MIP6 Working Group V. Devarapalli Internet-Draft Nokia Expires: August 24, 2005 February 20, 2005 Mobile IPv6 Operation with IKEv2 and the revised IPsec Architecture draft-ietf-mip6-ikev2-ipsec-01.txt Status of this Memo This document is an Internet-Draft and is subject to all provisions of Section 3 of RFC 3667. 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 become aware will be disclosed, in accordance with RFC 3668. 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 August 24, 2005. Copyright Notice Copyright (C) The Internet Society (2005). Abstract This document describes Mobile IPv6 operation with the revised IPsec architecture and IKEv2. Devarapalli Expires August 24, 2005 [Page 1]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. What is applicable from RFC 3776? . . . . . . . . . . . . . . 5 3.1 Packet Formats . . . . . . . . . . . . . . . . . . . . . . 5 3.2 Requirements . . . . . . . . . . . . . . . . . . . . . . . 5 3.2.1 Home Agent Requirements . . . . . . . . . . . . . . . 5 3.2.2 Mobile Node Requirements . . . . . . . . . . . . . . . 6 4. Manual Configuration . . . . . . . . . . . . . . . . . . . . . 7 4.1 Binding Update and Acknowledgements . . . . . . . . . . . 7 4.2 Return Routabililty Messages . . . . . . . . . . . . . . . 8 4.3 Mobile Prefix Discovery Messages . . . . . . . . . . . . . 9 4.4 Payload Packets . . . . . . . . . . . . . . . . . . . . . 10 5. Dynamic Configuration . . . . . . . . . . . . . . . . . . . . 11 5.1 Security Policy Database Entries . . . . . . . . . . . . . 11 5.1.1 Binding Updates and Acknowledgements . . . . . . . . . 11 5.1.2 Return Routability Messages . . . . . . . . . . . . . 12 5.1.3 Mobile Prefix Discovery Messages . . . . . . . . . . . 13 5.1.4 Payload Packets . . . . . . . . . . . . . . . . . . . 13 5.2 Security Association negotiation using IKEv2 . . . . . . . 14 6. The use of EAP authentication . . . . . . . . . . . . . . . . 17 7. Dynamic Home Address Configuration . . . . . . . . . . . . . . 19 8. Security Considerations . . . . . . . . . . . . . . . . . . . 21 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 23 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 24 11.1 Normative References . . . . . . . . . . . . . . . . . . . 24 11.2 Informative References . . . . . . . . . . . . . . . . . . 24 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 25 Intellectual Property and Copyright Statements . . . . . . . . 26 Devarapalli Expires August 24, 2005 [Page 2]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 1. Introduction RFC 3776 describes how IPsec [11] is used with Mobile IPv6 [2] to protect the signaling messages. It also illustrates examples of Security Policy Database and Security Association Database entries that can be used to protect Mobile IPv6 signaling messages. The IPsec architecture has been revised [5]. Among the many changes, the list of selectors has been expanded to included the Mobility Header message type. This has an impact on how security policies and security associations are configured for protecting mobility header messages. It becomes easier to differentiate between the various Mobility Header messages based on the type value instead of checking if a particular mobility header message is being sent on a tunnel interface between the mobile node and the home agent, as it was in RFC 3776. The revised IPsec architecture specification also includes ICMP message type and code as selectors. This makes it possible to protect Mobile Prefix Discovery messages without applying the same security associations to all ICMPv6 messages. This document discusses new requirements for the Home Agent and the mobile node to use the revised IPsec architecture and IKEv2. Section 3.2 lists the requirements. Section 3 describes the differences with RFC 3776. Section 4 describes the required Security Policy Database (SPD) and Security Association Database (SAD) entries. The Internet Key Exchange (IKE) has also been substantially revised and simplified [4]. This document describes how IKEv2 can be used to setup security associations for Mobile IPv6. The use of EAP within IKEv2 is allowed to authenticate the mobile node to the Home Agent. This is described in Section 6. A method for dynamically configuring a home address from the Home Agent using the Configuration Payload in IKEv2 is described in Section 7. Devarapalli Expires August 24, 2005 [Page 3]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [1]. Devarapalli Expires August 24, 2005 [Page 4]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 3. What is applicable from RFC 3776? 3.1 Packet Formats The mobile node and the Home Agent must support the packet formats as defined in Section 3 of RFC 3776. This document does not update the packet formats described in RFC 3776. 3.2 Requirements The mobile node and the Home Agent MUST support the requirements listed in Section 4 of RFC 3776 with the following exceptions. o It is not required to configure security policies per interface in order to protect return routability signaling messages. Since the Mobility Header message type is a selector, it is easy to differentiate HoTi and HoT messages from other Mobility Header messages. o It is necessary to avoid a condition where a mobile node could use its security association to send a Binding Update on behalf of another mobile node. With manual IPsec configuration, the Home Agent MUST be able to verify that a security association was created for a particular home address. With dynamic keying, it should be possible for the Home Agent to verify that the identity presented in the IKE_AUTH exchange is allowed to create security associations for a particular home address. o The mobile node should use its Care-of Address as source address in protocol exchanges, when using dynamic keying. However, the security associations MUST be created for the home address of the mobile node. o The mobile node and the Home Agent MUST create security associations based on the home address, so that the security associations survive change in Care-of Address. When using IKEv2 as the key exchange protocol, the home address should be carried in the TSi payload during the CREATE_CHILD_SA exchange [4]. 3.2.1 Home Agent Requirements This section describes additional requirements on the Home Agent. o The Home Agent MUST support Mobility Header message type as an IPsec selector. Devarapalli Expires August 24, 2005 [Page 5]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 o The Home Agent MUST support ICMPv6 message type as an IPsec selector. o The Home Agent MUST be able to distinguish between HoTi messages sent to itself, when it is acting as a Correspondent Node, from those sent to Correspondent Nodes when it is acting as a Home Agent, based on the destination address of the packet. o The Home Agent MAY use the Peer Authorization Database (PAD) [5] to store per-mobile node state. The PAD entry for a mobile node can contain a shared key, public key or a trust anchor to verify the mobile node's certificate for authenticating the mobile node. o The Home Agent MAY support remote configuration of home address as described in Section 7. When the Home Agent receives a configuration payload with a CFG_REQUEST for INTERNAL_IP6_ADDR, it must reply with a valid home address for the mobile node. The Home Agent could pick a home address from a local database or from a DHCPv6 server on the home link. o The Home Agent MAY support authentication using EAP in IKEv2 as described in Section 2.16 of [4]. 3.2.2 Mobile Node Requirements This section describes additional requirements on the mobile node. o The mobile node MUST support Mobility Header message type as an IPsec selector. o The mobile node MUST support ICMPv6 message type as an IPsec selector. o The mobile node MAY support EAP as an authentication mechanism when using IKEv2 to setup security associations for protecting Mobile IPv6 signaling messages. o The mobile node MAY support the mechanism described in Section 7 to dynamically configure a home address. Devarapalli Expires August 24, 2005 [Page 6]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 4. Manual Configuration This section describes the SPD and SAD entries that can be used to protect Mobile IPv6 signaling messages. For the examples described in this document, a mobile node with home address, "home_address_1", a Home Agent with address, "home_agent_1" and a user of the mobile node with identity "user_1" are assumed. If the home address of the mobile node changes, the SPD and SAD entries need to re-created or updated for the new home address. 4.1 Binding Update and Acknowledgements The following are the SPD and SAD entries on the mobile node and the Home Agent to protect Binding Updates and Acknowledgements. Devarapalli Expires August 24, 2005 [Page 7]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 mobile node SPD-S: - IF source = home_address_1 & destination = home_agent_1 & proto = MH & mh_type = BU Then use SA SA1 mobile node SPD-I: - IF source = home_agent_1 & destination = home_address_1 & proto = MH & mh_type = BAck Then use SA SA2 mobile node SAD: - SA1(OUT, spi_a, home_agent_1, ESP, TRANSPORT): source = home_address_1 & destination = home_agent_1 & proto = MH & mh_type = BU - SA2(IN, spi_b, home_address_1, ESP, TRANSPORT): source = home_agent_1 & destination = home_address_1 & proto = MH & mh_type = BAck home agent SPD-S: - IF source = home_agent_1 & destination = home_address_1 & proto = MH & mh_type = BAck Then use SA SA2 home agent SPD-I: - IF source = home_address_1 & destination = home_agent_1 & proto = MH & mh_type = BU Then use SA SA1 home agent SAD: - SA2(OUT, spi_b, home_address_1, ESP, TRANSPORT): source = home_agent_1 & destination = home_address_1 & proto = MH & mh_type = BAck - SA1(IN, spi_a, home_agent_1, ESP, TRANSPORT): source = home_address_1 & destination = home_agent_1 & proto = MH & mh_type = BU 4.2 Return Routabililty Messages The following are the SPD and SAD entries on the mobile node and the Home Agent to protect Return Routability messages. Devarapalli Expires August 24, 2005 [Page 8]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 mobile node SPD-S: - IF source = home_address_1 & destination = any & proto = MH & mh_type = HoTi Then use SA SA3 mobile node SPD-I: - IF destination = home_address_1 & source = any & proto = MH & mh_type = HoT Then use SA SA4 mobile node SAD: - SA3(OUT, spi_c, home_agent_1, ESP, TUNNEL): source = home_address_1 & destination = any & proto = MH & mh_type = HoTi - SA4(IN, spi_d, care_of_address_1, ESP, TUNNEL): source = any & destination = home_address_1 & proto = MH & mh_type = HoT home agent SPD-S: - IF destination = home_address_1 & source = any & proto = MH & mh_type = HoT Then use SA SA4 home agent SPD-I: - IF source = home_address_1 & destination = any & proto = MH & mh_type = HoTi Then use SA SA3 home agent SAD: - SA4(OUT, spi_d, care_of_address_1, ESP, TUNNEL): source = any & destination = home_address_1 & proto = MH & mh_type = HoT - SA3(IN, spi_c, home_agent_1, ESP, TUNNEL): source = home_address_1 & destination = any & proto = MH & mh_type = HoTi 4.3 Mobile Prefix Discovery Messages The following are the SPD and SAD entries used to protect Mobile Prefix Discovery messages. Devarapalli Expires August 24, 2005 [Page 9]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 mobile node SPD-S: - IF source = home_address_1 & destination = home_agent_1 & proto = ICMPv6 & icmp6_type = MPS Then use SA SA5. mobile node SPD-I: - IF source = home_agent_1 & destination = home_address_1 & proto = ICMPv6 & icmp6_type = MPA Then use SA SA6 mobile node SAD: - SA5(OUT, spi_e, home_agent_1, ESP, TRANSPORT): source = home_address_1 & destination = home_agent_1 & proto = ICMPv6 & icmp6_type = MPS - SA6(IN, spi_f, home_address_1, ESP, TRANSPORT): source = home_agent_1 & destination = home_address_1 & proto = ICMPv6 & icmp6_type = MPA home agent SPD-S: - IF source = home_agent_1 & destination = home_address_1 & proto = ICMPv6 & icmp6_type = MPA Then use SA SA6 home agent SPD-I: - IF source = home_address_1 & destination = home_agent_1 & proto = ICMPv6 & icmp6_type = MPS Then use SA SA5 home agent SAD: - SA6(OUT, spi_f, home_address_1, ESP, TRANSPORT): source = home_agent_1 & destination = home_address_1 & proto = ICMPv6 & icmp6_type = MPA - SA5(IN, spi_e, home_agent_1, ESP, TRANSPORT): source = home_address_1 & destination = home_agent_1 & proto = ICMPv6 & icmp6_type = MPS 4.4 Payload Packets Payload traffic tunneled through the Home Agent can be protected by IPsec, if required. The mobile node and the Home Agent use ESP in tunnel mode to protect the tunneled traffic. The SPD and SAD entries shown in Section 5.2.4 of [3] are applicable here. Devarapalli Expires August 24, 2005 [Page 10]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 5. Dynamic Configuration This section describes the use of IKEv2 to setup the required security associations. 5.1 Security Policy Database Entries The following sections describe the security policy entries on the mobile node and the Home Agent. In the examples shown below, the identity of the user of the mobile node is assumed to be user_1, the home address of the mobile node is assumed to be home_address_1 and the IPv6 address of the Home Agent is assumed to be home_agent_1. 5.1.1 Binding Updates and Acknowledgements The following are the SPD entries on the mobile node and the Home Agent for protecting Binding Updates and Acknowledgements. mobile node SPD-S: - IF destination = home_agent_1 & proto = MH & mh_type = BU Then use SA ESP transport mode IDi = user_1, IDr = home_agent_1, TSi = home_address_1 mobile node SPD-I: - IF source = home_agent_1 & proto = MH & mh_type = BAck Then use SA ESP transport mode IDi = user_1, IDr = home_agent_1, TSi = home_address_1 home agent SPD-S: - IF source = home_agent_1 & proto = MH & mh_type = BAck Then use SA ESP transport mode IDr = user_1, IDi = home_agent_1, TSr = home_address_1 home agent SPD-I: - IF destination = home_agent_1 & proto = MH & mh_type = BU Then use SA ESP transport mode IDr = user_1, IDi = home_agent_1, TSr = home_address_1 In the examples shown above, the home address of the mobile node might not be available all the time. When the mobile node acquires a new home address, it must add the address to the corresponding SPD entries. The Mobility Header type is negotiated by placing it in the most Devarapalli Expires August 24, 2005 [Page 11]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 significant eight bits of the 16 bit local "port" selector during IKEv2 exchange. For more details, refer to [5]. The TSi and TSr payloads in the above examples will contain many other selectors apart from home_address_1. For the sake of brevity, they are not shown here. 5.1.2 Return Routability Messages The following are the SPD entries on the mobile node and the Home Agent for protecting the Return Routability messages. mobile node SPD-S: - IF proto = MH & mh_type = HoTi Then use SA ESP tunnel mode IDi = user_1, outer src addr = coa outer dst addr = home_agent_1, inner src addr = home_address_1 mobile node SPD-I: - IF destination = home_address_1 & proto = MH & mh_type = HoT Then use SA ESP tunnel mode IDi = user_1, outer src addr = home_agent_1, outer dst addr = coa, home agent SPD-S: - IF proto = MH & mh_type = HoT Then use SA ESP tunnel mode IDr = user_1, outer src addr = home_agent_1, outer dst addr = coa, inner dst addr = home_address_1 home agent SPD-I: - IF proto = MH & mh_type = HoTi Then use SA ESP tunnel mode IDr = user_1, outer src addr = coa, outer dst addr = home_agent_1, inner src addr = home_address_1 When the mobile node's Care-of Address changes the SPD entries on both the mobile node and the Home Agent must be updated. The Home Agent knows about the change in Care-of Address of the mobile node when it receives a Binding Update from the mobile node. Devarapalli Expires August 24, 2005 [Page 12]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 5.1.3 Mobile Prefix Discovery Messages The following are the SPD entries on the mobile node and the Home Agent for protecting Mobile Prefix Discovery messages. mobile node SPD-S: - IF destination = home_agent_1 & proto = ICMPv6 & icmp6_type = MPS Then use SA ESP transport mode IDi = user_1, IDr = home_agent_1, TSi = home_address_1 mobile node SPD-I: - IF source = home_agent_1 & proto = ICMPv6 & icmp6_type = MPA Then use SA ESP transport mode IDi = user_1, IDr = home_agent_1, TSi = home_address_1 home agent SPD-S: - IF source = home_agent_1 & proto = ICMPv6 & icmp6_type = MPA Then use SA ESP transport mode IDr = user_1, IDi = home_agent_1, TSr = home_address_1 home agent SPD-I: - IF destination = home_agent_1 & proto = ICMPv6 & icmp6_type = MPS Then use SA ESP transport mode IDr = user_1, IDi = home_agent_1, TSr = home_address_1 In the examples shown above, the home address of the mobile node might not be available all the time. When the mobile node acquires a new home address, it must add the address to the corresponding SPD entries. The TSi and TSr payloads in the above examples will contain many other selectors apart from home_address_1. For brevity, they are not show here. 5.1.4 Payload Packets The following are the SPD entries on the mobile node and the Home Agent if payload traffic exchanged between the mobile node and its Correspondent Node needs to be protected. The SPD entries are similar to the entries for protecting Return Routability messages and have lower priority than the above SPD entries. Devarapalli Expires August 24, 2005 [Page 13]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 mobile node SPD-S: - IF interface = IPv6 tunnel to home_agent_1 & proto = X Then use SA ESP tunnel mode IDi = user_1, outer src addr = coa outer dst addr = home_agent_1, inner src addr = home_address_1 mobile node SPD-I: - IF destination = home_address_1 & proto = X & source = any_cn Then use SA ESP tunnel mode IDi = user_1, outer src addr = home_agent_1, outer dst addr = coa, home agent SPD-S: - IF interface = IPv6 tunnel to home_address_1 & proto = X Then use SA ESP tunnel mode IDr = user_1, outer src addr = home_agent_1, outer dst addr = coa, inner dst addr = home_address_1 home agent SPD-I: - IF interface = IPv6 tunnel to home_address_1 & proto = X Then use SA ESP tunnel mode IDr = user_1, outer src addr = coa, outer dst addr = home_agent_1, inner src addr = home_address_1 5.2 Security Association negotiation using IKEv2 Mobile IPv6 signaling messages are typically initiated by the mobile node. The mobile node sends a Binding Update to the Home Agent whenever it moves and acquires a new Care-of Address. The mobile node initiates an IKEv2 protocol exchange if the required security associations are not present. The default mechanism used for mutual authentication is a shared secret between the mobile node and the Home Agent. The Home Agent uses the identity of the mobile node to identify the corresponding shared secret. If public key based mechanism is used, the Home Agent and the mobile node use their Devarapalli Expires August 24, 2005 [Page 14]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 private keys to generate the AUTH payload. The mobile node and the Home Agent should use CERTREQ and CERT payloads if the identities need to be verified. If the mobile node is configured with the Home Agent information including the public key that corresponds to the Home Agent, then the mobile node MAY exclude the CERTREQ payload in message 3. Similarly, the Home Agent MAY exclude the CERTREQ payload in message 2, if it is configured with the mobile node information. If a shared secret is being used, the mobile node uses the shared secret to generate the AUTH payload in the IKE_AUTH exchange. If the mobile node is using a public key based mechanism, then it uses its private key to generate the AUTH payload in the IKE_AUTH exchange. Mobile Node Home Agent ----------- ---------- HDR, SAi1, KEi, Ni --> <-- HDR, SAr1, KEr, Nr, [CERTREQ] HDR, SK {IDi, [CERT,] [CERTREQ,] [IDr,] AUTH, SAi2, TSi, TSr} --> <-- HDR, SK {IDr, [CERT,] AUTH, SAr2, TSi, TSr} The mobile node MUST always includes its identity in the IDi payload in the IKE_AUTH exchange. The mobile node could use the following different types of identities to identity itself to the Home Agent. o Home Address - The mobile node could use its statically configured home address as its identity. In this case the ID Type field is set to ID_IPV6_ADDR. o FQDN - The mobile node can use a Fully Qualified Domain Name as the identifier and set the ID Type field to ID_FQDN. o RFC 822 identifier - If the mobile node uses a RFC 822 identifier [9], it sets the ID Type field to ID_RFC822_ADDR. After the IKE_AUTH exchange completes, the mobile node and the Home Agent initiate CREATE_CHILD_SA exchanges to negotiate security associations for protecting Binding Update/Binding Ack messages, Return Routability signaling, Mobile Prefix Discovery messages and optionally payload traffic. The CREATE_CHILD_SA exchanges are protected by the security association created during the IKE_AUTH exchange. It is important that the security associations are created based on the home address of the mobile node, so that the security Devarapalli Expires August 24, 2005 [Page 15]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 associations survive Care-of Address change. The mobile node MUST set the TSi (Traffic Selector-initiator) payload to its home address in the CREATE_CHILD_SA exchange in order to create the security associations for the home address. Mobile Node Home Agent ----------- ---------- HDR, SK {[N], SA, Ni, [KEi], [TSi, TSr]} --> <-- HDR, SK {SA, Nr, [KEr], [TSi, TSr]} Devarapalli Expires August 24, 2005 [Page 16]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 6. The use of EAP authentication In addition to using public key signatures and shared secrets, EAP [10] can be used with IKEv2 for authenticating the mobile node to the Home Agent. The mobile node indicates that it wants to use EAP by including the IDi payload but leaving out the AUTH payload in the first message during the IKE_AUTH exchange. The Home Agent then includes an EAP payload if it is willing to use an extensible authentication method. Security associations are not created until the subsequent IKE_AUTH exchange after successful EAP authentication. The use of EAP adds at least two round trips to the IKE negotiation. Mobile Node Home Agent ------------ ---------- HDR, SAi1, KEi, Ni --> <-- HDR, SAr1, KEr, Nr, [CERTREQ] HDR, SK {IDi, [CERTREQ,] [IDr,] SAi2, TSi, TSr}--> <-- HDR, SK {IDr, [CERT,] AUTH, EAP } HDR, SK {EAP} --> <-- HDR, SK {EAP (success)} HDR, SK {AUTH} --> <-- HDR, SK {AUTH, SAr2, TSi, TSr} Some EAP methods generate a shared key on the mobile node and the Home Agent once the EAP authentication succeeds. In this case, the shared key is used to generate the AUTH payloads in the subsequent messages. The shared key, if used to generate the AUTH payloads, MUST NOT be used for any other purpose. For more details, refer to [4]. The use of EAP between the mobile node and the Home Agent might require the Home Agent to contact an authorization server like the AAA Home server, on the home link, to authenticate the mobile node. Please refer to [7] for more details. The IKEv2 specification [4] requires that public key based mechanism Devarapalli Expires August 24, 2005 [Page 17]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 be used to authenticate the Home Agent to the mobile node, when EAP is used. But, if the EAP method that is used, supports mutual authentication and and key generation, then the mobile node could use EAP itself to authenticate the Home Agent. The mobile node can request that the Home Agent also use EAP to authenticate itself, by including the EAP_ONLY_AUTHENTICATION notification payload [8] in message 3. If the Home Agent agrees to use EAP, it omits the public key based AUTH and CERT payloads in message 4. More details can be found in [8]. Devarapalli Expires August 24, 2005 [Page 18]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 7. Dynamic Home Address Configuration The mobile node can dynamically configure a home address by including a Configuration Payload in the IKE_AUTH exchange, with a request for an address from the home link. The mobile node should include an INTERNAL_IP6_ADDRESS attribute in the CFG_REQUEST Payload. The mobile node MAY also include the INTERNAL_IP6_SUBNET attribute if it wants to obtain information about the IPv6 prefixes on the home link. If the mobile node wants to configure a DNS server from the home link it can request for the DNS server information by including an INTERNAL_IP6_DNS attribute in the CFG_REQUEST payload. When the Home Agent receives a configuration payload with a CFG_REQUEST for INTERNAL_IP6_ADDRESS, it replies with a valid home address for the mobile node. The INTERNAL_IP6_ADDRESS attribute in the CFG_REPLY contains the prefix length of the home prefix in addition to a 128 bit home address. The Home Agent could use a local database or contact a DHCPv6 server on the home link to allocate a home address. The Home Agent should also include an INTERNAL_ADDRESS_EXPIRY attribute to indicate to the mobile node, the duration for which the dynamically allocated home address is valid. Mobile Node Home Agent ----------- ---------- HDR, SK {IDi, [CERT,] [CERTREQ,] [IDr,] AUTH, CP(CFG_REQUEST), SAi2, TSi, TSr} --> <-- HDR, SK {IDr, [CERT,] AUTH, CP(CFG_REPLY), SAr2, TSi, TSr} The mobile node could suggest a home address that it wants to use in the CFG_REQUEST. For example, this could be a home address that it was allocated before or could be an address the mobile node auto-configured from the IPv6 prefix on the home link. The Home Agent could let the mobile node use the same home address by setting the INTERNAL_IP6_ADDRESS attribute in the CFG_REPLY payload to the same home address. If the Home Agent wants the mobile node to use a different home address, it sends a new home address in the INTERNAL_IP_ADDRESS attribute in the CFG_REPLY payload. The Mobile Node MUST stop using its old home address and start using the newly allocated home address. In case the Home Agent is unable to allocate a home address for the mobile node during the IKE_AUTH exchange, it MUST send a Notify Payload with an INTERNAL_ADDRESS_FAILURE message. Devarapalli Expires August 24, 2005 [Page 19]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 If the CFG_REQUEST from the mobile node had the INTERNAL_IP6_SUBNET attribute, the Home Agent SHOULD send prefix information for the all prefixes on the home link. Note, that this prefix information in the INTERNAL_IP6_SUBNET does not carry all the information that is typically present when received through a router advertisement. The mobile node should still rely on Mobile Prefix Discovery [2] to obtain complete information about the prefixes on the home link. Devarapalli Expires August 24, 2005 [Page 20]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 8. Security Considerations This document describes how IPsec can be used to secure Mobile IPv6 signaling messages. Please refer to RFC 3775 and RFC 3776 for security considerations related to the use of IPsec with Mobile IPv6. Devarapalli Expires August 24, 2005 [Page 21]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 9. IANA Considerations This document requires no action from IANA. Devarapalli Expires August 24, 2005 [Page 22]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 10. Acknowledgements The author would like to thank Mika Joutsenvirta and Pasi Eronen for reviewing the draft. Devarapalli Expires August 24, 2005 [Page 23]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 11. References 11.1 Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [2] Johnson, D., Perkins, C. and J. Arkko, "Mobility Support in IPv6", RFC 3775, June 2004. [3] Arkko, J., Devarapalli, V. and F. Dupont, "Using IPsec to Protect Mobile IPv6 Signaling Between Mobile Nodes and Home Agents", RFC 3776, June 2004. [4] Kaufman, C., "Internet Key Exchange (IKEv2) Protocol", Internet-Draft draft-ietf-ipsec-ikev2-17, October 2004. [5] Kent, S. and K. Seo, "Security Architecture for the Internet Protocol", Internet-Draft draft-ietf-ipsec-rfc2401bis-05, December 2004. [6] Kent, S., "IP Encapsulating Security Payload (ESP)", Internet-Draft draft-ietf-ipsec-esp-v3-09, October 2004. 11.2 Informative References [7] Giaretta, G., "Goals for AAA-HA interface", Internet-Draft draft-giaretta-mip6-aaa-ha-goals-00, September 2004. [8] Eronen, P., "Extension for EAP Authentication in IKEv2", Internet-Draft draft-eronen-ipsec-ikev2-eap-auth-02, October 2004. [9] Crocker, D., "Standard for the format of ARPA Internet text messages", STD 11, RFC 822, August 1982. [10] Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J. and H. Levkowetz, "Extensible Authentication Protocol (EAP)", RFC 3748, June 2004. [11] Kent, S. and R. Atkinson, "Security Architecture for the Internet Protocol", RFC 2401, November 1998. [12] Harkins, D. and D. Carrel, "The Internet Key Exchange (IKE)", RFC 2409, November 1998. Devarapalli Expires August 24, 2005 [Page 24]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 Author's Address Vijay Devarapalli Nokia Research Center 313 Fairchild Drive Mountain View, CA 94043 USA Email: vijay.devarapalli@nokia.com Devarapalli Expires August 24, 2005 [Page 25]
Internet-Draft Mobile IPv6 with IKEv2 and revised IPsec February 2005 Intellectual Property Statement 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. Disclaimer of Validity 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. Copyright Statement Copyright (C) The Internet Society (2005). 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. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Devarapalli Expires August 24, 2005 [Page 26]
