scope:

The purpose of the present document is to define specifications on how to carry REM Dispatches and REM-MD Messages between REM-MDs as XML Information Set as defined by the SOAP specification: "for exchanging structured and typed information between peers in a decentralized, distributed environment" (SOAP Version 1.2, Part 0: Primer), commonly called "Web Services". The present document comes as a completion of the current specifications (TS 102 640, especially parts 2 [2] and 5 [5]), which defines S/MIME envelopes as message format to be transported over SMTP protocol.

REM over SOAP will prove useful in several contexts, due to the fact that Web Services are largely considered a well established and flexible technology, providing detailed specifications for the different functional building blocks (addressing, security and trust, reliable delivery). Building blocks are combinable and open for extension/profiling according to the needs of specific application- and communication scenarios.

Several initiatives are ongoing pointing in this direction: we remark European projects SPOCS and STORK, which aim at bridging existing eDelivery systems in several European MSs. The necessity to have them all interchange trusted messages requires the involvement of "eDelivery Gateways" based on a "eDelivery meta-protocol", in order to avoid a non-scalable one-to-one bridging. Requirements for the meta-protocol normally involve the usage of a Web Services based transport (see e.g. STORK D6.4.1 [i.2], SPOCS D3.2 [i.1]). REM specifications as defined in TS 102 640 would be a natural candidate for the above meta-protocol role, once a proper binding to SOAP is defined.

Unlike the protocol stack defined for e-mail, standard Web Service specifications define no general message format to structure the content of more or less "unbounded" asynchronous exchange of messages and electronic documents: the SOAP body normally is seen as an opaque object, whose structure and semantics are agreed upon a specific Web Service provider and their respective consumers. Most of mentioned eDelivery solutions based on SOAP/Web Services define their domestic format for such general communication scenarios. To be able to provide interoperable message exchange functionality between such solutions as well as the SMTP/(S)MIME based world, the present document for REM/SOAP binding includes the definition of an XML-based exchange format for message contents, which may be used for mapping between different domestic and/or standardized message structures.

A further challenge of bridging the SMTP- and Web Services solutions is having to deal with different schemes of electronic addresses of end-entities (e.g. e-mail addresses as defined by RFC 5322 [11], URLs of http-resources, constructs following ISO/IEC 15459-3 [25] for unique identifier schemes). To this purpose, the definition of electronic addresses in REM has been extended to take into account the "addressing schema".

To meet the expectations above, the present document provides:

a) Rules for building a REM-MD Envelope (and, consequently, a REM Dispatch or a REM-MD Message) as well defined XML Information Sets (Infoset).

b) Rules for secure transport of the above REM-MD XML Infosets using SOAP, combined with appropriate bricks of the Web Services stack (profiling of WS-Addressing and WS-Security).

REM-MD Evidence formats respect TS 102 640-2 [2] specifications in xml flavour.

The structure of the present document is as follows:

• Clause 2 contains the list of normative and informative references.

• Clause 3 includes definitions of the relevant concepts to the present document and abbreviations.

• Clause 4 contains the specification of REM-MD XML Infosets to be used for enveloping messages. Specific syntax is addressed by annex A.

• Clause 5 contains the specification of the SOAP messages as exchanged between REM-MDs, which covers the profiling of the standard WS-bricks used. Profiling details are addressed by annex B.

• Clause 6 deals with the definition of Web Services for interoperability.

• Annex A provides XML Schema for REM XML Infosets as used inside SOAP messages.

• Annex B provides a profiling for WS Addressing inside SOAP header.

• Annex C provides WSDL specification, defining the REM-MD Web Service endpoint.