WSRP Description and Transport Issues SC

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WSRP Description and Transport Issues SC

• wsrp-webservice_at_lists.oasis-open.org
• Andre Kramer, Citrix Systems Inc.
• 6th WSRP F2F, Grenoble, France
• 12th-14th May, 2003

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Proposed Charter

• Responsible for mapping WSRP operations and types
  (new factors?) to WSDL
• Determine binding to SOAP (and other transports!)
• Evaluate our Web Service description and its
  impact on common Web Service Stacks
• Leverage attachment mechanisms
• Facilitate WS/SOAP (WS Security) and transport
  security 2.0?
• Investigate performance of WSRP?
• Others ?

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Proposed Deliverables

• WSDL service description
• WSDL issue resolution recommendations
• Standards coordination (WS-I.org)
• WSRP WSDL Report (cf. 5th f2f Note)
• Attachment mechanisms investigation
• Application level security investigation?
• My wish list 2.0
• interoperable, standards based WS security
• defines consumer / producer trust relationship
• communicates user identity and roles
• digital sig, multi-hop, non-repudiation?
• secure navigational state?
• Others?

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Attachment Mechanisms

• WSRP XML and Markup XML right?
• So whats the problem?
• Almost all current HTML is not XML
• Portlets produce Markup Fragments not Documents
• Different character sets (SOAP message v.s.
  Markup)
• Input (and Output) of binary Documents
• Perceived performance problems with in-band
  binary

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Current in-band support

• Encode markup as an xsstring
• Encoded using XML character entities (lt etc)
• Done automatically by Web Service Stacks
• Some producers can use lt!CDATA gt
• Encode markup as a xsbase64Binary
• About x 1.3
• Done automatically by Web Service Stacks
• Natural for binary documents (byte not String)
• Future? Encode XML Markup as
• ltany namespace"other" /gt
• Needs better parsing support in Web Service
  Stacks
• Could leverage HTML TIDY
• Could be re-considered for 2.0

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Out-of-band

• By reference (URLs, c.f. Portlet resources)
• Via http (non SOAP binding for getMarkup)
• Via multi-media protocol (SMIL, RTP, DIME)
• Using various attachment mechanisms
• SOAP Messages with Attachments (W3C Note 11 Dec
  2000)
• SOAP 1.2 Attachment Feature (W3C Working Draft 24
  Sept 2002)
• WS-Attachments 17 June 2002 (Microsoft, IBM)
• Proposed Infoset Addendum to SOAP Messages with
  Attachments BEA/Microsoft/ATT/SAP/Tibco/Cano/TBD
  , V 0.6 draft, 24 March 2003
• WS-I.org
• has tabled attachments for Basic Profile (1.1)
• Disclaimer Citrix is not directly involved with
  these efforts

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Why have both?

• In-band preserves XML Infoset
• keeps XML-abilities
• One tool set, one charset (UTF-8 -)
• Canonical representation, digital signing
• Multiple transports (WSDL bindings)
• Tools and intermediate message processors see
  data
• SOAP header data as well as body
• Out-of-band may not buy much performance
• Out-of-band builds on common practice
• Multi-part MIME
• Soap-with-Attachments (SwA) supported by JAXRPC
• Natural for posting binary documents
• cf. our UploadContext

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Claim DIME today

• DIME (Internet-Draft) is a binary encapsulation
  protocol
• binary packet headers
• with len type or URIs, MB/ME/CF bits
• I.e. not XML!
• Championed by Microsoft, IBM
• Companion WS-Attachments IETF Internet-Draft
• Microsoft WSE 1.0 no streaming, WS-Routing
  header
• Apache Axis support not scoped
• WSRP 1.0
• Only one markup returned or array of binary
  inputs
• Can use DIME at the sub-WS level
• Citrix prototype uses WSE 1.0
• Declares a DIME (read-only) registration
  property
• Or can detect DIME Attachment at registration
• Fishes for DIME attachments at runtime

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Soap-with-Attachments SwA

• Simple
• multipart/related content type (RFC2387)
• MUST put the SOAP Envelope as first/root MIME
  part
• MAY send additional MIME parts with root
• Use URIs to id parts (receivers SHOULD consult
  parts)
• JAX-RPC
• WSDL1.1 has MIME extensions (Section 5)
• Only for SOAP (multipart/related) in practice
• (ltmimemimeXML part/gt is underspecified IMHO)
• Not supported by all wsdl tools (or WS stacks)
• ltmimecontext/gt optionally types markup MIME
  format
• How to leverage this in WSRP? / or MIME type
  specific wsdls?
• WSDL 1.2?

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WS-Attachments

• Specifies Compound SOAP structures
• URIs reference parts
• E.g. useful if WSRP had header body markup
  parts
• SOAP message attachments in a DIME message
• Does not have to be MIME
• Maps to DIME records (application/soapxml first)
• HTTP binding (application/dime)
• WSDL Extensions for SOAP in DIME
• Microsoft DRAFT, 8 May 2002
• Moves base64Binary or hexBinary elements to DIME
  records
• Location (URL) and type (MIME, URI or XML Doc
  element)
• Layouts (closed-content, open-content)
• WSDL
• Element app-info annotation ltcontentmediaType
  valuetext/html/gt
• wsdlinput/output ltdimemessage layoutauri
  wsdlrequiredtrue/gt
• SOAP
• lt reflocationuuid12DA3C9C-74D3-4446-B995-B150
  362D9413gt
• Faults MAY be DIME encapsulated

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XML Infoset friendly proposals

• Want binary to be directly included in message
• XML does this when in memory today
• Why not allow this on the wire too? c.f. WAP
• Can convert to base64 as required
• E.g. when digitally signing a document
• XInclude-like mechanism to merge in data?

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New Infoset-friendly Proposal

• The Proposed Infoset Addendum to SwA
• Aligned with XML Infoset
• Backwards compatible SwA message syntax
• Alternative (in-band) message syntax for non-SwA
  processors
• Converts between base64 in-band and SwA (or
  other) out-of-band
• swaMediaType attribute
• Specifies MIME type of base64 element (when
  in-band)
• xbincInclude element
• References out-of-band opaque data by URI (just a
  href)
• XbincDoInclude header controls processing
• FatalIncludeFault SOAP fault
• swaRepresentation header block
• Allows sending along cached representations
• swaAccept attribute
• Annotates schema declarations (I.e. XML Schema in
  WSDL)
• ltxselement name typeswaBinary
  swaAcceptimage/jpeg image/gif/gt

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Recommendations?

• Experiment with DIME, SwA,
• Wait for WS-I.org (1.1 including Attachments)
• Canvas your WS-I.org representation!
• Wait for WSDL extensions?
• Wait for Infoset friendly SwA?
• Support both in-band and out-of-band in 1.1/2.0
• Add negotiation to WSRP?
• Keep xsstring xsbase64Binary for interop