Sieve Working Group P. Saint-Andre
Internet-Draft XMPP Standards Foundation
Intended status: Standards Track A. Melnikov
Expires: April 3, 2008 Isode Limited
October 1, 2007
Sieve Notification Mechanism: xmpp
draft-ietf-sieve-notify-xmpp-05
Status of this Memo
By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on April 3, 2008.
Copyright Notice
Copyright (C) The IETF Trust (2007).
Abstract
This document describes a profile of the Sieve extension for
notifications, to allow notifications to be sent over the Extensible
Messaging and Presence Protocol (XMPP), also known as Jabber.
Saint-Andre & Melnikov Expires April 3, 2008 [Page 1]
Internet-Draft SIEVE-XMPP October 2007
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. Definition . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Notify parameter "method" . . . . . . . . . . . . . . . . 3
2.2. Notify tag ":from" . . . . . . . . . . . . . . . . . . . . 4
2.3. Notify tag ":options" . . . . . . . . . . . . . . . . . . 4
2.4. Notify tag ":importance" . . . . . . . . . . . . . . . . . 4
2.5. Notify tag ":message" . . . . . . . . . . . . . . . . . . 4
3. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Requirements Conformance . . . . . . . . . . . . . . . . . . . 5
5. Internationalization Considerations . . . . . . . . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . 7
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Normative References . . . . . . . . . . . . . . . . . . . 7
8.2. Informative References . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 9
Intellectual Property and Copyright Statements . . . . . . . . . . 10
Saint-Andre & Melnikov Expires April 3, 2008 [Page 2]
Internet-Draft SIEVE-XMPP October 2007
1. Introduction
1.1. Overview
The [NOTIFY] extension to the [SIEVE] mail filtering language is a
framework for providing notifications by employing URIs to specify
the notification mechanism. This document defines how xmpp URIs (see
[XMPP-URI]) are used to generate notifications via the Extensible
Messaging and Presence Protocol (see [XMPP]), which is widely
implemented in Jabber instant messaging technologies.
1.2. Terminology
This document inherits terminology from [NOTIFY], [SIEVE], and
[XMPP].
The capitalized key words "MUST", "MUST NOT", "REQUIRED", "SHALL",
"SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT
RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be
interpreted as described in [TERMS].
2. Definition
The xmpp mechanism results in the sending of an XMPP message to
notify a recipient about an email message. The general XMPP syntax
is as follows:
o The notification MUST be an XMPP <message/> stanza.
o The value of the XMPP 'type' attribute MUST be 'headline' or
'normal'.
o The value of the XMPP 'from' attribute MUST be the XMPP address of
the notification service.
o The XMPP <message/> stanza MAY include a <subject/> child element
whose value is some configurable text indicating that the message
is a Sieve notification.
o The notification SHOULD include a URL for the recipient to use as
a hint in locating the message, encapsulated as the XML character
data of a <url/> child element of an <x/> element qualified by the
'jabber:x:oob' namespace as specified in [OOB].
The recommended mapping of the Sieve notify action into XMPP syntax
is described in the following sections.
2.1. Notify parameter "method"
The "method" parameter MUST be a URI that conforms to the xmpp URI
scheme (as specified in [XMPP-URI]) and that identifies an XMPP
Saint-Andre & Melnikov Expires April 3, 2008 [Page 3]
Internet-Draft SIEVE-XMPP October 2007
account associated with the email inbox. The URI MAY include the
resource identifier portion of an XMPP address but SHOULD NOT include
an authority component, query component, or fragment identifier
component. The processing application MUST extract an XMPP address
from the URI in accordance with the processing rules specified in
[XMPP-URI]. The resulting XMPP address MUST be encapsulated in XMPP
syntax as the value of the XMPP 'to' attribute.
2.2. Notify tag ":from"
The ":from" tag has no special meaning for this notification
mechanism, and this specification puts no restriction on its use. As
noted, the value of the XMPP 'from' attribute specified in the XMPP
notification message MUST be the XMPP address of the notification
service itself. The value of the ":from" tag MAY be transformed into
XMPP syntax; if so, it SHOULD be encapsulated as the value of an XMPP
[SHIM] header named "Reply-To".
2.3. Notify tag ":options"
The ":options" tag has no special meaning for this notification
mechanism. Any handling of this tag is the responsibility of an
implementation.
2.4. Notify tag ":importance"
The ":importance" tag has no special meaning for this notification
mechanism, and this specification puts no restriction on its use.
The value of the ":importance" tag MAY be transformed into XMPP
syntax (in addition to or instead of including in the default
message); if so, it MUST be encapsulated as the value of an XMPP
[SHIM] header named "Urgency", and the XML character of that header
MUST be "high" if the value of the ":importance" tag is "1", "medium"
if the value of the ":importance" tag is "2", or "low" if the value
of the ":importance" tag is "3".
2.5. Notify tag ":message"
If included, the ":message" tag MUST be transformed into the XML
character data of an XMPP <body/> element. If not included, the rule
specified in [NOTIFY] SHOULD be followed, as shown in the examples
below.
3. Examples
In the following examples, the sender of the email has an address of
<mailto:juliet@example.org>, the entity to be notified has an XMPP
Saint-Andre & Melnikov Expires April 3, 2008 [Page 4]
Internet-Draft SIEVE-XMPP October 2007
address of romeo@example.com (resulting in an XMPP URI of
<xmpp:romeo@example.com>), and the notification service has an XMPP
address of notify.example.com (resulting in an XMPP URI of <xmpp:
notify.example.com>).
The following is a basic Sieve notify action with only a method:
notify "xmpp:romeo@example.com"
The resulting XMPP <message/> stanza might be as follows:
<message from='notify.example.com'
to='romeo@example.com'
xml:lang='en'>
<subject>A Sieve instant notification!</subject>
<body><juliet@example.org> Wherefore art thou?</body>
</message>
The following is a more advanced Sieve notify action with a method,
importance, subject, and message, as well as a URL pointing to the
message:
notify :importance "1"
:message "Contact Juliet immediately!"
"xmpp:romeo@example.com?message;subject=SIEVE"
The resulting XMPP <message/> stanza might be as follows:
<message from='notify.example.com'
to='romeo@example.com'
xml:lang='en'>
<subject>SIEVE</subject>
<body>Contact Juliet immediately!</body>
<headers xmlns='http://jabber.org/protocol/shim'>
<header name='Urgency'>high</header>
</headers>
<x xmlns='jabber:x:oob'>
<url>
imap://romeo@example.com/INBOX;UIDVALIDITY=385759045/;UID=20
</url>
</x>
</message>
4. Requirements Conformance
Section 3.8 of [NOTIFY] specifies a set of requirements for Sieve
notification methods. The conformance of the xmpp notification
Saint-Andre & Melnikov Expires April 3, 2008 [Page 5]
Internet-Draft SIEVE-XMPP October 2007
mechanism is provided here.
1. An implementation of the xmpp notification method SHOULD NOT
modify the final notification text (e.g., to limit the length);
however, a given deployment MAY do so (e.g., if recipients pay
per character or byte for XMPP messages). Modification of
characters themselves should not be necessary, since XMPP
character data is encoded in [UTF-8].
2. An implementation MAY ignore parameters specified in the ":from",
":importance", and ":options" tags.
3. There is no recommended default message for an implementation to
include if the ":message" argument is not specified.
4. A notification sent via the xmpp notification method MAY include
a timestamp in the textual message.
5. The value of the XMPP 'from' attribute MUST be the XMPP address
of the xmpp notification service. The value of the Sieve ":from"
tag MAY be transformed into the value of an XMPP [SHIM] header
named "Reply-To".
6. An implementation MUST NOT include any other extraneous
information not specified in parameters to the notify action.
7. In accordance with [XMPP-URI], an implementation MUST ignore any
URI action or parameter it does not understand (i.e., the URI
MUST be processed as if the action or parameter were not
present). It is RECOMMENDED to support the XMPP "message" query
type (see [QUERIES]) and the associated "body" and "subject"
parameters, which parameters SHOULD be mapped to the XMPP <body/>
and <subject/> child elements of the XMPP <message/> stanza type,
respectively. However, if included then the Sieve notify
":message" parameter MUST be mapped to the XMPP <body/> element,
overriding the "body" parameter (if any) included in the XMPP
URI.
8. In response to a notify_method_capability test for the "online"
notification-capability, an implementation SHOULD return a value
of "yes" if it has knowledge of an active presence session for
the specified notification-uri and a value of "no" if it does not
have such knowledge.
9. An implementation SHOULD NOT attempt to retry delivery of a
notification if it receives an XMPP error of type "auth" or
"cancel", MAY attempt to retry delivery if it receives an XMPP
error of type "wait", and MAY attempt to retry delivery if it
receives an XMPP error of "modify" but only if it makes
appropriate modifications to the notification (see [XMPP]); in
any case the number of retries SHOULD be limited to a
configurable number no less than 3 and no more than 10. An
implementation MAY throttle notifications if the number of
notifications within a given time period becomes excessive
according to local service policy. Duplicate suppression (if
any) is a matter of implementation and is not specified herein.
Saint-Andre & Melnikov Expires April 3, 2008 [Page 6]
Internet-Draft SIEVE-XMPP October 2007
5. Internationalization Considerations
Although an XMPP address may contain nearly any [UNICODE] character,
the value of the "method" parameter MUST be a Uniform Resource
Identifier (see [URI]) rather than an Internationalized Resource
Identifier (see [IRI]). The rules specified in [XMPP-URI] MUST be
followed when generating XMPP URIs.
In accordance with Section 13 of RFC 3920, all data sent over XMPP
MUST be encoded in [UTF-8].
6. Security Considerations
Depending on the information included, sending a notification can be
comparable to forwarding mail to the notification recipient. Care
must be taken when forwarding mail automatically, to ensure that
confidential information is not sent into an insecure environment.
In particular, implementations MUST conform to the security
considerations given in [NOTIFY], [SIEVE], and [XMPP].
7. IANA Considerations
The following template provides the IANA registration of the Sieve
notification mechanism specified in this document:
To: iana@iana.org
Subject: Registration of new Sieve notification mechanism
Mechanism name: xmpp
Mechanism URI: RFC4622
Mechanism-specific tags: none
Standards Track/IESG-approved experimental RFC number: this RFC
Person and email address to contact for further information:
Peter Saint-Andre <stpeter@jabber.org>
This information should be added to the list of Sieve notification
mechanisms maintained at
<http://www.iana.org/assignments/sieve-notification>.
8. References
8.1. Normative References
[NOTIFY] Melnikov, A., Leiba, B., Segmuller, W., and T. Martin,
"Sieve Extension: Notifications",
draft-ietf-sieve-notify-08 (work in progress), July 2007.
Saint-Andre & Melnikov Expires April 3, 2008 [Page 7]
Internet-Draft SIEVE-XMPP October 2007
[OOB] Saint-Andre, P., "Out of Band Data", XSF XEP 0066,
August 2006.
[QUERIES] Saint-Andre, P., "XMPP URI Scheme Query Components", XSF
XEP 0147, September 2006.
[SHIM] Saint-Andre, P. and J. Hildebrand, "Stanza Headers and
Internet Metadata", XSF XEP 0131, August 2005.
[SIEVE] Showalter, T. and P. Guenther, "Sieve: An Email Filtering
Language", draft-ietf-sieve-3028bis-12 (work in progress),
February 2007.
[TERMS] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[XMPP-URI]
Saint-Andre, P., "Internationalized Resource Identifiers
(IRIs) and Uniform Resource Identifiers (URIs) for the
Extensible Messaging and Presence Protocol (XMPP)",
draft-saintandre-rfc4622bis-01 (work in progress),
June 2007.
8.2. Informative References
[IRI] Duerst, M. and M. Suignard, "Internationalized Resource
Identifiers (IRIs)", RFC 3987, January 2005.
[UNICODE] The Unicode Consortium, "The Unicode Standard, Version
3.2.0", 2000.
The Unicode Standard, Version 3.2.0 is defined by The
Unicode Standard, Version 3.0 (Reading, MA, Addison-
Wesley, 2000. ISBN 0-201-61633-5), as amended by the
Unicode Standard Annex #27: Unicode 3.1
(http://www.unicode.org/reports/tr27/) and by the Unicode
Standard Annex #28: Unicode 3.2
(http://www.unicode.org/reports/tr28/).
[URI] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, January 2005.
[UTF-8] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, November 2003.
[XMPP] Saint-Andre, P., "Extensible Messaging and Presence
Protocol (XMPP): Core", RFC 3920, October 2004.
Saint-Andre & Melnikov Expires April 3, 2008 [Page 8]
Internet-Draft SIEVE-XMPP October 2007
Authors' Addresses
Peter Saint-Andre
XMPP Standards Foundation
Email: stpeter@jabber.org
URI: https://stpeter.im/
Alexey Melnikov
Isode Limited
Email: Alexey.Melnikov@isode.com
Saint-Andre & Melnikov Expires April 3, 2008 [Page 9]
Internet-Draft SIEVE-XMPP October 2007
Full Copyright Statement
Copyright (C) The IETF Trust (2007).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org.
Acknowledgment
Funding for the RFC Editor function is provided by the IETF
Administrative Support Activity (IASA).
Saint-Andre & Melnikov Expires April 3, 2008 [Page 10]
