idnits 2.17.1 draft-nir-ipsecme-childless-01.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** The document seems to lack a License Notice according IETF Trust Provisions of 28 Dec 2009, Section 6.b.ii or Provisions of 12 Sep 2009 Section 6.b -- however, there's a paragraph with a matching beginning. Boilerplate error? (You're using the IETF Trust Provisions' Section 6.b License Notice from 12 Feb 2009 rather than one of the newer Notices. See https://trustee.ietf.org/license-info/.) Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (July 13, 2009) is 5372 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: 'IDr' is mentioned on line 173, but not defined ** Obsolete normative reference: RFC 4306 (Obsoleted by RFC 5996) ** Obsolete normative reference: RFC 4718 (Obsoleted by RFC 5996) Summary: 3 errors (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group Y. Nir 3 Internet-Draft Check Point 4 Intended status: Standards Track H. Tschofenig 5 Expires: January 14, 2010 NSN 6 H. Deng 7 China Mobile 8 R. Singh 9 Cisco 10 July 13, 2009 12 A Childless Initiation of the IKE SA 13 draft-nir-ipsecme-childless-01 15 Status of this Memo 17 This Internet-Draft is submitted to IETF in full conformance with the 18 provisions of BCP 78 and BCP 79. 20 Internet-Drafts are working documents of the Internet Engineering 21 Task Force (IETF), its areas, and its working groups. Note that 22 other groups may also distribute working documents as Internet- 23 Drafts. 25 Internet-Drafts are draft documents valid for a maximum of six months 26 and may be updated, replaced, or obsoleted by other documents at any 27 time. It is inappropriate to use Internet-Drafts as reference 28 material or to cite them other than as "work in progress." 30 The list of current Internet-Drafts can be accessed at 31 http://www.ietf.org/ietf/1id-abstracts.txt. 33 The list of Internet-Draft Shadow Directories can be accessed at 34 http://www.ietf.org/shadow.html. 36 This Internet-Draft will expire on January 14, 2010. 38 Copyright Notice 40 Copyright (c) 2009 IETF Trust and the persons identified as the 41 document authors. All rights reserved. 43 This document is subject to BCP 78 and the IETF Trust's Legal 44 Provisions Relating to IETF Documents in effect on the date of 45 publication of this document (http://trustee.ietf.org/license-info). 46 Please review these documents carefully, as they describe your rights 47 and restrictions with respect to this document. 49 Abstract 51 This document describes an extension to the IKEv2 protocol that 52 allows an IKE SA to be created and authenticated without generating a 53 child SA. 55 Table of Contents 57 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 58 1.1. Conventions Used in This Document . . . . . . . . . . . . . 3 59 2. Usage Scenarios . . . . . . . . . . . . . . . . . . . . . . . . 3 60 3. Protocol Outline . . . . . . . . . . . . . . . . . . . . . . . 4 61 4. VID Payload . . . . . . . . . . . . . . . . . . . . . . . . . . 4 62 5. Modified IKE_AUTH Exchange . . . . . . . . . . . . . . . . . . 5 63 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 64 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 65 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 66 8.1. Normative References . . . . . . . . . . . . . . . . . . . 6 67 8.2. Informative References . . . . . . . . . . . . . . . . . . 6 68 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 70 1. Introduction 72 IKEv2, as specified in [RFC4306] requires, that the IKE_AUTH exchange 73 try to create a child SA along with the IKE SA. This requirement is 74 sometimes inconvenient or superfluous, as some implementations need 75 to use IKE for authentication only, while others would like to set up 76 the IKE SA before there is any actual traffic to protect. 78 An IKE SA without any child SA is not a fruitless endeavor. Even 79 without Child SAs, an IKE SA allows: 80 o Checking the liveness status of the peer via liveness checks. 81 o Quickly setting up child SAs without public key operations, and 82 without user interaction. 83 o Authentication of the peer. 84 o Detection of NAT boxes between two hosts on the Internet 86 1.1. Conventions Used in This Document 88 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 89 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 90 document are to be interpreted as described in [RFC2119]. 92 2. Usage Scenarios 94 Several scenarios motivated this proposal: 95 o Interactive remote access VPN: the user tells the client to 96 "connect", which may involve interactive authentication. There is 97 still no traffic, but some may come later. Since there is no 98 traffic, it is impossible for the gateway to know what selectors 99 to use (how to narrow down the client's proposal). 100 o Location aware security, as in [SecureBeacon]. The user is 101 roaming between trusted and untrusted networks. While in an 102 untrusted network, all traffic should be encrypted, but on the 103 trusted network, only the IKE SA needs to be maintained. 104 o An IKE SA may be needed between peers even when there is not IPsec 105 traffic. Such IKE peers use liveness checks, and report to the 106 administrator the status of the "VPN links". 107 o IKE may be used on some physically secure links, where 108 authentication is necessary, but traffic protection is not. An 109 example of this in the PON links as described in [3GPP.33.820]. 110 o Childless IKE can be used for [EAP-IKEv2] where we use IKEv2 as a 111 method for user authentication. 112 o A node receiving IPsec traffic with an unrecognized SPI should 113 send an INVALID_SPI notification. If this traffic comes from a 114 peer, which it recognizes based on its IP address, then this node 115 may set up an IKE SA so as to be able to send the notification in 116 a protected IKE_INFORMATIONAL exchange. 118 o A future extension may have IKE SAs used for generating keying 119 material for applications, without ever requiring child SAs. This 120 is similar to what [extractors] is doing in TLS. 122 In some of these cases it may be possible to create a dummy Child SA 123 and then remove it, but this creates undesirable side effects and 124 race conditions. Moreover, the IKE peer might see the deletion of 125 the Child SA as a reason to delete the IKE SA. 127 3. Protocol Outline 129 The decision of whether or not to support an IKE_AUTH exchage without 130 the piggy-backed child SA negotiation is ultimately up to the 131 reponsder. A supporting resonder MUST include the VID payload, 132 described in Section 4, within the IKE_SA_INIT response. 134 A supporting initiator MAY send the modified IKE_AUTH request, 135 described in Section 5, if the VID payload was included in the 136 IKE_SA_INIT response. The initiator MUST NOT send the modified 137 IKE_AUTH request if the VID was not present. 139 A supporting responder that advertised the VID payload in the 140 IKE_SA_INIT response MUST process a modified IKE_AUTH request, and 141 MUST reply with a modified IKE_AUTH response. Such a responder MUST 142 NOT reply with a modified IKE_AUTH response if the initiator did not 143 send a modified IKE_AUTH request. 145 A supporting responder that has been configured not to support this 146 extension to the protocol MUST behave as the same as if it didn't 147 support this extension. It MUST NOT advertise the capability with a 148 VID payload, and it SHOULD reply with an INVALID_SYNTAX Notify 149 payload if the client sends an IKE_AUTH request that is modified as 150 described in Section 5. 152 4. VID Payload 154 The VID payload is as described in [RFC4306] with a 16-octets data 155 field as follows: 157 73da4b423dd9f75563b15b9f918650fc 159 This value was obtained by hashing the string "Will do IKE_AUTH 160 without child SA payloads" using the MD5 algorithms. Note that this 161 is only an explanation, and the actual content of the VID data MUST 162 be the value above. 164 5. Modified IKE_AUTH Exchange 166 For brevity, only the EAP version of an AUTH exchange will be 167 presented here. The non-EAP version is very similar. The figures 168 below are based on appendix A.3 of [RFC4718]. 170 first request --> IDi, 171 [N(INITIAL_CONTACT)], 172 [[N(HTTP_CERT_LOOKUP_SUPPORTED)], CERTREQ+], 173 [IDr], 174 [CP(CFG_REQUEST)], 175 [V+] 177 first response <-- IDr, [CERT+], AUTH, 178 EAP, 179 [V+] 181 / --> EAP 182 repeat 1..N times | 183 \ <-- EAP 185 last request --> AUTH 187 last response <-- AUTH, 188 [CP(CFG_REPLY)], 189 [N(ADDITIONAL_TS_POSSIBLE)], 190 [V+] 192 Note what is missing: 193 o The optional notifications: IPCOMP_SUPPORTED, USE_TRANSPORT_MODE, 194 ESP_TFC_PADDING_NOT_SUPPORTED, and NON_FIRST_FRAGMENTS_ALSO. 195 o The SA payload. 196 o The traffic selector payloads. 197 o Any notification, extension payload or VendorID that has to do 198 with child SA negotiation. 200 6. Security Considerations 202 TBA 204 7. IANA Considerations 206 There are no IANA considerations for this document. 208 8. References 209 8.1. Normative References 211 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 212 Requirement Levels", BCP 14, RFC 2119, March 1997. 214 [RFC4306] Kaufman, C., "Internet Key Exchange (IKEv2) Protocol", 215 RFC 4306, December 2005. 217 [RFC4718] Eronen, P. and P. Hoffman, "IKEv2 Clarifications and 218 Implementation Guidelines", RFC 4718, October 2006. 220 8.2. Informative References 222 [3GPP.33.820] 223 3GPP, "Security of H(e)NB", 3GPP TR 33.820 8.0.0, 224 March 2009. 226 [EAP-IKEv2] 227 Tschofenig, H., Kroeselberg, D., Pashalidis, A., Ohba, Y., 228 and F. Bersani, "The Extensible Authentication Protocol- 229 Internet Key Exchange Protocol version 2 (EAP-IKEv2) 230 Method", RFC 5106, February 2008. 232 [SecureBeacon] 233 Sheffer, Y. and Y. Nir, "Secure Beacon: Securely Detecting 234 a Trusted Network", draft-sheffer-ipsecme-secure-beacon 235 (work in progress), June 2009. 237 [extractors] 238 Rescorla, E., "Keying Material Exporters for Transport 239 Layer Security (TLS)", draft-ietf-tls-extractor (work in 240 progress), March 2009. 242 Authors' Addresses 244 Yoav Nir 245 Check Point Software Technologies Ltd. 246 5 Hasolelim st. 247 Tel Aviv 67897 248 Israel 250 Email: ynir@checkpoint.com 251 Hannes Tschofenig 252 Nokia Siemens Networks 253 Linnoitustie 6 254 Espoo 02600 255 Finland 257 Phone: +358 (50) 4871445 258 Email: Hannes.Tschofenig@gmx.net 259 URI: http://www.tschofenig.priv.at 261 Hui Deng 262 China Mobile 263 53A,Xibianmennei Ave. 264 Xuanwu District 265 Beijing 100053 266 China 268 Email: denghui02@gmail.com 270 Rajeshwar Singh Jenwar 271 Cisco Systems, Inc. 272 O'Shaugnessy Road 273 Bangalore, Karnataka 560025 274 India 276 Phone: +91 80 4103 3563 277 Email: rsj@cisco.com