RFC 4227 PROPOSED STANDARD SOAP · BEEP · MESSAGING

SOAP over BEEP: Using the Simple Object Access Protocol (SOAP) in Blocks Extensible Exchange Protocol (BEEP)

How to carry SOAP messages over BEEP, the framing protocol designed for building application protocols.

On rfc-editor.org ↗
PUBLISHED
January 2006
AUTHORS
E. O'Tuathail, M. Rose
STREAM
IETF
BUILDS ON
RFC 3288 — Using the Simple Object Access Protocol (SOAP) in Blocks Extensible Exchange Protocol (BEEP)
UPDATED BY
RFC 8553 — DNS Attrleaf Fixes
PROFILE URI FOR SOAP 1.2
http://iana.org/beep/soap/1.2
MEDIA TYPE FOR SOAP ENVELOPES
application/soap+xml
EXCHANGE PATTERN THAT MUST BE SUPPORTED
request-response
SHORT NAME OF THE TCP PORT
soap-beep
CIPHER NAMED FOR THE TLS TUNING PROFILE
TLS_RSA_WITH_AES_EDE_CBC_SHA
DOI
10.17487/RFC4227
ERRATA
Reported errata

RFC text

Contents
Original text · RFC Editor View on rfc-editor.org ↗
Network Working Group                                      E. O'Tuathail
Request for Comments: 4227                                  Clipcode.com
Obsoletes: 3288                                                  M. Rose
Category: Standards Track                   Dover Beach Consulting, Inc.
                                                            January 2006


             Using the Simple Object Access Protocol (SOAP)
             in Blocks Extensible Exchange Protocol (BEEP)


Status of This Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2006).

Abstract

   This memo specifies a Simple Object Access Protocol (SOAP) binding to
   the Blocks Extensible Exchange Protocol (BEEP) core.  A SOAP binding
   describes how SOAP messages are transmitted in the network.

   The SOAP is an XML-based (eXtensible Markup Language) messaging
   protocol used to implement a wide variety of distributed messaging
   models.  It defines a message format and describes a variety of
   message patterns, including, but not limited to, Remote Procedure
   Calling (RPC), asynchronous event notification, unacknowledged
   messages, and forwarding via SOAP intermediaries.

Table of Contents

   1. Introduction ....................................................3
   2. BEEP Profile Identification .....................................3
      2.1. Profile Initialization .....................................4
   3. SOAP Message Packages ...........................................6
   4. SOAP Message Patterns ...........................................8
      4.1. One-Way Message ............................................8
      4.2. Request-Response Exchange ..................................8
      4.3. Request/N-Responses Exchange ...............................8
      4.4. Error Handling .............................................9
   5. SOAP Protocol Binding Framework Conformance .....................9
      5.1. Binding Name ...............................................9
      5.2. Base URI ...................................................9
      5.3. Supported SOAP Message Exchange Patterns ...................9
      5.4. Supported Features .........................................9
      5.5. MEP Operation .............................................10
           5.5.1. Behavior of Requesting SOAP Node ...................10
                  5.5.1.1. Init ......................................10
                  5.5.1.2. Requesting ................................10
                  5.5.1.3. Sending+Receiving .........................10
                  5.5.1.4. Success and Fail ..........................11
           5.5.2. Behavior of Responding SOAP Node ...................11
                  5.5.2.1. Init ......................................11
                  5.5.2.2. Receiving .................................11
                  5.5.2.3. Receiving+Sending .........................11
                  5.5.2.4. Success and Fail ..........................11
   6. URL Schemes ....................................................11
      6.1. The soap.beep URL Scheme ..................................11
           6.1.1. Resolving IP/TCP Address Information ...............12
      6.2. The soap.beeps URL Scheme .................................13
   7. Registration Templates .........................................13
      7.1. SOAP Profile Feature Registration Template ................13
   8. Initial Registrations ..........................................13
      8.1. Registration: The SOAP Profile ............................13
      8.2. Registration: The soap.beep URL Scheme ....................14
      8.3. Registration: The soap.beeps URL Scheme ...................14
      8.4. Registration: The System (Well-Known) TCP Port
           Number for SOAP ...........................................15
   9. Security Considerations ........................................15
   10. IANA Considerations ...........................................16
   11. Changes from RFC 3288 .........................................16
   12. Acknowledgements ..............................................17
   13. References ....................................................17
      13.1. Normative References .....................................17
      13.2. Informative References ...................................18
   A. Appendix - SOAP with Attachments (Informative) .................19

1.  Introduction

   This memo specifies how SOAP envelopes [15] are transmitted using a
   BEEP profile [1].  Conforming implementations MUST support SOAP
   version 1.2 [15] and MAY support other versions, such as SOAP version
   1.1 [17].  This memo specifies how SOAP envelopes [15] are
   transmitted using a BEEP profile [1].  Unlike its predecessor,
   RFC3288 [16], this memo does not mandate the use of SOAP version 1.1.

   Throughout this memo, the term "envelope" refers to the top-level
   element exchanged by SOAP senders and receivers.  For example, when
   referring to SOAP version 1.2, the term "envelope" refers to the
   "Envelope" element defined in Section 5.1 of [2].  Furthermore, the
   terms "peer", "client", "server", "one-to-one", and "one-to-many" are
   used in the context of BEEP.  In particular, Sections 2.1 and 2.1.1
   of [1] discuss BEEP roles and exchange styles.

2.  BEEP Profile Identification

   The BEEP profile for SOAP is identified as

       http://iana.org/beep/soap/VERSION

   in the BEEP "profile" element during channel creation. where
   "VERSION" refers to the numeric version of the SOAP specification.

   For example,

       http://iana.org/beep/soap/1.2

   refers to version 1.2.

   Note that RFC 3288 [16] used

       http://iana.org/beep/soap

   for the purposes of profile identification for SOAP version 1.1
   envelopes [17].  If an implementation of this memo chooses to
   implement SOAP version 1.1, then it should support both this Uniform
   Resource Identifier (URI) for profile identification as well as
   "http://iana.org/beep/soap/1.1".

   In BEEP, when the first channel is successfully created, the
   "serverName" attribute in the "start" element identifies the "virtual
   host" associated with the peer acting in the server role, e.g.,

       <start number='1' serverName='stockquoteserver.example.com'>
           <profile uri='http://iana.org/beep/soap/1.2' />
       </start>

   The "serverName" attribute is analogous to HTTP's "Host" request-
   header field (cf. Section 14.23 of [4]).

   There are two states in the BEEP profile for SOAP, "boot" and
   "ready":

   o  In the "boot" state, the peer requesting the creation of the
      channel sends a "bootmsg" (either during channel initialization or
      in a "MSG" message).

      *  If the other peer sends a "bootrpy" (either during channel
         initialization or in an "RPY" message), then the "ready" state
         is entered

      *  Otherwise, the other peer sends an "error" (either during
         channel initialization or in an "ERR" message), then no state
         change occurs.

   o  In the "ready" state, either peer begins a SOAP message pattern by
      sending a "MSG" message containing an envelope.  The other peer
      completes the message pattern either by

      *  sending back an "RPY" message containing an envelope or

      *  sending back zero or more "ANS" messages, each containing an
         envelope, followed by a "NUL" message.

      Regardless, no state change occurs.

2.1.  Profile Initialization

   The boot message is used for two purposes:

      resource identification: each channel bound to the BEEP profile
      for SOAP provides access to a single resource (a network data
      object or service).

      feature negotiation: if new features of SOAP (such as compression)
      emerge, their use can be negotiated.

   The DTD syntax for the boot message and its response are:

       <!ELEMENT bootmsg     EMPTY>
       <!ATTLIST bootmsg
                 resource    CDATA             #REQUIRED
                 features    NMTOKENS          "">

       <!ELEMENT bootrpy     EMPTY>
       <!ATTLIST bootrpy
                 features    NMTOKENS          "">

   The boot message contains a mandatory and an optional attribute:

   o  the "resource" attribute, which is analogous to HTTP's "abs_path"
      Request-URI parameter (cf. Section 5.1.2 of [4]) and

   o  the "features" attribute, which, if present, contains one or more
      feature tokens, each indicating an optional feature of the BEEP
      profile for SOAP that is being requested for possible use over the
      channel.

   Section 7.1 defines a registration template for optional features.

   If the peer acting in the server role recognizes the requested
   resource, it replies with the boot response that contains one
   optional attribute:

   o  The "features" attribute, if present, contains a subset of the
      feature tokens in the boot message, indicating which features may
      be used over the channel.  (If not present or empty, then no
      features may be used.)

   Otherwise, if the boot message is improperly formed, or if the
   requested resource is not recognized, the peer acting in the server
   role replies with an error message (cf. Section 7.1 of [1]).
   Typically, the boot message and its response are exchanged during
   channel initialization (cf. Section 2.3.1.2 of [1]).

   For example, here the boot message and its response are exchanged
   during channel initialization:

       C: <start number='1' serverName='stockquoteserver.example.com'>
       C:     <profile uri='http://iana.org/beep/soap/1.2'>
       C:         <![CDATA[<bootmsg resource='/StockQuote' />]]>
       C:     </profile>
       C: </start>
       S: <profile uri='http://iana.org/beep/soap/1.2'>
       S:     <![CDATA[<bootrpy />]]>
       S: </profile>

   The channel bound to the BEEP profile for SOAP is now in the "ready"
   state.

   Alternatively, here is an example in which the boot exchange is
   unsuccessful:

       C: <start number='1' serverName='stockquoteserver.example.com'>
       C:     <profile uri='http://iana.org/beep/soap/1.2'>
       C:         <![CDATA[<bootmsg resource='/StockPick' />]]>
       C:     </profile>
       C: </start>

       S: <profile uri='http://iana.org/beep/soap/1.2'>
       S:     <![CDATA[<error code='550'>resource not
       S:                                supported</error>]]>
       S: </profile>

   Although the channel was created successfully, it remains in the
   "boot" state.

3.  SOAP Message Packages

   The BEEP profile for SOAP transmits envelopes encoded as UTF-8 and
   SHOULD use the media type "application/soap+xml" [5], e.g.,


   MSG 1 1 . 0 284
   Content-Type: application/soap+xml

   <env:Envelope
        xmlns:env="http://www.w3.org/2003/05/soap-envelope">
     <env:Header>
      <m:GetLastTradePrice xmlns:m="Some-URI" />
     </env:Header>
     <env:Body>
       <symbol xmlns:p="Some-URI" >DIS</symbol>
     </env:Body>
   </env:Envelope>
   END

   To provide compatibility with RFC 3288 [16], it MAY use the media
   type "application/xml" [6].

   In addition, an implementation of the BEEP profile for SOAP MAY
   support transmission of envelopes using the MTOM [7] / XOP [8]
   packaging technique, e.g.,

   MSG 1 2 . 283 1436
   MIME-Version: 1.0
   Content-Type: Multipart/Related;boundary=MIME_boundary;
       type="application/xop+xml";
       start="<mymessage.xml@example.org>";
       startinfo="application/soap+xml; action=
   Content-Description: A SOAP message with my pic and sig in it

   --MIME_boundary
   Content-Type: application/xop+xml;
       charset=UTF-8;
       type="application/soap+xml; action=
   Content-Transfer-Encoding: 8bit
   Content-ID: <mymessage.xml@example.org>

   <soap:Envelope
       xmlns:soap='http://www.w3.org/2003/05/soap-envelope'
       xmlns:xmlmime='http://www.w3.org/2004/11/xmlmime'>
     <soap:Body>
       <m:data xmlns:m='http://example.org/stuff'>
         <m:photo
     xmlmime:contentType='image/png'><xop:Include
       xmlns:xop='http://www.w3.org/2004/08/xop/include'
       href='cid:http://example.org/me.png'/></m:photo>
         <m:sig
     xmlmime:contentType='application/pkcs7-signature'><xop:Include
       xmlns:xop='http://www.w3.org/2004/08/xop/include'
       href='cid:http://example.org/my.hsh'/></m:sig>
       </m:data>
     </soap:Body>
   </soap:Envelope>

   --MIME_boundary
   Content-Type: image/png
   Content-Transfer-Encoding: binary
   Content-ID: <http://example.org/me.png>

   // binary octets for png

   --MIME_boundary
   Content-Type: application/pkcs7-signature
   Content-Transfer-Encoding: binary
   Content-ID: <http://example.org/my.hsh>
   // binary octets for signature

   --MIME_boundary--
   END

   Consult Section 4.1 of XOP [8] for guidance on MIME Multipart/Related
   usage.  Because BEEP provides an 8-bit-wide path, a "transformative"
   Content-Transfer-Encoding (e.g., "base64" or "quoted-printable")
   should not be used.  Note that MIME [9] requires that the value of
   the "Content-ID" header be globally unique.  As stated in Section 4
   of XOP [8], XOP may be used with diverse packaging mechanisms.  When
   an implementation of BEEP in SOAP does support MTOM/XOP, it SHOULD
   support the MIME Multipart/Related XOP Package format, and MAY
   support others.  Additional formats could, in the future, include XOP
   package formats specific to BEEP (e.g., sending the attachments on a
   different channel to the SOAP channel, which would avoid searching
   for the MIME boundary tags and allows lazy delivery of attachments,
   delivering them only when really needed.)

4.  SOAP Message Patterns

4.1.  One-Way Message

   A one-way message involves sending a message without any response
   being returned.

   The BEEP profile for SOAP achieves this using a one-to-many exchange,
   in which the client sends a "MSG" message containing an envelope, and
   the server immediately sends back a "NUL" message, before processing
   the contents of the envelope.

4.2.  Request-Response Exchange

   A request/response exchange involves sending a request, which results
   in a response being returned.

   The BEEP profile for SOAP achieves this using a one-to-one exchange,
   in which the client sends a "MSG" message containing an envelope, and
   the server sends back a "RPY" message containing an envelope.

4.3.  Request/N-Responses Exchange

   A request/N-responses exchange involves sending a request, which
   results in zero or more responses being returned.

   The BEEP profile for SOAP achieves this using a one-to-many exchange,
   in which the client sends a "MSG" message containing an envelope, and
   the server sends back zero or more "ANS" messages, each containing an
   envelope, followed by a "NUL" message.

4.4.  Error Handling

   The BEEP profile for SOAP does not use the "ERR" message for SOAP
   faults.  When performing one-to-one exchanges, whatever SOAP response
   (including SOAP faults) generated by the server is always returned in
   the "RPY" message.  When performing one-to-many exchanges, whatever
   SOAP response (including SOAP faults) generated by the server is
   always returned in the "ANS" messages.

   If there is an error with the BEEP message unrelated to the SOAP
   envelope (e.g., poorly formed MIME message or MIME Content-Type not
   supported), then the server responds with an ERR message (see Section
   7.1 of [1]) with an appropriate reply code (e.g., see Section 8 of
   [1]).

5.  SOAP Protocol Binding Framework Conformance

5.1.  Binding Name

   This binding is identified by a URI that is exactly the same as the
   profile URI for BEEP in SOAP (see Section 2).

5.2.  Base URI

   The Base URI for the SOAP envelope is the URI of the resource
   identified in the bootmsg.

5.3.  Supported SOAP Message Exchange Patterns

   An implementation of this binding MUST support the following SOAP
   Message Exchange Pattern (MEP):

   o  "http://www.w3.org/2003/05/soap/mep/request-response/" (see
      Section 6.2 of [3])

5.4.  Supported Features

   An implementation of this binding MAY support the following feature:
   "http://www.w3.org/2003/05/soap/features/action/" (see Section 6.5 of
   [3].)

5.5.  MEP Operation

   For binding instances conforming to this specification:

   o  A SOAP node instantiated at the BEEP peer that initiates the
      message exchange may assume the role (i.e., the property http://
      www.w3.org/2003/05/soap/bindingFramework/ExchangeContext/Role ) of
      "RequestingSOAPNode".

   o  A SOAP node instantiated at the other BEEP peer may assume the
      role (i.e., the property http://www.w3.org/2003/05/soap/
      bindingFramework/ExchangeContext/Role) of "RespondingSOAPNode".

5.5.1.  Behavior of Requesting SOAP Node

   The overall flow of the behavior of a requesting SOAP node follows a
   state machine description consistent with Section 6.2 of [3].

   In order to avoid deadlock during streaming (see Section 6.2.3 of
   [3]), the requesting SOAP node MUST be able to process incoming SOAP
   response information while the SOAP request is still being
   transmitted.

5.5.1.1.  Init

   In the "Init" state, a BEEP message is formulated according to
   Section 3, transmission of the message begins, and then the state
   changes to "Requesting".

5.5.1.2.  Requesting

   In the "Requesting" state, more of the request message is transmitted
   and the arrival of the response is awaited.  When the beginning of
   the response message is received, if it is a BEEP ERR message, then
   the state transitions to "Fail"; otherwise, the state transitions to
   "Sending+Receiving".

5.5.1.3.  Sending+Receiving

   In the "Sending+Receiving" state, the transmission of the request
   message and receiving of the response message are completed.  The
   response message is assumed to contain a SOAP envelope serialized
   according to the rules for carrying SOAP messages in the media type
   given in the Content-Type header field.  Once the receipt of the
   response is completed, the state transitions to "Success".

5.5.1.4.  Success and Fail

   "Success" and "Fail" are the terminal states for the state machine.

5.5.2.  Behavior of Responding SOAP Node

   The overall flow of the behavior of a responding SOAP node follows a
   state machine description consistent with Section 6.2 of [3]

5.5.2.1.  Init

   In the "Init" state, the binding awaits the start of the inbound
   request.  In this state, it may only generate ERR messages (in
   accordance with Section 4.4).

5.5.2.2.  Receiving

   The binding begins to receive the request message and prepares the
   start of the response, in accordance with Section 3.  When ready to
   transmit the response, the state transitions to "Receiving+Sending".

5.5.2.3.  Receiving+Sending

   The binding completes the receiving of the request and sending of the
   response and then transitions to "Success" state.

5.5.2.4.  Success and Fail

   "Success" and "Fail" are the terminal states that indicate completion
   of the message exchange.

6.  URL Schemes

   This memo defines two URL schemes, "soap.beep" and "soap.beeps",
   which identify the use of SOAP over BEEP over TCP.  Note that, at
   present, a "generic" URL scheme for SOAP is not defined.

6.1.  The soap.beep URL Scheme

   The "soap.beep" URL scheme uses the "generic URI" syntax defined in
   Section 3 of [10], specifically:

   o  the value "soap.beep" is used for the scheme component and

   o  the server-based naming authority defined in Section 3.2.2 of [10]
      is used for the authority component.

   o  the path component maps to the "resource" component of the boot
      message sent during profile initialization (if absent, it defaults
      to "/").

   The values of both the scheme and authority components are case-
   insensitive.

   For example, the URL

       soap.beep://stockquoteserver.example.com/StockQuote

   might result in the example shown in Section 2.1.

6.1.1.  Resolving IP/TCP Address Information

   The "soap.beep" URL scheme indicates the use of the BEEP profile for
   SOAP running over TCP/IP.

   If the authority component contains a domain name and a port number,
   e.g.,

       soap.beep://stockquoteserver.example.com:1026

   then the DNS is queried for the A Resource Records corresponding to
   the domain name, and the port number is used directly.

   If the authority component contains a domain name and no port number,
   e.g.,

       soap.beep://stockquoteserver.example.com

   the Service Record algorithm [11] is used with a service parameter of
   "soap-beep" and a protocol parameter of "tcp" to determine the IP/TCP
   addressing information.  If no appropriate SRV RRs are found (e.g.,
   for "_soap-beep._tcp.stockquoteserver.example.com"), then the DNS is
   queried for the A RRs corresponding to the domain name and the port
   number used is assigned by the IANA for the registration in Section
   8.4.

   If the authority component contains an IP address, e.g.,

       soap.beep://192.0.2.0:1026

   then the DNS is not queried, and the IP address is used directly.  If
   a port number is present, it is used directly; otherwise, the port
   number used is assigned by the IANA for the registration in Section
   8.4.

   While the use of literal IPv6 addresses in URLs is discouraged, if a
   literal IPv6 address is used in a "soap.beep" URL, it must conform to
   the syntax specified in [12].

6.2.  The soap.beeps URL Scheme

   The "soap.beeps" URL scheme is identical, in all ways, to the
   "soap.beep" URL scheme specified in Section 6.1, with the exception
   that prior to starting the BEEP profile for SOAP, the BEEP session
   must be tuned for privacy.  In particular, note that both URL schemes
   use the identical algorithms and parameters for address resolution as
   specified in Section 6.1.1 (e.g., the same service name for SRV
   lookups, the same port number for TCP, and so on).

   There are two ways to perform privacy tuning on a BEEP session,
   either

   o  a transport security profile may be successfully started or

   o  a user authentication profile that supports transport security may
      be successfully started.

   Regardless, upon completion of the negotiation process, a tuning
   reset occurs in which both BEEP peers issue a new greeting.  Consult
   Section 3 of [1] for an example of how a BEEP peer may choose to
   issue different greetings based on whether privacy is in use.

7.  Registration Templates

7.1.  SOAP Profile Feature Registration Template

   When a feature for the BEEP profile for SOAP is registered, the
   following information is supplied:

   Feature Identification: specify a string that identifies this
      feature.  Unless the feature is registered with the IANA, the
      feature's identification must start with "x-".

   Feature Semantics: specify the semantics of the feature.

   Contact Information: specify the electronic contact information for
      the author of the feature.

8.  Initial Registrations

8.1.  Registration: The SOAP Profile

   Profile Identification: http://iana.org/beep/soap/VERSION
   Messages exchanged during Channel Creation: bootmsg, bootrpy

   Messages starting one-to-one exchanges: bootmsg, a SOAP "envelope"

   Messages in positive replies: bootrpy, a SOAP "envelope"

   Messages in negative replies: error

   Messages in one-to-many exchanges: a SOAP "envelope"

   Message Syntax: a SOAP envelope

   Message Semantics: corresponds to the relevant SOAP specification,
      e.g., for SOAP version 1.2, cf. [2].

   Contact Information: Eamon O'Tuathail <eamon.otuathail@clipcode.com>,
      Marshall Rose <mrose@dbc.mtview.ca.us>

8.2.  Registration: The soap.beep URL Scheme

   URL scheme name: soap.beep

   URL scheme syntax: cf. Section 6.1

   Character encoding considerations: cf. the "generic URI" syntax
      defined in Section 3 of [10]

   Intended usage: identifies a SOAP resource made available using the
      BEEP profile for SOAP

   Applications using this scheme: cf. "Intended usage", above

   Interoperability considerations: n/a

   Security Considerations: cf. Section 9

   Relevant Publications: cf. [2] for SOAP version 1.2

   Contact Information: Eamon O'Tuathail <eamon.otuathail@clipcode.com>,
      Marshall Rose <mrose@dbc.mtview.ca.us>

   Author/Change controller: the IESG

8.3.  Registration: The soap.beeps URL Scheme

   URL scheme name: soap.beeps

   URL scheme syntax: cf. Section 6.2
   Character encoding considerations: cf. the "generic URI" syntax
      defined in Section 3 of [10]

   Intended usage: identifies a SOAP resource made available using the
      BEEP profile for SOAP after the BEEP session has been tuned for
      privacy

   Applications using this scheme: cf. "Intended usage", above

   Interoperability considerations: n/a

   Security Considerations: cf. Section 9

   Relevant Publications: cf. [2] for SOAP version 1.2

   Contact Information: Eamon O'Tuathail <eamon.otuathail@clipcode.com>,
      Marshall Rose <mrose@dbc.mtview.ca.us>

   Author/Change controller: the IESG

8.4.  Registration: The System (Well-Known) TCP Port Number for SOAP
      over BEEP

   Protocol Number: TCP

   Message Formats, Types, Opcodes, and Sequences: cf. Section 2.1

   Functions: cf. [2] for SOAP version 1.2

   Use of Broadcast/Multicast: none

   Proposed Name: SOAP over BEEP

   Short name: soap-beep

   Contact Information: Eamon O'Tuathail <eamon.otuathail@clipcode.com>,
      Marshall Rose <mrose@dbc.mtview.ca.us>

9.  Security Considerations

   Although service provisioning is a policy matter, at a minimum, all
   implementations MUST provide the following tuning profiles:

   for authentication: http://iana.org/beep/SASL/DIGEST-MD5

   for confidentiality: http://iana.org/beep/TLS (using the
      TLS_RSA_WITH_AES_EDE_CBC_SHA cipher)
   for both: http://iana.org/beep/TLS (using the
      TLS_RSA_WITH_AES_EDE_CBC_SHA cipher supporting client-side
      certificates)

   Furthermore, implementations may choose to offer MIME-based security
   services providing message integrity and confidentiality, such as
   OpenPGP [13] or S/MIME [14].

   Regardless, consult [1]'s Section 9 for a discussion of BEEP-specific
   security issues.

10.  IANA Considerations

   Previously, the IANA registered "http://iana.org/beep/soap" for use
   with RFC 3288 [16].  This memo requires that the IANA register a
   URI-prefix of

       http://iana.org/beep/soap/VERSION

   to correspond to the family of profiles defined Section 8.1.

   The IANA has registered "soap.beep" and "soap.beeps" as URL schemes,
   as specified in Section 8.2 and Section 8.3, respectively.

   The IANA has also registered "SOAP over BEEP" as a TCP port number,
   as specified in Section 8.4.

   The IANA now broadens these three registries to support the family of
   BEEP profiles defined by this URI prefix.

   Finally, the IANA maintains a list of SOAP profile features, cf.
   Section 7.1.  The IESG is responsible for assigning a designated
   expert to review the specification prior to the IANA making the
   assignment.  Prior to contacting the IESG, developers of SOAP profile
   features must use the mailing list beepwg@lists.beepcore.org to
   solicit commentary.

11.  Changes from RFC 3288

   This memo differs from RFC 3288 [16] in one substantive way: a URL
   prefix is defined to support a family of BEEP profiles corresponding
   to different versions of SOAP.  Similarly, the IANA registrations in
   Section 8.1, Section 8.3, and Section 8.4 are updated to reflect this
   broadening.

   Support for W3C MTOM/XOP packaging has been added.

   A new section was added to discuss the distributed state machine of
   the Request-Response MEP.

   In non-substantive ways, a small number of typographical errors were
   corrected.

12.  Acknowledgements

   The authors gratefully acknowledge the contributions of: Christopher
   Ferris, Huston Franklin, Alexey Melnikov, Bill Mills, and Roy T.
   Fielding.

13.  References

13.1.  Normative References

   [1]   Rose, M., "The Blocks Extensible Exchange Protocol Core", RFC
         3080, March 2001.

   [2]   Nielsen, H., Mendelsohn, N., Gudgin, M., Hadley, M., and J.
         Moreau, "SOAP Version 1.2 Part 1: Messaging Framework", W3C REC
         REC-soap12-part1-20030624, June 2003.

   [3]   Nielsen, H., Hadley, M., Moreau, J., Mendelsohn, N., and M.
         Gudgin, "SOAP Version 1.2 Part 2: Adjuncts", W3C REC REC-
         soap12-part2-20030624, June 2003.

   [4]   Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L.,
         Leach, P., and T. Berners-Lee, "Hypertext Transfer Protocol --
         HTTP/1.1", RFC 2616, June 1999.

   [5]   Baker, M. and M. Nottingham, "The "application/soap+xml" media
         type", RFC 3902, September 2004.

   [6]   Murata, M., St. Laurent, S., and D. Kohn, "XML Media Types",
         RFC 3023, January 2001.

   [7]   Nottingham, M., Mendelsohn, N., Gudgin, M., and H. Ruellan,
         "SOAP Message Transmission Optimization Mechanism", W3C REC
         REC-soap12-mtom-20050125, January 2005.

   [8]   Nottingham, M., Mendelsohn, N., Gudgin, M., and H. Ruellan,
         "XML-binary Optimized Packaging", W3C REC REC-xop10-20050125,
         January 2005.

   [9]   Freed, N. and N. Borenstein, "Multipurpose Internet Mail
         Extensions (MIME) Part One: Format of Internet Message Bodies",
         RFC 2045, November 1996.

   [10]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
         Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986,
         January 2005.

   [11]  Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for
         specifying the location of services (DNS SRV)", RFC 2782,
         February 2000.

   [12]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
         Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986,
         January 2005.

   [13]  Elkins, M., Del Torto, D., Levien, R., and T. Roessler, "MIME
         Security with OpenPGP", RFC 3156, August 2001.

   [14]  Ramsdell, B., "Secure/Multipurpose Internet Mail Extensions
         (S/MIME) Version 3.1 Message Specification", RFC 3851, July
         2004.

13.2.  Informative References

   [15]  Mitra, N., "SOAP Version 1.2 Part 0: Primer", W3C REC REC-
         soap12-part0-20030624, June 2003.

   [16]  O'Tuathail, E. and M. Rose, "Using the Simple Object Access
         Protocol (SOAP) in Blocks Extensible Exchange Protocol (BEEP)",
         RFC 3288, June 2002.

   [17]  Box, D., Ehnebuske, D., Kakivaya, G., Layman, A., Mendelsohn,
         N., Nielsen, H., Thatte, S., and D. Winer, "Simple Object
         Access Protocol (SOAP) 1.1", W3C NOTE NOTE-SOAP-20000508, May
         2000.

   [18]  Levinson, E., "The MIME Multipart/Related Content-type", RFC
         2387, August 1998.

   [19]  Barton, J., Thatte, S., and H. Nielsen, "SOAP Messages with
         Attachments", W3C NOTE NOTE-SOAP-attachments-20001211, December
         2000.

   [20]  Levinson, E., "Content-ID and Message-ID Uniform Resource
         Locators", RFC 2392, August 1998.

   [21]  Palme, J., Hopmann, A., and N. Shelness, "MIME Encapsulation of
         Aggregate Documents, such as HTML (MHTML)", RFC 2557, March
         1999.

Appendix A.  SOAP with Attachments (Informative)

   To provide compatibility with RFC3288 [16], a BEEP profile for SOAP
   MAY allow envelopes to be transmitted as the root part of a
   "multipart/related" [18] content, and with subordinate parts
   referenced using the rules of Section 3 of [19] (i.e., using either
   the "Content-ID:" [20] or "Content-Location:" [21] headers), e.g.,

    MSG 1 2 . 278 657
    Content-Type: multipart/related; boundary="MIME_boundary";
                  type=application/xml;
                  start="<claim061400a.xml@claiming-it.com>"

    --MIME_boundary
    Content-Type: application/xml
    Content-ID: <claim061400a.xml@claiming-it.com>

    <?xml version='1.0' ?>
    <env:Envelope
         xmlns:env="http://www.w3.org/2003/05/soap-envelope">
     ..
    </env:Header>
    <env:Body>
    <theSignedForm href="cid:claim061400a.tiff@claiming-it.com" />
     ..
    </env:Body>
    </env:Envelope>

    --MIME_boundary
    Content-Type: image/tiff
    Content-Transfer-Encoding: binary
    Content-ID: <claim061400a.tiff@claiming-it.com>

     ...binary TIFF image...
    --MIME_boundary--
    END

   Consistent with Section 2 of [19], it is strongly recommended that
   the multipart contain a "start" parameter, and that the root part
   contain a "Content-ID:" header.  However, because BEEP provides an
   8bit-wide path, a "transformative" Content-Transfer-Encoding (e.g.,
   "base64" or "quoted-printable") should not be used.  Further note
   that MIME [9] requires that the value of the "Content-ID" header be
   globally unique.

Authors' Addresses

   Eamon O'Tuathail
   Clipcode.com
   24 Thomastown Road
   Dun Laoghaire
   Dublin
   IE

   Phone: +353 1 2350 424
   EMail: eamon.otuathail@clipcode.com
   URI:   http://www.clipcode.com/


   Marshall T. Rose
   Dover Beach Consulting, Inc.
   POB 255268
   Sacramento, CA  95865-5268
   US

   Phone: +1 916 483 8878
   EMail: mrose@dbc.mtview.ca.us

Full Copyright Statement

   Copyright (C) The Internet Society (2006).

   This document is subject to the rights, licenses and restrictions
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ISO Plain Language

On this page
PROBLEMSOAP says what a message looks like but not how to put it on the network. BEEP is a framing protocol built for exactly that job, but the two had never been joined up.
MECHANISMThe document defines a BEEP profile for SOAP, a boot exchange that identifies the resource and negotiates features, and a mapping from the three SOAP message patterns onto BEEP's MSG, RPY, ANS and NUL messages.
WHAT IT REPLACEDThis obsoletes RFC 3288 and adds support for the MTOM and XOP packaging technique, so that SOAP messages can carry attachments without base64 encoding them.

§1What This Document Specifies

The memo specifies a Simple Object Access Protocol binding to the BEEP core. A SOAP binding describes how SOAP messages are transmitted in the network.

SOAP is an XML-based messaging protocol used to implement a wide variety of distributed messaging models. It defines a message format and describes a variety of message patterns, including but not limited to Remote Procedure Calling, asynchronous event notification, unacknowledged messages, and forwarding via SOAP intermediaries.

Conforming implementations MUST support SOAP version 1.2 and MAY support other versions, such as SOAP version 1.1. Unlike its predecessor, RFC 3288, the memo does not mandate the use of SOAP version 1.1. Throughout the memo, the term envelope refers to the top-level element exchanged by SOAP senders and receivers, and the terms peer, client, server, one-to-one and one-to-many are used in the context of BEEP.

SOAP is the message; BEEP is the envelope it travels in. This document says exactly how a SOAP message is placed inside BEEP's framing, so that two programs can talk to each other without either of them knowing anything about the other's network.

§2The Profile and Its Two States

The BEEP profile for SOAP is identified as http://iana.org/beep/soap/VERSION in the BEEP profile element during channel creation, where VERSION refers to the numeric version of the SOAP specification. For example, http://iana.org/beep/soap/1.2 refers to version 1.2. RFC 3288 used http://iana.org/beep/soap for profile identification for SOAP version 1.1 envelopes, so an implementation that chooses to implement SOAP 1.1 should support both that URI and http://iana.org/beep/soap/1.1.

In BEEP, when the first channel is successfully created, the serverName attribute in the start element identifies the virtual host associated with the peer acting in the server role. The serverName attribute is analogous to HTTP's Host request-header field.

There are two states in the BEEP profile for SOAP, boot and ready. In the boot state, the peer requesting the creation of the channel sends a bootmsg, either during channel initialization or in a MSG message. If the other peer sends a bootrpy, then the ready state is entered. Otherwise the other peer sends an error, and no state change occurs. In the ready state, either peer begins a SOAP message pattern by sending a MSG message containing an envelope. The other peer completes the message pattern either by sending back an RPY message containing an envelope, or by sending back zero or more ANS messages, each containing an envelope, followed by a NUL message. Regardless, no state change occurs.

A BEEP channel for SOAP starts in a kind of waiting room where the two ends sort out which service is being used and what optional features they both understand. Once that is done the channel is ready and the actual messages flow.

THE TWO STATES OF A BEEP CHANNEL FOR SOAP
  • boot start
  • ready
FromToEvent
bootreadybootrpy received
bootbooterror received, no state change

§2.1Profile Initialization and the Boot Message

The boot message is used for two purposes: resource identification, since each channel bound to the BEEP profile for SOAP provides access to a single resource, a network data object or service; and feature negotiation, so that if new features of SOAP emerge, their use can be negotiated.

The boot message contains a mandatory resource attribute, which is analogous to HTTP's abs_path Request-URI parameter, and an optional features attribute, which if present contains one or more feature tokens, each indicating an optional feature of the BEEP profile for SOAP that is being requested for possible use over the channel. If the peer acting in the server role recognizes the requested resource, it replies with the boot response, which contains one optional features attribute holding a subset of the feature tokens in the boot message, indicating which features may be used over the channel. If not present or empty, no features may be used.

Otherwise, if the boot message is improperly formed or if the requested resource is not recognized, the peer acting in the server role replies with an error message. Typically the boot message and its response are exchanged during channel initialization, but the channel remains in the boot state after an unsuccessful exchange.

The boot exchange does two jobs at once: it names the service the client wants, and it lets the two ends agree on optional extras. If the server does not recognise the name, it says so and the channel stays unusable.

§3SOAP Message Packages

The BEEP profile for SOAP transmits envelopes encoded as UTF-8 and SHOULD use the media type application/soap+xml. To provide compatibility with RFC 3288, it MAY use the media type application/xml.

In addition, an implementation of the BEEP profile for SOAP MAY support transmission of envelopes using the MTOM and XOP packaging technique, which sends a MIME multipart body whose parts are referenced from the XML rather than embedded in it. Because BEEP provides an 8-bit-wide path, a transformative Content-Transfer-Encoding such as base64 or quoted-printable should not be used. When an implementation of BEEP in SOAP does support MTOM and XOP, it SHOULD support the MIME Multipart/Related XOP Package format, and MAY support others. Additional formats could in the future include XOP package formats specific to BEEP, for example sending the attachments on a different channel to the SOAP channel, which would avoid searching for the MIME boundary tags and allows lazy delivery of attachments, delivering them only when really needed.

Ordinarily the whole SOAP message, attachments and all, is one XML document in UTF-8. The optional packaging technique splits the attachments out into separate parts and points at them from the XML, so large binary files are not wasted through a text encoding.

A SOAP ENVELOPE CARRIED IN A BEEP MSG MESSAGE
MSG with a SOAP envelope
MSG 1 1 . 0 284
Content-Type: application/soap+xml

<env:Envelope
     xmlns:env="http://www.w3.org/2003/05/soap-envelope">
  <env:Header>
   <m:GetLastTradePrice xmlns:m="Some-URI" />
  </env:Header>
  <env:Body>
    <symbol xmlns:p="Some-URI" >DIS</symbol>
  </env:Body>
</env:Envelope>
END

§4SOAP Message Patterns

A one-way message involves sending a message without any response being returned. The BEEP profile for SOAP achieves this using a one-to-many exchange, in which the client sends a MSG message containing an envelope, and the server immediately sends back a NUL message, before processing the contents of the envelope.

A request and response exchange involves sending a request, which results in a response being returned. The BEEP profile for SOAP achieves this using a one-to-one exchange, in which the client sends a MSG message containing an envelope, and the server sends back an RPY message containing an envelope.

A request and N-responses exchange involves sending a request, which results in zero or more responses being returned. The BEEP profile for SOAP achieves this using a one-to-many exchange, in which the client sends a MSG message containing an envelope, and the server sends back zero or more ANS messages, each containing an envelope, followed by a NUL message.

For error handling, the BEEP profile for SOAP does not use the ERR message for SOAP faults. When performing one-to-one exchanges, whatever SOAP response, including SOAP faults, generated by the server is always returned in the RPY message. When performing one-to-many exchanges, whatever SOAP response, including SOAP faults, generated by the server is always returned in the ANS messages. If there is an error with the BEEP message unrelated to the SOAP envelope, for example a poorly formed MIME message or an unsupported MIME Content-Type, then the server responds with an ERR message with an appropriate reply code.

Three shapes of conversation map onto BEEP's messages. A question and an answer is one MSG and one RPY. A question with several answers is one MSG, then any number of ANS, then a NUL to say that is all. A SOAP-level error is not an error at this level; it comes back as an ordinary reply.

THE BEEP MESSAGES THAT CARRY SOAP ENVELOPES
ClientServer
  1. MSGThe client sends a SOAP envelope.
  2. RPYOne-to-one exchange: the answer comes back in a reply.
  3. ANSOne-to-many exchange: zero or more answers, each carrying an envelope.
  4. NULThe NUL message ends the one-to-many exchange.

§5.5The Requesting and Responding State Machines

For binding instances conforming to the specification, a SOAP node instantiated at the BEEP peer that initiates the message exchange may assume the role of RequestingSOAPNode, and a SOAP node instantiated at the other BEEP peer may assume the role of RespondingSOAPNode.

The requesting node starts in the Init state, where a BEEP message is formulated and transmission begins, and then the state changes to Requesting. In the Requesting state more of the request message is transmitted and the arrival of the response is awaited. When the beginning of the response message is received, if it is a BEEP ERR message then the state transitions to Fail; otherwise the state transitions to Sending and Receiving. In that state the transmission of the request message and the receiving of the response message are completed, and once the receipt of the response is completed the state transitions to Success. Success and Fail are the terminal states of the machine.

The responding node starts in Init, where it awaits the start of the inbound request and may only generate ERR messages. It then moves to Receiving, where it begins to receive the request message and prepares the start of the response, and then to Receiving and Sending, where the receiving of the request and the sending of the response are completed before the transition to the Success state. Success and Fail are the terminal states that indicate completion of the message exchange.

The document spells out the steps each side goes through, so that a slow reply cannot deadlock a sender that is still streaming its request. The requesting side must be able to read the beginning of the answer while it is still writing the question.

§6The soap.beep and soap.beeps URL Schemes

The memo defines two URL schemes, soap.beep and soap.beeps, which identify the use of SOAP over BEEP over TCP. The soap.beep URL scheme uses the generic URI syntax: the value soap.beep is used for the scheme component and the server-based naming authority is used for the authority component. The path component maps to the resource component of the boot message sent during profile initialization, and if absent it defaults to a single slash. The values of both the scheme and authority components are case-insensitive.

The soap.beep URL scheme indicates the use of the BEEP profile for SOAP running over TCP/IP. If the authority component contains a domain name and a port number, then the DNS is queried for the A resource records corresponding to the domain name and the port number is used directly. If the authority contains a domain name and no port number, the Service Record algorithm is used with a service parameter of soap-beep and a protocol parameter of tcp; if no appropriate SRV records are found, the DNS is queried for the A records and the port number assigned by IANA is used. If the authority contains an IP address, the DNS is not queried and the address is used directly, with the port taken from the URL or from the IANA assignment.

The soap.beeps URL scheme is identical in all ways to the soap.beep URL scheme, with the exception that prior to starting the BEEP profile for SOAP the BEEP session must be tuned for privacy. Both URL schemes use the identical algorithms and parameters for address resolution. There are two ways to perform privacy tuning on a BEEP session: a transport security profile may be successfully started, or a user authentication profile that supports transport security may be successfully started. Upon completion of the negotiation, a tuning reset occurs in which both BEEP peers issue a new greeting.

A soap.beep address names a SOAP service: the host part says where to connect and the path part says which service to ask for. The soap.beeps form is the same, except that the connection must be made private first, so the two ends negotiate encryption before saying anything else.

THE TWO URL SCHEMES
  • soap.beepIdentifies a SOAP resource reached with the BEEP profile for SOAP over TCP/IP.
  • soap.beepsIdentical, except that the BEEP session must first be tuned for privacy.
  • The pathMaps to the resource component of the boot message, and defaults to a single slash if absent.
  • Finding the addressA port number in the URL is used directly; otherwise the DNS SRV record with the service name soap-beep is looked up, then the IANA-assigned port.

§9Security Considerations

Although service provisioning is a policy matter, at a minimum all implementations MUST provide the following tuning profiles: for authentication, http://iana.org/beep/SASL/DIGEST-MD5; for confidentiality, http://iana.org/beep/TLS using the TLS_RSA_WITH_AES_EDE_CBC_SHA cipher; and for both, http://iana.org/beep/TLS using the same cipher but supporting client-side certificates.

Furthermore, implementations may choose to offer MIME-based security services providing message integrity and confidentiality, such as OpenPGP or S/MIME. Regardless, the BEEP core specification's Section 9 holds a discussion of BEEP-specific security issues.

Every implementation has to offer at least one way to authenticate the peer and one way to encrypt the session. It may also protect the messages themselves, for instance with S/MIME, on top of the protection of the channel.

THE TUNING PROFILES EVERY IMPLEMENTATION MUST OFFER
  • AuthenticationThe tuning profile http://iana.org/beep/SASL/DIGEST-MD5 must be provided.
  • ConfidentialityThe tuning profile http://iana.org/beep/TLS must be provided, using the TLS_RSA_WITH_AES_EDE_CBC_SHA cipher.
  • BothThe same TLS profile, but supporting client-side certificates.
  • Message-level securityImplementations may also offer MIME-based services such as OpenPGP or S/MIME.

§9References