diff options
| author | Christian Pointner <equinox@anytun.org> | 2008-03-19 18:42:24 +0000 |
|---|---|---|
| committer | Christian Pointner <equinox@anytun.org> | 2008-03-19 18:42:24 +0000 |
| commit | e40efd4ab6cb6bcb25f8dda72fd7c0a5a6ca2fbb (patch) | |
| tree | 46eb561d31cdb233b9be9908b5924d5c4f729a43 | |
| parent | fixed nat detection @ anyrtpproxy (diff) | |
added revision 2 of internet draft
| -rw-r--r-- | draft-gsenger-secure-anycast-tunneling-protocol-02.html | 696 | ||||
| -rw-r--r-- | draft-gsenger-secure-anycast-tunneling-protocol-02.txt | 952 | ||||
| -rw-r--r-- | draft-gsenger-secure-anycast-tunneling-protocol-02.xml | 299 |
3 files changed, 1947 insertions, 0 deletions
diff --git a/draft-gsenger-secure-anycast-tunneling-protocol-02.html b/draft-gsenger-secure-anycast-tunneling-protocol-02.html new file mode 100644 index 0000000..8b5e98d --- /dev/null +++ b/draft-gsenger-secure-anycast-tunneling-protocol-02.html @@ -0,0 +1,696 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html lang="en"><head><title>secure anycast tunneling protocol (SATP)</title> +<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> +<meta name="description" content="secure anycast tunneling protocol (SATP)"> +<meta name="keywords" content="satp, Internet-Draft, secure anycast tunneling protocol, anycast, tunnel, secure, protocol"> +<meta name="generator" content="xml2rfc v1.31 (http://xml.resource.org/)"> +<style type='text/css'><!-- + body { + font-family: verdana, charcoal, helvetica, arial, sans-serif; + font-size: small; color: #000; background-color: #FFF; + margin: 2em; + } + h1, h2, h3, h4, h5, h6 { + font-family: helvetica, monaco, "MS Sans Serif", arial, sans-serif; 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} + a:active { color: #633; background-color: transparent; } + + p { margin-left: 2em; margin-right: 2em; } + p.copyright { font-size: x-small; } + p.toc { font-size: small; font-weight: bold; margin-left: 3em; } + table.toc { margin: 0 0 0 3em; padding: 0; border: 0; vertical-align: text-top; } + td.toc { font-size: small; font-weight: bold; vertical-align: text-top; } + + ol.text { margin-left: 2em; margin-right: 2em; } + ul.text { margin-left: 2em; margin-right: 2em; } + li { margin-left: 3em; } + + /* RFC-2629 <spanx>s and <artwork>s. */ + em { font-style: italic; } + strong { font-weight: bold; } + dfn { font-weight: bold; font-style: normal; } + cite { font-weight: normal; font-style: normal; } + tt { color: #036; } + tt, pre, pre dfn, pre em, pre cite, pre span { + font-family: "Courier New", Courier, monospace; font-size: small; + } + pre { + text-align: left; padding: 4px; + color: #000; background-color: #CCC; + } + pre dfn { color: #900; } + pre em { color: #66F; background-color: #FFC; font-weight: normal; } + pre .key { color: #33C; font-weight: bold; } + pre .id { color: #900; } + pre .str { color: #000; background-color: #CFF; } + pre .val { color: #066; } + pre .rep { color: #909; } + pre .oth { color: #000; background-color: #FCF; } + pre .err { background-color: #FCC; } + + /* RFC-2629 <texttable>s. */ + table.full, table.headers, table.none { + font-size: small; text-align: center; border-width: 2px; + vertical-align: top; border-collapse: collapse; + } + table.full { border-style: solid; border-color: black; } + table.headers, table.none { border-style: none; } + th { + font-weight: bold; border-color: black; + border-width: 2px 2px 3px 2px; + } + table.full th { border-style: solid; } + table.headers th { border-style: none none solid none; } + table.none th { border-style: none; } + table.full td { + border-style: solid; border-color: #333; + border-width: 1px 2px; + } + table.headers td, table.none td { border-style: none; } + + hr { height: 1px; } + hr.insert { + width: 80%; border-style: none; border-width: 0; + color: #CCC; background-color: #CCC; + } +--></style> +</head> +<body> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<table summary="layout" width="66%" border="0" cellpadding="0" cellspacing="0"><tr><td><table summary="layout" width="100%" border="0" cellpadding="2" cellspacing="1"> +<tr><td class="header">Network Working Group</td><td class="header">O. Gsenger</td></tr> +<tr><td class="header">Internet-Draft</td><td class="header">January 2008</td></tr> +<tr><td class="header">Intended status: Informational</td><td class="header"> </td></tr> +<tr><td class="header">Expires: July 4, 2008</td><td class="header"> </td></tr> +</table></td></tr></table> +<h1><br />secure anycast tunneling protocol (SATP)<br />draft-gsenger-secure-anycast-tunneling-protocol-01</h1> + +<h3>Status of this Memo</h3> +<p> +By submitting this Internet-Draft, +each author represents that any applicable patent or other IPR claims of which +he or she is aware have been or will be disclosed, +and any of which he or she becomes aware will be disclosed, +in accordance with Section 6 of BCP 79.</p> +<p> +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.</p> +<p> +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.”</p> +<p> +The list of current Internet-Drafts can be accessed at +<a href='http://www.ietf.org/ietf/1id-abstracts.txt'>http://www.ietf.org/ietf/1id-abstracts.txt</a>.</p> +<p> +The list of Internet-Draft Shadow Directories can be accessed at +<a href='http://www.ietf.org/shadow.html'>http://www.ietf.org/shadow.html</a>.</p> +<p> +This Internet-Draft will expire on July 4, 2008.</p> + +<h3>Copyright Notice</h3> +<p> +Copyright © The Internet Society (2008).</p> + +<h3>Abstract</h3> + +<p>The secure anycast tunneling protocol (SATP) defines a protocol used for communication between any combination of unicast and anycast tunnel endpoints. It allows tunneling of every ETHER TYPE protocol (ethernet, ip ...). SATP directly includes cryptography and message authentication based on the methodes used by SRTP. It can be used as an encrypted alternative to <a class='info' href='#RFC2003'>IP Encapsulation within IP<span> (</span><span class='info'>Perkins, C., “IP Encapsulation within IP,” October 1996.</span><span>)</span></a> [3] and <a class='info' href='#RFC2784'>Generic Routing Encapsulation (GRE)<span> (</span><span class='info'>Farinacci, D., Li, T., Hanks, S., Meyer, D., and P. Traina, “Generic Routing Encapsulation (GRE),” March 2000.</span><span>)</span></a> [4]. It supports both anycast receivers and senders. + +</p><a name="toc"></a><br /><hr /> +<h3>Table of Contents</h3> +<p class="toc"> +<a href="#anchor1">1.</a> +Introduction<br /> + <a href="#anchor2">1.1.</a> +Notational Conventions<br /> +<a href="#anchor3">2.</a> +Motivation and usage scenarios<br /> + <a href="#anchor4">2.1.</a> +Usage scenarions<br /> + <a href="#anchor5">2.1.1.</a> +Tunneling from unicast hosts over anycast routers to other unicast hosts<br /> + <a href="#anchor6">2.1.2.</a> +Tunneling from unicast hosts to anycast networks<br /> + <a href="#anchor7">2.1.3.</a> +Redundant tunnel connection of 2 networks<br /> + <a href="#anchor8">2.2.</a> +Encapsulation<br /> +<a href="#anchor9">3.</a> +Using SATP on top of IP<br /> + <a href="#anchor10">3.1.</a> +Fragmentation<br /> + <a href="#anchor11">3.2.</a> +ICMP messages<br /> +<a href="#anchor12">4.</a> +Protocol specification<br /> + <a href="#anchor13">4.1.</a> +Header format<br /> + <a href="#anchor14">4.2.</a> +sequence number<br /> + <a href="#anchor15">4.3.</a> +sender ID<br /> + <a href="#anchor16">4.4.</a> +MUX<br /> + <a href="#anchor17">4.5.</a> +payload type field<br /> + <a href="#anchor18">4.6.</a> +payload<br /> + <a href="#anchor19">4.7.</a> +padding (OPTIONAL)<br /> + <a href="#anchor20">4.8.</a> +padding count (OPTIONAL)<br /> + <a href="#anchor21">4.9.</a> +MKI (OPTIONAL)<br /> + <a href="#anchor22">4.10.</a> +authentication tag (RECOMMENDED)<br /> + <a href="#anchor23">4.11.</a> +Encryption<br /> +<a href="#anchor24">5.</a> +Security Considerations<br /> + <a href="#anchor25">5.1.</a> +Replay protection<br /> +<a href="#anchor26">6.</a> +IANA Considerations<br /> +<a href="#rfc.references1">7.</a> +References<br /> + <a href="#rfc.references1">7.1.</a> +Normative References<br /> + <a href="#rfc.references2">7.2.</a> +Informational References<br /> +<a href="#rfc.authors">§</a> +Author's Address<br /> +<a href="#rfc.copyright">§</a> +Intellectual Property and Copyright Statements<br /> +</p> +<br clear="all" /> + +<a name="anchor1"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.1"></a><h3>1. +Introduction</h3> + +<p>SATP is a mixture of a generic encapsulation protocol like <a class='info' href='#RFC2784'>GRE<span> (</span><span class='info'>Farinacci, D., Li, T., Hanks, S., Meyer, D., and P. Traina, “Generic Routing Encapsulation (GRE),” March 2000.</span><span>)</span></a> [4] and a secure tunneling protocol as <a class='info' href='#RFC2401'>IPsec<span> (</span><span class='info'>Kent, S. and R. Atkinson, “Security Architecture for the Internet Protocol,” November 1998.</span><span>)</span></a> [5] in tunnel mode. It can be used to build redundant virtual private network (VPN) connections. It supports peer to peer tunnels, where tunnel endpoints can be any combination of unicast, multicast or anycast hosts, so it defines a <a class='info' href='#RFC1546'>Host Anycast Service<span> (</span><span class='info'>Partridge, C., Mendez, T., and W. Milliken, “Host Anycasting Service,” November 1993.</span><span>)</span></a> [6]. Encryption is done per packet, so the protocol is robust against packet loss and routing changes. + To save some header overhead it uses the encryption techniques of <a class='info' href='#RFC3711'>SRTP<span> (</span><span class='info'>Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, “The Secure Real-time Transport Protocol (SRTP),” March 2004.</span><span>)</span></a> [1]. + +</p> +<a name="anchor2"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.1.1"></a><h3>1.1. +Notational Conventions</h3> + +<p>The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in <a class='info' href='#RFC2119'>RFC2119<span> (</span><span class='info'>Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” March 1997.</span><span>)</span></a> [2]. +</p> +<a name="anchor3"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.2"></a><h3>2. +Motivation and usage scenarios</h3> + +<p>This section gives an overview of possible usage scenarios. Please note, that the protocols used in the figures are only examples and that SATP itself does not care about either transport protocols or encapsulated protocols. Routing is not done by SATP and each implemetation MAY choose it's own way of doing this task (e.g. using functions provided by the operating system). SATP is used only to encapsulate and encrypt data. +</p> +<a name="anchor4"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.2.1"></a><h3>2.1. +Usage scenarions</h3> + +<a name="anchor5"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.2.1.1"></a><h3>2.1.1. +Tunneling from unicast hosts over anycast routers to other unicast hosts</h3> +<br /><hr class="insert" /> +<a name="tunnel_mode"></a> + +<p>An example of SATP used to tunnel in a unicast client - anycast server model +</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre> + --------- router ----------- + / \ + unicast ------+---------- router ------------+------ unicast + host \ / host + --------- router ----------- + + unicast | encrypted | anycast | encrypted | unicast + tunnel | communication | tunnel | communication | tunnel + endpoint | using SATP | endpoint | using SATP | endpoint +</pre></div><table border="0" cellpadding="0" cellspacing="2" align="center"><tr><td align="center"><font face="monaco, MS Sans Serif" size="1"><b> Figure 1 </b></font><br /></td></tr></table><hr class="insert" /> + +<p>In this scenario the payload gets encapsuleted into a SATP packet by a unicast host and gets transmitted to one of the anycast routers. It than gets decapsulated by the router. This router makes a routing descision based on the underlying protocol and transmits a new SATP package to one or more unicast hosts depending on the routing descition. +</p> +<a name="anchor6"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.2.1.2"></a><h3>2.1.2. +Tunneling from unicast hosts to anycast networks</h3> +<br /><hr class="insert" /> +<a name="open_tunnel_mode"></a> + +<p>An example of SATP used to encrypt data between a unicast host and anycast networks +</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre> + -------Router -+---- DNS Server + / \ + / --- 6to4 Router + / + unicast -------+----------Router --+--- DNS Server + host \ \ + \ --- 6to4 Router + \ + -------Router -+---- DNS Server + \ + --- 6to4 Router + + unicast | encrypted | anycast | plaintext + tunnel | communication | tunnel | anycast + endpoint | using SATP | endpoint | services + +</pre></div><table border="0" cellpadding="0" cellspacing="2" align="center"><tr><td align="center"><font face="monaco, MS Sans Serif" size="1"><b> Figure 2 </b></font><br /></td></tr></table><hr class="insert" /> + +<p>When the unicast hosts wants to transmit data to one of the anycast DNS servers, it encapsulates the data and sends a SATP packet to the anycast address of the routers. The packet arrives at one of the routers, gets decapsulated and routed to the DNS server. This method can be used to tunnel between a clients and networks providing anycast services. It can also be used the other way to virtually locate a unicast service within anycasted networks. +</p> +<a name="anchor7"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.2.1.3"></a><h3>2.1.3. +Redundant tunnel connection of 2 networks</h3> +<br /><hr class="insert" /> +<a name="connect_networks"></a> + +<p>An example of SATP used to connect 2 networks +</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre> + Router ----------- ---------------Router + / \ / \ + Network - Router ------------x Network + A \ / \ / B + Router ----------- ---------------Router + + | packets | packets | packets | + plaintext | get | take a | get | plaintext + packets | de/encrypted | random | de/encrypted | packets + |de/encapsulated| path |de/encapsulated| + +</pre></div><table border="0" cellpadding="0" cellspacing="2" align="center"><tr><td align="center"><font face="monaco, MS Sans Serif" size="1"><b> Figure 3 </b></font><br /></td></tr></table><hr class="insert" /> + +<p>Network A has multiple routers, that act as gateway/tunnel endpoints to another network B. This is done to build a redundant encrypted tunnel connection between the two networks. All tunnel endpoints of network A share the same anycast address and all tunnel endpoints of network B share another anycast address. When a packet from network A gets transmitted to network B, it first arrives on one of network A's border routers. Which router is used is determined by network A's internal routing. This router encapsulates the package and sends it to the anycast address of the network B routers. The SATP packet arrives at one of network B's routers and gets decapsulated and routed to it's destination within network B. +</p> +<a name="anchor8"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.2.2"></a><h3>2.2. +Encapsulation</h3> + +<p>SATP does not depend on which lower layer protocols is used, but this section gives an example of how packets could look like. + +</p><br /><hr class="insert" /> +<a name="transport_udp"></a> + +<p>Examples of SATP used with different lower layer and payload protocols +</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre> + +------+-----+-------------------------------+ + | | | +----------------+-----+ | + | IPv6 | UDP | SATP | Ethernet 802.3 | ... | | + | | | +----------------+-----+ | + +------+-----+-------------------------------+ + +Tunneling of Ethernet over UDP/IPv6 + + +------+-----+---------------------------+ + | | | +------+-----+-----+ | + | IPv4 | UDP | SATP | IPv6 | UDP | RTP | | + | | | +------+-----+-----+ | + +------+-----+---------------------------+ + +Tunneling of IPv6 over UDP/IPv4 with RTP payload + + +------+-------------------------------+ + | | +----------------+-----+ | + | IPv6 | SATP | Ethernet 802.3 | ... | | + | | +----------------+-----+ | + +------+-------------------------------+ + +Tunneling of Ethernet over IPv6 + + +------+---------------------------+ + | | +------+-----+-----+ | + | IPv4 | SATP | IPv6 | UDP | RTP | | + | | +------+-----+-----+ | + +------+---------------------------+ + +Tunneling of IPv6 over IPv4 with RTP payload +</pre></div><table border="0" cellpadding="0" cellspacing="2" align="center"><tr><td align="center"><font face="monaco, MS Sans Serif" size="1"><b> Figure 4 </b></font><br /></td></tr></table><hr class="insert" /> + +<a name="anchor9"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.3"></a><h3>3. +Using SATP on top of IP</h3> + +<a name="anchor10"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.3.1"></a><h3>3.1. +Fragmentation</h3> + +<p> + The only way of fully supporting fragmentation would be to synchronise fragments between all anycast servers. This is considered to be too much overhead, so there are two non perfect solutions for these problems. Either fragmentation HAS TO be disabled or if not all fragments arrive at the same server the ip datagramm HAS TO be discarded. As routing changes are not expected to occure very frequently, the encapsulated protocol can do a retransmission and all fragments will arrive at the new server. + +</p> +<p>If the payload type is IP and the ip headers's Don't Fragment (DF) bit is set, than the DF bit of the outer IP header HAS TO be set as well. +</p> +<a name="anchor11"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.3.2"></a><h3>3.2. +ICMP messages</h3> + +<p>ICMP messages MUST be relayed according to <a class='info' href='#RFC2003'>rfc2003 section 4<span> (</span><span class='info'>Perkins, C., “IP Encapsulation within IP,” October 1996.</span><span>)</span></a> [3]. This is needed for path MTU detection. +</p> +<a name="anchor12"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.4"></a><h3>4. +Protocol specification</h3> + +<a name="anchor13"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.4.1"></a><h3>4.1. +Header format</h3> +<br /><hr class="insert" /> +<a name="prot_header_table"></a> + +<p>Protocol Format +</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre> + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | sequence number | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | + | sender ID | MUX | | + +#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+ | + | | payload type | | | + | +-------------------------------+ | | + | | .... payload ... | | + | | +-------------------------------+ | + | | | padding (OPT) | pad count(OPT)| | + +#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+-+ + | ~ MKI (OPTIONAL) ~ | + | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | + | : authentication tag (RECOMMENDED) : | + | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | + | | + +- Encrypted Portion Authenticated Portion ---+ +</pre></div><table border="0" cellpadding="0" cellspacing="2" align="center"><tr><td align="center"><font face="monaco, MS Sans Serif" size="1"><b> Figure 5 </b></font><br /></td></tr></table><hr class="insert" /> + +<p> +</p> +<a name="anchor14"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.4.2"></a><h3>4.2. +sequence number</h3> + +<p>The sequence number is a 32 bit unsigned integer in network byte order. It starts with a random value and is increased by 1 for every sent packet. After the maximum value, it starts over from 0. This overrun causes the ROC to be increased. +</p> +<a name="anchor15"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.4.3"></a><h3>4.3. +sender ID</h3> + +<p>The sender ID is a 16 bit unsigned integer. It HAS TO be unique for every sender sharing the same anycast address +</p> +<a name="anchor16"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.4.4"></a><h3>4.4. +MUX</h3> + +<p>The MUX (multiplex) field is a 16 bit unsigned integer. It is used to destinguish multible tunnel connections. +</p> +<a name="anchor17"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.4.5"></a><h3>4.5. +payload type field</h3> + +<p>The payload type field defines the payload protocol. ETHER TYPE protocol numbers are used. <a href='http://www.iana.org/assignments/ethernet-numbers'>See IANA assigned ethernet numbers</a> . The values 0000-05DC are reserverd and MUST NOT be used. + <br /><hr class="insert" /> +<a name="prot_type_table"></a> + +<p>Some examples for protocol types +</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre> +HEX +0000 Reserved +.... Reserved +05DC Reserved +0800 Internet IP (IPv4) +6558 transparent ethernet bridging +86DD IPv6 +</pre></div><table border="0" cellpadding="0" cellspacing="2" align="center"><tr><td align="center"><font face="monaco, MS Sans Serif" size="1"><b> Figure 6 </b></font><br /></td></tr></table><hr class="insert" /> + + + +<a name="anchor18"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.4.6"></a><h3>4.6. +payload</h3> + +<p>A packet of the type payload type (e.g. an IP packet). +</p> +<a name="anchor19"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.4.7"></a><h3>4.7. +padding (OPTIONAL)</h3> + +<p>Padding of max 255 octets. +None of the pre-defined encryption transforms uses any padding; for + these, the plaintext and encrypted payload sizes match exactly. Transforms are based on transforms of the SRTP protocol and these transforms might use the RTP padding format, so a RTP like padding is supported. If the padding count field is present, than the padding count field MUST be set to the padding lenght. +</p> +<a name="anchor20"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.4.8"></a><h3>4.8. +padding count (OPTIONAL)</h3> + +<p>The number of octets of the padding field. This field is optional. It's presence is signaled by the key management and not by this protocol. If this field isn't present, the padding field MUST NOT be present as well. +</p> +<a name="anchor21"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.4.9"></a><h3>4.9. +MKI (OPTIONAL)</h3> + +<p>The MKI (Master Key Identifier) is OPTIONAL and of configurable length. See <a class='info' href='#RFC3711'>SRTP Section 3.1<span> (</span><span class='info'>Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, “The Secure Real-time Transport Protocol (SRTP),” March 2004.</span><span>)</span></a> [1] for details +</p> +<a name="anchor22"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.4.10"></a><h3>4.10. +authentication tag (RECOMMENDED)</h3> + +<p>The authentication tag is RECOMMENDED and of configurable length. It contains a cryptographic checksum of the sender ID, sequence number and the encrypted portion, but not of the MKI. On sender side encryption HAS TO be done before calculating the authentication tag. A receiver HAS TO calculate the authentication tag before decrypting the encrypted portion. +</p> +<a name="anchor23"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.4.11"></a><h3>4.11. +Encryption</h3> + +<p>Encryption is done in the same way as for <a class='info' href='#RFC3711'>SRTP<span> (</span><span class='info'>Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, “The Secure Real-time Transport Protocol (SRTP),” March 2004.</span><span>)</span></a> [1]. This section will only discuss some small changes that HAVE TO be made. Please read <a class='info' href='#RFC3711'>SRTP RFC3711 section 3-9<span> (</span><span class='info'>Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, “The Secure Real-time Transport Protocol (SRTP),” March 2004.</span><span>)</span></a> [1] for details. +</p> +<p>The least significant bits of SSRC are replaced by the sender ID and the rest is filled with zeros. For the SRTP SEQ the 16 least significant bits of the SATP sequence number are used and the 16 most significant bits of the sequence number replace the 16 least significant bits of the SRTP ROC. +</p><br /><hr class="insert" /> +<a name="srtp_vs_satp"></a> + +<p>Difference between SRTP and SATP +</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre> + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | SATP sequence number | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + = + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | SRTP ROC least significant | SRTP SEQ | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | SATP MUX | SATP sender ID | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + = + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | SRTP SSRC | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +</pre></div><table border="0" cellpadding="0" cellspacing="2" align="center"><tr><td align="center"><font face="monaco, MS Sans Serif" size="1"><b> Figure 7 </b></font><br /></td></tr></table><hr class="insert" /> + +<a name="anchor24"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.5"></a><h3>5. +Security Considerations</h3> + +<p>As SATP uses the same encrytion technics as <a class='info' href='#RFC3711'>SRTP<span> (</span><span class='info'>Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, “The Secure Real-time Transport Protocol (SRTP),” March 2004.</span><span>)</span></a> [1], it shares the same security issues. This section will only discuss some small changes. Please read <a class='info' href='#RFC3711'>SRTP RFC3711 section 9<span> (</span><span class='info'>Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, “The Secure Real-time Transport Protocol (SRTP),” March 2004.</span><span>)</span></a> [1] for details. +</p> +<a name="anchor25"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.5.1"></a><h3>5.1. +Replay protection</h3> + +<p>Replay protection is done by a replay list. Every anycast receiver has it's own replay list, which SHOULDN'T be syncronised, because of massive overhead. This leads to an additional possible attack. A attacker is able to replay a captured packet once to every anycast receiver. This attack is considered of be very unlikely, because multiple attack hosts in different loactions are needed to reach the seperate anycast receivers and the number of replays is limited to the count of receivers - 1. Such replays might also happen because of routing problems, so a payload protocol HAS TO be robust against a small number of duplicated packages. The window size and position HAS TO be syncronised between multible anycast receivers to limit this attack. +</p> +<a name="anchor26"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.6"></a><h3>6. +IANA Considerations</h3> + +<p>The protocol is intended to be used on top of IP or on top of UDP (to be compatible with NAT routers), so UDP and IP protocol numbers have to be assiged by IANA. +</p> +<a name="rfc.references"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<a name="rfc.section.7"></a><h3>7. +References</h3> + +<a name="rfc.references1"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<h3>7.1. Normative References</h3> +<table width="99%" border="0"> +<tr><td class="author-text" valign="top"><a name="RFC3711">[1]</a></td> +<td class="author-text">Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, “<a href="ftp://ftp.isi.edu/in-notes/rfc3711.txt">The Secure Real-time Transport Protocol (SRTP)</a>,” RFC 3711, March 2004.</td></tr> +<tr><td class="author-text" valign="top"><a name="RFC2119">[2]</a></td> +<td class="author-text"><a href="mailto:sob@harvard.edu">Bradner, S.</a>, “<a href="ftp://ftp.isi.edu/in-notes/rfc2119.txt">Key words for use in RFCs to Indicate Requirement Levels</a>,” BCP 14, RFC 2119, March 1997 (<a href="ftp://ftp.isi.edu/in-notes/rfc2119.txt">TXT</a>, <a href="http://xml.resource.org/public/rfc/html/rfc2119.html">HTML</a>, <a href="http://xml.resource.org/public/rfc/xml/rfc2119.xml">XML</a>).</td></tr> +<tr><td class="author-text" valign="top"><a name="RFC2003">[3]</a></td> +<td class="author-text"><a href="mailto:perk@watson.ibm.com">Perkins, C.</a>, “<a href="ftp://ftp.isi.edu/in-notes/rfc2003.txt">IP Encapsulation within IP</a>,” RFC 2003, October 1996 (<a href="ftp://ftp.isi.edu/in-notes/rfc2003.txt">TXT</a>, <a href="http://xml.resource.org/public/rfc/html/rfc2003.html">HTML</a>, <a href="http://xml.resource.org/public/rfc/xml/rfc2003.xml">XML</a>).</td></tr> +</table> + +<a name="rfc.references2"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<h3>7.2. Informational References</h3> +<table width="99%" border="0"> +<tr><td class="author-text" valign="top"><a name="RFC2784">[4]</a></td> +<td class="author-text"><a href="mailto:dino@procket.com">Farinacci, D.</a>, <a href="mailto:tony1@home.net">Li, T.</a>, <a href="mailto:stan_hanks@enron.net">Hanks, S.</a>, <a href="mailto:dmm@cisco.com">Meyer, D.</a>, and <a href="mailto:pst@juniper.net">P. Traina</a>, “<a href="ftp://ftp.isi.edu/in-notes/rfc2784.txt">Generic Routing Encapsulation (GRE)</a>,” RFC 2784, March 2000.</td></tr> +<tr><td class="author-text" valign="top"><a name="RFC2401">[5]</a></td> +<td class="author-text"><a href="mailto:kent@bbn.com">Kent, S.</a> and <a href="mailto:rja@corp.home.net">R. Atkinson</a>, “<a href="ftp://ftp.isi.edu/in-notes/rfc2401.txt">Security Architecture for the Internet Protocol</a>,” RFC 2401, November 1998 (<a href="ftp://ftp.isi.edu/in-notes/rfc2401.txt">TXT</a>, <a href="http://xml.resource.org/public/rfc/html/rfc2401.html">HTML</a>, <a href="http://xml.resource.org/public/rfc/xml/rfc2401.xml">XML</a>).</td></tr> +<tr><td class="author-text" valign="top"><a name="RFC1546">[6]</a></td> +<td class="author-text"><a href="mailto:craig@bbn.com">Partridge, C.</a>, <a href="mailto:tmendez@bbn.com">Mendez, T.</a>, and <a href="mailto:milliken@bbn.com">W. Milliken</a>, “<a href="ftp://ftp.isi.edu/in-notes/rfc1546.txt">Host Anycasting Service</a>,” RFC 1546, November 1993.</td></tr> +</table> + +<a name="rfc.authors"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<h3>Author's Address</h3> +<table width="99%" border="0" cellpadding="0" cellspacing="0"> +<tr><td class="author-text"> </td> +<td class="author-text">Othmar Gsenger</td></tr> +<tr><td class="author-text"> </td> +<td class="author-text">Puerstingerstr 32</td></tr> +<tr><td class="author-text"> </td> +<td class="author-text">Saalfelden 5760</td></tr> +<tr><td class="author-text"> </td> +<td class="author-text">AT</td></tr> +<tr><td class="author" align="right">Phone: </td> +<td class="author-text"></td></tr> +<tr><td class="author" align="right">Email: </td> +<td class="author-text"><a href="mailto:satp@gsenger.com">satp@gsenger.com</a></td></tr> +<tr><td class="author" align="right">URI: </td> +<td class="author-text"><a href="http://www.gsenger.com/satp/">http://www.gsenger.com/satp/</a></td></tr> +</table> +<a name="rfc.copyright"></a><br /><hr /> +<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table> +<h3>Full Copyright Statement</h3> +<p class='copyright'> +Copyright © The Internet Society (2008).</p> +<p class='copyright'> +This document is subject to the rights, +licenses and restrictions contained in BCP 78, +and except as set forth therein, +the authors retain all their rights.</p> +<p class='copyright'> +This document and the information contained herein are provided +on an “AS IS” basis and THE CONTRIBUTOR, +THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), +THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM +ALL WARRANTIES, +EXPRESS OR IMPLIED, +INCLUDING 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.</p> +<h3>Intellectual Property</h3> +<p class='copyright'> +The IETF takes no position regarding the validity or scope of any +Intellectual Property Rights or other rights that might be claimed +to pertain to the implementation or use of the technology +described in this document or the extent to which any license +under such rights might or might not be available; nor does it +represent that it has made any independent effort to identify any +such rights. +Information on the procedures with respect to +rights in RFC documents can be found in BCP 78 and BCP 79.</p> +<p class='copyright'> +Copies of IPR disclosures made to the IETF Secretariat and any +assurances of licenses to be made available, +or the result of an attempt made to obtain a general license or +permission for the use of such proprietary rights by implementers or +users of this specification can be obtained from the IETF on-line IPR +repository at <a href='http://www.ietf.org/ipr'>http://www.ietf.org/ipr</a>.</p> +<p class='copyright'> +The IETF invites any interested party to bring to its attention +any copyrights, +patents or patent applications, +or other +proprietary rights that may cover technology that may be required +to implement this standard. +Please address the information to the IETF at <a href='mailto:ietf-ipr@ietf.org'>ietf-ipr@ietf.org</a>.</p> +<h3>Acknowledgment</h3> +<p class='copyright'> +Funding for the RFC Editor function is provided by +the IETF Administrative Support Activity (IASA).</p> +</body></html> diff --git a/draft-gsenger-secure-anycast-tunneling-protocol-02.txt b/draft-gsenger-secure-anycast-tunneling-protocol-02.txt new file mode 100644 index 0000000..994847f --- /dev/null +++ b/draft-gsenger-secure-anycast-tunneling-protocol-02.txt @@ -0,0 +1,952 @@ + + + +Network Working Group O. Gsenger +Internet-Draft January 2008 +Intended status: Informational +Expires: July 4, 2008 + + + secure anycast tunneling protocol (SATP) + draft-gsenger-secure-anycast-tunneling-protocol-01 + +Status of this Memo + + By submitting this Internet-Draft, each author represents that any + applicable patent or other IPR claims of which he or she is aware + have been or will be disclosed, and any of which he or she becomes + aware will be disclosed, in accordance with Section 6 of BCP 79. + + 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." + + The list of current Internet-Drafts can be accessed at + http://www.ietf.org/ietf/1id-abstracts.txt. + + The list of Internet-Draft Shadow Directories can be accessed at + http://www.ietf.org/shadow.html. + + This Internet-Draft will expire on July 4, 2008. + +Copyright Notice + + Copyright (C) The Internet Society (2008). + + + + + + + + + + + + + + +Gsenger Expires July 4, 2008 [Page 1] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + +Abstract + + The secure anycast tunneling protocol (SATP) defines a protocol used + for communication between any combination of unicast and anycast + tunnel endpoints. It allows tunneling of every ETHER TYPE protocol + (ethernet, ip ...). SATP directly includes cryptography and message + authentication based on the methodes used by SRTP. It can be used as + an encrypted alternative to IP Encapsulation within IP [3] and + Generic Routing Encapsulation (GRE) [4]. It supports both anycast + receivers and senders. + + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 1.1. Notational Conventions . . . . . . . . . . . . . . . . . . 3 + 2. Motivation and usage scenarios . . . . . . . . . . . . . . . . 4 + 2.1. Usage scenarions . . . . . . . . . . . . . . . . . . . . . 4 + 2.1.1. Tunneling from unicast hosts over anycast routers + to other unicast hosts . . . . . . . . . . . . . . . . 4 + 2.1.2. Tunneling from unicast hosts to anycast networks . . . 5 + 2.1.3. Redundant tunnel connection of 2 networks . . . . . . 5 + 2.2. Encapsulation . . . . . . . . . . . . . . . . . . . . . . 6 + 3. Using SATP on top of IP . . . . . . . . . . . . . . . . . . . 8 + 3.1. Fragmentation . . . . . . . . . . . . . . . . . . . . . . 8 + 3.2. ICMP messages . . . . . . . . . . . . . . . . . . . . . . 8 + 4. Protocol specification . . . . . . . . . . . . . . . . . . . . 9 + 4.1. Header format . . . . . . . . . . . . . . . . . . . . . . 9 + 4.2. sequence number . . . . . . . . . . . . . . . . . . . . . 9 + 4.3. sender ID . . . . . . . . . . . . . . . . . . . . . . . . 9 + 4.4. MUX . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 + 4.5. payload type field . . . . . . . . . . . . . . . . . . . . 10 + 4.6. payload . . . . . . . . . . . . . . . . . . . . . . . . . 10 + 4.7. padding (OPTIONAL) . . . . . . . . . . . . . . . . . . . . 10 + 4.8. padding count (OPTIONAL) . . . . . . . . . . . . . . . . . 10 + 4.9. MKI (OPTIONAL) . . . . . . . . . . . . . . . . . . . . . . 10 + 4.10. authentication tag (RECOMMENDED) . . . . . . . . . . . . . 10 + 4.11. Encryption . . . . . . . . . . . . . . . . . . . . . . . . 11 + 5. Security Considerations . . . . . . . . . . . . . . . . . . . 12 + 5.1. Replay protection . . . . . . . . . . . . . . . . . . . . 12 + 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 + 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14 + 7.1. Normative References . . . . . . . . . . . . . . . . . . . 14 + 7.2. Informational References . . . . . . . . . . . . . . . . . 14 + Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 16 + Intellectual Property and Copyright Statements . . . . . . . . . . 17 + + + + + +Gsenger Expires July 4, 2008 [Page 2] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + +1. Introduction + + SATP is a mixture of a generic encapsulation protocol like GRE [4] + and a secure tunneling protocol as IPsec [5] in tunnel mode. It can + be used to build redundant virtual private network (VPN) connections. + It supports peer to peer tunnels, where tunnel endpoints can be any + combination of unicast, multicast or anycast hosts, so it defines a + Host Anycast Service [6]. Encryption is done per packet, so the + protocol is robust against packet loss and routing changes. To save + some header overhead it uses the encryption techniques of SRTP [1]. + +1.1. Notational Conventions + + The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this + document are to be interpreted as described in RFC2119 [2]. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Gsenger Expires July 4, 2008 [Page 3] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + +2. Motivation and usage scenarios + + This section gives an overview of possible usage scenarios. Please + note, that the protocols used in the figures are only examples and + that SATP itself does not care about either transport protocols or + encapsulated protocols. Routing is not done by SATP and each + implemetation MAY choose it's own way of doing this task (e.g. using + functions provided by the operating system). SATP is used only to + encapsulate and encrypt data. + +2.1. Usage scenarions + +2.1.1. Tunneling from unicast hosts over anycast routers to other + unicast hosts + + An example of SATP used to tunnel in a unicast client - anycast + server model + + --------- router ----------- + / \ + unicast ------+---------- router ------------+------ unicast + host \ / host + --------- router ----------- + + unicast | encrypted | anycast | encrypted | unicast + tunnel | communication | tunnel | communication | tunnel + endpoint | using SATP | endpoint | using SATP | endpoint + + Figure 1 + + In this scenario the payload gets encapsuleted into a SATP packet by + a unicast host and gets transmitted to one of the anycast routers. + It than gets decapsulated by the router. This router makes a routing + descision based on the underlying protocol and transmits a new SATP + package to one or more unicast hosts depending on the routing + descition. + + + + + + + + + + + + + + + +Gsenger Expires July 4, 2008 [Page 4] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + +2.1.2. Tunneling from unicast hosts to anycast networks + + An example of SATP used to encrypt data between a unicast host and + anycast networks + + -------Router -+---- DNS Server + / \ + / --- 6to4 Router + / + unicast -------+----------Router --+--- DNS Server + host \ \ + \ --- 6to4 Router + \ + -------Router -+---- DNS Server + \ + --- 6to4 Router + + unicast | encrypted | anycast | plaintext + tunnel | communication | tunnel | anycast + endpoint | using SATP | endpoint | services + + + Figure 2 + + When the unicast hosts wants to transmit data to one of the anycast + DNS servers, it encapsulates the data and sends a SATP packet to the + anycast address of the routers. The packet arrives at one of the + routers, gets decapsulated and routed to the DNS server. This method + can be used to tunnel between a clients and networks providing + anycast services. It can also be used the other way to virtually + locate a unicast service within anycasted networks. + +2.1.3. Redundant tunnel connection of 2 networks + + An example of SATP used to connect 2 networks + + Router ----------- ---------------Router + / \ / \ + Network - Router ------------x Network + A \ / \ / B + Router ----------- ---------------Router + + | packets | packets | packets | + plaintext | get | take a | get | plaintext + packets | de/encrypted | random | de/encrypted | packets + |de/encapsulated| path |de/encapsulated| + + + + + +Gsenger Expires July 4, 2008 [Page 5] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + + Figure 3 + + Network A has multiple routers, that act as gateway/tunnel endpoints + to another network B. This is done to build a redundant encrypted + tunnel connection between the two networks. All tunnel endpoints of + network A share the same anycast address and all tunnel endpoints of + network B share another anycast address. When a packet from network + A gets transmitted to network B, it first arrives on one of network + A's border routers. Which router is used is determined by network + A's internal routing. This router encapsulates the package and sends + it to the anycast address of the network B routers. The SATP packet + arrives at one of network B's routers and gets decapsulated and + routed to it's destination within network B. + +2.2. Encapsulation + + SATP does not depend on which lower layer protocols is used, but this + section gives an example of how packets could look like. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Gsenger Expires July 4, 2008 [Page 6] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + + Examples of SATP used with different lower layer and payload + protocols + + +------+-----+-------------------------------+ + | | | +----------------+-----+ | + | IPv6 | UDP | SATP | Ethernet 802.3 | ... | | + | | | +----------------+-----+ | + +------+-----+-------------------------------+ + + Tunneling of Ethernet over UDP/IPv6 + + +------+-----+---------------------------+ + | | | +------+-----+-----+ | + | IPv4 | UDP | SATP | IPv6 | UDP | RTP | | + | | | +------+-----+-----+ | + +------+-----+---------------------------+ + + Tunneling of IPv6 over UDP/IPv4 with RTP payload + + +------+-------------------------------+ + | | +----------------+-----+ | + | IPv6 | SATP | Ethernet 802.3 | ... | | + | | +----------------+-----+ | + +------+-------------------------------+ + + Tunneling of Ethernet over IPv6 + + +------+---------------------------+ + | | +------+-----+-----+ | + | IPv4 | SATP | IPv6 | UDP | RTP | | + | | +------+-----+-----+ | + +------+---------------------------+ + + Tunneling of IPv6 over IPv4 with RTP payload + + Figure 4 + + + + + + + + + + + + + + + +Gsenger Expires July 4, 2008 [Page 7] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + +3. Using SATP on top of IP + +3.1. Fragmentation + + The only way of fully supporting fragmentation would be to + synchronise fragments between all anycast servers. This is + considered to be too much overhead, so there are two non perfect + solutions for these problems. Either fragmentation HAS TO be + disabled or if not all fragments arrive at the same server the ip + datagramm HAS TO be discarded. As routing changes are not expected + to occure very frequently, the encapsulated protocol can do a + retransmission and all fragments will arrive at the new server. + + If the payload type is IP and the ip headers's Don't Fragment (DF) + bit is set, than the DF bit of the outer IP header HAS TO be set as + well. + +3.2. ICMP messages + + ICMP messages MUST be relayed according to rfc2003 section 4 [3]. + This is needed for path MTU detection. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Gsenger Expires July 4, 2008 [Page 8] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + +4. Protocol specification + +4.1. Header format + + Protocol Format + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | sequence number | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | + | sender ID | MUX | | + +#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+ | + | | payload type | | | + | +-------------------------------+ | | + | | .... payload ... | | + | | +-------------------------------+ | + | | | padding (OPT) | pad count(OPT)| | + +#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+-+ + | ~ MKI (OPTIONAL) ~ | + | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | + | : authentication tag (RECOMMENDED) : | + | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | + | | + +- Encrypted Portion Authenticated Portion ---+ + + Figure 5 + +4.2. sequence number + + The sequence number is a 32 bit unsigned integer in network byte + order. It starts with a random value and is increased by 1 for every + sent packet. After the maximum value, it starts over from 0. This + overrun causes the ROC to be increased. + +4.3. sender ID + + The sender ID is a 16 bit unsigned integer. It HAS TO be unique for + every sender sharing the same anycast address + +4.4. MUX + + The MUX (multiplex) field is a 16 bit unsigned integer. It is used + to destinguish multible tunnel connections. + + + + + + + +Gsenger Expires July 4, 2008 [Page 9] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + +4.5. payload type field + + The payload type field defines the payload protocol. ETHER TYPE + protocol numbers are used. See IANA assigned ethernet numbers [7] . + The values 0000-05DC are reserverd and MUST NOT be used. + + Some examples for protocol types + + HEX + 0000 Reserved + .... Reserved + 05DC Reserved + 0800 Internet IP (IPv4) + 6558 transparent ethernet bridging + 86DD IPv6 + + Figure 6 + +4.6. payload + + A packet of the type payload type (e.g. an IP packet). + +4.7. padding (OPTIONAL) + + Padding of max 255 octets. None of the pre-defined encryption + transforms uses any padding; for these, the plaintext and encrypted + payload sizes match exactly. Transforms are based on transforms of + the SRTP protocol and these transforms might use the RTP padding + format, so a RTP like padding is supported. If the padding count + field is present, than the padding count field MUST be set to the + padding lenght. + +4.8. padding count (OPTIONAL) + + The number of octets of the padding field. This field is optional. + It's presence is signaled by the key management and not by this + protocol. If this field isn't present, the padding field MUST NOT be + present as well. + +4.9. MKI (OPTIONAL) + + The MKI (Master Key Identifier) is OPTIONAL and of configurable + length. See SRTP Section 3.1 [1] for details + +4.10. authentication tag (RECOMMENDED) + + The authentication tag is RECOMMENDED and of configurable length. It + contains a cryptographic checksum of the sender ID, sequence number + + + +Gsenger Expires July 4, 2008 [Page 10] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + + and the encrypted portion, but not of the MKI. On sender side + encryption HAS TO be done before calculating the authentication tag. + A receiver HAS TO calculate the authentication tag before decrypting + the encrypted portion. + +4.11. Encryption + + Encryption is done in the same way as for SRTP [1]. This section + will only discuss some small changes that HAVE TO be made. Please + read SRTP RFC3711 section 3-9 [1] for details. + + The least significant bits of SSRC are replaced by the sender ID and + the rest is filled with zeros. For the SRTP SEQ the 16 least + significant bits of the SATP sequence number are used and the 16 most + significant bits of the sequence number replace the 16 least + significant bits of the SRTP ROC. + + Difference between SRTP and SATP + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | SATP sequence number | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + = + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | SRTP ROC least significant | SRTP SEQ | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | SATP MUX | SATP sender ID | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + = + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | SRTP SSRC | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + Figure 7 + + + + + + + + + + +Gsenger Expires July 4, 2008 [Page 11] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + +5. Security Considerations + + As SATP uses the same encrytion technics as SRTP [1], it shares the + same security issues. This section will only discuss some small + changes. Please read SRTP RFC3711 section 9 [1] for details. + +5.1. Replay protection + + Replay protection is done by a replay list. Every anycast receiver + has it's own replay list, which SHOULDN'T be syncronised, because of + massive overhead. This leads to an additional possible attack. A + attacker is able to replay a captured packet once to every anycast + receiver. This attack is considered of be very unlikely, because + multiple attack hosts in different loactions are needed to reach the + seperate anycast receivers and the number of replays is limited to + the count of receivers - 1. Such replays might also happen because + of routing problems, so a payload protocol HAS TO be robust against a + small number of duplicated packages. The window size and position + HAS TO be syncronised between multible anycast receivers to limit + this attack. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Gsenger Expires July 4, 2008 [Page 12] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + +6. IANA Considerations + + The protocol is intended to be used on top of IP or on top of UDP (to + be compatible with NAT routers), so UDP and IP protocol numbers have + to be assiged by IANA. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Gsenger Expires July 4, 2008 [Page 13] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + +7. References + +7.1. Normative References + + [1] Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. + Norrman, "The Secure Real-time Transport Protocol (SRTP)", + RFC 3711, March 2004. + + [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement + Levels", BCP 14, RFC 2119, March 1997. + + [3] Perkins, C., "IP Encapsulation within IP", RFC 2003, + October 1996. + +7.2. Informational References + + [4] Farinacci, D., Li, T., Hanks, S., Meyer, D., and P. Traina, + "Generic Routing Encapsulation (GRE)", RFC 2784, March 2000. + + [5] Kent, S. and R. Atkinson, "Security Architecture for the + Internet Protocol", RFC 2401, November 1998. + + [6] Partridge, C., Mendez, T., and W. Milliken, "Host Anycasting + Service", RFC 1546, November 1993. + + + + + + + + + + + + + + + + + + + + + + + + + + + +Gsenger Expires July 4, 2008 [Page 14] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + +URIs + + [7] <http://www.iana.org/assignments/ethernet-numbers> + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Gsenger Expires July 4, 2008 [Page 15] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + +Author's Address + + Othmar Gsenger + Puerstingerstr 32 + Saalfelden 5760 + AT + + Phone: + Email: satp@gsenger.com + URI: http://www.gsenger.com/satp/ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Gsenger Expires July 4, 2008 [Page 16] + +Internet-Draft secure anycast tunneling protocol (SATP) January 2008 + + +Full Copyright Statement + + Copyright (C) The Internet Society (2008). + + This document is subject to the rights, licenses and restrictions + contained in BCP 78, and except as set forth therein, the authors + retain all their rights. + + This document and the information contained herein are provided on an + "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS + OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET + ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, + INCLUDING 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. + + +Intellectual Property + + The IETF takes no position regarding the validity or scope of any + Intellectual Property Rights or other rights that might be claimed to + pertain to the implementation or use of the technology described in + this document or the extent to which any license under such rights + might or might not be available; nor does it represent that it has + made any independent effort to identify any such rights. Information + on the procedures with respect to rights in RFC documents can be + found in BCP 78 and BCP 79. + + Copies of IPR disclosures made to the IETF Secretariat and any + assurances of licenses to be made available, or the result of an + attempt made to obtain a general license or permission for the use of + such proprietary rights by implementers or users of this + specification can be obtained from the IETF on-line IPR repository at + http://www.ietf.org/ipr. + + The IETF invites any interested party to bring to its attention any + copyrights, patents or patent applications, or other proprietary + rights that may cover technology that may be required to implement + this standard. Please address the information to the IETF at + ietf-ipr@ietf.org. + + +Acknowledgment + + Funding for the RFC Editor function is provided by the IETF + Administrative Support Activity (IASA). + + + + + +Gsenger Expires July 4, 2008 [Page 17] + diff --git a/draft-gsenger-secure-anycast-tunneling-protocol-02.xml b/draft-gsenger-secure-anycast-tunneling-protocol-02.xml new file mode 100644 index 0000000..4b76189 --- /dev/null +++ b/draft-gsenger-secure-anycast-tunneling-protocol-02.xml @@ -0,0 +1,299 @@ +<?xml version='1.0'?> + <!DOCTYPE rfc SYSTEM 'rfcXXXX.dtd' [ + + <!ENTITY rfc1546 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.1546.xml'> + <!ENTITY rfc3711 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.3711.xml'> + <!ENTITY rfc3068 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.3068.xml'> + <!ENTITY rfc2784 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.2784.xml'> + <!ENTITY rfc2401 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.2401.xml'> + <!ENTITY rfc2119 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml'> + <!ENTITY rfc2003 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.2003.xml'> +]> +<?rfc toc='yes'?> + <rfc ipr='full3978' docName='draft-gsenger-secure-anycast-tunneling-protocol-01'> + <front> + <title>secure anycast tunneling protocol (SATP)</title> + + <author initials='O.G.' surname='Gsenger' + fullname='Othmar Gsenger'> + <organization></organization> + + <address> + <postal> + <street>Puerstingerstr 32</street> + <city>Saalfelden</city> + <code>5760</code> + <country>AT</country> + </postal> + + <phone></phone> + <email>satp@gsenger.com</email> + <uri>http://www.gsenger.com/satp/</uri> + </address> + </author> + + <date month='January' year='2008' /> + + <area>General</area> + <workgroup></workgroup> + <keyword>satp</keyword> + <keyword>Internet-Draft</keyword> + <keyword>secure anycast tunneling protocol</keyword> + <keyword>anycast</keyword> + <keyword>tunnel</keyword> + <keyword>secure</keyword> + <keyword>protocol</keyword> + <abstract> + <t>The secure anycast tunneling protocol (SATP) defines a protocol used for communication between any combination of unicast and anycast tunnel endpoints. It allows tunneling of every ETHER TYPE protocol (ethernet, ip ...). SATP directly includes cryptography and message authentication based on the methodes used by SRTP. It can be used as an encrypted alternative to <xref target="RFC2003">IP Encapsulation within IP</xref> and <xref target="RFC2784">Generic Routing Encapsulation (GRE)</xref>. It supports both anycast receivers and senders. + </t> + </abstract> + </front> + <middle> + <section title='Introduction'> + <t>SATP is a mixture of a generic encapsulation protocol like <xref target="RFC2784">GRE</xref> and a secure tunneling protocol as <xref target="RFC2401">IPsec</xref> in tunnel mode. It can be used to build redundant virtual private network (VPN) connections. It supports peer to peer tunnels, where tunnel endpoints can be any combination of unicast, multicast or anycast hosts, so it defines a <xref target="RFC1546">Host Anycast Service</xref>. Encryption is done per packet, so the protocol is robust against packet loss and routing changes. + To save some header overhead it uses the encryption techniques of <xref target="RFC3711">SRTP</xref>. + </t> + <section title='Notational Conventions'> + <t>The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in <xref target="RFC2119">RFC2119</xref>.</t> + </section> + </section> + <section title="Motivation and usage scenarios"> + <t>This section gives an overview of possible usage scenarios. Please note, that the protocols used in the figures are only examples and that SATP itself does not care about either transport protocols or encapsulated protocols. Routing is not done by SATP and each implemetation MAY choose it's own way of doing this task (e.g. using functions provided by the operating system). SATP is used only to encapsulate and encrypt data.</t> + <section title="Usage scenarions"> + + <section title='Tunneling from unicast hosts over anycast routers to other unicast hosts'> + <figure anchor="tunnel_mode"> + <preamble>An example of SATP used to tunnel in a unicast client - anycast server model</preamble> + <artwork> + --------- router ----------- + / \ + unicast ------+---------- router ------------+------ unicast + host \ / host + --------- router ----------- + + unicast | encrypted | anycast | encrypted | unicast + tunnel | communication | tunnel | communication | tunnel + endpoint | using SATP | endpoint | using SATP | endpoint + </artwork> + </figure> + <t>In this scenario the payload gets encapsuleted into a SATP packet by a unicast host and gets transmitted to one of the anycast routers. It than gets decapsulated by the router. This router makes a routing descision based on the underlying protocol and transmits a new SATP package to one or more unicast hosts depending on the routing descition.</t> + </section> + + <section title='Tunneling from unicast hosts to anycast networks'> + <figure anchor="open_tunnel_mode"> + <preamble>An example of SATP used to encrypt data between a unicast host and anycast networks</preamble> + <artwork> + -------Router -+---- DNS Server + / \ + / --- 6to4 Router + / + unicast -------+----------Router --+--- DNS Server + host \ \ + \ --- 6to4 Router + \ + -------Router -+---- DNS Server + \ + --- 6to4 Router + + unicast | encrypted | anycast | plaintext + tunnel | communication | tunnel | anycast + endpoint | using SATP | endpoint | services + + </artwork> + </figure> + <t>When the unicast hosts wants to transmit data to one of the anycast DNS servers, it encapsulates the data and sends a SATP packet to the anycast address of the routers. The packet arrives at one of the routers, gets decapsulated and routed to the DNS server. This method can be used to tunnel between a clients and networks providing anycast services. It can also be used the other way to virtually locate a unicast service within anycasted networks.</t> + </section> + <section title='Redundant tunnel connection of 2 networks'> + <figure anchor="connect_networks"> + <preamble>An example of SATP used to connect 2 networks</preamble> + <artwork> + Router ----------- ---------------Router + / \ / \ + Network - Router ------------x Network + A \ / \ / B + Router ----------- ---------------Router + + | packets | packets | packets | + plaintext | get | take a | get | plaintext + packets | de/encrypted | random | de/encrypted | packets + |de/encapsulated| path |de/encapsulated| + + </artwork> + </figure> + + <t>Network A has multiple routers, that act as gateway/tunnel endpoints to another network B. This is done to build a redundant encrypted tunnel connection between the two networks. All tunnel endpoints of network A share the same anycast address and all tunnel endpoints of network B share another anycast address. When a packet from network A gets transmitted to network B, it first arrives on one of network A's border routers. Which router is used is determined by network A's internal routing. This router encapsulates the package and sends it to the anycast address of the network B routers. The SATP packet arrives at one of network B's routers and gets decapsulated and routed to it's destination within network B.</t> + </section> + </section> + <section title="Encapsulation"> + <t>SATP does not depend on which lower layer protocols is used, but this section gives an example of how packets could look like. + </t> + <figure anchor="transport_udp"> + <preamble>Examples of SATP used with different lower layer and payload protocols</preamble> + <artwork> + +------+-----+-------------------------------+ + | | | +----------------+-----+ | + | IPv6 | UDP | SATP | Ethernet 802.3 | ... | | + | | | +----------------+-----+ | + +------+-----+-------------------------------+ + +Tunneling of Ethernet over UDP/IPv6 + + +------+-----+---------------------------+ + | | | +------+-----+-----+ | + | IPv4 | UDP | SATP | IPv6 | UDP | RTP | | + | | | +------+-----+-----+ | + +------+-----+---------------------------+ + +Tunneling of IPv6 over UDP/IPv4 with RTP payload + + +------+-------------------------------+ + | | +----------------+-----+ | + | IPv6 | SATP | Ethernet 802.3 | ... | | + | | +----------------+-----+ | + +------+-------------------------------+ + +Tunneling of Ethernet over IPv6 + + +------+---------------------------+ + | | +------+-----+-----+ | + | IPv4 | SATP | IPv6 | UDP | RTP | | + | | +------+-----+-----+ | + +------+---------------------------+ + +Tunneling of IPv6 over IPv4 with RTP payload + </artwork> + </figure> + </section> + </section> + <section title="Using SATP on top of IP"> + <section title="Fragmentation"> + <t> + The only way of fully supporting fragmentation would be to synchronise fragments between all anycast servers. This is considered to be too much overhead, so there are two non perfect solutions for these problems. Either fragmentation HAS TO be disabled or if not all fragments arrive at the same server the ip datagramm HAS TO be discarded. As routing changes are not expected to occure very frequently, the encapsulated protocol can do a retransmission and all fragments will arrive at the new server. + </t><t>If the payload type is IP and the ip headers's Don't Fragment (DF) bit is set, than the DF bit of the outer IP header HAS TO be set as well.</t> + </section> + <section title="ICMP messages"> + <t>ICMP messages MUST be relayed according to <xref target="RFC2003">rfc2003 section 4</xref>. This is needed for path MTU detection.</t> + </section> + </section> + <section title="Protocol specification"> + <section title="Header format"> + <figure anchor="prot_header_table"> + <preamble>Protocol Format</preamble> + <artwork> + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | sequence number | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | + | sender ID | MUX | | + +#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+ | + | | payload type | | | + | +-------------------------------+ | | + | | .... payload ... | | + | | +-------------------------------+ | + | | | padding (OPT) | pad count(OPT)| | + +#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+-+ + | ~ MKI (OPTIONAL) ~ | + | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | + | : authentication tag (RECOMMENDED) : | + | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | + | | + +- Encrypted Portion Authenticated Portion ---+ +</artwork> +</figure> +<t></t> + </section> + <section title="sequence number"> + <t>The sequence number is a 32 bit unsigned integer in network byte order. It starts with a random value and is increased by 1 for every sent packet. After the maximum value, it starts over from 0. This overrun causes the ROC to be increased.</t> + </section> + <section title="sender ID"> + <t>The sender ID is a 16 bit unsigned integer. It HAS TO be unique for every sender sharing the same anycast address</t> + </section> + <section title="MUX"> + <t>The MUX (multiplex) field is a 16 bit unsigned integer. It is used to destinguish multible tunnel connections.</t> + </section> + <section title="payload type field"> + <t>The payload type field defines the payload protocol. ETHER TYPE protocol numbers are used. <eref target="http://www.iana.org/assignments/ethernet-numbers">See IANA assigned ethernet numbers</eref> . The values 0000-05DC are reserverd and MUST NOT be used. + <figure anchor="prot_type_table"> + <preamble>Some examples for protocol types</preamble> + <artwork> +HEX +0000 Reserved +.... Reserved +05DC Reserved +0800 Internet IP (IPv4) +6558 transparent ethernet bridging +86DD IPv6 +</artwork> +</figure> +</t> + </section> + <section title="payload"> + <t>A packet of the type payload type (e.g. an IP packet).</t> + </section> + <section title="padding (OPTIONAL)"> + <t>Padding of max 255 octets. +None of the pre-defined encryption transforms uses any padding; for + these, the plaintext and encrypted payload sizes match exactly. Transforms are based on transforms of the SRTP protocol and these transforms might use the RTP padding format, so a RTP like padding is supported. If the padding count field is present, than the padding count field MUST be set to the padding lenght.</t> + </section> + <section title="padding count (OPTIONAL)"> + <t>The number of octets of the padding field. This field is optional. It's presence is signaled by the key management and not by this protocol. If this field isn't present, the padding field MUST NOT be present as well.</t> + </section> + <section title="MKI (OPTIONAL)"> + <t>The MKI (Master Key Identifier) is OPTIONAL and of configurable length. See <xref target="RFC3711">SRTP Section 3.1</xref> for details</t> + </section> + <section title="authentication tag (RECOMMENDED)"> + <t>The authentication tag is RECOMMENDED and of configurable length. It contains a cryptographic checksum of the sender ID, sequence number and the encrypted portion, but not of the MKI. On sender side encryption HAS TO be done before calculating the authentication tag. A receiver HAS TO calculate the authentication tag before decrypting the encrypted portion.</t> + </section> + <section title="Encryption"> + <t>Encryption is done in the same way as for <xref target="RFC3711">SRTP</xref>. This section will only discuss some small changes that HAVE TO be made. Please read <xref target="RFC3711">SRTP RFC3711 section 3-9</xref> for details. </t><t>The least significant bits of SSRC are replaced by the sender ID and the rest is filled with zeros. For the SRTP SEQ the 16 least significant bits of the SATP sequence number are used and the 16 most significant bits of the sequence number replace the 16 least significant bits of the SRTP ROC.</t> + <figure anchor="srtp_vs_satp"> + <preamble>Difference between SRTP and SATP</preamble> + <artwork> + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | SATP sequence number | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + = + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | SRTP ROC least significant | SRTP SEQ | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | SATP MUX | SATP sender ID | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + = + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | SRTP SSRC | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + </artwork> + </figure> + </section> + </section> + <section title="Security Considerations"> + <t>As SATP uses the same encrytion technics as <xref target="RFC3711">SRTP</xref>, it shares the same security issues. This section will only discuss some small changes. Please read <xref target="RFC3711">SRTP RFC3711 section 9</xref> for details.</t> + <section title="Replay protection"> + <t>Replay protection is done by a replay list. Every anycast receiver has it's own replay list, which SHOULDN'T be syncronised, because of massive overhead. This leads to an additional possible attack. A attacker is able to replay a captured packet once to every anycast receiver. This attack is considered of be very unlikely, because multiple attack hosts in different loactions are needed to reach the seperate anycast receivers and the number of replays is limited to the count of receivers - 1. Such replays might also happen because of routing problems, so a payload protocol HAS TO be robust against a small number of duplicated packages. The window size and position HAS TO be syncronised between multible anycast receivers to limit this attack.</t> + </section> + </section> + <section title="IANA Considerations"> + <t>The protocol is intended to be used on top of IP or on top of UDP (to be compatible with NAT routers), so UDP and IP protocol numbers have to be assiged by IANA.</t> + </section> + </middle> + <back> + <references title="Normative References"> + &rfc3711; + &rfc2119; + &rfc2003; + </references> + <references title="Informational References"> + &rfc2784; + &rfc2401; + &rfc1546; + </references> + </back> + </rfc> |