general written by an organization separate from the author of the
>>> resource server (such as Dovecot), which is different from the author of
>>> the authorization server.  The authorization server may have several scopes
>>> it supports, so even using the discovery protocol, the client doesn't know
>>> how to choose the scopes it needs to request without those scopes being
>>> hard-coded per authorization server, or entered by the user.  This would
>>> allow the client, AS, and resource server too use a common set of scopes to
>>> specify that this domain is offering groupware services and the scopes the
>>> client needs to request.  It requires cooperation from the AS
>>> administrator, true, but both client and server know what the appropriate
>>> scopes are without further configuration.
>>>
>>> These clients may be used across thousandds of AS domains and having to
>>> hard-code the scopes for each is going to deter adoption of Oauth2
>>> authentication, by limiting it to only a few domains.
>>>
>>> Another use case is connecting voice assistants to calendars hosted on
>>> servers of small organizations.  The voice assistant needs to know what
>>> scopes to request for the token to access the users calendar.  Right now
>>> that is limited to just the calendar services of a few large players which
>>> are hard-coded.
>>>
>>> Having the user enter the necessary scopes by hand, where the client has
>>> that capability, leads to a poor user experience.
>>>
>>> The point of these scopes is to allow small players in the field to use
>>> common implementations and have them work for a wide set of users without
>>> placing an undue burden on the user.
>>>
>>>
>>> On Sun, Apr 2, 2023 at 9:57 PM Clinton Bunch <[e-mail]>
>>> wrote:
>>>
>>>> On 4/2/2023 2:49 PM, Warren Parad wrote:
>>>>
>>>> But why these scopes?
>>>>
>>>> Separate read and write scopes for the three pieces of a groupware
>>>> service seemed appropriate.  And separating the three pieces of groupware
>>>> seemed appropriate as not all domains or users will use all of them.
>>>>
>>>> But since the most common use cases would include both read and write,
>>>> I defined short-hand scopes that included both permissions.
>>>>
>>>> If that doesn't answer your question, then I'm not sure what you're
>>>> looking for.
>>>>
>>>>
>>>> On Sun, Apr 2, 2023 at 9:37 PM Clinton Bunch <[e-mail]>
>>>> wrote:
>>>>
>>>>>
>>>>>
>>>>> On 4/2/2023 2:26 PM, Warren Parad wrote:
>>>>>
>>>>> Sorry, I'm asking why these scopes at all? I personally have never
>>>>> seen any of them used ever (and I'm not being hyperbolic), How did you come
>>>>> up with these suggestions?
>>>>>
>>>>> The naming seemed logical given the IANA URI namespace.  I was looking
>>>>> for something that would be a common set of scopes for this application
>>>>> domain that wasn't tied to a single vendor.
>>>>>
>>>>> The purpose *could* be served by widespread adoption of Google's
>>>>> scopes such as
>>>>>
>>>>> https://www.googleapis.com/auth/calendar
>>>>>
>>>>> but I believe that the reliance on a specific vendor name would hamper
>>>>> wide-spread adoption, so a namespace defined by a neutral party such as
>>>>> IETF seemed best.
>>>>>
>>>>> On Sun, Apr 2, 2023 at 8:46 PM Clinton Bunch <[e-mail]>
>>>>> wrote:
>>>>>
>>>>>> On 4/2/2023 1:34 PM, Warren Parad wrote:
>>>>>>
>>>>>> I propose a set of nine well-known scopes
>>>>>>
>>>>>>
>>>>>> Can you elaborate on what you mean by "well-known"? Is there some
>>>>>> canonical list, where these were pulled from?
>>>>>>
>>>>>> I was trying to avoid the use of standard, as that implies they must
>>>>>> be used.  To encourage adoption, I didn't want to imply that the large
>>>>>> providers would be required to change their software to accommodate these,
>>>>>> though it would be nice if they did.  These scopes are not currently in use
>>>>>> as far as I know.
>>>>>>
>>>>>> The sense of well-known is that once this was published they would be
>>>>>> well-known scopes that could be implemented with well-defined semantics.
>>>>>>
>>>>>>
>>>>>> - Warren
>>>>>>
>>>>>> On Sun, Apr 2, 2023 at 8:12 PM Clinton Bunch <[e-mail]>
>>>>>> wrote:
>>>>>>
>>>>>>> This seemed the most appropriate working group to post this
>>>>>>> suggestion.
>>>>>>>
>>>>>>> I would like to see a new Internet-Draft/RFC to add some well-known
>>>>>>> scopes to the IANA registry to promote adoption of Oauth in
>>>>>>> Groupware
>>>>>>> domains.  I will try to write it myself, but have no experience with
>>>>>>> I-Ds or as a technical writer and could use some help.
>>>>>>>
>>>>>>> Since the publication of RFC 7628 there is a push to migrate
>>>>>>> groupware
>>>>>>> servers to use Oauth2.  This is hampered by the fact that there are
>>>>>>> several different server implementations and client implementations
>>>>>>> are
>>>>>>> often written by different organizations with little overlap.  One
>>>>>>> of
>>>>>>> the barriers to widespread adoption is that each authorization
>>>>>>> server
>>>>>>> has a different set of scopes to cover the necessary user
>>>>>>> authorizations.  One groupware client I know has only a few Auth
>>>>>>> Servers
>>>>>>> available that are hardcoded and nearly every one has a different
>>>>>>> set of
>>>>>>> scopes.  Servers have to have appropriate scopes configured by the
>>>>>>> administrator in order for the server to know which scopes to
>>>>>>> check.  It
>>>>>>> also makes it hard for clients to know which scopes to request
>>>>>>> without
>>>>>>> some sort of configuration file provided by the domain or worse,
>>>>>>> having
>>>>>>> the user enter the appropriate scopes by hand.  The latter
>>>>>>> especially
>>>>>>> seems like a support headache for the admin of the groupware servers.
>>>>>>>
>>>>>>> I propose a set of nine well-known scopes be added to the Oauth URI
>>>>>>> IANA
>>>>>>> registry to address this.
>>>>>>>
>>>>>>> urn:ietf:params:oauth:scope:mail:read        - Authorization to read
>>>>>>> email (IMAP,POP)
>>>>>>> urn:ietf:params:oauth:scope:mail:send        - Authorization to send
>>>>>>> mail on the user's behalf (SMTP)
>>>>>>> urn:ietf:params:oauth:scope:mail            - Combination of the
>>>>>>> previous two scopes
>>>>>>> urn:ietf:params:oauth:scope:calendar:read        - Authorization to
>>>>>>> read
>>>>>>> calendar entries
>>>>>>> urn:ietf:params:oauth:scope:calendar:update    - Authorization to
>>>>>>> update/create/delete calendar entries
>>>>>>> urn:ietf:params:oauth:scope:calendar        - Combination of the
>>>>>>> previous two scopes
>>>>>>> urn:ietf:params:oauth:scope:contacts:read        - Authorization to
>>>>>>> read
>>>>>>> contacts information
>>>>>>> urn:ietf:params:oauth:scope:contacts:update    - Authorization to
>>>>>>> update/create/delete contact information.
>>>>>>> urn:ietf:params:oauth:scope:contacts        - Combination of the
>>>>>>> previous two scopes
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> OAuth mailing list
>>>>>>> [e-mail]
>>>>>>> https://www.ietf.org/mailman/listinfo/oauth
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>