Internet-Draft JMAP Sieve October 2022
Murchison Expires 27 April 2023 [Page]
Workgroup:
JMAP
Internet-Draft:
draft-ietf-jmap-sieve-12
Published:
Intended Status:
Standards Track
Expires:
Author:
K. Murchison
Fastmail

JMAP for Sieve Scripts

Abstract

This document specifies a data model for managing Sieve scripts on a server using the JSON Meta Application Protocol (JMAP).

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 27 April 2023.

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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.

Servers MUST support all properties specified for the new data type defined in this document.

For compatibility with publishing requirements, line breaks have been inserted inside long JSON strings, with the following continuation lines indented. To form the valid JSON example, any line breaks inside a string must be replaced with a space and any other white space after the line break removed.

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:

  • maxSizeScriptName: UnsignedInt

    The maximum length, in (UTF-8) octets, allowed for the name of a SieveScript. For compatibility with ManageSieve, this MUST be at least 512 (up to 128 Unicode characters).

  • 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.

  • maxNumberScripts: UnsignedInt|null

    The maximum number of Sieve scripts the server is willing to store for the user, or null for no limit.

  • maxNumberRedirects: UnsignedInt|null

    The maximum number of Sieve "redirect" actions a script can perform during a single evaluation or null for no limit. Note that this is different from the total number of "redirect" actions a script can contain.

  • sieveExtensions: String[]

    A list of case-sensitive Sieve capability strings (as listed in Sieve "require" action; see [RFC5228], Section 3.2) indicating the extensions supported by the Sieve engine.

  • notificationMethods: String[]|null

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

  • externalLists: String[]|null

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

2. Sieve Scripts

A SieveScript object represents a single Sieve [RFC5228] script for filtering email messages at time of final delivery.

A SieveScript object has the following properties:

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].

2.1.1. Examples

Request (and response) to list all scripts:

{
  "using": [ "urn:ietf:params:jmap:core",
             "urn:ietf:params:jmap:sieve" ],
  "methodCalls": [
    ["SieveScript/get", {
      "accountId": "ken"
    }, "0"]
  ]
}

{
  "methodResponses": [
    [
      "SieveScript/get",
      {
        "state": "1634915373.240633104-120",
        "list": [
          {
            "id": "2d647053-dded-418d-917a-63eda3ac8f7b",
            "name": "test1",
            "isActive": true,
            "blobId": "S123"
          }
        ],
        "notFound": [],
        "accountId": "ken"
      },
      "0"
    ]
  ]
}

Request (and response) to download the script (assuming that the JMAP Download URL has been advertised in the JMAP Session object as having a path of "/jmap/download/{accountId}/{blobId}/{name}?accept={type}"). Note that the request-line has been wrapped for presentation purposes only.

GET
 /jmap/download/ken/S123/test1.siv?accept=application/sieve
 HTTP/1.1
Host: jmap.example.com
Authorization: Basic a2VuOnBhc3N3b3Jk

HTTP/1.1 200 OK
Date: Fri, 22 Oct 2021 15:27:38 GMT
Content-Type: application/sieve; charset=utf-8
Content-Disposition: attachment; filename="test1.siv"
Content-Length: 49

require ["fileinto"];
fileinto "INBOX.target";

Request (and response) to fetch the content of a single script:

{
  "using": [ "urn:ietf:params:jmap:core",
             "urn:ietf:params:jmap:blob",
             "urn:ietf:params:jmap:sieve" ],
  "methodCalls": [
    ["SieveScript/get", {
      "accountId": "ken",
      "ids": [ "2d647053-dded-418d-917a-63eda3ac8f7b" ]
    }, "0"],
    ["Blob/get", {
      "accountId": "ken",
      "#ids": {
        "resultOf": "0",
        "name": "SieveScript/get",
        "path": "/list/*/blobId"
      }
    }, "1"]
  ]
}

{
  "methodResponses": [
    [
      "SieveScript/get",
      {
        "state": "1634915373.240633104-120",
        "list": [
          {
            "id": "2d647053-dded-418d-917a-63eda3ac8f7b",
            "name": "test1",
            "isActive": true,
            "blobId": "S123"
          }
        ],
        "notFound": [],
        "accountId": "ken"
      },
      "0"
    ],
    [
      "Blob/get",
      {
        "list": [
          {
            "id": "S123",
           "data:asText":
 "require [\"fileinto\"];\\r\\nfileinto \"INBOX.target\";\\r\\n",
            "size": 49
          }
        ],
        "notFound": [],
        "accountId": "ken"
      },
      "1"
    ]
  ]
}

2.2. SieveScript/set

This is a standard "/set" method as described in [RFC8620], Section 5.3 but with the following additional request argument, which may be omitted:

  • onSuccessActivateScript: Id|null (optional)

    If null, the currently active SieveScript (if any) will be deactivated if and only if all of the creations, modifications, and destructions (if any) succeed. Otherwise, the id of the SieveScript to activate if and only if all of the creations, modifications, and destructions (if any) succeed. (For references to SieveScript creations, this is equivalent to a creation-reference, so the id will be the creation id prefixed with a "#".) If this argument is not present in the request, the currently active SieveScript (if any) will remain as such.

    The id of any activated SieveScript MUST be reported in either the "created" or "updated" argument in the response as appropriate. The id of any deactivated SieveScript MUST be reported in the "updated" argument in the response.

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

Script content must first be uploaded as a blob using either the standard upload mechanism (see [RFC8620] Section 6.1) or the JMAP Blob management extension (see [I-D.ietf-jmap-blob] Section 3.1).

If the SieveScript can not be created or updated because it would result in two SieveScripts with the same name, the server MUST reject the request with an "alreadyExists" SetError. An "existingId" property of type "Id" MUST be included on the SetError object with the id of the existing SieveScript.

If the SieveScript can not be created or updated because its size exceeds the "maxSizeScript" limit, the server MUST reject the request with a "tooLarge" SetError.

If the Sieve Script can not be created because it would exceed the "maxNumberScripts" limit, the server MUST reject the request with an "overQuota" SetError.

The active SieveScript MUST NOT be destroyed unless it is first deactivated in a separate SieveScript/set method call.

The following extra SetError types are defined:

For "create" and "update":

  • invalidScript:

    The SieveScript content violates the Sieve [RFC5228] grammar and/or one or more extensions mentioned in the script's "require" statement(s) are not supported by the Sieve interpreter. The description property on the SetError object SHOULD contain a specific error message giving at least the line number of the first error.

For "destroy":

  • scriptIsActive:

    The SieveScript is active.

2.2.1. Examples

Request (and response) to upload a script requiring the Imap4Flags [RFC5232] Extension (assuming that the JMAP Upload URL has been advertised in the JMAP Session object as having a path of "/jmap/upload/{accountId}/"):

POST /jmap/upload/ken/ HTTP/1.1
Host: jmap.example.com
Authorization: Basic a2VuOnBhc3N3b3Jk
Content-Type: application/sieve
Content-Length: 98

require "imapflags";

if address :is ["To", "Cc"] "jmap@ietf.org" {
  setflag "\\Flagged";
}


HTTP/1.1 201 Created
Date: Thu, 10 Dec 2020 17:14:31 GMT
Content-Type: application/json; charset=utf-8
Content-Length: 171

{
  "accountId": "ken",
  "blobId": "Gabcc83e44a6e19991c4568d0b94e1767c83dd123",
  "type": "application/sieve"
  "size": 98
}

Request (and response) to create and activate a script using the uploaded blob:

{
  "using": [ "urn:ietf:params:jmap:core",
             "urn:ietf:params:jmap:sieve" ],
  "methodCalls": [
    ["SieveScript/set", {
      "accountId": "ken",
      "create": {
        "A": {
          "name": null,
          "blobId": "Gabcc83e44a6e19991c4568d0b94e1767c83dd123"
        }
      },
      "onSuccessActivateScript": "#A"
    }, "0"]
  ]
}

{
  "methodResponses": [
    [
      "SieveScript/set",
      {
        "oldState": "1603741717.50737918-4096",
        "newState": "1603741751.227268529-4096",
        "created": {
          "A": {
            "id": "dd1b164f-8cdc-448c-9f54",
            "name": "ken-20201210T171432-0",
            "blobId": "Sdd1b164f-8cdc-448c-9f54",
            "isActive": true
          }
        },
        "updated": null,
        "destroyed": null,
        "notCreated": null,
        "notUpdated": null,
        "notDestroyed": null,
        "accountId": "ken"
      },
      "0"
    ]
  ]
}

Request (and response) to update script content using the JMAP Blob management extension [I-D.ietf-jmap-blob]:

{
  "using": [ "urn:ietf:params:jmap:core",
             "urn:ietf:params:jmap:blob",
             "urn:ietf:params:jmap:sieve" ],
  "methodCalls": [
    ["Blob/upload", {
      "accountId": "ken",
      "create": {
        "B": {
          "data": [ {
            "data:asText":
              "redirect \"ken@example.com\"\r\n;"
           } ],
          "type": "application/sieve"
        }
      }
    }, "1"],
    ["SieveScript/set", {
      "accountId": "ken",
      "update": { "dd1b164f-8cdc-448c-9f54": {
        "blobId": "#B"
        }
      }
    }, "2"]
  ]
}

{
  "methodResponses": [
    [
      "Blob/upload",
      {
        "oldState": null,
        "newState": "1603741700.309607123-0128",
        "created": {
          "B": {
            "id": "G969c83e44a6e10871c4568d0b94e1767c83ddeae",
            "blobId": "G969c83e44a6e10871c4568d0b94e1767c83ddeae",
            "type": "application/sieve",
            "size": 29
          }
        },
        "notCreated": null,
        "accountId": "ken"
      },
      "1"
    ],
    [
      "SieveScript/set",
      {
        "oldState": "1603741751.227268529-4096",
        "newState": "1603742603.309607868-4096",
        "created": null,
        "updated": {
          "dd1b164f-8cdc-448c-9f54": null
        },
        "destroyed": null,
        "notCreated": null,
        "notUpdated": null,
        "notDestroyed": null,
        "accountId": "ken"
      },
      "2"
    ]
  ]
}

Request (and response) to update script name and deactivate:

{
  "using": [ "urn:ietf:params:jmap:core",
             "urn:ietf:params:jmap:sieve" ],
  "methodCalls": [
    ["SieveScript/set", {
      "accountId": "ken",
      "update": { "dd1b164f-8cdc-448c-9f54": {
        "name": "myscript"
        }
      },
      "onSuccessActivateScript": null
    }, "3"]
  ]
}

{
  "methodResponses": [
    [
      "SieveScript/set",
      {
        "oldState": "1603742603.309607868-4096",
        "newState": "1603742967.852315428-4096",
        "created": null,
        "updated": {
          "dd1b164f-8cdc-448c-9f54": {
            "isActive": false
          }
        },
        "destroyed": null,
        "notCreated": null,
        "notUpdated": null,
        "notDestroyed": null,
        "accountId": "ken"
      },
      "3"
    ]
  ]
}

Request (and response) to activate a script:

{
  "using": [ "urn:ietf:params:jmap:core",
             "urn:ietf:params:jmap:sieve" ],
  "methodCalls": [
    ["SieveScript/set", {
      "accountId": "ken",
      "onSuccessActivateScript": "dd1b164f-8cdc-448c-9f54"
    }, "4"]
  ]
}

{
  "methodResponses": [
    [
      "SieveScript/set",
      {
        "oldState": "1603742967.852315428-4096",
        "newState": "1603744460.316617118-4096",
        "created": null,
        "updated": {
          "dd1b164f-8cdc-448c-9f54": {
            "isActive": true
          }
        },
        "destroyed": null,
        "notCreated": null,
        "notUpdated": null,
        "notDestroyed": null,
        "accountId": "ken"
      },
      "4"
    ]
  ]
}

Requests (and responses) to deactivate and destroy the active script:

{
  "using": [ "urn:ietf:params:jmap:core",
             "urn:ietf:params:jmap:sieve" ],
  "methodCalls": [
    ["SieveScript/set", {
      "accountId": "ken",
      "onSuccessActivateScript": null
    }, "5"],
    ["SieveScript/set", {
      "accountId": "ken",
      "destroy": [ "dd1b164f-8cdc-448c-9f54" ]
    }, "6"]
  ]
}

{
  "methodResponses": [
    [
      "SieveScript/set",
      {
        "oldState": "1603744460.316617118-4096",
        "newState": "1603744637.575375572-4096",
        "created": null,
        "updated": {
          "dd1b164f-8cdc-448c-9f54": {
            "isActive": false
          }
        },
        "destroyed": null,
        "notCreated": null,
        "notUpdated": null,
        "notDestroyed": null,
        "accountId": "ken"
      },
      "5"
    ],
    [
      "SieveScript/set",
      {
        "oldState": "1603744637.575375572-4096",
        "newState": "1603744637.854390875-4096",
        "created": null,
        "updated": null,
        "destroyed": [
          "dd1b164f-8cdc-448c-9f54"
        ],
        "notCreated": null,
        "notUpdated": null,
        "notDestroyed": null,
        "accountId": "ken"
      },
      "6"
    ]
  ]
}

2.3. SieveScript/query

This is a standard "/query" method as described in [RFC8620], Section 5.5. A FilterCondition object has the following properties, either of which may be omitted:

  • name: String

    The SieveScript "name" property contains the given string.

  • isActive: Boolean

    The "isActive" property of the SieveScript must be identical to the value given to match the condition.

The following SieveScript properties MUST be supported for sorting:

2.4. SieveScript/validate

This method is used by the client to verify Sieve script validity without storing the script on the server, providing similar functionality to the CHECKSCRIPT command in [RFC5804].

The method takes the following arguments:

  • accountId: Id

    The id of the account to use.

  • blobId: Id

    The id of the blob containing the raw octets of the script to validate, subject to the same requirements in Section 2.

The response has the following arguments:

  • accountId: Id

    The id of the account used for this call.

  • error: SetError|null

    A "invalidScript" SetError object if the script content is invalid (see Section 2.2), or null if the script content is valid.

As with the SieveScript/set (Section 2.2) method, script content must first be uploaded as a blob using either the standard upload mechanism (see [RFC8620] Section 6.1) or the JMAP Blob management extension (see [I-D.ietf-jmap-blob] Section 3.1).

3. Compatibility with JMAP Vacation Response

Section 8 of [RFC8621] defines a VacationResponse object to represent an autoresponder to incoming email messages. Servers that implement the VacationResponse as a Sieve script that resides amongst other user scripts are subject to the following requirements:

4. Security Considerations

All security considerations of JMAP [RFC8620] and Sieve [RFC5228] apply to this specification.

5. IANA Considerations

5.1. 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 4

5.2. JMAP Error Codes Registry

The following sub-sections register two new error codes in the JMAP Error Codes registry, as defined in [RFC8620].

5.2.1. invalidScript

JMAP Error Code: invalidScript

Intended use: common

Change controller: IETF

Reference: This document, Section 2.2

Description: The SieveScript violates the Sieve grammar [RFC5228] and/or one or more extensions mentioned in the script's "require" statement(s) are not supported by the Sieve interpreter.

5.2.2. scriptIsActive

JMAP Error Code: scriptIsActive

Intended use: common

Change controller: IETF

Reference: This document, Section 2.2

Description: The client tried to destroy the active SieveScript.

6. 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.

The author would also like to thank the following individuals for contributing their ideas and support for writing this specification: Bron Gondwana, Neil Jenkins, Alexey Melnikov, and Ricardo Signes.

7. References

7.1. Normative References

[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC3629]
Yergeau, F., "UTF-8, a transformation format of ISO 10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, , <https://www.rfc-editor.org/info/rfc3629>.
[RFC3986]
Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, DOI 10.17487/RFC3986, , <https://www.rfc-editor.org/info/rfc3986>.
[RFC5198]
Klensin, J. and M. Padlipsky, "Unicode Format for Network Interchange", RFC 5198, DOI 10.17487/RFC5198, , <https://www.rfc-editor.org/info/rfc5198>.
[RFC5228]
Guenther, P., Ed. and T. Showalter, Ed., "Sieve: An Email Filtering Language", RFC 5228, DOI 10.17487/RFC5228, , <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, , <https://www.rfc-editor.org/info/rfc5435>.
[RFC6134]
Melnikov, A. and B. Leiba, "Sieve Extension: Externally Stored Lists", RFC 6134, DOI 10.17487/RFC6134, , <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, , <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, , <https://www.rfc-editor.org/info/rfc8620>.
[RFC8621]
Jenkins, N. and C. Newman, "The JSON Meta Application Protocol (JMAP) for Mail", RFC 8621, DOI 10.17487/RFC8621, , <https://www.rfc-editor.org/info/rfc8621>.

7.2. Informative References

[I-D.ietf-jmap-blob]
Gondwana, B., "JMAP Blob management extension", Work in Progress, Internet-Draft, draft-ietf-jmap-blob-14, , <https://datatracker.ietf.org/doc/html/draft-ietf-jmap-blob-14>.
[RFC5232]
Melnikov, A., "Sieve Email Filtering: Imap4flags Extension", RFC 5232, DOI 10.17487/RFC5232, , <https://www.rfc-editor.org/info/rfc5232>.
[RFC5463]
Freed, N., "Sieve Email Filtering: Ihave Extension", RFC 5463, DOI 10.17487/RFC5463, , <https://www.rfc-editor.org/info/rfc5463>.
[RFC5804]
Melnikov, A., Ed. and T. Martin, "A Protocol for Remotely Managing Sieve Scripts", RFC 5804, DOI 10.17487/RFC5804, , <https://www.rfc-editor.org/info/rfc5804>.

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

Changes since ietf-11:

Changes since ietf-10:

Changes since ietf-09:

Changes since ietf-08:

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Changes since ietf-06:

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Changes since ietf-04:

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Changes since murchison-01:

Changes since murchison-00:

Author's Address

Kenneth Murchison
Fastmail US LLC
1429 Walnut Street - Suite 1201
Philadelphia, PA 19102
United States of America