Subject: I-D ACTION:draft-ietf-sip-sec-agree-00.txt

From: [email-masked]
Date: Thu, 25 Apr 2002 08:24:11 -0400

A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the Session Initiation Protocol Working Group of the IETF.

	Title		: Security Mechanism Agreement for SIP Sessions
	Author(s)	: J. Arkko et al.
	Filename	: draft-ietf-sip-sec-agree-00.txt
	Pages		: 16
	Date		: 24-Apr-02
	
SIP has a number of security mechanisms for hop-by-hop and end-to-end
protection. Some of the security mechanisms have been built in to the
SIP protocol, such as HTTP authentication or secure attachments. In
these mechanisms there are even alternative algorithms and parameters.
Currently it isn't possible to select which security mechanisms to use
over a connection. In particular, even if some mechanisms such as
OPTIONS were used to make this selection, the selection would be vul¡
nerable against the Bidding-Down attack.  This document defines a
header for negotiating the security mechanisms within SIP. A SIP
entity applying this mechanism must always require some minimum secu¡
rity (i.e. integrity protection) from all communicating parties in
order to secure the negotiation, but the negotiation can agree on
which specific minimum security is used.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-sip-sec-agree-00.txt

To remove yourself from the IETF Announcement list, send a message to 
ietf-announce-request with the word unsubscribe in the body of the message.

Internet-Drafts are also available by anonymous FTP. Login with the username
"anonymous" and a password of your e-mail address. After logging in,
type "cd internet-drafts" and then
	"get draft-ietf-sip-sec-agree-00.txt".

A list of Internet-Drafts directories can be found in
http://www.ietf.org/shadow.html 
or ftp://ftp.ietf.org/ietf/1shadow-sites.txt

Internet-Drafts can also be obtained by e-mail.

Send a message to:
	[email-masked].
In the body type:
	"FILE /internet-drafts/draft-ietf-sip-sec-agree-00.txt".
	
NOTE:	The mail server at ietf.org can return the document in
	MIME-encoded form by using the "mpack" utility.  To use this
	feature, insert the command "ENCODING mime" before the "FILE"
	command.  To decode the response(s), you will need "munpack" or
	a MIME-compliant mail reader.  Different MIME-compliant mail readers
	exhibit different behavior, especially when dealing with
	"multipart" MIME messages (i.e. documents which have been split
	up into multiple messages), so check your local documentation on
	how to manipulate these messages.

Below is the data which will enable a MIME compliant mail reader
implementation to automatically retrieve the ASCII version of the
Internet-Draft.