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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group J. Laganier 3 Internet-Draft Luminate Wireless, Inc. 4 Obsoletes: 5203 (if approved) L. Eggert 5 Intended status: Standards Track NetApp 6 Expires: August 3, 2016 January 31, 2016 8 Host Identity Protocol (HIP) Registration Extension 9 draft-ietf-hip-rfc5203-bis-10 11 Abstract 13 This document specifies a registration mechanism for the Host 14 Identity Protocol (HIP) that allows hosts to register with services, 15 such as HIP rendezvous servers or middleboxes. This document 16 obsoletes RFC5203. 18 Status of This Memo 20 This Internet-Draft is submitted in full conformance with the 21 provisions of BCP 78 and BCP 79. 23 Internet-Drafts are working documents of the Internet Engineering 24 Task Force (IETF). Note that other groups may also distribute 25 working documents as Internet-Drafts. The list of current Internet- 26 Drafts is at http://datatracker.ietf.org/drafts/current/. 28 Internet-Drafts are draft documents valid for a maximum of six months 29 and may be updated, replaced, or obsoleted by other documents at any 30 time. It is inappropriate to use Internet-Drafts as reference 31 material or to cite them other than as "work in progress." 33 This Internet-Draft will expire on August 3, 2016. 35 Copyright Notice 37 Copyright (c) 2016 IETF Trust and the persons identified as the 38 document authors. All rights reserved. 40 This document is subject to BCP 78 and the IETF Trust's Legal 41 Provisions Relating to IETF Documents 42 (http://trustee.ietf.org/license-info) in effect on the date of 43 publication of this document. Please review these documents 44 carefully, as they describe your rights and restrictions with respect 45 to this document. Code Components extracted from this document must 46 include Simplified BSD License text as described in Section 4.e of 47 the Trust Legal Provisions and are provided without warranty as 48 described in the Simplified BSD License. 50 Table of Contents 52 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 53 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 54 3. HIP Registration Extension Overview . . . . . . . . . . . . . 3 55 3.1. Registrar Announcing Its Ability . . . . . . . . . . . . 4 56 3.2. Requester Requesting Registration . . . . . . . . . . . . 4 57 3.3. Registrar Granting or Refusing Service(s) Registration . 4 58 4. Parameter Formats and Processing . . . . . . . . . . . . . . 6 59 4.1. Encoding Registration Lifetimes with Exponents . . . . . 6 60 4.2. REG_INFO . . . . . . . . . . . . . . . . . . . . . . . . 7 61 4.3. REG_REQUEST . . . . . . . . . . . . . . . . . . . . . . . 7 62 4.4. REG_RESPONSE . . . . . . . . . . . . . . . . . . . . . . 8 63 4.5. REG_FAILED . . . . . . . . . . . . . . . . . . . . . . . 9 64 5. Establishing and Maintaining Registrations . . . . . . . . . 11 65 6. Security Considerations . . . . . . . . . . . . . . . . . . . 11 66 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 67 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 12 68 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12 69 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 70 10.1. Normative References . . . . . . . . . . . . . . . . . . 13 71 10.2. Informative References . . . . . . . . . . . . . . . . . 13 72 Appendix A. Changes from RFC 5203 . . . . . . . . . . . . . . . 15 73 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 75 1. Introduction 77 This document specifies an extension to the Host Identity Protocol 78 (HIP) [RFC7401]. The extension provides a generic means for a host 79 to register with a service. The service may, for example, be a HIP 80 rendezvous server [I-D.ietf-hip-rfc5204-bis] or a middlebox 81 [RFC3234]. 83 This document makes no further assumptions about the exact type of 84 service. Likewise, this document does not specify any mechanisms to 85 discover the presence of specific services or means to interact with 86 them after registration. Future documents may describe those 87 operations. 89 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 90 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 91 document are to be interpreted as described in RFC 2119 [RFC2119]. 93 2. Terminology 95 In addition to the terminology defined in the HIP Architecture 96 [I-D.ietf-hip-rfc4423-bis], the HIP specification [RFC7401], and the 97 HIP Rendezvous Extension [I-D.ietf-hip-rfc5204-bis], this document 98 defines and uses the following terms: 100 Requester: 101 a HIP node registering with a HIP registrar to request 102 registration for a service. 104 Registrar: 105 a HIP node offering registration for one or more services. 107 Service: 108 a facility that provides requesters with new capabilities or 109 functionalities operating at the HIP layer. Examples include 110 firewalls that support HIP traversal or HIP rendezvous servers. 112 Registration: 113 shared state stored by a requester and a registrar, allowing the 114 requester to benefit from one or more HIP services offered by the 115 registrar. Each registration has an associated finite lifetime. 116 Requesters can extend established registrations through re- 117 registration (i.e., perform a refresh). 119 Registration Type: 120 an identifier for a given service in the registration protocol. 121 For example, the rendezvous service is identified by a specific 122 registration type. 124 3. HIP Registration Extension Overview 126 This document does not specify the means by which a requester 127 discovers the availability of a service, or how a requester locates a 128 registrar. After a requester has discovered a registrar, it either 129 initiates HIP base exchange or uses an existing HIP association with 130 the registrar. In both cases, registrars use additional parameters, 131 which the remainder of this document defines, to announce their 132 quality and grant or refuse registration. Requesters use 133 corresponding parameters to register with the service. Both the 134 registrar and the requester MAY also include in the messages 135 exchanged additional HIP parameters specific to the registration type 136 requested. Other documents will define parameters and how they shall 137 be used. 139 The HIP base exchange, including the definition of the HIP I1, R1, 140 I2, and R2 packets, is defined in RFC7401 [RFC7401]. The following 141 sections describe the differences between this registration handshake 142 and the standard HIP base exchange [RFC7401]. 144 3.1. Registrar Announcing Its Ability 146 A host that is capable and willing to act as a registrar vis-a-vis a 147 specific requester SHOULD include a REG_INFO parameter in the R1 148 packets it sends during all base exchanges with that requester. If 149 it is currently unable to provide services due to transient 150 conditions, it SHOULD include an empty REG_INFO, i.e., one with no 151 services listed. If services can be provided later, it SHOULD send 152 UPDATE packets indicating the current set of services available in a 153 new REG_INFO parameter to all hosts it is associated with. 155 3.2. Requester Requesting Registration 157 To request registration with a service, a requester constructs and 158 includes a corresponding REG_REQUEST parameter in an I2 or UPDATE 159 packet it sends to the registrar. 161 If the requester has no HIP association established with the 162 registrar, it SHOULD send the REG_REQUEST at the earliest 163 possibility, i.e., in the I2 packet. This minimizes the number of 164 packets that need to be exchanged with the registrar. A registrar 165 MAY end a HIP association that does not carry a REG_REQUEST by 166 including a NOTIFY with the type REG_REQUIRED in the R2. In this 167 case, no HIP association is created between the hosts. The 168 REG_REQUIRED notification error type is 51. 170 3.3. Registrar Granting or Refusing Service(s) Registration 172 Once registration has been requested, the registrar is able to 173 authenticate the requester based on the host identity included in I2. 175 If the registrar knows the Host Identities (HIs) of all the hosts 176 that are allowed to register for service(s), it SHOULD reject 177 registrations from unknown hosts. However, since it may be 178 infeasible to pre-configure the registrar with all the HIs, the 179 registrar SHOULD also support HIP certificates 180 [I-D.ietf-hip-rfc6253-bis] to allow for certificate based 181 authentication. 183 When a requester wants to register with a registrar, it SHOULD check 184 if it has a suitable certificate for authenticating with the 185 registrar. How the suitability is determined and how the 186 certificates are obtained is out of scope for this document. If the 187 requester has one or more suitable certificates, the host SHOULD 188 include them (or just the most suitable one) in a CERT parameter to 189 the HIP packet along with the REG_REQUEST parameter. If the 190 requester does not have any suitable certificates, it SHOULD send the 191 registration request without the CERT parameter to test whether the 192 registrar accepts the request based on the host's identity. 194 When a registrar receives a HIP packet with a REG_REQUEST parameter, 195 and it requires authentication for at least one of the Registration 196 Types listed in the REG_REQUEST parameter, it MUST first check 197 whether the HI of the requester is in the allowed list for all the 198 Registration Types in the REG_REQUEST parameter. If the requester is 199 in the allowed list (or the registrar does not require any 200 authentication), the registrar MUST proceed with the registration. 202 If the requester was not in the allowed list and the registrar 203 requires the requester to authenticate, the registrar MUST check 204 whether the packet also contains a CERT parameter. If the packet 205 does not contain a CERT parameter, the registrar MUST reject the 206 registrations requiring authentication with Failure Type 0 207 (Registration requires additional credentials). If the certificate 208 is valid and accepted (issued for the requester and signed by a 209 trusted issuer), the registrar MUST proceed with the registration. 210 If the certificate in the parameter is not accepted, the registrar 211 MUST reject the corresponding registrations with Failure Type [IANA 212 TBD] (Invalid certificate). 214 After successful authorization, the registrar includes a REG_RESPONSE 215 parameter in its response, which contains the service type(s) for 216 which it has authorized registration, and zero or more REG_FAILED 217 parameters containing the service type(s) for which it has not 218 authorized registration or registration has failed for other reasons. 219 This response can be either an R2 or an UPDATE message, respectively, 220 depending on whether the registration was requested during the base 221 exchange, or using an existing association. In particular, 222 REG_FAILED with a failure type of zero indicates the service(s) 223 type(s) that require further credentials for registration. 225 If the registrar requires further authorization and the requester has 226 additional credentials available, the requester SHOULD try to 227 register again with the service after the HIP association has been 228 established. 230 Successful processing of a REG_RESPONSE parameter creates 231 registration state at the requester. In a similar manner, successful 232 processing of a REG_REQUEST parameter creates registration state at 233 the registrar and possibly at the service. Both the requester and 234 registrar can cancel a registration before it expires, if the 235 services afforded by a registration are no longer needed by the 236 requester, or cannot be provided any longer by the registrar (for 237 instance, because its configuration has changed). 239 +-----+ I1 +-----+-----+ 240 | |--------------------->| | S1 | 241 | |<---------------------| | | 242 | | R1(REG_INFO:S1,S2,S3)| +-----+ 243 | RQ | | R | S2 | 244 | | I2(REG_REQ:S1) | | | 245 | |--------------------->| +-----+ 246 | |<---------------------| | S3 | 247 | | R2(REG_RESP:S1) | | | 248 +-----+ +-----+-----+ 250 A requester (RQ) registers for service (S1) with a registrar (R) of 251 services (S1), (S2), and (S3), with which it has no current HIP 252 association. 254 +-----+ +-----+-----+ 255 | | UPDATE(REG_INFO:S) | | | 256 | |<---------------------| | | 257 | RQ |--------------------->| R | S | 258 | | UPDATE(REG_REQ:S) | | | 259 | | UPDATE(REG_RESP:S) | | | 260 | |<---------------------| | | 261 +-----+ +-----+-----+ 263 A requester (RQ) registers for service (S) with a registrar (R) of 264 services (S), with which it currently has a HIP association 265 established. 267 4. Parameter Formats and Processing 269 This section describes the format and processing of the new 270 parameters introduced by the HIP registration extension. The 271 encoding of these new parameters is conforms to the HIPv2 TLV format 272 described in section 5.2.1 of RFC7401 [RFC7401]. 274 4.1. Encoding Registration Lifetimes with Exponents 276 The HIP registration uses an exponential encoding of registration 277 lifetimes. 279 The special value 0 (zero) of the lifetime field MUST be interpreted 280 as representing a special lifetime duration of 0 (zero) seconds, and 281 is used to request and grant cancellation of a registration. 283 The non-zero values of the lifetime field used throughout this 284 document MUST be interpreted as an exponent value representing a 285 lifetime duration of 2^((lifetime - 64)/8) seconds. 287 This allows a compact encoding of 255 different lifetime durations 288 (in addition to the special lifetime duration of zero seconds) 289 ranging from 2^(63/8) seconds (i.e., ~4 ms) to 2^(191/8) seconds 290 (i.e., ~178 days) into an 8-bit integer field. 292 4.2. REG_INFO 294 0 1 2 3 295 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 1 296 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 297 | Type | Length | 298 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 299 | Min Lifetime | Max Lifetime | Reg Type #1 | Reg Type #2 | 300 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 301 | ... | ... | Reg Type #n | | 302 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Padding + 303 | | 304 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 306 Type 930 307 Length Length in octets, excluding Type, Length, and Padding. 308 Min Lifetime Minimum registration lifetime. 309 Max Lifetime Maximum registration lifetime. 310 Reg Type The registration types offered by the registrar. 312 Other documents will define specific values for registration types. 313 See Section 7 for more information. 315 Registrars include the parameter in R1 packets in order to announce 316 their registration capabilities. The registrar SHOULD include the 317 parameter in UPDATE packets when its service offering has changed. 318 HIP_SIGNATURE_2 protects the parameter within the R1 packets. 320 The registrar indicates the minimum and maximum registration lifetime 321 that it is willing to offer to a requester. A requester SHOULD NOT 322 request registration with lifetime greater than the maximum 323 registration lifetime or smaller than the minimum registration 324 lifetime. 326 4.3. REG_REQUEST 327 0 1 2 3 328 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 1 329 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 330 | Type | Length | 331 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 332 | Lifetime | Reg Type #1 | Reg Type #2 | Reg Type #3 | 333 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 334 | ... | ... | Reg Type #n | | 335 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Padding + 336 | | 337 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 339 Type 932 340 Length Length in octets, excluding Type, Length, and Padding. 341 Lifetime Requested registration lifetime. 342 Reg Type The preferred registration types in order of preference. 344 Other documents will define specific values for registration types. 345 See Section 7 for more information. 347 A requester includes the REG_REQUEST parameter in I2 or UPDATE 348 packets to register with a registrar's service(s). If the 349 REG_REQUEST parameter is in an UPDATE packet, the registrar MUST NOT 350 modify the registrations of registration types that are not listed in 351 the parameter. Moreover, the requester MUST NOT include the 352 parameter unless the registrar's R1 packet or latest received UPDATE 353 packet has contained a REG_INFO parameter with the requested 354 registration types. 356 The requester MUST NOT include more than one REG_REQUEST parameter in 357 its I2 or UPDATE packets, while the registrar MUST be able to process 358 one or more REG_REQUEST parameters in received I2 or UPDATE packets. 360 When the registrar receives a registration with a lifetime that is 361 either smaller or greater than the minimum or maximum lifetime, 362 respectively, then it SHOULD grant the registration for the minimum 363 or maximum lifetime, respectively. 365 HIP_SIGNATURE protects the parameter within the I2 and UPDATE 366 packets. 368 4.4. REG_RESPONSE 369 0 1 2 3 370 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 1 371 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 372 | Type | Length | 373 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 374 | Lifetime | Reg Type #1 | Reg Type #2 | Reg Type #3 | 375 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 376 | ... | ... | Reg Type #n | | 377 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Padding + 378 | | 379 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 381 Type 934 382 Length Length in octets, excluding Type, Length, and Padding. 383 Lifetime Granted registration lifetime. 384 Reg Type The granted registration types in order of preference. 386 Other documents will define specific values for registration types. 387 See Section 7 for more information. 389 The registrar SHOULD includes an REG_RESPONSE parameter in its R2 or 390 UPDATE packet only if a registration has successfully completed. 392 The registrar MUST NOT include more than one REG_RESPONSE parameter 393 in its R2 or UPDATE packets, while the requester MUST be able to 394 process one or more REG_RESPONSE parameters in received R2 or UPDATE 395 packets. 397 The requester MUST be prepared to receive any registration lifetime, 398 including ones beyond the minimum and maximum lifetime indicated in 399 the REG_INFO parameter. It MUST NOT expect that the returned 400 lifetime will be the requested one, even when the requested lifetime 401 falls within the announced minimum and maximum. 403 HIP_SIGNATURE protects the parameter within the R2 and UPDATE 404 packets. 406 4.5. REG_FAILED 407 0 1 2 3 408 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 1 409 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 410 | Type | Length | 411 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 412 | Failure Type | Reg Type #1 | Reg Type #2 | Reg Type #3 | 413 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 414 | ... | ... | Reg Type #n | | 415 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Padding + 416 | | 417 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 419 Type 936 420 Length Length in octets, excluding Type, Length, and Padding. 421 Failure Type Reason for failure. 422 Reg Type The registration types that failed with the specified 423 reason. 425 Failure Type Reason 426 ------------ -------------------------------------------- 427 0 Registration requires additional credentials 428 1 Registration type unavailable 429 [TBD-IANA] Insufficient resources 430 [TBD-IANA] Invalid certificate 431 [TBD-IANA]-200 Unassigned 432 201-255 Reserved by IANA for private use 434 Other documents will define specific values for registration types. 435 See Section 7 for more information. 437 Failure type zero (0) indicates that the registrar requires 438 additional credentials to authorize a requester to register with the 439 registration types listed in the parameter. Failure type one (1) 440 indicates that the requested service type is unavailable at the 441 registrar. Failure type ([TBD-IANA-Insufficient-resources]) 442 indicates that the registrar does not currently have enough resources 443 to register the requester for the service(s); when that is the case 444 the requester MUST NOT reattempt immediately to register for the same 445 service(s), and MAY attempt to contact another registrar to register 446 for these service(s). Failure type ([TBD-IANA-Invalid-Certificates]) 447 indicates that the registrar could not validate the certificate 448 provided by the requester to register for the service(s); when that 449 is the case the requester MUST NOT reattempt to register for the same 450 set of services while providing the same certificate, and MAY attempt 451 to register for the same set of service(s) with a different 452 certificate, or with a different set of service(s) with the same 453 certificate. 455 The registrar SHOULD include a REG_FAILED parameter in its R2 or 456 UPDATE packet, if registration with the registration types listed has 457 not completed successfully and a requester is asked to try again with 458 additional credentials. 460 HIP_SIGNATURE protects the parameter within the R2 and UPDATE 461 packets. 463 5. Establishing and Maintaining Registrations 465 Establishing and/or maintaining a registration may require additional 466 information not available in the transmitted REG_REQUEST or 467 REG_RESPONSE parameters. Therefore, registration type definitions 468 MAY define dependencies for HIP parameters that are not defined in 469 this document. Their semantics are subject to the specific 470 registration type specifications. 472 The minimum lifetime both registrars and requesters MUST support is 473 10 seconds, while they SHOULD support a maximum lifetime of 120 474 seconds, at least. These values define a baseline for the 475 specification of services based on the registration system. They 476 were chosen to be neither too short nor too long, and to accommodate 477 for existing timeouts of state established in middleboxes (e.g., NATs 478 and firewalls.) 480 A zero lifetime is reserved for canceling purposes. Requesting a 481 zero lifetime for a registration type is equal to canceling the 482 registration of that type. A requester MAY cancel a registration 483 before it expires by sending a REG_REQ to the registrar with a zero 484 lifetime. A registrar SHOULD respond and grant a registration with a 485 zero lifetime. A registrar (and an attached service) MAY cancel a 486 registration before it expires, at its own discretion. However, if 487 it does so, it SHOULD send a REG_RESPONSE with a zero lifetime to all 488 registered requesters. 490 6. Security Considerations 492 This section discusses the threats on the HIP registration protocol, 493 and their implications on the overall security of HIP. In 494 particular, it argues that the extensions described in this document 495 do not introduce additional threats to HIP. 497 The extensions described in this document rely on the HIP base 498 exchange and do not modify its security characteristics, e.g., 499 digital signatures or HMAC. Hence, the only threat introduced by 500 these extensions is related to the creation of soft registration 501 state at the registrar. 503 Registrars act on a voluntary basis and are willing to accept being a 504 responder and then to create HIP associations with a number of 505 potentially unknown hosts. Because they have to store HIP 506 association state anyway, adding a certain amount of time-limited HIP 507 registration state should not introduce any serious additional 508 threats, especially because HIP registrars may cancel registrations 509 at any time at their own discretion, e.g., because of resource 510 constraints during an attack. 512 7. IANA Considerations 514 This section is to be interpreted according to the Guidelines for 515 Writing an IANA Considerations Section in RFCs [RFC5226]. 517 This document updates the IANA Registry for HIP Parameters Types by 518 replacing references to [RFC5203] by references to this document. 520 This document also updates the registry for registration failure 521 types by making the following failure type definitions and 522 reservations: 524 Failure Type Reason 525 ------------ -------------------------------------------- 526 [TBD-IANA] Insufficient resources 527 [TBD-IANA] Invalid certificate 529 8. Contributors 531 Teemu Koponen co-authored an earlier, experimental version of this 532 specification [RFC5203]. 534 9. Acknowledgments 536 The following people (in alphabetical order) have provided thoughtful 537 and helpful discussions and/or suggestions that have helped to 538 improve this document: Jeffrey Ahrenholz, Miriam Esteban, Ari 539 Keranen, Mika Kousa, Pekka Nikander, and Hannes Tschofenig. 541 Lars Eggert has received funding from the European Union's Horizon 542 2020 research and innovation program 2014-2018 under grant agreement 543 No. 644866. This document reflects only the authors' views and the 544 European Commission is not responsible for any use that may be made 545 of the information it contains. 547 Ari Keranen suggested inclusion of the text specifying requester 548 authorization based on certificates as a direct adaption of text 549 found in HIP native NAT traversal specification 550 [I-D.ietf-hip-native-nat-traversal]. 552 Thanks to Joel M. Halpern for performing the Gen-ART review of this 553 document as part of the publication process. 555 10. References 557 10.1. Normative References 559 [I-D.ietf-hip-rfc5204-bis] 560 Laganier, J. and L. Eggert, "Host Identity Protocol (HIP) 561 Rendezvous Extension", draft-ietf-hip-rfc5204-bis-07 (work 562 in progress), December 2015. 564 [I-D.ietf-hip-rfc6253-bis] 565 Heer, T. and S. Varjonen, "Host Identity Protocol 566 Certificates", draft-ietf-hip-rfc6253-bis-06 (work in 567 progress), December 2015. 569 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 570 Requirement Levels", BCP 14, RFC 2119, 571 DOI 10.17487/RFC2119, March 1997, 572 . 574 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 575 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 576 DOI 10.17487/RFC5226, May 2008, 577 . 579 [RFC7401] Moskowitz, R., Ed., Heer, T., Jokela, P., and T. 580 Henderson, "Host Identity Protocol Version 2 (HIPv2)", 581 RFC 7401, DOI 10.17487/RFC7401, April 2015, 582 . 584 10.2. Informative References 586 [I-D.ietf-hip-native-nat-traversal] 587 Keranen, A. and J. Melen, "Native NAT Traversal Mode for 588 the Host Identity Protocol", draft-ietf-hip-native-nat- 589 traversal-10 (work in progress), January 2016. 591 [I-D.ietf-hip-rfc4423-bis] 592 Moskowitz, R. and M. Komu, "Host Identity Protocol 593 Architecture", draft-ietf-hip-rfc4423-bis-13 (work in 594 progress), December 2015. 596 [RFC3234] Carpenter, B. and S. Brim, "Middleboxes: Taxonomy and 597 Issues", RFC 3234, DOI 10.17487/RFC3234, February 2002, 598 . 600 [RFC5203] Laganier, J., Koponen, T., and L. Eggert, "Host Identity 601 Protocol (HIP) Registration Extension", RFC 5203, 602 DOI 10.17487/RFC5203, April 2008, 603 . 605 Appendix A. Changes from RFC 5203 607 o Updated references to revised HIP specifications. 609 o Added a new registration failure type for use in case of 610 insufficient resources available at the HIP registrar. 612 o Added requester authorization based on certificates, and new 613 registration failure type for invalid certificate. 615 Authors' Addresses 617 Julien Laganier 618 Luminate Wireless, Inc. 619 Cupertino, CA 620 USA 622 EMail: julien.ietf@gmail.com 624 Lars Eggert 625 NetApp 626 Sonnenallee 1 627 Kirchheim 85551 628 Germany 630 Phone: +49 151 12055791 631 EMail: lars@netapp.com 632 URI: http://eggert.org