Network Working Group M. Baker
Request for Comments: 3902 Independent
Category: Informational M. Nottingham
BEA Systems
September 2004
The "application/soap+xml" media type
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2004).
Abstract
This document defines the "application/soap+xml" media type which can
be used to describe SOAP 1.2 messages serialized as XML 1.0.
1. Introduction
SOAP version 1.2 (SOAP) is a lightweight protocol intended for
exchange of structured information between peers in a decentralized,
distributed environment. It defines an extensible messaging
framework that contains a message construct based on XML technologies
that can be exchanged over a variety of underlying protocols.
This specification defines the media type "application/soap+xml"
which can be used to identify SOAP 1.2 message envelopes that have
been serialized with XML 1.0. Such serializations are useful as the
basis of "wire formats" for SOAP 1.2 Protocol Binding Specifications
[W3C.REC-soap12-part1-20030624], or in other situations where an XML
serialization of a SOAP envelope is required.
The "application/soap+xml" media type explicitly identifies SOAP 1.2
message envelopes that have been serialised with XML 1.0; message
envelopes with a different SOAP namespace version or using another
XML serialisation MUST NOT use it.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
Baker & Nottingham Informational [Page 1]
RFC 3902 The "application/soap+xml" media type September 2004
2. Registration
MIME media type name: application
MIME subtype name: soap+xml
Required parameters: none
Optional parameters:
"charset": This parameter has identical semantics to the charset
parameter of the "application/xml" media type as specified in
RFC 3023 [RFC3023].
"action": This optional parameter can be used to specify the URI
that identifies the intent of the message. In SOAP 1.2, it
serves a similar purpose as the SOAPAction HTTP header field
did in SOAP 1.1. Namely, its value identifies the intent of
the message.
The value of the action parameter is an absolute URI-reference
as defined by RFC 2396 [RFC2396], which MUST be non-empty.
SOAP places no restrictions on the specificity of the URI or
that it is resolvable. Although the purpose of the action
parameter is to indicate the intent of the SOAP message there
is no mechanism for automatically computing the value based on
the SOAP envelope. In other words, the value has to be
determined out of band. It is recommended that the same value
be used to identify sets of message types that are logically
connected in some manner, for example part of the same
"service". It is strongly RECOMMENDED that the URI be globally
unique and stable over time.
Use of the action parameter is OPTIONAL. SOAP Receivers MAY
use it as a hint to optimize processing, but SHOULD NOT require
its presence in order to operate.
Encoding considerations: Identical to those of "application/xml" as
described in RFC 3023 [RFC3023], section 3.2, as applied to the
SOAP envelope infoset.
Security considerations: Because SOAP can carry application defined
data whose semantics is independent from that of any MIME wrapper
(or context within which the MIME wrapper is used), one should not
expect to be able to understand the semantics of the SOAP message
based on the semantics of the MIME wrapper alone. Therefore,
whenever using the "application/soap+xml" media type, it is
strongly RECOMMENDED that the security implications of the context
within which the SOAP message is used is fully understood. The
security implications are likely to involve both the specific SOAP
binding to an underlying protocol as well as the application-
Baker & Nottingham Informational [Page 2]
RFC 3902 The "application/soap+xml" media type September 2004
defined semantics of the data carried in the SOAP message (though
one must be careful when doing this, as discussed in SOAP 1.2 Part
1 [W3C.REC-soap12-part1-20030624], section Binding to
Application-Specific Protocols).
Also, see SOAP 1.2 Part 1 [W3C.REC-soap12-part1-20030624], the
entire section Security Considerations.
In addition, as this media type uses the "+xml" convention, it
shares the same security considerations as described in RFC 3023
[RFC3023], section 10.
The action parameter is not a security mechanism, and SHOULD NOT
be used for authentication. If the action parameter is used to
make decisions (e.g., dispatch, filtering), it is RECOMMENDED that
the basis for such decisions should be confirmed by examining the
SOAP Envelope.
Interoperability considerations: There are no known interoperability
issues.
Published specification: SOAP 1.2 Part 1
[W3C.REC-soap12-part1-20030624] and SOAP 1.2 Part 2
[W3C.REC-soap12-part2-20030624].
Applications which use this media type: Various SOAP 1.2 conformant
toolkits use this media type.
Additional information:
File extension: SOAP messages are not required or expected to be
stored as files.
Fragment identifiers: Identical to that of "application/xml" as
described in RFC 3023 [RFC3023], section 5.
Base URI: As specified in RFC 3023 [RFC3023], section 6. Also see
SOAP 1.2 Part 1 [W3C.REC-soap12-part1-20030624], section Use of
URIs in SOAP.
Macintosh File Type code: TEXT
Person and email address to contact for further information:
World Wide Web Consortium