Re: [Id-event] SAML subject identifier type

[Brian Campbell <[e-mail]>]

+ 1 to what Yaron is saying here. I'd include also the "iss-sub" subject
identifier type
https://tools.ietf.org/html/draft-ietf-secevent-subject-identifiers-05#section-3.4
as already having semantics covering what's described in the ID Token
Claims Subject Identifier Type in the RISC document referenced. And all
those things represent a durable subject rather than a session, which
strikes me as appropriate for a document that describes identifying
subjects. A SAML assertion ID, however, which is an identifier of an XML
document that is only indirectly related to a session by an association
that likely isn't maintained, does not seem appropriate as a "subject
identifier".

On Tue, Jul 14, 2020 at 4:01 PM Yaron Sheffer <[e-mail]> wrote:

> Hi Atul,
>
>
>
> The ID Token subject type, as described in the document you are
> referencing, does not add any semantics, compared to a “phone number” or
> “email” subject type. So I don’t see the value in adding it.
>
>
>
> In addition, it does not, actually, describe an ID Token. In fact the text
> is very clear that it describes a “subject” (a durable entity) rather than
> a session, and does it by citing various claims included in the ID token.
> So as a subject identifier type, it is not at all equivalent to a SAML
> assertion.
>
>
>
> As to the SAML Assertion subject type, I think these use cases could be
> addressed by adding information to the event.
>
>
>
> Thanks,
>
>                 Yaron
>
>
>
> *From: *Atul Tulshibagwale <[e-mail]>
> *Date: *Tuesday, July 14, 2020 at 23:26
> *To: *Yaron Sheffer <[e-mail]>
> *Cc: *Chris Phillips <[e-mail]>, "[e-mail]" <
> [e-mail]>
> *Subject: *Re: [Id-event] SAML subject identifier type
>
>
>
> Hi Yaron,
>
> There are a few SSE use cases where the events are about a specific single
> sign-on session. You're right that this should not be limited to SAML. The
> RISC profile of SETs (based on which we are doing the SSE work) had the ID
> Token subject identifier type, which for some reason is missing in this
> spec (I did not realize until now). The specific events that need to refer
> to sessions are:
>
>    - Identity provider context change: The conditions under which a SAML
>    assertion or OIDC token was generated are no longer valid. This can be due
>    to various things, including a password change.
>    - Session property change: A session has been determined to have been
>    compromised
>    - Revocation: The issuer of the single sign-on SAML assertion or ID
>    Token needs to be revoke
>
> I can also add the ID Token claim from the RISC profile
> <https://bitbucket.org/openid/risc/src/master/openid-risc-profile-1_0.txt#lines-250>
> to my pull request.
>
>
>
> Thanks,
>
> Atul
>
>
>
>
>
> On Tue, Jul 14, 2020 at 12:32 PM Yaron Sheffer <[e-mail]>
> wrote:
>
> I need a lot more context here. So far, subject IDs have denoted durable
> entities, such as email addresses, phone numbers, account. This is adding a
> subject ID that denotes an ephemeral entity, basically similar to a session
> ID. This looks weird from an architectural point of view, and also begs the
> question, why specifically SAML and not other session types.
>
>
>
> Thanks,
>
>                 Yaron
>
>
>
> *From: *Id-event <[e-mail]> on behalf of Atul
> Tulshibagwale <atultulshi=[e-mail]>
> *Date: *Tuesday, July 14, 2020 at 00:14
> *To: *Chris Phillips <[e-mail]>
> *Cc: *"[e-mail]" <[e-mail]>
> *Subject: *Re: [Id-event] SAML subject identifier type
>
>
>
> Just clarifying the proposal as it stands today (before incorporating
> Chris's input):
>
> The following section should be added in the "Subject Identifier Types"
> section:
>
> 4.9.  SAML Subject Identifier Type
>
>    The SAML [SAML.REF] Subject Identifier Type describes a subject by
>    the assertion identifier in the SAML assertion that was used to
>    convey the subject's information to the Receiver.  Subject
>    Identifiers of this type MUST contain an ` assertion_id"claim.  The
>    value of this claim is a string that is equal to the Assertion
>    Identifier in the SAML assertion.  The SAML Subject Identifier Type
>    is identified by the name "saml`.
>
>    Below is a non-normative example Subject Identifier for the SAML
>    Subject Identifier Type:
>
>    {
>      "subject_type": "saml",
>      "assertion_id": "_f551d88963ab4e3decb7cfe8f4dcc3f5",
>    }
>
>      Figure 8: Example: Subject Identifier for SAML Subject Identifier
>                                    Type.
>
>
>
>
>
> On Mon, Jul 13, 2020 at 1:22 PM Atul Tulshibagwale <[e-mail]>
> wrote:
>
> Hi Chris,
>
> I was proposing using the "assertion id" (SAML Core
> <http://docs.oasis-open.org/security/saml/v2.0/saml-core-2.0-os.pdf>
> spec, line 553) in the proposal, not the "subject-id" as defined in SAML
> (spec section 3.3). The main reason was to be able to refer to a session
> that was established using a specific assertion. If it's useful, we could
> perhaps extend the SAML subject identifier type in this spec to include
> either the assertion_id or the subject_id claim.
>
>
>
> Thanks,
>
> Atul
>
>
>
>
>
> On Mon, Jul 13, 2020 at 10:30 AM Chris Phillips <[e-mail]>
> wrote:
>
> Hi.
>
> Quiet lurker observing..
>
> Thanks for consider the SAML elements..
>
>
>
> Atul, are you referring to the actual session identifier that someone may
> have where the Subject-Id was exchanged OR the actual Subject-id itself in
> your reference in the proposal with the github link?
>
>
>
> I’m trying to square what I see on the git delta on line 294-296 in
> https://github..com/richanna/secevent/pull/1/commits/b20b6692eb50628927476ca78f9be077ace88994
> <https://github.com/richanna/secevent/pull/1/commits/b20b6692eb50628927476ca78f9be077ace88994>
>
>
>
>
>
> And a Subject-id as shown in the example in 3.3.3 here:
> https://docs.oasis-open.org/security/saml-subject-id-attr/v1.0/cs01/saml-subject-id-attr-v1.0-cs01.html#_Toc536097229
> <https://docs.oasis-open.org/security/saml-subject-id-attr/v1.0/cs01/saml-subject-id-attr-v1..0-cs01..html#_Toc536097229>
>
>
>
> What you offered in the example is not a Subject-id  per the OASIS SAML
> spec as written in section 3.3.1
>
>
>
> Am I mis-interpreting something?
>
>
>
> C
>
>
>
>
>
> *From: *Id-event <[e-mail]> on behalf of Atul
> Tulshibagwale <atultulshi=[e-mail]>
> *Date: *Monday, July 13, 2020 at 12:17 PM
> *To: *"[e-mail]" <[e-mail]>
> *Subject: *[Id-event] SAML subject identifier type
>
>
>
> Hi all,
>
> Based on the discussions in the SSE working group within the OpenID
> Foundation, we would like to propose that the subject identifier
> specification include a SAML subject identifier type. This is so that
> sessions established across peers using SAML may be identified in events
> that include the subject identifier.
>
>
>
>  A SAML subject identifier has only one claim within it, the assertion id
> of the SAML assertion used to establish the single sign-on session.
>
>
>
> This change is also included in my proposal here
> <https://github.com/richanna/secevent/pull/1>.
>
>
>
> Thanks,
>
> Atul
>
>
>
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