[Docs] [txt|pdf|xml|html] [Tracker] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01

Independent Submission                                      K. Murchison
Internet-Draft                                                  FastMail
Intended status: Standards Track                           March 5, 2020
Expires: September 6, 2020


                         JMAP for Sieve Scripts
                     draft-murchison-jmap-sieve-01

Abstract

   This document specifies a data model for managing Sieve scripts on a
   server using JMAP.

Open Issues

   o  How should doing /set{create} with an existing script name be
      handled?  Should it fail or overwrite the existing script?  Should
      the /set request include an 'overwrite' boolean argument?

   o  Should setting isActive==true on a script automatically deactivate
      any other existing active script, or should the client have to do
      so itself (as is currently documented)?

   o  Do we want/need a SieveScript/copy method?

   o  Do we want to leverage draft-ietf-jmap-quotas to query Sieve
      script storage quotas?

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   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."

   This Internet-Draft will expire on September 6, 2020.






Murchison               Expires September 6, 2020               [Page 1]


Internet-Draft                 JMAP Sieve                     March 2020


Copyright Notice

   Copyright (c) 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Notational Conventions  . . . . . . . . . . . . . . . . .   3
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     1.3.  Addition to the Capabilities Object . . . . . . . . . . .   3
       1.3.1.  urn:ietf:params:jmap:sieve  . . . . . . . . . . . . .   3
   2.  Sieve Scripts . . . . . . . . . . . . . . . . . . . . . . . .   4
     2.1.  SieveScript/get . . . . . . . . . . . . . . . . . . . . .   5
     2.2.  SieveScript/set . . . . . . . . . . . . . . . . . . . . .   5
     2.3.  SieveScript/validate  . . . . . . . . . . . . . . . . . .   5
   3.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
     4.1.  JMAP Capability Registration for "sieve"  . . . . . . . .   6
     4.2.  JMAP Error Codes Registry . . . . . . . . . . . . . . . .   7
       4.2.1.  scriptIsActive  . . . . . . . . . . . . . . . . . . .   7
   5.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   7
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     6.2.  Informative References  . . . . . . . . . . . . . . . . .   8
   Appendix A.  Change History (To be removed by RFC Editor before
                publication) . . . . . . . . . . . . . . . . . . . .   8
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   JMAP ([RFC8620] - JSON Meta Application Protocol) is a generic
   protocol for synchronizing data, such as mail, calendars or contacts,
   between a client and a server.  It is optimized for mobile and web
   environments, and aims to provide a consistent interface to different
   data types.





Murchison               Expires September 6, 2020               [Page 2]


Internet-Draft                 JMAP Sieve                     March 2020


   This specification defines a data model for managing Sieve [RFC5228]
   scripts on a server using JMAP.  The data model is designed to allow
   a server to provide consistent access to the same scripts via
   ManageSieve [RFC5804] as well as JMAP, however the functionality
   offered over the two protocols may differ.

1.1.  Notational Conventions

   The 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 BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   Type signatures, examples, and property descriptions in this document
   follow the conventions established in Section 1.1 of [RFC8620].  Data
   types defined in the core specification are also used in this
   document.

1.2.  Terminology

   The same terminology is used in this document as in the core JMAP
   specification, see [RFC8620], Section 1.6.

   The term SieveScript (with this specific capitalization) is used to
   refer to the data type defined in this document and instances of
   those data types.

1.3.  Addition to the Capabilities Object

   The capabilities object is returned as part of the JMAP Session
   object; see [RFC8620], Section 2.  This document defines one
   additional capability URI.

1.3.1.  urn:ietf:params:jmap:sieve

   This represents support for the SieveScript data type and associated
   API methods.  The value of this property in the JMAP Session
   capabilities property is an empty object.

   The value of this property in an account's accountCapabilities
   property is an object that MUST contain the following information on
   server capabilities:

   o  *maxNumberRedirects*: "UnsignedInt|null" The maximum number of
      Sieve "redirect" actions a script can perform during a single
      evaluation (see [RFC5804], Section 1.7), or "null" for no limit.




Murchison               Expires September 6, 2020               [Page 3]


Internet-Draft                 JMAP Sieve                     March 2020


   o  *maxNumberScripts*: "UnsignedInt|null" The maximum number of Sieve
      scripts the server is willing to store for the user, or "null" for
      no limit.

   o  *maxSizeScript*: "UnsignedInt|null" The maximum size (in octets)
      of a Sieve script the server is willing to store for the user, or
      "null" for no limit.

   o  *sieveExtensions*: "String[]" A list of Sieve extensions (as
      listed in Sieve "require" action [RFC5228], Section 3.2) supported
      by the Sieve engine.

   o  *notificationMethods*: "String[]|null" A list of URI schema parts
      [RFC3986] for notification methods supported by the Sieve
      "enotify" extension [RFC5435], or "null" if the extension is not
      supported by the Sieve engine.

   o  *externalLists*: "String[]|null" A list of URI schema parts
      [RFC3986] for externally stored list types supported by the Sieve
      "extlists" extension [RFC6134], or "null" if the extension is not
      supported by the Sieve engine.

2.  Sieve Scripts

   A *SieveScript* object represents a single script on the server and
   has the following properties:

   o  *id*: "Id" (immutable; server-set) The id of the script.

   o  *name*: "String" The user-visible name for the script, subject to
      the requirements in [RFC5804], Section 1.6.

   o  *content*: "String" The Sieve code in the script.  Note that any
      double (") quote or backslash (\) characters appearing in the
      script content MUST be escaped by prefixing them with a backslash
      (\).

   o  *isActive*: "Boolean" (default: false) Is this the user's active
      script?












Murchison               Expires September 6, 2020               [Page 4]


Internet-Draft                 JMAP Sieve                     March 2020


   Example (using the Imap4Flags [RFC5232] Extension):

   {
     "id": "665c423a-6991-4733-8c7c-52b299572c66",
     "name": "example.siv",
     "content":
        "require [ \"imap4flags\" ];\r\nkeep :flags \"\\\\flagged\";",
     "isActive": false
   }

2.1.  SieveScript/get

   This is a standard "/get" method as described in [RFC8620],
   Section 5.1.  The _ids_ argument may be "null" to fetch all at once.

   This method provides similar functionality to the GETSCRIPT and
   LISTSCRIPTS commands in [RFC5804].

2.2.  SieveScript/set

   This is a standard "/set" method as described in [RFC8620],
   Section 5.3.

   This method provides similar functionality to the PUTSCRIPT,
   DELETESCRIPT, RENAMESCRIPT, and SETACTIVE commands in [RFC5804].

   Per [RFC5804], Section 1.4, a user may have multiple Sieve scripts on
   the server, yet only one script may be active.  Therefore, when
   changing the active script, the call to this method MUST both set the
   _isActive_ argument on the currently active script to "false" and set
   it to "true" on the script to be activated.

   The following extra SetError type is defined:

   For "create" and "update":

   o  *scriptIsActive*: The "isActive" argument was true and the user
      already has another active script.  The SetError object SHOULD
      also include the *id* property of the currently active script.

2.3.  SieveScript/validate

   This method is used by the client to verify Sieve script validity
   without storing the script on the server.

   The method provides similar functionality to the CHECKSCRIPT command
   in [RFC5804].




Murchison               Expires September 6, 2020               [Page 5]


Internet-Draft                 JMAP Sieve                     March 2020


   The server MUST check the submitted script for syntactic validity,
   which includes checking that all Sieve extensions mentioned in Sieve
   script "require" statement(s) are supported by the Sieve interpreter.
   (Note that if the Sieve interpreter supports the Sieve "ihave"
   extension [RFC5463], any unrecognized/unsupported extension mentioned
   in the "ihave" test MUST NOT cause the syntactic validation failure.)

   The *SieveScript/validate* method takes the following arguments:

   o  *accountId*: "Id" The id of the account to use.

   o  *content*: "String" The Sieve code to validate.  Note that any
      double (") quote or backslash (\) characters appearing in the
      script content MUST be escaped by prefixing them with a backslash
      (\).

   The response has the following arguments:

   o  *accountId*: "Id" The id of the account used for this call.

   o  *isValid*: "Boolean" Is the Sieve code valid?

   o  *errorDescription*: "String" A description of the error to show to
      the user, or an empty string if the Sieve code is valid.

3.  Security Considerations

   All security considerations of JMAP [RFC8620] apply to this
   specification.

4.  IANA Considerations

4.1.  JMAP Capability Registration for "sieve"

   IANA will register the "sieve" JMAP Capability as follows:

   Capability Name: "urn:ietf:params:jmap:sieve"

   Specification document: this document

   Intended use: common

   Change Controller: IETF

   Security and privacy considerations: this document, Section 3






Murchison               Expires September 6, 2020               [Page 6]


Internet-Draft                 JMAP Sieve                     March 2020


4.2.  JMAP Error Codes Registry

   The following sub-section registers a new error code in the JMAP
   Error Codes registry, as defined in [RFC8620].

4.2.1.  scriptIsActive

   JMAP Error Code: scriptIsActive

   Intended use: common

   Change controller: IETF

   Reference: This document, section 2.5

   Description: The client tried to activate a Sieve script, but another
   acript is already active.

5.  Acknowledgments

   The concepts in this document are based largely on those in
   [RFC5804].  The author would like to thank the authors of that
   document for providing both inspiration and some borrowed text for
   this document.

6.  References

6.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66,
              RFC 3986, DOI 10.17487/RFC3986, January 2005,
              <https://www.rfc-editor.org/info/rfc3986>.

   [RFC5228]  Guenther, P., Ed. and T. Showalter, Ed., "Sieve: An Email
              Filtering Language", RFC 5228, DOI 10.17487/RFC5228,
              January 2008, <https://www.rfc-editor.org/info/rfc5228>.

   [RFC5435]  Melnikov, A., Ed., Leiba, B., Ed., Segmuller, W., and T.
              Martin, "Sieve Email Filtering: Extension for
              Notifications", RFC 5435, DOI 10.17487/RFC5435, January
              2009, <https://www.rfc-editor.org/info/rfc5435>.




Murchison               Expires September 6, 2020               [Page 7]


Internet-Draft                 JMAP Sieve                     March 2020


   [RFC5804]  Melnikov, A., Ed. and T. Martin, "A Protocol for Remotely
              Managing Sieve Scripts", RFC 5804, DOI 10.17487/RFC5804,
              July 2010, <https://www.rfc-editor.org/info/rfc5804>.

   [RFC6134]  Melnikov, A. and B. Leiba, "Sieve Extension: Externally
              Stored Lists", RFC 6134, DOI 10.17487/RFC6134, July 2011,
              <https://www.rfc-editor.org/info/rfc6134>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8620]  Jenkins, N. and C. Newman, "The JSON Meta Application
              Protocol (JMAP)", RFC 8620, DOI 10.17487/RFC8620, July
              2019, <https://www.rfc-editor.org/info/rfc8620>.

6.2.  Informative References

   [RFC5232]  Melnikov, A., "Sieve Email Filtering: Imap4flags
              Extension", RFC 5232, DOI 10.17487/RFC5232, January 2008,
              <https://www.rfc-editor.org/info/rfc5232>.

   [RFC5463]  Freed, N., "Sieve Email Filtering: Ihave Extension",
              RFC 5463, DOI 10.17487/RFC5463, March 2009,
              <https://www.rfc-editor.org/info/rfc5463>.

Appendix A.  Change History (To be removed by RFC Editor before
             publication)

   Changes since -00:

   o  Added IANA registration for "scriptIsActive" JMAP error code.

   o  Added open issue about /set{create} with an existing script name.

Author's Address

   Kenneth Murchison
   Fastmail US LLC
   1429 Walnut Street - Suite 1201
   Philadelphia, PA  19102
   USA

   Email: murch@fastmailteam.com







Murchison               Expires September 6, 2020               [Page 8]


Html markup produced by rfcmarkup 1.129d, available from https://tools.ietf.org/tools/rfcmarkup/