[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: RE: [wss] Comments on SAML Token Profile
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-securit 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-SAML- 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
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]