Internet DRAFT - draft-murchison-jmap-sieve
draft-murchison-jmap-sieve
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
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This Internet-Draft will expire on September 6, 2020.
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Copyright Notice
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document authors. All rights reserved.
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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.
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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.
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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?
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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].
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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
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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>.
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[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
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