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

Status of This Memo

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Table of Contents

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.

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:

2. Sieve Scripts

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

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":

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].

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:

The response has the following arguments:

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

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.
[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.
[RFC5228] Guenther, P. and T. Showalter, "Sieve: An Email Filtering Language", RFC 5228, DOI 10.17487/RFC5228, January 2008.
[RFC5435] Melnikov, A., Leiba, B., Segmuller, W. and T. Martin, "Sieve Email Filtering: Extension for Notifications", RFC 5435, DOI 10.17487/RFC5435, January 2009.
[RFC5804] Melnikov, A. and T. Martin, "A Protocol for Remotely Managing Sieve Scripts", RFC 5804, DOI 10.17487/RFC5804, July 2010.
[RFC6134] Melnikov, A. and B. Leiba, "Sieve Extension: Externally Stored Lists", RFC 6134, DOI 10.17487/RFC6134, July 2011.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017.
[RFC8620] Jenkins, N. and C. Newman, "The JSON Meta Application Protocol (JMAP)", RFC 8620, DOI 10.17487/RFC8620, July 2019.

6.2. Informative References

[RFC5232] Melnikov, A., "Sieve Email Filtering: Imap4flags Extension", RFC 5232, DOI 10.17487/RFC5232, January 2008.
[RFC5463] Freed, N., "Sieve Email Filtering: Ihave Extension", RFC 5463, DOI 10.17487/RFC5463, March 2009.

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

Changes since -00:

Author's Address

Kenneth Murchison Fastmail US LLC 1429 Walnut Street - Suite 1201 Philadelphia, PA 19102 USA EMail: murch@fastmailteam.com