Network Working Group                                         D. Eastlake
Request for Comments: 2935                                       Motorola
Category: Standards Track                                        C. Smith
                                                     Royal Bank of Canada
                                                           September 2000

         Internet Open Trading Protocol (IOTP) HTTP Supplement

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 (2000).  All Rights Reserved.


   Internet Open Trading Protocol (IOTP) messages will be carried as
   Extensible Markup Language (XML) documents.  As such, the goal of
   mapping to the transport layer is to ensure that the underlying XML
   documents are carried successfully between the various parties.

   This document describes that mapping for the Hyper Text Transport
   Protocol (HTTP), Versions 1.0 and 1.1.

Table of Contents

   1.  Introduction................................................... 2
   2.  HTTP Servers and Clients....................................... 2
   3.  HTTP Net Locations............................................. 2
   4.  Consumer Clients............................................... 2
   4.1 Starting the IOTP Client and the Merchant IOTP Server.......... 3
   4.2 Ongoing IOTP Messages.......................................... 3
   4.3 Stopping an IOTP Transaction................................... 4
   5.  Starting the Payment handler and Deliverer IOTP Servers........ 5
   6.  Security Considerations........................................ 5
   7.  IANA Considerations............................................ 5
   8.  References..................................................... 6
   9.  Authors' Addresses............................................. 7
   10. Full Copyright Statement....................................... 9

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RFC 2935                  IOTP HTTP Supplement            September 2000

1. Introduction

   Internet Open Trading Protocol (IOTP) [RFC2801] messages will be
   carried as XML [XML] documents.  As such, the goal of mapping to the
   transport layer is to ensure that the underlying XML documents are
   carried successfully between the various parties.

   This document describes that mapping for the Hyper Text Transport
   Protocol (HTTP), Versions 1.0 and 1.1 [RFCs 1945, 2616].

   There may be future documents describing IOTP over email (SMTP), TCP,
   cable TV, or other transports.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   document are to be interpreted as described in [RFC2119].

2. HTTP Servers and Clients

   The structure of IOTP maps on to the structure of HTTP in the
   following way:

      The merchant, payment handler, delivery handler, and customer care
      roles are all represented by HTTP servers.  Each may be
      represented by a separate server, or they may be combined in any

      The consumer role is represented by an HTTP client.

   Note: A Merchant, may act in the role of a consumer, for example to
   deposit electronic cash.  In this case the Merchant, as an
   organization rather than as a role, would need to be supported by an
   HTTP client.

3. HTTP Net Locations

   The Net Locations contained within the IOTP specification are all
   URIs [RFC 2396].  If a secure connection is required or desired a
   secure channel that both the HTTP Server and Client support MUST be
   used. Examples of such channels are SSL version 3 or TLS [RFC 2246].

4. Consumer Clients

   In most environments, the consumer agent will initially be an HTML
   browser.  However, current browsers do not provide the needed
   capability to act as an agent for the consumer for an IOTP
   transaction. This leads to two requirements:

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RFC 2935                  IOTP HTTP Supplement            September 2000

   a method of starting and passing control to the IOTP client, and

   a method of closing down the IOTP client cleanly and passing control
   back to the HTML browser once the IOTP Transaction has finished.

4.1 Starting the IOTP Client and the Merchant IOTP Server

   At some point, the HTTP client at the consumer will send an HTTP
   request that is interpreted as an "IOTP Startup Request" by the
   Merchant HTTP server.  This might, for example, be the result of
   clicking on a "pay" button.  This message is a stand-in for a request
   message of some form and the Merchant Server will respond with the
   first IOTP Message in the form of an XML document.

   The MIME type for all IOTP messages is: "APPLICATION/IOTP"; however
   "APPLICATION/X-IOTP" has been in use for experimentation and
   development and SHOULD also be recognized.  See section 7 below for
   the MIME type registration template for APPLICATION/IOTP.  Because
   HTTP is binary clean, no content-transfer-encoding is required.  (See
   [RFC 2376] re the application/xml type which has some similar

   This HTTP response will be interpreted by the HTML browser as a
   request to start the application associated with MIME type
   "APPLICATION/IOTP", and to pass the content of this message to that

   At this point, the IOTP client will be started and have the first

   IOTP messages are short-lived. Therefore, the HTTP server SHOULD
   avoid having its responses cached.  In HTTP V1.0, the "nocache"
   pragma can be used.  This can be neglected on SSL/TLS secured
   connections which are not cached and on HTTP POST requests in HTTP
   v1.1 as in v1.1 POST responses are not cached.

4.2 Ongoing IOTP Messages

   Data from earlier IOTP Messages in a transaction MUST be retained by
   the IOTP Client so that it may (1) be copied to make up part of later
   IOTP messages, (2) used in calculations to verify signatures in later
   IOTP message, (3) be resent in some cases where a request has timed
   out without response, (4) used as input to the Customer Care role in
   later versions of IOTP, etc.  The way in which the data is copied
   depends on the IOTP Transaction.  The data MUST be retained until the
   end of the transaction, whether by success, failure, or cancelation,
   and as long thereafter as it is desired for any of the parties to
   inquire into it.

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RFC 2935                  IOTP HTTP Supplement            September 2000

   The IOTP messages contain Net Locations (e.g. the PayReqNetLocn)
   which for HTTP will contain the URIs to which the IOTP client MUST
   send IOTP messages.

   Subsequent IOTP messages (XML documents) will be sent using the POST
   function of HTTP.  The HTTP client MUST perform full HTTP POST

   The XML documents MUST be sent in a manner compatible with the
   external encodings allowed by the XML [XML] specification.

4.3 Stopping an IOTP Transaction

   The following should be read in conjunction with [RFC 2801].

   An IOTP Transaction is complete when

   -- the IOTP client decides to fail the IOTP Transaction for some
      reason either by canceling the transaction or as a result of
      discovering an error in an IOTP message received, or

   -- a "time out" occurs or a connection fails, e.g. a response to an
      IOTP Message, has not been received after some user-defined period
      of Time (including retransmissions).

   An IOTP Client which processes an IOTP Transaction which:

   -- completes successfully (i.e. it has not received an Error Block
      with a HardError or a Cancel Block) MUST direct the browser to the
      Net Location specified in SuccessNetLocn in the Protocol Options
      Component, i.e., cause it to do an HTTP GET with that URL.

   -- does not complete successfully, because it has received some Error
      Trading Block, MUST display the information in the Error Message,
      stop the transaction, and pass control to the browser so that it
      will do a GET on the Error Net Location specified for the role
      from which the error was received.

   -- is cancelled since a Cancel Block has been received, MUST stop the
      IOTP Transaction and hand control to the browser so that it will
      do a GET on the on the Cancel Net Location specified for the role
      from which the Cancel Block was received.

   -- is in error because an IOTP Message does not conform to this
      specification, MUST send an IOTP Message containing a Error
      Trading Block to role from which the erroneous message was
      received and the ErrorLogNetLoc specified for that role, stop the

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RFC 2935                  IOTP HTTP Supplement            September 2000

      IOTP Transaction, and hand control to the browser so that it will
      do a GET from the Error Net Location specified for the role from
      which the bad message was received.

   -- has a "time out", MUST display a message describing the time out.
      May give the user the option of cancelling or retrying and/or may
      automatically retry.  On failure due to time out, treat as an
      error above.

   Each implementation of an IOTP client may decide whether or not to
   terminate the IOTP Client application immediately upon completing an
   IOTP Transaction or whether to wait until it is closed down as a
   result of, for example, user shut down or browser shut down.

5. Starting the Payment handler and Deliverer IOTP Servers

   Payment Handler and Deliverer IOTP Servers are started by receiving
   an IOTP Message which contains:

   -- for a Payment handler, a Payment Request Block, and

   -- for a Delivery Handler, a Delivery Request Block

6. Security Considerations

   Security of Internet Open Trade Protocol messages is primarily
   dependent on signatures within IOTP as described in [RFC 2801] and
   [RFC 2802].  Privacy protection for IOTP interactions can be obtained
   by using a secure channel for IOTP messages, such as SSL/TLS [RFC

   Note that the security of payment protocols transported by IOTP is
   the responsibility of those payment protocols, NOT of IOTP.

7. IANA Considerations

   This specification defines the APPLICATION/IOTP MIME type.  The
   registration template is as follows [RFC 2048]:


      Subject: Registration of MIME media type APPLICATION/IOTP

      MIME media type name: APPLICATION

      MIME subtype name: IOTP

      Required parameters: (none)

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RFC 2935                  IOTP HTTP Supplement            September 2000

      Optional parameters: charset - see RFC 2376

      Encoding considerations: Content is XML and may in some cases
      require quoted printable or base64 encoding.  However, no encoding
      is required for HTTP transport which is expected to be common.

      Security considerations: IOTP includes provisions for digital
      authentication but for confidentiality, other mechanisms such as
      TLS should be used.  See RFC 2801 and RFC 2802.

      Interoperability considerations: See RFC 2801.

      Published specification: See RFC 2801 and RFC 2802.

      Applications which use this media type:  Internet Open Trading
      Protocol applications.

      Additional information: (none)

      Person & email address to contact for further information:
         Name: Donald E. Eastlake 3rd

      Intended usage: COMMON

      Author/Change controller: IETF

8. References

   [RFC 1945] Berners-Lee, T., Fielding, R. and H. Frystyk, "Hypertext
              Transfer Protocol -- HTTP/1.0", RFC 1945, May 1996.

   [RFC 2048] Freed, N., Klensin, J. and J. Postel, "Multipurpose
              Internet Mail Extensions (MIME) Part Four: Registration
              Procedure", RFC 2048, November 1996.

   [RFC 2119] Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC 2246] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0",
              RFC 2246, January 1999.

   [RFC 2376] Whitehead, E. and M. Murata, "XML Media Types", RFC 2376,
              July 1998.

   [RFC 2396] Berners-Lee, T., Rielding, R. and L. Masinter, "Uniform
              Resource Identifiers (URI): Generic Syntax", RFC 2396,
              August 1998.

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RFC 2935                  IOTP HTTP Supplement            September 2000

   [RFC 2616] 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.

   [RFC 2801] Burdett, D., "Internet Open Trading Protocol - IOTP
              Version 1.0", RFC 2801, April 2000.

   [RFC 2802] Davidson, K. and Y. Kawatsura, "Digital Signatures for the
              v1.0 Internet Open Trading Protocol (IOTP)", RFC 2802,
              April 2000

   [XML]      Bray, T., Paoli, J. and C. Sperberg-McQueen, "Extensible
              Markup Language (XML) 1.0" <>,
              February 1998.

9. Authors' Addresses

   Donald E. Eastlake 3rd
   140 Forest Avenue
   Hudson, MA 01749 USA

   Phone: +1 978-562-2827(h)
          +1 508-261-5434(w)
   Fax:   +1 508-261-4447(w)

   Chris J. Smith
   Royal Bank of Canada
   277 Front Street West
   Toronto, Ontario M5V 3A4 CANADA

   Phone: +1 416-348-6090
   Fax:   +1 416-348-2210

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RFC 2935                  IOTP HTTP Supplement            September 2000

10.  Full Copyright Statement

   Copyright (C) The Internet Society (2000).  All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assigns.

   This document and the information contained herein is provided on an


   Funding for the RFC Editor function is currently provided by the
   Internet Society.

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