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What do OpenID, Higgins, I-Names, and XDI Have in Common?. An OASIS Webinar on XRI and XRDS. May 6, 2008. What do OpenID, Higgins, i-names, and XDI have in common? They all use two new OASIS technologies you may not even have heard of yet.
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What do OpenID, Higgins, I-Names, and XDI Have in Common? An OASIS Webinar on XRI and XRDS May 6, 2008
What doOpenID, Higgins, i-names, and XDI have in common? They all use two new OASIS technologies you may not even have heard of yet. How did these specifications already become key building blocks of the Internet identity layer? What problems do they solve? Where do they fit with the work of other OASIS Technical Committees? That’s what we’ll cover today...
OASIS XRI Technical Committee Formed January 2003
XRI (Extensible Resource Identifier) • A new type of Internet identifier (URI) designed expressly for digital identity • An open standard for abstractstructured identifiers • Abstract, i.e., identifiers upon which discovery can be performed • Structured, i.e., a syntactic framework for expressing identifiers – “XML for identifiers”
XRDS (Extensible Resource Descriptor Sequence) • A simple, extensible service discovery format for XRIs or URLs • The logical equivalent of a DNS resource record at the XRI layer of identification • The discovery format used by OpenID 2.0, OAuth, and Higgins
Synonyms AbstractIdentifierLayer ReassignableXRI “i-names” PersistentXRI “i-numbers” XRDSDocu-ment XRDSResolution Domain Name TN(Tele-phoneNumber) Otherconcreteidentifiertypes ConcreteIdentifierLayer IP Address Local Path/Query URI/IRI
Examples of XRI i-names • Human-friendly reassignable identifiers =gmw =用例 @boeing @cordance*drummond.reed +flower $xml
Examples of XRI i-numbers • Persistent identifiers (never reassigned) =!7a42.cd93.40f4.18e5 =!7a42.cd93.40f4.18e5!283 @!b3a7.5537.9fea.31ec +!3792 +!3792!14
Examples of XRI cross-references • Identifiers reused across contexts =(mailto:gabe.wachob@gmail.com) =(http://equalsdrummond.name) @(http://boeing.com) @cordance*(urn:isbn:0-395-36341-1) +flower*(http://en.wikipedia.org/rose)
Examples of XRIs transformed into URIs • XRI Syntax 2.0 defines a strict trans-formation of an XRI into an IRI and URI xri://=drummond.reed xri://=%E7%94%A8%E4%BE%8B xri://@!b3a7.5537.9fea.31ec!133 xri://=(mailto:gabe.wachob@gmail.com) xri://@cordance*(urn:isbn:0-395-36341-1)
Example XRDS document <XRDS xmlns=“xri://$xrds”> <XRD xmlns=“xri://$xrd*($v*2.0)”> <Query>*example</Query> <Expires>2005-05-30T09:30:10Z</Expires> <ProviderID>xri://=</ProviderID> <EquivID>xri://=example.name</EquivID> <CanonicalID>xri://=!7c4.58ff.7c9a.e285</CanonicalID> <Service priority=“10”> <Type>xri://$res*auth*($v*2.0)</Type> <URI>http://res.example.com/=!7c4.58ff.7c9a.e285/</URI></Service> <Service priority=“10”> <Type>http://openid.net/server/1.0</Type> <Type>http://specs.openid.net/auth/2.0/signon</Type> <Path>+openid</Path> <URI>http://authn.example.com/openid/</URI> </Service> </XRD> </XRDS> Query and synonyms Service #1 Service #2
XRI Syntax 2.0 Explicit syntax for reassignable and persistent identifiers Global context symbols Cross-references for identifier reuse across contexts Flexible delegation at all levels of hierarchy Lossless transformation into IRI and URI forms XRI Resolution 2.0 HTTP(S)-based resolution protocol XRDS: simple XML discovery document format Synonym management and verification Service endpoint selection logic Redirect and Ref processing The XRI 2.0 specifications
Why have XRI and XRDS already become key building blocks of the Internet identity layer?
Not only have XRI and XRDS become an integral part of OpenID 2.0, but the XRI technical community is now a strong part of the OpenID community. — Bill Washburn Executive Director, OpenID Foundation
XRI and XRDS have become essential elements of the Higgins Project. Without them, we couldn’t fully implement the abstract data model that is the heart of Higgins and the key to user-controlled identity and data sharing. — Paul Trevithick Higgins Project Lead
Where are XRI and XRDS being used today? • OpenID 2.0 • OAuth Discovery • Higgins Project • XDI.org i-name/i-number registries • XDI data sharing
Case Study: the top 3 problems XRI/XRDS solved for OpenID 2.0 • Extensible service discovery • OpenID recycling • Automatic secure resolution http://middleware.internet2.edu/idtrust/2008/papers/01-reed-openid-xri-xrds.pdf
What is OpenID? • An open community specification for user-centric Internet authentication • Based on the concept that users can have their own globally-resolvable identifiers and OpenID authentication providers • Primary use case: eliminate the need for different usernames and passwords at every website
3 2 XRDSDocument 4 5 1 Relying Party(RP) OpenID Provider(OP) Discovery =drummond.reed User
Problem #1:Extensible service discovery • OpenID 2.0 need to describe what versions an OpenID identifier supports • Also what OpenID extensions it supports (SREG, AX, PAPE, etc.) • And what other services may be available (e.g., OAuth, SAML, XDI) • And it needed redundant, prioritized OpenID provider endpoint URLs
Solution: XRDS documents • Simple, standard discovery format • Can be hosted on any blog, web server, IdM system, etc. • Easily extensible using new URIs or XRIs to define service types • Can be extended with elements from any other namespace
<XRDS xmlns=“xri://$xrds”> <XRD xmlns=“xri://$xrd*($v*2.0)”> <Query>*example</Query> <Expires>2005-05-30T09:30:10Z</Expires> <ProviderID>xri://=</ProviderID> <CanonicalID>xri://=!7c4.58ff.7c9a.e285</CanonicalID> <Service> <Type>xri://$res*auth*($v*2.0)</Type> <URI>http://res.example.com/=! 7c4.58ff.7c9a.e285/</URI></Service> <Service priority=“10”><Type>http://openid.net/server/1.0</Type> <Type>http://specs.openid.net/auth/2.0/signon</Type> <Path>+openid</Path> <URI>http://authn.example.com/openid/</URI> <URI>https://secure-authn.example.com/openid/</URI> <openid:delegate>http://example.com/bob</openid:delegate> </Service> </XRD> </XRDS>
Problem #2:OpenID recycling • With usernames/passwords, usernames can be recycled • The service provider controls the binding with the credential • With OpenID, that’s no longer true • The user controls the binding to the credential! • Losing control of the identifier = losing control of the credential
Solution: persistent synonyms • Bind a recyclable OpenID identifier with a non-recyclable (persistent) identifier, e.g., an XRI i-number • Always authenticate based on the persistent i-number • Treat the recyclable identifier as only a temporary handle for the i-number • The user always stays protected
<XRDS xmlns=“xri://$xrds”> <XRD xmlns=“xri://$xrd*($v*2.0)”> <Query>*example</Query> <Expires>2005-05-30T09:30:10Z</Expires> <ProviderID>xri://=</ProviderID> <CanonicalID>xri://=!7c4.58ff.7c9a.e285</CanonicalID> <Service> <Type>xri://$res*auth*($v*2.0)</Type> <URI>http://res.example.com/=!1234.5678.a1b2.c3d4/</URI></Service> <Service> <Type>http://openid.net/openid/1.1</Type> <Type>http://openid.net/openid/2.0</Type> <Path>+openid</Path> <URI>http://authn.example.com/openid/</URI> </Service> </XRD> </XRDS>
Problem #3:Automatic secure resolution • OpenID could not specify HTTPS resolution for all OpenID URLs • Too many users do not have access to HTTPS certs or infrastructure • Thus the default had to be HTTP • This forces users with HTTPS URLs to type the entire string, e.g.,https://my.openid.identifier.tld
Solution:XRI secure resolution • As abstract identifiers, XRIs always map to concrete identifiers • This mapping process - XRI resolution - offers three trusted modes: • HTTPS, SAML, or both • So XRI i-names used as OpenIDs can use HTTPS resolution as the default • No need for users to know/do anything
XRI and XRDS are also building blocks for other identity solutions • OAuth • XRDS discovery format • Higgins Project • Context discovery and resolution • XDI.org XRI registries • i-name/i-number registries & resolution • SAML and Information Cards • Privacy-protected identifier claims
What is the relationship of XRI and XRDS with other OASIS TCs and the IDtrust Member Section?
XDI (XRI Data Interchange) • The XDI controlled data sharing protocol is based entirely on XRIs • A globally addressable RDF graph where the address of every node is an RDF statement structured as an XRI subject-xri / predicate-xri / object-xri • Enables a simple portable authorization format called XDI link contracts
ORMS (Open Reputation Management Services) • Newest TC in the OASIS IDtrust member section • Will define neutral, vendor-independent specs for exchanging reputation data • XRI and XDI TC members participating • XRI for durable subject identifiers • XDI for controlled data sharing
PKI-Related TCs • Digital Signature Services eXtended (DSS-X)Advancing new profiles for the DSS OASIS Standard • Enterprise Key Management Infrastructure (EKMI)Defining symmetric key management protocols • Public Key Infrastructure (PKI) AdoptionAdvancing the use of digital certificates as a foundation for managing access to network resources and conducting electronic transactions
Conclusion • Abstract structured identifiers offer 3 key features for the Internet identity layer • Simple, safe, strong identifiers • Simple, extensible, secure service discovery • Interoperability between multiple identity protocols and frameworks • XRI and XRDS are building blocks everyone can use
Contact us • Gabe Wachob, XRI TC Co-Chair • http://xri.net/=gmw • gabe.wachob@wachob.com • Drummond Reed, XRI TC Co-Chair • http://xri.net/=drummond.reed • drummond.reed@cordance.net • Wikipedia • http://en.wikipedia.org/XRI • http://en.wikipedia.org/XRDS
Learn through the IDtrust Knowledgebase of educational materials and background on the standards • Share news, events, presentations, white papers, product listings, opinions, questions, and recommendations through postings, blogs, forums, and directories. • Collaborate with others online through a wiki interface http://idtrust.xml.org
What is the relationship of XRI to URNs? • Uniform Resource Names are specified by IETF RFC 2141 • They are persistent (non-recyclable) identifiers • XRI combines both URNs and HFNs (human-friendly names) in one syntax and resolution protocol
What is the relationship of XRI to the Handle System? • Handle is a persistent object identifier system developed by CNRI • Specified in RFCs 3650, 3651, 3652 • Handle does not include HFNs or other structured identifier features of XRI • Handle does not use XML or HTTP for resolution
Does XRI introduce new Internet namespaces? • Yes. Although it can describe and reuse many types of existing identifiers, it also includes four formal namespaces at the XRI level of identification = for personal identifiers @ for organizational identifiers + for generic tags $ for specific tags
Does the XRI TC specify public registry services? • No, the scope of the XRI TC is limited to the technical specifications for XRI and specified XRIs (the $ space) • XDI.org, a member of the XRI TC, offers public XRI registry services • XDI.org is a completely separate non-profit organization
What IPR applies to XRI and XRDS? • The TC operates under the OASIS “RF on Limited Terms” mode (standard royalty-free terms) • This has been mandatory from the TC’s original charter • XDI.org made the initial contribution of IPR for what was then called XNS when the TC was formed in 2003
How does Higgins use XRI and XRDS? • Higgins uses an abstract data model to access data in different contexts (distributed repositories) • XRI is used for addressing contexts and entities within contexts • XRDS is used to resolve the metadata a Higgins component needs to open a Higgins context
What open source implementions of XRI and XRDS are available? • OpenXRI (Java) • http://www.openxri.org • Barx (Ruby) • http://xrisoft.org • MyXDI (C++) • http://www.ootao.com