OASIS eXtensible Access Control Markup Language (XACML) TC

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Re: [xacml] Potential SAML issues

  • 1.  Re: [xacml] Potential SAML issues

    Posted 01-15-2002 21:16
    NISHIMURA Toshihiro wrote: > > Hello, > > Sekhar Vajjhala - Sun Microsystems wrote: > > ISSUE: saml:Action is a string > > > > saml:Action is currently specified as a string . Making Action > > an abstract type would allow it to be extended. This would allow > > the content model to be defined by a schema external to the SAML > > spec. > > > > Thus what constitues an action could be determined by the J2SE > > schema. > > In SAML, saml:Action is used only in saml:Actions and saml:Actions > have Namespace as an attribute. > So it is possible to write action(s) such as: > <saml:Actions Namespace= urn:J2SEPermission:java.io.FilePermission > > <saml:Action>write</saml:Action> > </saml:Actions> > or > <saml:Actions Namespace= urn:J2SEPermission > > <saml:Action>java.io.FilePermission:write</saml:Action> > </saml:Actions> > > But it will be useful if we can write something like: > <saml:Action> > <J2SEPermission class= java.io.FilePermission >write</J2SEPermission> > </saml:Action> That was the idea ( although the syntax may be different). > > > ISSUE: saml:AuthorizationQuery requires actions. > > > > If actions are optional for XACML, then why should <saml:Actions> > > be required in <saml:AuthorizationQuery> ? Both the wording in > > the SAML assertions draft as well as the SAML schema place > > such a requirement. saml:Actions should be optional in the > > AuthorizationQuery to accomodate queries without actions. > > > > At least for now, I don't anticipate this as an issue for J2SE. > > In the latest SAML spec (core-25), AuthorizationDecisionQuery element > has Resource attribute and Actions element and both of them are > required . Does this cause much problems? > (Resource attribute is optional for AuthorizationDecisionStatement > element.) > > As for J2SE case, I think there is an issue in terminology. > Sekhar wrote:: > A J2SE permission consists of > > a. target ( resource in XACML terminology ) > b. action (optional) > ( http://lists.oasis-open.org/archives/xacml/200112/msg00045.html ) > > In the example of FilePermission, everyone will agreee on that > /tmp/* indicates resources(targets) and read,write indicates > action(s). > > In regard to AWTPermission, the J2SE document says: > This is in the same spirit as the RuntimePermission; it's a > permission without actions. The targets for this class are: > > accessClipboard > accessEventQueue > listenToAllAWTEvents > showWindowWithoutWarningBanner > ( http://java.sun.com/j2se/1.4/docs/guide/security/spec/security-spec.doc3.html#20327 ) > > It says that accessClipboard is a target, however, I think it is > possible to say accessClipboard is an action (in XACML terminology). It is possible but would not be correct. > > > ISSUE: single subject in AuthorizationQuery > > > > saml:AuthorizationQuery currently only contains a single > > Subject. While a saml:Subject can support multiple NameIdentifier > > or SubjectConfirmation or AssertionSpecifier elements, it > > is required that they all belong to the same principal. So > > a single subject cannot be used for unrelated principals. > > > > In J2SE, there is a need to base access control on multiple > > principals which are not related and this therefore points to > > to a need for more than one Subject in the saml:AuthorizationQuery > > > > NOTE: The way out of this appears to be extend > > SubjectQueryAbstractType. > > Is this the same issue with ISSUE:[DS-11-01:MultipleSubjectAssertions] > in draft-sstc-saml-issues-06.pdf? As I understand from the XACML Policy model sub committee meeting yesterday, there is already an open issue against what I described above. I did not check the above issue that you mentioned above. Sekhar > > Regards, > Toshi > --- > NISHIMURA Toshihiro (FAMILY Given) > nishimura.toshi@jp.fujitsu.com > XML Application Technology Dept., PROJECT-A XML, FUJITSU LIMITED -- Sekhar