I-D ACTION:draft-undery-sip-auth-01.txt

[Internet-Drafts@ietf.org]

A New Internet-Draft is available from the on-line Internet-Drafts directories.


	Title		: Enhanced Usage of HTTP Digest Authentication for SIP
	Author(s)	: J. Undery, S. Sen, V. Torvinen
	Filename	: draft-undery-sip-auth-01.txt
	Pages		: 7
	Date		: 14-Jun-02
	
HTTP Digest has some shortcomings if applied for SIP. Firstly, SIP 
UA has serious difficulties to distinguish the source of 
Authentication-Info and Proxy-Authentication-Info headers in SIP 
forking situations. This is due to the absence of the ærealmÆ 
parameter in these headers. Secondly, HTTP authentication is 
particularly vulnerable against MITM bid-down attacks on the list of 
algorithms (e.g., MD-5, SHA-1) or the desired security level (auth, 
auth-int). Thirdly, HTTP authentication provides limited integrity 
protection of only the message body. In SIP, important information 
can be carried in many of the headers that may need integrity 
protection. This draft proposes to add the realm parameter in the *-
Authentication-Info headers, recommends a format for computing the 
nonce for detection of bid-down attack and proposes a mechanism for 
integrity protection of SIP headers using MIME body.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-undery-sip-auth-01.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-undery-sip-auth-01.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:
	mailserv@ietf.org.
In the body type:
	"FILE /internet-drafts/draft-undery-sip-auth-01.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.

<ftp://ftp.ietf.org/internet-drafts/draft-undery-sip-auth-01.txt>