Network Working Group Tim Martin
Document: draft-ietf-managesieve-03.txt Mirapoint Inc.
Expires January 21, 2003 16 July 2002
A Protocol for Remotely Managing Sieve Scripts
<draft-martin-managesieve-04.txt>
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026. Internet-Drafts are
working documents of the Internet Engineering Task Force (IETF), its
areas, and its working groups. Note that other groups may also
distribute working documents as Internet-Drafts.
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."
To view the list Internet-Draft Shadow Directories, see
http://www.ietf.org/shadow.html.
Distribution of this memo is unlimited.
Abstract
Sieve scripts allow users to filter incoming email. Message stores
are commonly sealed servers so users cannot log into them, yet users
must be able to update their scripts on them. This document
describes a protocol "sieve" for securely managing Sieve scripts on
a remote server. This protocol allows a user to have multiple
scripts, and also alerts a user to syntactically flawed scripts.
This an interim measure as it is hoped that eventually Sieve scripts
will be stored on ACAP. This document is intended to proceed on the
experimental track.
Expires January 21, 2003 Martin [Page 1]
Internet Draft Managing Sieve Scripts July 16, 2002
Table of Contents
Status of this Memo . . . . . . . . . . . . . . . . . . . . . . . . 1
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Conventions Used in the Document . . . . . . . . . . . . . . 4
1.3. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.4. Response Codes . . . . . . . . . . . . . . . . . . . . . . . 5
1.5. Active Script . . . . . . . . . . . . . . . . . . . . . . . . 6
1.6. Quotas . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.7. Script Names . . . . . . . . . . . . . . . . . . . . . . . . 7
1.8. Capabilities . . . . . . . . . . . . . . . . . . . . . . . . 7
2. Commands . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1. AUTHENTICATE Command . . . . . . . . . . . . . . . . . . . . 8
2.2. STARTTLS Command . . . . . . . . . . . . . . . . . . . . . . 10
2.3. LOGOUT Command . . . . . . . . . . . . . . . . . . . . . . . 10
2.4. CAPABILITY Command . . . . . . . . . . . . . . . . . . . . . 11
2.5. HAVESPACE Command . . . . . . . . . . . . . . . . . . . . . . 11
2.6. PUTSCRIPT Command . . . . . . . . . . . . . . . . . . . . . . 11
2.7. LISTSCRIPTS Command . . . . . . . . . . . . . . . . . . . . . 13
2.8. SETACTIVE Command . . . . . . . . . . . . . . . . . . . . . . 13
2.9. GETSCRIPT Command . . . . . . . . . . . . . . . . . . . . . . 13
2.10. DELETESCRIPT Command . . . . . . . . . . . . . . . . . . . . 14
3. Sieve URL Scheme . . . . . . . . . . . . . . . . . . . . . . 14
4. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . . 15
5. Security Considerations . . . . . . . . . . . . . . . . . . . 18
6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 18
7. Copyright . . . . . . . . . . . . . . . . . . . . . . . . . . 18
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 19
9. Author's Address . . . . . . . . . . . . . . . . . . . . . . 19
Expires January 21, 2003 Martin [Page 2]
Internet Draft Managing Sieve Scripts July 16, 2002
Expires January 21, 2003 Martin [Page 3]
Internet Draft Managing Sieve Scripts July 16, 2002
1. Introduction
1.1. Changes
Changes since 03
-Add referals and Sieve URLs
-Lots of spelling/grammer fixes
-Don't give capabilities after successful STARTTLS. This is because
it isn't consistant with AUTHENTICATE. There is language specifying
that a client should re-issue a CAPABILITY command after
AUTHENTICATE/STARTTLS.
-Putting a script of length 0 doesn't remove the script. If this
functionality is desired, the DELETESCRIPT command should be used.
Changes since 02
-add BYE response
-typo on line 588
-allow ANONYMOUS access for sieve script verification
-updated SIEVE spec reference
Changes since 01
-changed contact info
Changes since 00
-added response codes (from ACAP)
-removed special-ok response from authenticate command (response
codes obsolete it)
-changed service name to "sieve"
-ABNF fixes
-Alexey's wording changes
-Eliminated lame PLAIN paragraph
Expires January 21, 2003 Martin [Page 3]
Internet Draft Managing Sieve Scripts July 16, 2002
Changes since PRE
-dropped synchronized literals. added HAVESPACE command
-changed capability response syntax. added CAPABILITY command
-allowed pipelining
- "sieve" -> "Sieve". Other minor fixes
-made script names more flexible
-added starttls support
1.2. Conventions Used in the Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [KEYWORDS].
In examples, "C:" and "S:" indicate lines sent by the client and
server respectively. Line breaks that do not start a new "C:" or
"S:" exist for editorial reasons.
1.3. Syntax
This a line oriented protocol much like [IMAP4rev1] or [ACAP]. There
are three types: ATOMS, numbers and strings. Strings may be quoted
or literal. See [ACAP] for detailed descriptions of these types.
Each command consists of an atom followed by zero or more strings
and numbers terminated by a newline.
All client queries are replied to with either an OK, NO, or BYE
response. Each response may be followed by a response code (see
response codes section) and by a string consisting of human readable
text in the local language. The contents of the string SHOULD be
shown to the user and implementations MUST NOT attempt to parse the
message for meaning.
The BYE command may be used if the server wishes to close the
connection. A server may wish to do this because the client was idle
Expires January 21, 2003 Martin [Page 4]
Internet Draft Managing Sieve Scripts July 16, 2002
too long or there were too many failed authentication attempts. This
command can be issued at any time and should be immediately followed
by a server hang-up of the connection. If a server has a inactivity
timeout resulting in client autologout it MUST be no less than 30
minutes.
IANA registration is pending. Current implementations generally use
port number 2000.
1.4. Response Codes
An OK, NO, or BYE response from the server MAY contain a response
code to describe the event in a more detailed machine parsable
fashion. A response code consists of data inside parentheses in the
form of an atom, possibly followed by a space and arguments.
Response codes are defined when there is a specific action that a
client can take based upon the additional information. In order to
support future extension, the response code is represented as a
slash-separated hierarchy with each level of hierarchy representing
increasing detail about the error. Clients MUST tolerate additional
hierarchical response code detail which they don't understand.
The currently defined response codes are:
AUTH-TOO-WEAK
This response code is returned on a tagged NO result from an
AUTHENTICATE command. It indicates that site security policy forbids
the use of the requested mechanism for the specified authentication
identity.
ENCRYPT-NEEDED
This response code is returned on NO result from an AUTHENTICATE
command. It indicates that site security policy requires the use of
a strong encryption mechanism for the specified authentication
identity and mechanism.
QUOTA
The command would have placed the user above the site-defined quota
constraints.
REFERRAL
This response code may be returned with a BYE result from any
Expires January 21, 2003 Martin [Page 5]
Internet Draft Managing Sieve Scripts July 16, 2002
command, and includes a mandatory parameter that indicates what
server to access to manage this user's sieve scripts. The server
will be specified by a Sieve URL (see "Sieve URL Scheme" section).
The scriptname portion of the URL MUST NOT be specified. The client
should authenticate to the specified server and use it for all
further commands in the current session.
SASL
This response code can occur in the OK response to a successful
AUTHENTICATE command and includes the optional final server response
data from the server as specified by [SASL].
TRANSITION-NEEDED
This response code occurs on a NO response to an AUTHENTICATE
command. It indicates that the user name is valid, but the entry in
the authentication database needs to be updated in order to permit
authentication with the specified mechanism. This can happen if a
user has an entry in a system authentication database such as Unix
/etc/passwd, but does not have credentials suitable for use by the
specified mechanism.
TRYLATER
A command failed due to a temporary server failure. The client MAY
continue using local information and try the command later.
Client implementations MUST tolerate response codes that they do not
recognize.
1.5. Active Script
A user may have multiple Sieve scripts on the server, yet only one
script may be used for filtering of incoming messages. This is the
active script. Users may have zero or one active scripts and MUST
use the SETACTIVE command described below for changing the active
script or disabling Sieve processing. For example, a user may have
an everyday script they normally use and a special script they use
when they go on vacation. Users can change which script is being
used without having to download and upload a script stored somewhere
else.
Expires January 21, 2003 Martin [Page 6]
Internet Draft Managing Sieve Scripts July 16, 2002
1.6. Quotas
Servers SHOULD impose quotas to prevent malicious users from
overflowing available storage. If a command would place a user over
a quota setting, servers MUST reply with a NO response. Client
implementations MUST be able to handle commands failing because of
quota restrictions.
1.7. Script Names
Sieve script names may contain any valid UTF8 characters, but names
must be at least one octet long. Script names zero octets in length
have special meaning. (see SETACTIVE command section) Servers MUST
allow names of up to 128 UTF8 octets in length, and may allow longer
names.
1.8. Capabilities
Server capabilities are sent by the server upon a client connection.
Clients may request the capabilities at a later time by issuing the
CAPABILITY command described later. The capabilities consist of a
series of lines each with one or two strings. The first string is
the name of the capability. The second optional string is the value
associated with that capability.
The following capabilities are defined here:
IMPLEMENTATION - Name of implementation and version
SASL - List of SASL mechanisms supported by the server, each
separated by a space
SIEVE - List of space separated Sieve extensions supported
STARTTLS - If TLS[TLS] is supported by this implementation
A client implementation MUST ignore any other capabilities given
that it does not understand.
Example:
S: "IMPLEMENTATION" "CMU Cyrus Sieved v001"
S: "SASL" "KERBEROS_V4 GSSAPI"
S: "SIEVE" "FILEINTO VACATION"
Expires January 21, 2003 Martin [Page 7]
Internet Draft Managing Sieve Scripts July 16, 2002
S: "STARTTLS"
S: OK
2. Commands
The following commands are valid. Prior to successful authentication
only the AUTHENTICATE, CAPABILITY, STARTTLS, and LOGOUT commands are
valid. Servers MUST reject all other commands with a NO response.
Clients may pipeline commands (send more than one command at a time
without waiting for completion of the first command ). However, a
group of commands sent together MUST NOT have a HAVESPACE command
anywhere but the last command in the list.
2.1. AUTHENTICATE Command
Arguments:
String - mechanism
String - initial data (optional)
The AUTHENTICATE command indicates a SASL [SASL] authentication
mechanism to the server. If the server supports the requested
authentication mechanism, it performs an authentication protocol
exchange to authenticate and identify the user. Optionally, it also
negotiates a security layer for subsequent protocol interactions.
If the requested authentication mechanism is not supported, the
server rejects the AUTHENTICATE command by sending a NO response.
The authentication protocol exchange consists of a series of server
challenges and client answers that are specific to the
authentication mechanism. A server challenge consists of a string
followed by an endline. The contents of the string is a base-64
encoding of the SASL data. The client answer consists of a string
with the base-64 encoding of the SASL data followed by an endline.
If the mechanism dictates that the final response be sent by the
server this data MAY be placed within the data portion of the SASL
response code to save a round trip.
The optional initial-response argument to the AUTHENTICATE command
is used to save a round trip when using authentication mechanisms
that are defined to send no data in the initial challenge. When the
initial-response argument is used with such a mechanism, the initial
empty challenge is not sent to the client and the server uses the
data in the initial-response argument as if it were sent in response
to the empty challenge. If the initial-response argument to the
Expires January 21, 2003 Martin [Page 8]
Internet Draft Managing Sieve Scripts July 16, 2002
AUTHENTICATE command is used with a mechanism that sends data in the
initial challenge, the server rejects the AUTHENTICATE command by
sending a tagged NO response.
The service name specified by this protocol's profile of SASL is
"sieve"
If a security layer is negotiated through the SASL authentication
exchange, it takes effect immediately following the CRLF that
concludes the authentication exchange for the client, and the CRLF
of the OK response for the server.
Implementations MAY advertise the ANONYMOUS SASL mechanism [SASL-
ANON]. This indicates that the server supports ANONYMOUS sieve
script syntax verification. Only the CAPABILITY, PUTSCRIPT and
LOGOUT commands are available to the anonymous user. All other
commands MUST give NO responses. Furthermore the PUTSCRIPT command
SHOULD NOT store any data. In this mode a positive response to the
PUTSCRIPT command indicates that the given script does not have any
syntax errors.
Server implementations SHOULD support authorization so that an
administrator can administer a user's scripts. Authorization is when
a user authenticates as himself but logs in as another user.
If an AUTHENTICATE command fails with a NO response, the client may
try another authentication mechanism by issuing another AUTHENTICATE
command. In other words, the client may request authentication
types in decreasing order of preference.
Examples:
S: "IMPLEMENTATION" "CMU Cyrus Sieved v001"
S: "SASL" "KERBEROS_V4 GSSAPI"
S: "SIEVE" "FILEINTO VACATION"
S: "STARTTLS"
S: OK
C: Authenticate "KERBEROS_V4"
S: "6UM4Ig=="
C: "BAYBQU5EUkVXLkNNVS5FRFUAOCjDCH77GOzSSOF1Df2Kb0zzPe
QJIrweAPyo6Q1T9xuYtCGylDqRYlbUFa77esDOtBJdDE5qRXcwHXQE5Dg
amqj0LqecZtKUCc8g2xpcqxn1fc/CH6QdZLOAGVpHTN1AX2Y="
S: "cmnEYo1x6wc="
C: "kjuaMkUeg2okQh+we2uiJw=="
S: OK
Expires January 21, 2003 Martin [Page 9]
Internet Draft Managing Sieve Scripts July 16, 2002
C: Authenticate "PLAIN" "QJIrweAPyo6Q1T9xu"
S: BYE "Too many failed authentication attempts"
Server closes connection
2.2. STARTTLS Command
The STARTTLS command requests to commencement of a TLS negotiation.
The negotiation begins immediately after the CRLF in the OK
response. After a client issues a STARTTLS command, it MUST NOT
issue further commands until a server response is seen and the TLS
negotiation is complete.
The STARTTLS command is only valid in non-authenticated state. The
server remains in non-authenticated state, even if client
credentials are supplied during the TLS negotiation. The SASL [SASL]
EXTERNAL mechanism MAY be used to authenticate once TLS clie nt
credentials are successfully exchanged, but servers supporting the
STARTTLS command are not required to support the EXTERNAL mechanism.
After the TLS layer is established, the server MUST re-issue the
capability results. This is necessary to protect against man-in-the-
middle attacks which alter the capabilities list prior to STARTTLS.
The client MUST discard cached capability information and replace it
with the new information. The server MAY advertise different
capabilities after STARTTLS.
Example:
C: STARTTLS
S: OK
<TLS negotiation, further commands are under TLS layer>
2.3. LOGOUT Command
The client sends the LOGOUT command when it is finished with a
connection and wishes to terminate it. The server MUST reply with an
OK response and terminate the connection. The server MUST ignore
commands issued by the client after the LOGOUT command.
Example:
C: Logout
S: OK
<connection terminated>
Expires January 21, 2003 Martin [Page 10]
Internet Draft Managing Sieve Scripts July 16, 2002
2.4. CAPABILITY Command
The CAPABILITY command requests the server capabilities as described
earlier in this document. While the capabilities are sent upon
connection, they may change during authentication. The client SHOULD
issue a CAPABILITY command after successful authentication or after
negotiating a security layer using STARTTLS.
Example:
S: "IMPLEMENTATION" "CMU Cyrus Sieved v001"
S: "SASL" "PLAIN KERBEROS_V4 GSSAPI"
S: "SIEVE" "FILEINTO VACATION"
S: "STARTTLS"
S: OK
2.5. HAVESPACE Command
Arguments:
String - name
Number - size
The HAVESPACE command is used to query the server for available
space. Clients specify the name they wish to save the script as and
it's size in octets. Servers respond with an NO if storing a script
with that name and size would fail or OK otherwise. Clients should
issue this command before attempting to place a script on the
server.
Example:
C: HAVESPACE "myscript" 999999
S: NO "Quota exceeded"
C: HAVESPACE "foobar" 435
S: OK
2.6. PUTSCRIPT Command
Arguments:
String - Script name
Expires January 21, 2003 Martin [Page 11]
Internet Draft Managing Sieve Scripts July 16, 2002
String - Script content
The PUTSCRIPT command is used by the client to submit a Sieve script
to the server.
If the script already exists upon success the old script will be
overwritten. The old script MUST NOT be overwritten if PUTSCRIPT
fails in any way. A script of zero length SHOULD be disallowed.
This command places the script on the server. It does not affect
whether the script is processed on incoming mail. The SETACTIVE
command is used to mark a script as active.
When submitting large scripts clients SHOULD use the HAVESPACE
command beforehand to query if the server is willing to accept a
script of that size.
The server MUST check the submitted script for syntactic validity.
If the script fails this test the server MUST reply with a NO
response. Any script that fails the validity test MUST NOT be stored
on the server. The message given with a NO response MUST be human
readable and SHOULD contain a specific error message giving line
number of the first error. Implementors should strive to produce
helpful error messages similar to those given by programming
language compilers. Client implementations should note that this may
be a multiline literal string with more than one error message
separated by newlines.
Example:
C: Putscript "foo" {31+}
C: #comment
C: InvalidSieveCommand
C:
S: NO "line 2: Syntax error"
C: Putscript "mysievescript" {110+}
C: require ["fileinto"];
C:
C: if envelope :contains "to" "tmartin+sent" {
C: fileinto "INBOX.sent";
C: }
S: OK
Expires January 21, 2003 Martin [Page 12]
Internet Draft Managing Sieve Scripts July 16, 2002
2.7. LISTSCRIPTS Command
This command lists the scripts the user has on the server. Upon
success a list of linebreak separated script names is returned
followed by an OK response. If there exists an active script the
atom ACTIVE is appended to the line of that script. The ACTIVE
string MUST NOT appear on more than one response line.
Example:
C: Listscripts
S: "summer_script"
S: "vacation_script"
S: "main_script" ACTIVE
S: OK
2.8. SETACTIVE Command
Arguments:
String - script name
This command sets a script active. If the script name is the empty
string (i.e. "") then any active script is disabled. If the script
does not exist on the server then the server MUST reply with a NO
response.
Examples:
C: Setactive "vacationscript"
S: Ok
C: Setactive ""
S: Ok
C: Setactive "baz"
S: No "There is no script by that name"
2.9. GETSCRIPT Command
Arguments:
String - Script name
This command gets the contents of the specified script. If the
script does not exist the server MUST reply with a NO response. Upon
Expires January 21, 2003 Martin [Page 13]
Internet Draft Managing Sieve Scripts July 16, 2002
success a string with the contents of the script is returned
followed by a OK response.
Example:
C: Getscript "myscript"
S: {48+}
S: #this is my wonderful script
S: reject "I reject all";
S:
S: OK
2.10. DELETESCRIPT Command
Parameters:
sieve-name - Script name
This command is used to delete a user's Sieve script. Servers MUST
reply with a NO response if the script does not exist. The server
MUST NOT allow the client to delete an active script and reply with
a NO response if attempted. If a client wishes to delete an active
script it should use the SETACTIVE command to disable the script
first.
Example:
C: Deletescript "foo"
S: Ok
C: Deletescript "baz"
S: No "You may not delete an active script"
3. Sieve URL Scheme
URL scheme name: "sieve"
URL scheme syntax:
Described using ABNF [RFC 2234] and ABNF entities from RFC 2396.
sieveurl = "sieve://" [ hostport ] "/" scriptname
scriptname = *pchar
Expires January 21, 2003 Martin [Page 14]
Internet Draft Managing Sieve Scripts July 16, 2002
Character encoding considerations: The script name, if present,
is in UTF-8. Non-ASCII characters must be escaped as described
in RFC 2396.
Intended usage: A sieve URL identifies a sieve server or a sieve
script on a sieve server. The latter always have the
application/sieve MIME type.
Applications and/or protocols which use this URL scheme name:
The protocol is described in this document.
Interoperability considerations: None.
Security considerations: None.
Relevant publications: This document and RFC 3028.
Person & email address to contact for further information:
Author of this document.
Author/Change controller: Author of this document.
4. Formal Syntax
The following syntax specification uses the augmented Backus-Naur
Form (BNF) notation as specified in [ABNF]. This uses the ABNF core
rules as specified in Appendix A of the ABNF specification [ABNF].
Except as noted otherwise, all alphabetic characters are case-
insensitive. The use of upper or lower case characters to define
token strings is for editorial clarity only. Implementations MUST
accept these strings in a case-insensitive fashion.
SAFE-CHAR = %x01-09 / %x0B-0C / %x0E-21 / %x23-5B / %x5D-7F
;; any TEXT-CHAR except QUOTED-SPECIALS
QUOTED-CHAR = SAFE-UTF8-CHAR / "\" QUOTED-SPECIALS
QUOTED-SPECIALS = <"> / "\"
SAFE-UTF8-CHAR = SAFE-CHAR / UTF8-2 / UTF8-3 / UTF8-4 /
UTF8-5 / UTF8-6
UTF8-1 = %x80-BF
Expires January 21, 2003 Martin [Page 15]
Internet Draft Managing Sieve Scripts July 16, 2002
UTF8-2 = %xC0-DF UTF8-1
UTF8-3 = %xE0-EF 2UTF8-1
UTF8-4 = %xF0-F7 3UTF8-1
UTF8-5 = %xF8-FB 4UTF8-1
UTF8-6 = %xFC-FD 5UTF8-1
auth-type = <"> auth-type-name <">
auth-type-name = iana-token
;; as defined in SASL [SASL]
command = command-authenticate / command-logout / command-getscript /
command-setactive / command-listscripts / command-deletescript /
command-putscript / command-capability / command-havespace /
command-starttls
command-authenticate = "AUTHENTICATE" SP auth-type [SP string] *(CRLF string)
command-capability = "CAPABILITY" CRLF
command-deletescript = "DELETESCRIPT" SP sieve-name CRLF
command-getscript = "GETSCRIPT" SP sieve-name CRLF
command-havespace = "HAVESPACE" SP sieve-name SP number CRLF
command-listscripts = "LISTSCRIPTS" CRLF
command-logout = "LOGOUT" CRLF
command-putscript = "PUTSCRIPT" SP sieve-name SP string CRLF
command-setactive = "SETACTIVE" SP sieve-name CRLF
command-starttls = "STARTTLS" CRLF
literal = "{" number "+}" CRLF *OCTET
;; The number represents the number of octets
;; MUST be literal-utf8 except for values
number = *DIGIT
;; A 32-bit unsigned number.
;; (0 <= n < 4,294,967,296)
Expires January 21, 2003 Martin [Page 16]
Internet Draft Managing Sieve Scripts July 16, 2002
quoted = <"> *QUOTED-CHAR <">
;; limited to 1024 octets between the <">s
resp-code = "AUTH-TOO-WEAK" / "ENCRYPT-NEEDED" /
"QUOTA" / resp-code-sasl / resp-code-referral
"TRANSITION-NEEDED" / "TRYLATER" /
resp-code-ext
resp-code-referral = "REFERRAL" SP sieveurl
resp-code-sasl = "SASL" SP string
resp-code-ext = iana-token [SP extension-data]
;; unknown codes MUST be tolerated by the client
response = response-authenticate / response-logout / response-getscript /
response-setactive / response-listscripts / response-deletescript /
response-putscript / response-capability / response-havespace /
response-starttls
response-authenticate = *(string CRLF) (response-oknobye)
response-capability = *(string [SP string] CRLF) response-oknobye
response-deletescript = response-oknobye
response-getscript = [string CRLF] response-oknobye
response-havespace = response-oknobye
response-listscripts = *(sieve-name [SP "ACTIVE"] CRLF) response-oknobye
;; ACTIVE may only occur with one sieve-name
response-logout = response-oknobye
response-oknobye = ("OK" / "NO" / "BYE") [SP "(" resp-code ")"] [SP string] CRLF
response-putscript = response-oknobye
response-setactive = response-oknobye
response-starttls = response-oknobye
sieve-name = string
string = quoted / literal
Expires January 21, 2003 Martin [Page 17]
Internet Draft Managing Sieve Scripts July 16, 2002
5. Security Considerations
The AUTHENTICATE command uses SASL [SASL] and TLS [TLS] to provide
basic authentication, authorization, integrity and privacy services.
When a SASL mechanism is used the security considerations for that
mechanism apply.
This protocol transactions are susceptible to passive observers or
man in the middle attacks which alter the data, unless the optional
encryption and integrity services of the AUTHENTICATE command are
enabled, or an external security mechanism is used for protection.
It may be useful to allow configuration of both clients and servers
to refuse to transfer sensitive information in the absence of strong
encryption.
6. Acknowledgments
Thanks to Simon Josefsson, Larry Greenfield, Allen Johnson, Chris
Newman, Lyndon Nerenberg, Alexey Melnikov, Tim Showalter, Sarah
Robeson, and Walter Wong for help with this document.
7. Copyright
Copyright (C) The Internet Society 1999. All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph
are included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
Expires January 21, 2003 Martin [Page 18]
Internet Draft Managing Sieve Scripts July 16, 2002
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
8. References
[KEYWORDS] S. Bradner, "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997
<ftp://ftp.isi.edu/in-notes/rfc2119.txt>
[ABNF] Crocker, Overell, "Augmented BNF for Syntax Specifications:
ABNF", RFC 2234, Internet Mail Consortium, Demon Internet Ltd, November
1997.
[ACAP] Newman, Myers, "ACAP -- Application Configuration Access Proto-
col", RFC 2244, Innosoft, Netscape, November 1997.
[IMAP4rev1] Crispin, M., "Internet Message Access Protocol - Version
4rev1", RFC 2060, October 1996.
[IMAP-URL] Newman, C.; "IMAP URL Scheme"; RFC 2192; Innosoft; September,
1997
[PLAIN] Newman, C. "Using TLS with IMAP, POP3 and ACAP", RFC 2595,
Innosoft, June 1999.
[SASL] Myers, J., "Simple Authentication and Security Layer (SASL)", RFC
2222, Netscape Communications, October 1997.
[SASL-ANON] Newman, C., "Anonymous SASL Mechanism", RFC 2245, November
1997.
[SIEVE] Showalter, T.; "Sieve: A Mail Filtering Language"; RFC 3028;
Mirapoint, Inc.; January 2001
[TLS] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0", RFC 2246,
January 1999.
9. Author's Address
Tim Martin
Mirapoint Inc.
909 Hermosa Court
Sunnyvale, CA 94085
Expires January 21, 2003 Martin [Page 19]
Internet Draft Managing Sieve Scripts July 16, 2002
Phone: (408) 720-3835
EMail: tmartin@mirapoint.com
Expires January 21, 2003 Martin [Page 20]