RE: [wss] Comments on SAML Token Profile

[Anthony Nadalin <drsecure@us.ibm.com>]

The core already describes mechanisms, don't see a need for a new mechanism. As previously indicated the core needs to be clear.

Anthony Nadalin | work 512.838.0085 | cell 512.289.4122
"Maneesh Sahu" <maneesh@westbridgetech.com>

"Maneesh Sahu" <maneesh@westbridgetech.com>

06/24/2004 07:36 PM

To	Michael McIntosh/Watson/IBM@IBMUS, "Levinson, Richard" <rlevinson@netegrity.com>
cc	Anthony Nadalin/Austin/IBM@IBMUS, <wss@lists.oasis-open.org>
Subject	RE: [wss] Comments on SAML Token Profile

Mike,
Your suggestion to simply processing is an excellent one. This could
apply to the REL Token profile too.

Instead of having a specific wss:SAMLToken wrapping just a
saml:Assertion, we could have a more generic element, say a
wss:SecurityTokenWrapper wrapping any type of token be it saml:Assertion
or the xrml Token.

--ms

-----Original Message-----
From: Michael McIntosh [mailto:mikemci@us.ibm.com]
Sent: Thursday, June 24, 2004 5:19 PM
To: Levinson, Richard
Cc: Anthony Nadalin; wss@lists.oasis-open.org
Subject: RE: [wss] Comments on SAML Token Profile

Richard,

The core obviously should be more clear in this area. The point I am
trying to make is that, regardless of any ambiguities present in the
core,
references to local tokens by URI should not require token specific
schema
processing.

I do not understand the resistence to this simple change. It does not
require any changes to SAML, the only impact is on the WSS: SAML Token
Profile. I think the benefits or token schema independent dereferencing
far outweigh any negative impact of the addition of an outer token
element.

Can you please explain your reason for not wanting to make this change?
Please don't say just because ambiguities in the core allow it.

Thanks,
Mike

"Levinson, Richard" <rlevinson@netegrity.com> wrote on 06/24/2004
08:00:11
PM:

> It appears to me that the WS-Security core spec is loose
> enough to accept both your interpretation and the interpretation
> that is in the SAML Token Profile spec. Lines 305-308 show
> the use of a "custom token" where the particular token
> has a wsu:ID that is referenced by the STR that has only
> a URI attribute.
>
> I think it is reasonable to consider a SAML Assertion to
> be a "custom token" in this sense, with the exception that
> the SAML Assertion does not allow the wsu:Id attribute.
>
> As such, the SAML Token profile has chosen to take advantage
> of the ValueType attribute which states "... specifications
> for individual token types MAY define specific processing
> rules and semantics around the value of the URI and how it
> SHALL be interpreted.". (lines 705-707)
>
> It would seem reasonable to me that when a recipient encounters
> a token with a particular ValueType that the recipient would
> know whether or not it contains the facilities for processing
> such a token. In the case of the SAML Assertion, the processing
> facility would seem to be little more than applying the same
> technique used to establish wsu:Id as an ID type attribute, i.e.
> to establish the AssertionID as an ID type attribute, as well,
> when dereferencing the URI with the SAML ValueType.
>
> If we were to take the "strict interpretation" then XML tokens
> would be divided into two classes: those that allow wsu:Id attr
> and can be peers of other tokens in the Security header and
> those that don't, which would have to reside one level lower.
>
> Possibly, the authors of the clauses that we are citing could
> weigh in and help us resolve the interpretations.
>
>    Rich Levinson
>    Netegrity
>
>
>
> -----Original Message-----
> From: Michael McIntosh [mailto:mikemci@us.ibm.com]
> Sent: Thursday, June 24, 2004 5:59 PM
> To: Levinson, Richard
> Cc: Anthony Nadalin; wss@lists.oasis-open.org
> Subject: RE: [wss] Comments on SAML Token Profile
>
> "Levinson, Richard" <rlevinson@netegrity.com> wrote on 06/22/2004
09:44:43
> AM:
>
> > I have reviewed this comment and I think it may be an overly
> > restrictive interpretation of the intended usage of the URI
attribute
> > described in
> the
> > WS-Security core spec, section 7.2, lines 699-701.
>
> The lines you reference state that "... If a fragment is specified,
then
it
> indicates the local ID of the token being referenced."
>
> I think you also must look at Section 4 (lines 363-374) which state
"There
> are many motivations for referencing other message elements such as
> signature references or correlating signatures to security tokens. For

this
> reason, this specification defines the wsu:Id attribute so that
recipients
> need not understand the full schema of the message for processing of
the
> security elements. That is, they need only "know" that the wsu:Id
attribute
> represents a schema type of ID which is used to reference elements.
However,
> because some key schemas used by this specification don't allow
attribute
> extensibility (namely XML Signature and XML Encryption), this
specification
> also allows use of their local ID attributes in addition to the wsu:Id
> attribute. As a consequence, when trying to locate an element
referenced
in
> a signature, the following attributes are considered:
> ? Local ID attributes on XML Signature elements ? Local ID attributes
on
XML
> Encryption elements ? Global wsu:Id attributes (described below) on
> elements"
>
> I think this make it clear that the intent is to require wsu:Id for ID

type
> attributes (other than those defined in XML Signature and XML
> Encryption) because doing otherwise would require the WSS processing
to
have
> access to and process the schema for every part of every message.
>
> Please explain why the SAML token profile could not add an outer
element
> containing a wsu:Id element?
>
> >
>
http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-sec
urit
> y-1.0.pdf
> >
> > In particular, the ValueType attribute (lines 702-708) appears to be
> intended
> > to provide token-specific processing rules to be applied in
> > conjunction
> with
> > the URI attribute. In the case of SAML 1.1 assertions, the SAML
> ValueType
> > indicates that the saml:AssertionID should be treated as an XML ID
> > type attribute. As described in section 4.2 lines 418-425, this may
be

> > done without requiring XML schema validation.
> >
> > I have also looked at the REL Token Profile specification that has
> > been approved by the TC and this appears to suggest using this same
> > mechanism with direct references in Table 2 (section 3.4 line 150)
and

> > shows this
> mechanism
> > used in the example in section 3.5.1 lines 308-309, 336-342,  and
> > again
> in
> > the example in section 3.6.1 lines 404-405, 423-425 (although the
> ValueType
> > appears to have been left out in this 2nd example).
>
> The REL Token Profile makes it clear that where a Local Direct
Reference
is
> used, that it be done using s reference to the wsu:Id attribute. The
other
> forms of reference are for external references.
>
> >
> >
>
http://www.oasis-open.org/apps/org/workgroup/wss/download.php/7347/oasis
-___
> _-wss-
> > REL-token-profile-1.0-draft08-clean.pdf ,
> >
> > From my reading of these documents plus the use of the STR mechanism

> > in scenario 3 of the SAML Interop, which is compliant with the
> recommended
> > usage in the SAML Token Profile (Section 3.3.1 lines 318-319, lines
> 326-331)
> >
> >
>
http://www.oasis-open.org/apps/org/workgroup/wss/download.php/6877/WSS-S
AML-
> 11.pdf
> >
> > it appears that both the SAML and REL authors and interop
participants
> have
> > interpreted the usage of ValueType and URI in the STR element to
allow
> for the
> > token (license or assertion) having its own ID-type attribute.
> >
> >     Rich Levinson
> >     Netegrity
> >
> >
> > From: Anthony Nadalin [mailto:drsecure@us.ibm.com]
> > Sent: Monday, June 21, 2004 2:39 PM
> > To: wss@lists.oasis-open.org
> > Subject: [wss] Comments on SAML Token Profile
>
> > We ran into some inconsistencies while participating in the recent
> > SAML
> interop.
> > The WSS core specification describes a "Direct Reference" mechanism
to
> be used with
> > STRs. A Reference element with a URI attribute is used. When the
> referenced token
> > is located within the Security header, the URI contains a shorthand
> XPointer
> > reference to the token. In order for this to work, the token element
> must contain
> > an attribute of type ID. WSS defines the wsu:Id attribute with type
ID
> for naming
> > the reference. Direct references within the message should not
require
> token
> > specific methods so we suggest the following actions be taken:
> >
> > 1) Errata to the WSS core to make it clear the tokens must have an
> attribute named wsu:Id.
> > 2) Change to the SAML Token Profile to use an wsu:Id attribute or
use
> > a
> wsse:KeyIdentifier
> >
> > Anthony Nadalin | work 512.838.0085 | cell 512.289.4122
>
>
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