One document matched: draft-bajko-mext-sod-03.xml


<?xml version="1.0" encoding="US-ASCII"?>
<!DOCTYPE rfc SYSTEM "rfc2629.dtd" [
<!ENTITY RFC2119 PUBLIC ''
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml'>
<!ENTITY RFC6275 PUBLIC ''
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.6275.xml'>
<!ENTITY RFC5555 PUBLIC ''
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.5555.xml'>
<!ENTITY RFC5846 PUBLIC ''
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.5846.xml'>
<!ENTITY RFC4877 PUBLIC ''
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.4877.xml'>
<!ENTITY I-D.ietf-mext-mip6-tls PUBLIC ''
'http://xml.resource.org/public/rfc/bibxml3/reference.I-D.ietf-mext-mip6-tls.xml'>
]>

<?rfc toc="yes"?>
<?rfc tocompact="yes"?>
<?rfc tocdepth="3"?>
<?rfc tocindent="yes"?>
<?rfc tocappendix="yes"?>
<?rfc symrefs="yes"?>
<?rfc sortrefs="yes"?>
<?rfc comments="yes"?>
<?rfc inline="yes"?>
<?rfc compact="yes"?>
<?rfc subcompact="no"?>
<rfc category="std"
     docName="draft-bajko-mext-sod-03"
     ipr="trust200902"
>
  <front>
    <title abbrev="Mobile IPv6: Security on demand">Security on Demand
    for Mobile IPv6 and Dual-stack Mobile IPv6</title>


      <author initials="G" surname="Bajko" fullname="Gabor Bajko">
         <organization>Nokia</organization>
         <address>
            <postal>
               <street>200 S Mathilda Avenue</street>
	    <city>Sunnyvale</city>
	    <region>CA</region>
               <code>94086</code>
               <country>USA</country>
            </postal>
            <email>gabor.bajko@nokia.com</email>
         </address>
      </author>

      <author initials="B" surname="Patil"
      fullname="Basavaraj Patil">
	<organization>Nokia</organization>
      <address>
         <postal>
            <street>6021 Connection drive</street>
            <city>Irving</city>
            <region>TX</region>
            <code>75039</code>
            <country>USA</country>
         </postal>
         <email>basavaraj.patil@nokia.com</email>
      </address>
      </author>

    <author fullname="Teemu Savolainen" initials="T" surname="Savolainen">
      <organization>Nokia</organization>
      <address>
         <postal>
            <street>Hermainkatu 12 D</street>
            <city>Tampere</city>
            <region>FI</region>
            <code>33720</code>
            <country>Finland</country>
         </postal>
         <email>teemu.savolainen@nokia.com</email>
      </address>
      </author>


    <date year="2011" />

    <area>Internet</area>

    <workgroup>Individual Submission</workgroup>
    <keyword>Mobile IPv6</keyword>
    <keyword>Dual stack Mobile IPv6</keyword>
    <keyword>Security</keyword>
    <keyword>Mobility</keyword>

    <abstract>
     <t>
       Mobile IPv6 and Dual-stack Mobile IPv6 protocols require the
       signaling messages between the mobile node and home agent to be
       secured. However security for  
       the user plane/traffic is optional and is a choice left to the
       mobile node.  
       This document proposes extensions to Mobile IPv6 signaling which 
       enables the user plane traffic to be secured on a need or
       on-demand basis. The mobile node or the home agent can request
       at any time security for the user plane traffic. Security for
       user plane traffic can be triggered as a result of policy or,
       mobility or, at the user's choice.  
     </t>
    </abstract>
  </front>

  <middle>
    <section title="Introduction">
      <t>
	Mobile IPv6 <xref target="RFC6275" /> and Dual-stack Mobile
	IPv6 <xref target="RFC5555" /> provide  
	the option to secure the user plane data between the Mobile Node 
	(MN) and and the Home Agent (HA) when needed. The user plane traffic 
	between the MN and HA is secured via an IPsec security association 
	(SA) which is established between them specifically for the purpose 
	of user plane data. IPsec is used for securing the user plane 
	traffic when the security between the MN and HA is based on IPsec. 
	However security between the MN and HA could also be enabled via 
	other protocols. The MEXT WG is evaluating on an experimental basis 
	various alternatives to IPsec such as the one specified in
	<xref target="I-D.ietf-mext-mip6-tls"/>. 
	</t>
      <t>
	As per the current specifications for MIP6 and DSMIP6, security of 
	the user plane traffic is optional. When the MN is attached to 3G/4G 
	network such as HSPA, LTE or EV-DO, the MN may not require security 
	for the user plane traffic since these networks already provide 
	ciphering over the air-interface and deploy hop-by-hop security, 
	which makes these networks secure. However the MN may attach to less 
	secure or unsecured accesses such as wireless lan (WLAN) or it may 
	roam in countries where the user may prefer the data between the MN 
	and the HA to be encrypted (even when using cellular accesses). 
	There is no solution in the protocol specification today which 
	provides the capability to trigger the security for the user plane 
	traffic on a need basis.  
      </t>
      <t>    
	The problem that is being addressed is the triggering of security 
	for user plane traffic between the MN and HA on a need basis. Policy 
	information at the MN or information provided to the MN via other 
	means at the time of attachment may assist the MN to determine if 
	security needs to be enabled for user plane traffic. The user may 
	also consciously decide to enable security when attached to certain 
	networks. Furthermore, the operator of HA may have policies that 
	define when user plane security is to be used. This document 
	describes a mechanism which can enable security for user plane 
	traffic on-demand or need. 
      </t>
      <t>
	An obvious implementation alternative would be to encrypt user plane 
	traffic always (as is commonly done with VPN use-cases), but that 
	would unnecessarily consume resources on the HA. For the HA operator 
	there is clear economic incentive to encrypt user-plane data only 
	when necessary. 
	The MIP6/DSMIP6 protocols only provide a means to secure the user 
	plane traffic but do not provide any mechanisms by which the 
	security is triggered as a result of mobility or the MN attaching 
	via different access networks. 
      </t>
      <t>
	As per the current MIP6 <xref target="RFC6275" />
	specification, only the MN has the  
	ability to enable security for user-plane traffic. The HA has no 
	ability to force the MN to secure user traffic. 
      </t>
    </section>
    
    <section title="When to apply Security to user plane traffic">
	<t>
	  An MN MUST have security for the control plane messages. Hence all 
	  signaling between the MN and HA are secured. The MN establishes an 
	  IPsec SA between itself and the assigned HA prior to sending a 
	  Binding Update. However, the MN is not required to establish an SA 
	  for securing the user plane traffic. It is up to the MN whether it 
	  establishes SAs for the control plane and user plane at the same 
	  time or if it only establishes the control plane SA. The MN may 
	  choose to establish the SA for user plane traffic at any time 
	  <xref target="RFC4877" />. 
	</t>
	<t>
	  When the MN attaches to an access network, it is usually able to 
	  determine if the access network is viewed as trusted or untrusted. 
	  The MN can make this determination, for example, based on the PLMN 
	  ID of the cellular network; or wifi_SSID/MAC_address of a wifi 
	  network; or location information provided by the MN, or user input. 
	  The MN has either a stored policy about trusted and untrusted access 
	  networks or it may be provided with such information from policy 
	  stores such as the ANDSF <xref target="23.402" /> or AAA
	  server at the time of  
	  network attachment. An interface exists generally between the policy 
	  store such as AAA or ANDSF and the Home Agent (HA).   
	  If the MN is attached to an access network which is viewed as 
	  trusted or where encryption is not allowed, the MN chooses not to 
	  secure the user plane traffic.  
	</t>
	<t>
	  If the MN is attached to an access network which is not trusted, the 
	  MN may want to secure its user plane traffic. The HA may also be 
	  able to determine from the source address of the binding update (BU) 
	  message the access network to which the MN is currently attached. 
	  Based on this information, the HA may require that the user plane 
	  traffic be encrypted on the MN-HA link. 
	</t>
	<t>
	  The MN or HA can determine when to use security for the user plane 
	  traffic using static policies or dynamic policies which can be 
	  obtained at the time of network attachment; or e.g. which are 
	  provisioned and maintained on a smartcard (eg, a UICC or SIM). 3GPP 
	  policy stores such as the ANDSF can also provide information about 
	  the access networks to which an MN is attached. Location of the MN 
	  can also be used as input. 
	</t>
    </section>
    
    <section title="Triggering user plane traffic security">
     <t>
       This document proposes extensions to MIPv6/DSMIPv6 protocol, 
       allowing the MN to signal to the HA its preference for user plane 
       traffic security, and for the HA to override that preference based 
       on the policy settings. 
     </t>
     <t>
       A new mobility option called as the "Security-on-demand" (SoD)
       is specified which is used to switch on or off the security for
       the user plane traffic. 
     </t>
     <t>
       The MN sends a binding update which includes the
       "Security-on-demand" mobility option set which is used to
       indicate whether security for the user plane traffic is to be
       switched On or Off. The HA  processes the binding update
       message from the MN and sends a  
       response acknowledging the request and including the "SoD"
       option for user plane traffic security. 
     </t>

     <t>
       The HA MAY always overwrite the MN's security preference on the user 
       plane traffic indicated in the Binding Update message, by setting 
       the SoD option in the the Binding Acknowledgement to a different value. 
       The MN SHALL always follow the indication in the Binding 
       Acknowledgement to set the security of the MN to HA user plane 
       traffic.
     </t>
    </section>
    
    <section title = "Extensions to Mobile IPv6">
     <section title = "Extensions to Binding Update and Binding Acknowledgement">
       <t>
	 This section defines the new Security-on-demand mobility
	 option for the Binding Update and the 
	 corresponding Binding Acknowledgement message. 
       </t>
       <t>
	 The security-on-demand mobility option has an alignment
	 requirement of 2n. Its format is as follows:
       </t>
       <t>

	 	    <figure title="Security on demand mobility option"
			    anchor="fig:Security on demand mobility option">
        <artwork><![CDATA[

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
                                   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                   |   Type =      |  Length =     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | SoD option    |     Reserved              	       	           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
				 
    
      ]]></artwork></figure>						      
       </t>
       <t>
	 <list style="empty">
	   <t>Type = TBD (To be assigned by IANA)</t>
	   <t>Length = 4</t>
	   <t>SoD Option = This option field defines whether security
	     is enabled or disabled as well as whether security is
	     integrity protected or encrypted</t>
	   </list>
       </t>

    </section>
     <section title="New binding Update Mobility Options">
       <t>
	 A new mobility Options for carrying location of the MN is defined to 
	 be used in a Binding Update message with the following
	 format: 

	 	    <figure title="MN location"
			    anchor="fig: Location info in BU">
        <artwork><![CDATA[

    
       0                   1                   2                   3 
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
      |   Type        |   Length      |N|   Reserved  |   Data ... 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
                            Data ...                                  | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
         
      ]]></artwork></figure>						      
       </t>
       <t>
	 Type: tbd
       </t>
       <t>
	 N set to 1 indicates that the data contains a location in XML 
         format as defined in RFC5139, N set to zero indicates that the 
         data part contains an http URI pointing to a resource where the 
         MN uploaded its location
       </t>
     </section>
    </section>
    
    <section title="HA initiated security for user plane traffic">
      <t>
	Mobile IPv6 signaling is primarily mobile initiated. The
	security for user plane traffic can be requested by the MN via
	the Binding Update request message and the HA has the ability
	to either approve or deny via the Binding Acknowledgment
	message. However the HA does not have a way to send an
	insolicited message to the MN and trigger the establishment of
	security for the user plane traffic.
      </t>
      <t>
	Mobile IPv6 defines Binding Revocation
	<xref target="RFC5846"/> which enables an HA to send an
	unsolicited message to the MN to revoke a binding. This is the
	only unsolicited signaling message that can be sent by HA to
	an MN. This I-D proposes extending the binding revocation
	message to indicate to the MN that security for the user plane
	traffic is required. The effect of sending the binding
	revocation message to the MN with the appropriate option
	included in it will cause the MN to send a Binding update with
	the SoD mobility option requesting security for user plane
	traffic. 
      </t>
    </section>

    <section anchor="IANA" title="IANA Considerations">
      <t>
	This document will require actions on the part of IANA to
	assign values for the new binding update mobility option.
      </t>
    </section>

    <section anchor="Security" title="Security Considerations">
	    <t>
	      This I-D introduces extensions to Mobile IPv6 signaling messages. 
	      There is no impact to the security model and architecture that is 
	      currently specified for MIP6 <xref target="RFC6275"
	      />. The extensions specified in  
	      this document do not introduce any new vulnerabilities of threats to 
	      the security architecture of Mobile IPv6.
	    </t> 
	    
    </section>

<section title="Summary">
  <t>
    Security for the user plane traffic between the MN and Home agent
    can be switched on or off as a result of policy, location or, request by the
    user. The ability to control and trigger the security for the user plane
    traffic rests with the MN as well as the HA with the HA having the final say.
  </t>
</section>

<section title="Acknowledgments">
  <t>
    The authors acknowledge the reviews by Julien Laganier, Jouni
    Korhonen, Stefano Faccin and Kent Leung. Their comments and
    suggestions will be incorporated in the next revision.
  </t>
</section>

  </middle>




  <back>
    <references title="Informative References">

      <reference anchor='23.402'>
	<front>
	  <title>3GPP TS 23.402, Architecture enhancements for non-3GPP 
          accesses, 
	    </title>

	  <author><organization>3rd generation partnership project (3GPP)
	  </organization> </author>
	  </front>
	  <format type='MSW'
		  target='http://www.3gpp.org/ftp/Specs/latest/Rel-9/23_series/23402-930.zip' />
	  </reference>

    </references>
    <references title="Normative References">
      &RFC6275;
      &RFC5555;
      &RFC4877;
      &RFC5846;
      &I-D.ietf-mext-mip6-tls;
    </references>
  </back>
</rfc>

PAFTECH AB 2003-20262026-04-24 08:56:30