EXTRA K. Murchison
Internet-Draft B. Gondwana
Intended status: Standards Track FastMail
Expires: March 25, 2018 September 21, 2017
IMAP4 Extension for Returning MYRIGHTS Information in Extended LIST
draft-ietf-extra-imap-list-myrights-00
Abstract
This document defines an extension to the to IMAP LIST command that
allows the client to request the set of rights that the logged-in
user has been granted on mailboxes, along with other information
typically returned by the LIST command.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions Used in This Document . . . . . . . . . . . . . . 2
3. MYRIGHTS Return Option to LIST Command . . . . . . . . . . . 2
4. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 3
5. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . . 3
6. Security Considerations . . . . . . . . . . . . . . . . . . . 4
7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 4
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
8.1. Registration of IMAP capability LIST-MYRIGHTS . . . . . . 4
8.2. Registration of LIST-EXTENDED option MYRIGHTS . . . . . . 4
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 4
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
10.1. Normative References . . . . . . . . . . . . . . . . . . 5
10.2. Informative References . . . . . . . . . . . . . . . . . 5
Appendix A. Change History (To be removed by RFC Editor before
publication) . . . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
IMAP clients typically fetch the set of rights granted on mailboxes
so they can expose the allowed functionality to the logged-in user.
In order to do that, the client is forced to issue a LIST or LSUB
command to list all available mailboxes, followed by a MYRIGHTS
command for each mailbox found. This document defines an extension
to the to IMAP LIST command that is identified by the capability
string "LIST-MYRIGHTS". The LIST-MYRIGHTS extension allows the
client to request the set of rights that the logged-in user has been
granted on mailboxes, along with other information typically returned
by the LIST command.
2. Conventions Used in This Document
In examples, "C:" indicates lines sent by a client that is connected
to a server. "S:" indicates lines sent by the server to the client.
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
[RFC2119].
3. MYRIGHTS Return Option to LIST Command
[RFC4314] defines the MYRIGHTS command which is used by an IMAP
client to determine the set of rights that the logged-in user has
been granted on a given mailbox. Frequently, a client will have to
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look up the rights for some or all of the mailboxes returned by the
LIST command. Doing so in multiple MYRIGHTS commands wastes
bandwidth and can degrade performance if the client does not pipeline
the requests.
This document extends the LIST command with a new return option,
"MYRIGHTS", which allows the client to request all of the desired
information in a single command. For each listable mailbox matching
the list pattern and selection options, the server MUST return an
untagged LIST response followed by an untagged MYRIGHTS response
containing the set of rights granted to the logged-in user.
If the server is unable to look up the set of rights for a given
mailbox, it MAY drop the corresponding MYRIGHTS reply. In such a
situation, the LIST command would still return a tagged OK reply.
4. Examples
In this example the "bar" mailbox doesn't exist, so it has no
MYRIGHTS reply.
C: A01 LIST "" % RETURN (MYRIGHTS)
S: * LIST () "." "INBOX"
S: * MYRIGHTS "INBOX" lrswipkxtecdan
S: * LIST () "." "foo"
S: * MYRIGHTS "foo" lrs
S: * LIST (\NonExistent) "." "bar"
S: A01 OK List completed.
In this example the LIST reply for the "foo" mailbox is returned
because it has matching children, but no MYRIGHTS reply is returned
because "foo" itself doesn't match the selection criteria.
C: A02 LIST (SUBSCRIBED RECURSIVEMATCH) "" % RETURN (MYRIGHTS)
S: * LIST (\Subscribed) "." "INBOX"
S: * MYRIGHTS "INBOX" lrswipkxtecdan
S: * LIST () "." "foo" (CHILDINFO ("SUBSCRIBED"))
S: A02 OK List completed.
5. Formal Syntax
The following syntax specification uses the augmented Backus-Naur
Form (BNF) as described in [RFC5234]. Terms not defined here are
taken from [RFC5258].
return-option =/ "MYRIGHTS"
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6. Security Considerations
This specification does not introduce any additional security
concerns beyond those described in [RFC5258].
7. Privacy Considerations
This specification does not introduce any additional privacy concerns
beyond those described in [RFC4314].
8. IANA Considerations
8.1. Registration of IMAP capability LIST-MYRIGHTS
This document defines the "LIST-MYRIGHTS" IMAP capability to be added
to the registry defined in Section 12 of [RFC3501].
8.2. Registration of LIST-EXTENDED option MYRIGHTS
This section registers the "MYRIGHTS" option to be added to the
registry defined in Section 9 of [RFC5258].
LIST-EXTENDED option name: MYRIGHTS
LIST-EXTENDED option type: RETURN
LIST-EXTENDED option description: Causes the LIST command to return
MYRIGHTS responses in addition to LIST responses.
Published specification: RFC XXXX, Section 3
Security considerations: RFC XXXX, Section 6
Intended usage: COMMON
Person and email address to contact for further
information:
Kenneth Murchison <murch@andrew.cmu.edu>
Owner/Change controller: IESG <iesg@ietf.org>
9. Acknowledgments
This document is based largely on [RFC5819]. The author would like
to thank the authors of that document for providing both inspiration
and some borrowed text for this document.
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10. References
10.1. 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>.
[RFC3501] Crispin, M., "INTERNET MESSAGE ACCESS PROTOCOL - VERSION
4rev1", RFC 3501, DOI 10.17487/RFC3501, March 2003,
<https://www.rfc-editor.org/info/rfc3501>.
[RFC4314] Melnikov, A., "IMAP4 Access Control List (ACL) Extension",
RFC 4314, DOI 10.17487/RFC4314, December 2005,
<https://www.rfc-editor.org/info/rfc4314>.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234,
DOI 10.17487/RFC5234, January 2008,
<https://www.rfc-editor.org/info/rfc5234>.
[RFC5258] Leiba, B. and A. Melnikov, "Internet Message Access
Protocol version 4 - LIST Command Extensions", RFC 5258,
DOI 10.17487/RFC5258, June 2008,
<https://www.rfc-editor.org/info/rfc5258>.
10.2. Informative References
[RFC5819] Melnikov, A. and T. Sirainen, "IMAP4 Extension for
Returning STATUS Information in Extended LIST", RFC 5819,
DOI 10.17487/RFC5819, March 2010,
<https://www.rfc-editor.org/info/rfc5819>.
Appendix A. Change History (To be removed by RFC Editor before
publication)
Changes from draft-murchison-imap-list-myrights-01:
o Renamed document to be a work product of the EXTRA WG.
o Updated authors' addresses.
Changes from draft-murchison-imap-list-myrights-00:
o Augmented Introduction with mention of "LIST-MYRIGHTS" capability
string.
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o Minor editorial changes.
Authors' Addresses
Kenneth Murchison
FastMail Pty Ltd
Level 2, 114 William Street
Melbourne, VIC 3000
Australia
Email: murch@fastmailteam.com
Bron Gondwana
FastMail Pty Ltd
Level 2, 114 William Street
Melbourne, VIC 3000
Australia
Email: brong@fastmailteam.com
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