idnits 2.17.1 draft-ietf-dhc-sedhcpv6-14.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. 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 (October 8, 2016) is 2756 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) == Unused Reference: 'RFC2460' is defined on line 1106, but no explicit reference was found in the text == Unused Reference: 'RFC3971' is defined on line 1115, but no explicit reference was found in the text == Unused Reference: 'RFC4443' is defined on line 1120, but no explicit reference was found in the text == Unused Reference: 'RFC5905' is defined on line 1130, but no explicit reference was found in the text == Unused Reference: 'RSA' is defined on line 1178, but no explicit reference was found in the text ** Obsolete normative reference: RFC 2460 (Obsoleted by RFC 8200) ** Obsolete normative reference: RFC 3315 (Obsoleted by RFC 8415) ** Obsolete normative reference: RFC 7283 (Obsoleted by RFC 8415) ** Downref: Normative reference to an Informational RFC: RFC 7435 ** Downref: Normative reference to an Informational RFC: RFC 7824 -- Obsolete informational reference (is this intentional?): RFC 2629 (Obsoleted by RFC 7749) -- Obsolete informational reference (is this intentional?): RFC 5226 (Obsoleted by RFC 8126) Summary: 5 errors (**), 0 flaws (~~), 6 warnings (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 DHC Working Group S. Jiang 3 Internet-Draft Huawei Technologies Co., Ltd 4 Intended status: Standards Track L. Li 5 Expires: April 11, 2017 Y. Cui 6 Tsinghua University 7 T. Jinmei 8 Infoblox Inc. 9 T. Lemon 10 Nominum, Inc. 11 D. Zhang 12 October 8, 2016 14 Secure DHCPv6 15 draft-ietf-dhc-sedhcpv6-14 17 Abstract 19 DHCPv6 includes no deployable security mechanism that can protect 20 end-to-end communication between DHCP clients and servers. This memo 21 describes a mechanism for using public key cryptography to provide 22 such security. The mechanism provides encryption in all cases, and 23 can be used for authentication based either on pre-sharing of 24 authorized certificates. 26 Status of This Memo 28 This Internet-Draft is submitted in full conformance with the 29 provisions of BCP 78 and BCP 79. 31 Internet-Drafts are working documents of the Internet Engineering 32 Task Force (IETF). Note that other groups may also distribute 33 working documents as Internet-Drafts. The list of current Internet- 34 Drafts is at http://datatracker.ietf.org/drafts/current/. 36 Internet-Drafts are draft documents valid for a maximum of six months 37 and may be updated, replaced, or obsoleted by other documents at any 38 time. It is inappropriate to use Internet-Drafts as reference 39 material or to cite them other than as "work in progress." 41 This Internet-Draft will expire on April 11, 2017. 43 Copyright Notice 45 Copyright (c) 2016 IETF Trust and the persons identified as the 46 document authors. All rights reserved. 48 This document is subject to BCP 78 and the IETF Trust's Legal 49 Provisions Relating to IETF Documents 50 (http://trustee.ietf.org/license-info) in effect on the date of 51 publication of this document. Please review these documents 52 carefully, as they describe your rights and restrictions with respect 53 to this document. Code Components extracted from this document must 54 include Simplified BSD License text as described in Section 4.e of 55 the Trust Legal Provisions and are provided without warranty as 56 described in the Simplified BSD License. 58 Table of Contents 60 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 61 2. Requirements Language and Terminology . . . . . . . . . . . . 3 62 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 63 4. Security Issues of DHCPv6 . . . . . . . . . . . . . . . . . . 4 64 5. Secure DHCPv6 Overview . . . . . . . . . . . . . . . . . . . 5 65 5.1. Solution Overview . . . . . . . . . . . . . . . . . . . . 5 66 5.2. New Components . . . . . . . . . . . . . . . . . . . . . 6 67 5.3. Support for Algorithm Agility . . . . . . . . . . . . . . 7 68 5.4. Caused change to RFC3315 . . . . . . . . . . . . . . . . 7 69 5.5. Applicability . . . . . . . . . . . . . . . . . . . . . . 8 70 6. DHCPv6 Client Behavior . . . . . . . . . . . . . . . . . . . 8 71 7. DHCPv6 Server Behavior . . . . . . . . . . . . . . . . . . . 12 72 8. Relay Agent Behavior . . . . . . . . . . . . . . . . . . . . 14 73 9. Processing Rules . . . . . . . . . . . . . . . . . . . . . . 14 74 9.1. Increasing Number Check . . . . . . . . . . . . . . . . . 14 75 10. Extensions for Secure DHCPv6 . . . . . . . . . . . . . . . . 15 76 10.1. New DHCPv6 Options . . . . . . . . . . . . . . . . . . . 15 77 10.1.1. Certificate Option . . . . . . . . . . . . . . . . . 15 78 10.1.2. Signature option . . . . . . . . . . . . . . . . . . 16 79 10.1.3. Increasing-number Option . . . . . . . . . . . . . . 18 80 10.1.4. Encrypted-message Option . . . . . . . . . . . . . . 18 81 10.2. New DHCPv6 Messages . . . . . . . . . . . . . . . . . . 19 82 10.3. Status Codes . . . . . . . . . . . . . . . . . . . . . . 19 83 11. Security Considerations . . . . . . . . . . . . . . . . . . . 20 84 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20 85 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22 86 14. Change log [RFC Editor: Please remove] . . . . . . . . . . . 22 87 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 24 88 15.1. Normative References . . . . . . . . . . . . . . . . . . 24 89 15.2. Informative References . . . . . . . . . . . . . . . . . 26 90 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 26 92 1. Introduction 94 The Dynamic Host Configuration Protocol for IPv6 (DHCPv6, [RFC3315]) 95 allows DHCPv6 servers to flexibly provide addressing and other 96 configuration information relating to local network infrastructure to 97 DHCP clients. The protocol provides no deployable security 98 mechanism, and consequently is vulnerable to various attacks. 100 This document provides a brief summary of the security 101 vulnerabilities of the DHCPv6 protocol and then describes a new 102 extension to the protocol that provides two additional types of 103 security: 105 o authentication of the DHCPv6 client and the DHCPv6 server to 106 defend against active attacks, such as spoofing. 108 o encryption between the DHCPv6 client and the DHCPv6 server in 109 order to protect the DHCPv6 communication from pervasive 110 monitoring. 112 The extension specified in this document applies only to end-to-end 113 communication between DHCP servers and clients. Options added by 114 relay agents in Relay-Forward messages, and options other than the 115 client message in Relay-Reply messages sent by DHCP servers, are not 116 protected. Such communications are already protected using the 117 mechanism described in section 21.1 in [RFC3315]. 119 This extension introduces two new DHCPv6 messages: the Encrypted- 120 Query and the Encrypted-Response messages. It defines four new 121 DHCPv6 options: the Certificate, the Signature, the Increasing- 122 number, and the Encrypted-message options. The Certificate, 123 Signature, and Increasing-number options are used for authentication. 124 The Encryption-Query message, Encryption-Response message and 125 Encrypted-message option are used for encryption. 127 2. Requirements Language and Terminology 129 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 130 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 131 document are to be interpreted as described in [RFC2119] when they 132 appear in ALL CAPS. When these words are not in ALL CAPS (such as 133 "should" or "Should"), they have their usual English meanings, and 134 are not to be interpreted as [RFC2119] key words. 136 3. Terminology 138 This section defines terminology specific to secure DHCPv6 used in 139 this document. 141 secure DHCPv6 client: A node that initiates a DHCPv6 request on a 142 link to obtain DHCPv6 configuration parameters from 143 one or more DHCPv6 servers using the encryption and 144 optional authentication mechanisms defined in this 145 document. 147 secure DHCPv6 server: A DHCPv6 server that implements the 148 authentication and encryption mechanisms defined in 149 this document, and is configured to use them. 151 4. Security Issues of DHCPv6 153 [RFC3315] defines an authentication mechanism with integrity 154 protection. This mechanism uses a symmetric key that is shared by 155 the client and server for authentication. It does not provide any 156 key distribution mechanism. 158 For this approach, operators can set up a key database for both 159 servers and clients from which the client obtains a key before 160 running DHCPv6. However, manual key distribution runs counter to the 161 goal of minimizing the configuration data needed at each host. 162 Consequently, there are no known deployments of this security 163 mechanism. 165 [RFC3315] provides an additional mechanism for preventing off-network 166 timing attacks using the Reconfigure message: the Reconfigure Key 167 authentication method. However, this method protects only the 168 Reconfigure message. The key is transmitted in plaintext to the 169 client in earlier exchanges and so this method is vulnerable to on- 170 path active attacks. 172 Anonymity Profile for DHCP Clients [RFC7844] explains how to generate 173 DHCPv4 or DHCPv6 requests that minimize the disclosure of identifying 174 information. However, the anonymity profile limits the use of the 175 certain options. It also cannot anticipate new options that may 176 contain private information is defined. In addition, the anonymity 177 profile does not work in cases where the client wants to maintain 178 anonymity from eavesdroppers but must identify itself to the DHCP 179 server with which it intends to communicate. 181 Privacy consideration for DHCPv6 [RFC7824] presents an analysis of 182 the privacy issues associated with the use of DHCPv6 by Internet 183 users. No solutions are presented. 185 Current DHCPv6 messages are still transmitted in cleartext and the 186 privacy information within the DHCPv6 message is not protected from 187 passive attack, such as pervasive monitoring [RFC7258]. 189 To better address the problem of passive monitoring and to achieve 190 authentication without requiring a symmetric key distribution 191 solution for DHCP, this document defines an asymmetric key 192 authentication and encryption mechanism. This protects against both 193 active attacks, such as spoofing, and passive attacks, such as 194 pervasive monitoring. 196 5. Secure DHCPv6 Overview 198 5.1. Solution Overview 200 The following figure illustrated secure DHCPv6 procedure. Briefly, 201 this extension establishes the server's identity with an anonymous 202 Information-Request exchange. Once the server's identity has been 203 established, the client may either choose to communicate with the 204 server or not. Not communicating with an unknown server avoids 205 revealing private information, but if there is no known server on a 206 particular link, the client will be unable to communicate with a DHCP 207 server. 209 If the client chooses to communicate with a server, it uses the 210 Encrypted-Query message to encapsulate its communications to the DHCP 211 server. The server responds with Encrypted-Response messages. 212 Normal DHCP messages are encapsulated in these two new messages using 213 the new defined Encrypted-message option. Besides the Encrypted- 214 message option, the Signature option is defined to verify the 215 integrity of the DHCPv6 messages and then authentication of client 216 and server. The Increasing number option is defined to detect replay 217 attack. 219 +-------------+ +-------------+ 220 |DHCPv6 Client| |DHCPv6 Server| 221 +-------------+ +-------------+ 222 | Information-request | 223 |----------------------------------------->| 224 | Option Request option | 225 | | 226 | Reply | 227 |<-----------------------------------------| 228 | Certificate option | 229 | Signature option | 230 | Increasing-number option | 231 | Server Identifier option | 232 | | 233 | Encryption-Query | 234 |----------------------------------------->| 235 | Encrypted-message option | 236 | Server Identifier option | 237 | | 238 | Encryption-Response | 239 |<-----------------------------------------| 240 | Encrypted-message option | 241 | | 243 Secure DHCPv6 Procedure 245 5.2. New Components 247 The new components of the mechanism specified in this document are as 248 follows: 250 o Servers and clients that use certificates first generate a public/ 251 private key pair and then obtain a certificate that signs the 252 public key. The Certificate option is defined to carry the 253 certificate of the sender. 255 o A signature generated using the private key which is used by the 256 receiver to verify the integrity of the DHCPv6 messages and then 257 authentication of the client/server. The Signature option is 258 defined to carry the signature. 260 o A Increasing-number that can be used to detect replayed packet. 261 The Timestamp is one of the possible implementation choices. The 262 Increasing-number option is defined to carry a strictly-increasing 263 serial number. 265 o The Encrypted-message option that contains the encrypted DHCPv6 266 message. 268 o The Encrypted-Query message that is sent from the secure DHCPv6 269 client to the secure DHCPv6 server. The Encrypted-Query message 270 MUST contain the Encrypted-message option. In addition, the 271 Server Identifier option MUST be contained if it is contained in 272 the original DHCPv6 message. The Encrypted-Query message MUST NOT 273 contain other options except the above options. 275 o The Encrypted-Response message that is sent from the secure DHCPv6 276 server to the secure DHCPv6 client. The Encrypted-Response 277 message MUST contain the Encrypted-message option. The Encrypted- 278 Response message MUST NOT contain any other options except it. 280 5.3. Support for Algorithm Agility 282 In order to provide a means of addressing problems that may emerge 283 with existing hash algorithms, signature algorithm and encryption 284 algorithms in the future, this document provides a mechanism to 285 support algorithm agility. The support for algorithm agility in this 286 document is mainly a algorithm notification mechanism between the 287 client and the server. The same client and server SHOULD use the 288 same algorithm in a single communication session. 290 If the server does not support the algorithm used by the client, the 291 server SHOULD reply with an AlgorithmNotSupported status code 292 (defined in Section 10.3) to the client. Upon receiving this status 293 code, the client MAY resend the message protected with the mandatory 294 algorithm. 296 5.4. Caused change to RFC3315 298 This protocol changes DHCPv6 message exchanges quite substantially: 299 previously, the client first sends a Solicit message, gets possibly 300 multiple Advertise messages, chooses the server (= sender of one of 301 the Advertises) that would be best for the client, and then sends a 302 Request to that chosen server. Now the server selection is done at 303 the key exchange phase (the initial Information-request and Reply 304 exchange). In addition, the Solicit and Rebind messages can be sent 305 only to a single server. If the client doesn't like the Advertise it 306 could restart the whole process, but it will be more expensive, and 307 there's no guarantee that other servers can provide a better 308 Advertise. For the privacy consideration, we have to give up the 309 previous server selection feature. 311 [RFC3315] provides an additional mechanism for preventing off-network 312 timing attacks using the Reconfigure message: the Reconfigure Key 313 authentication method. Secure DHCPv6 can protect the Reconfigure 314 message using the encryption method. So the Reconfigure Key 315 authentication method SHOULD NOT be used if Secure DHCPv6 is applied. 317 5.5. Applicability 319 In principle, secure DHCPv6 is applicable in any environment where 320 physical security on the link is not assured and attacks on DHCPv6 321 are a concern. In practice, however, authenticated and encrypted 322 DHCPv6 configuration will rely on some operational assumptions mainly 323 regarding public key distribution and management. In order to 324 achieve the more wide use of secure DHCPv6, opportunistic security 325 [RFC7435] can be applied to secure DHCPv6 deployment, which allows 326 DHCPv6 encryption in environments where support for authentication is 327 not available. 329 Secure DHCPv6 can achieve authentication and encryption based on pre- 330 sharing of authorized certificates. The One feasible environment in 331 an early deployment stage would be enterprise networks. In 332 enterprise networks, the client is manually pre-configured with the 333 trusted servers' public key and the server is also manually pre- 334 configured with the trusted clients' public keys. In some scenario, 335 such as coffee shop where the certificate cannot be validated and 336 don't want to be blocked from the Internet, then the DHCPv6 337 configuration process can be encrypted without authentication. 339 Note that this deployment scenario based on manual operation is not 340 different very much from the existing, shared-secret based 341 authentication mechanisms defined in [RFC3315] in terms of 342 operational costs. However, Secure DHCPv6 is still securer than the 343 shared-secret mechanism in that even if clients' keys stored for the 344 server are stolen that does not mean an immediate threat as these are 345 public keys. In addition, if some kind of PKI is used with Secure 346 DHCPv6, even if the initial installation of the certificates is done 347 manually, it will help reduce operational costs of revocation in case 348 a private key (especially that of the server) is compromised. 350 6. DHCPv6 Client Behavior 352 The secure DHCPv6 client is pre-configured with a certificate and its 353 corresponding private key for client authentication. If the client 354 is pre-configured with public key but not with a certificate, it can 355 generate the self-signed certificate. 357 The secure DHCPv6 client sends Information-request message as per 358 [RFC3315]. The Information-request message is used by the DHCPv6 359 client to request the server's identity verification information 360 without having addresses, prefixes or any non-security options 361 assigned to it. The Information-request message MUST NOT include any 362 other DHCPv6 options except the ORO option to minimize client's 363 privacy information leakage. The Option Request option in the 364 Information-request message MUST contain the option code of the 365 Certificate option. 367 When receiving the Reply messages from DHCPv6 servers, a secure 368 DHCPv6 client discards any DHCPv6 messages that meet any of the 369 following conditions: 371 o the Signature option is missing, 373 o multiple Signature options are present, 375 o the Certificate option is missing. 377 And then the client first checks the support of the hash algorithm, 378 signature algorithm and encryption algorithm that the server 379 supports. If the check fails, the Reply message is dropped. If the 380 hash algorithm field is zero, then it indicates that the hash 381 algorithm is fixed according to the corresponding signature 382 algorithm. If all the algorithms are supported, then the client also 383 uses the same algorithms in the return messages. 385 Then the client checks the authority of the server. The client 386 validates the certificates through the pre-configured local trusted 387 certificates list or other methods. A certificate that finds a match 388 in the local trust certificates list is treated as verified. The 389 message transaction-id is used as the identifier of the authenticated 390 server's public key for further message encryption. At this point, 391 the client has either recognized the certificate of the server, or 392 decided to drop the message. 394 The client MUST now authenticate the server by verifying the 395 signature and checking increasing number, if there is a Increasing- 396 number option. The order of two procedures is left as an 397 implementation decision. It is RECOMMENDED to check increasing 398 number first, because signature verification is much more 399 computationally expensive. If the decrypted message contains the 400 Increasing-number option, the client checks it according to the rule 401 defined in Section 9.1. For the message without an Increasing-number 402 option, according to the client's local policy, it MAY be acceptable 403 or rejected. If the server rejects such a message, the increasing 404 number check fails. 406 The Signature field verification MUST show that the signature has 407 been calculated as specified in Section 10.1.2. Only the messages 408 that get through both the signature verification and increasing 409 number check (if there is a Increasing-number option) are accepted. 410 Reply message that does not pass the above tests MUST be discarded. 412 If there are multiple authenticated DHCPv6 certs, the client selects 413 one DHCPv6 cert. The client can also choose other implementation 414 method depending on the client's local policy if the defined protocol 415 can also run normally. For example, the client can try multiple 416 transactions (each encrypted with different public key) at the "same" 417 time. It should be noted that the selected certificate may 418 correspond to multiple DHCPv6 servers. 420 If there are no authenticated DHCPv6 certs or existing servers fail 421 authentication, the client should retry a number of times. The 422 client conducts the server discovery process as per section 18.1.5 of 423 [RFC3315] to avoid the packet storm. In this way, it is difficult 424 for the rogue server to beat out a busy "real" server. And then the 425 client takes some alternative action depending on its local policy, 426 such as attempting to use an unsecured DHCPv6 server. 428 Once the server has been authenticated, the DHCPv6 client sends the 429 Encrypted-Query message to the DHCPv6 server. The Encrypted-Query 430 message contains the Encrypted-message option, which MUST be 431 constructed as explained in Section 10.1.4. In addition, the Server 432 Identifier option MUST be included if it is in the original message 433 (i.e. Request, Renew, Decline, Release) to avoid the need for other 434 servers receiving the message to attempt to decrypt it. The 435 Encrypted-message option contains the DHCPv6 message that is 436 encrypted using the public key contained in the selected cert. The 437 Encrypted-Query message MUST NOT contain any other DHCPv6 option 438 except the Server Identifier option and Encrypted-Message option. 440 The first DHCPv6 message sent from the client to the server, such as 441 Solicit message, MUST contain the Certificate option, Signature 442 option and Increasing-number option for client authentication. The 443 encryption text SHOULD be formatted as explain in [RFC5652]. The 444 Certificate option MUST be constructed as explained in 445 Section 10.1.1. It should be noted that a client's certificate for 446 the mandatory algorithm MUST be contained to ensure that the Reply 447 message with the error code can be encrypted using the mandatory 448 algorithm. In addition, one and only one Signature option MUST be 449 contained, which MUST be constructed as explained in Section 10.1.2. 450 One and only one Increasing-number option SHOULD be contained, which 451 MUST be constructed as explained in Section 10.1.3. 453 If the client has multiple certificates with different public/private 454 key pairs, the message transaction-id is also used as the identifier 455 of the client's private key for decryption. In addition, the 456 subsequent encrypted DHCPv6 message can contain the Increasing-number 457 option to defend against replay attack. 459 For the received Encrypted-Response message, the client MUST drop the 460 Encrypted-Response message if other DHCPv6 option except Encrypted- 461 message option is contained. Then, the client extracts the 462 Encrypted-message option and decrypts it using its private key to 463 obtain the original DHCPv6 message. Then it handles the message as 464 per [RFC3315]. If the decrypted DHCPv6 message contains the 465 Increasing-number option, the DHCPv6 client checks it according to 466 the rule defined in Section 9.1. If the client fails to get the 467 proper parameters from the chosen server, it sends the Encrypted- 468 Query message to another authenticated server for parameters 469 configuration until the client obtains the proper parameters. 471 When the decrypted message is Reply message with an error status 472 code, the error status code indicates the failure reason on the 473 server side. According to the received status code, the client MAY 474 take follow-up action: 476 o Upon receiving an AlgorithmNotSupported error status code, the 477 client SHOULD resend the message protected with one of the 478 mandatory algorithms. 480 o Upon receiving an AuthenticationFail error status code, the client 481 is not able to build up the secure communication with the server. 482 However, there may be other DHCPv6 servers available that 483 successfully complete authentication. The client MAY use the 484 AuthenticationFail as a hint and switch to other certificate if it 485 has another one; but otherwise treat the message containing the 486 status code as if it had not been received. But it SHOULD NOT 487 retry with the same certificate. However, if the client decides 488 to retransmit using the same certificate after receiving 489 AuthenticationFail, it MUST NOT retransmit immediately and MUST 490 follow normal retransmission routines defined in [RFC3315]. 492 o Upon receiving a DecryptionFail error status code, the client MAY 493 resend the message following normal retransmission routines 494 defined in [RFC3315]. 496 o Upon receiving a ReplayDetected error status code, the client MAY 497 resend the message with an adjusted Increasing-number option 498 according to the returned number from the DHCPv6 server. 500 o Upon receiving a SignatureFail error status code, the client MAY 501 resend the message following normal retransmission routines 502 defined in [RFC3315]. 504 7. DHCPv6 Server Behavior 506 The secure DHCPv6 server is pre-configured with a certificate and its 507 corresponding private key for server authentication. If the server 508 is pre-configured with public key but not with a certificate, it can 509 generate the self-signed certificate. 511 When the DHCPv6 server receives the Information-request message and 512 the contained Option Request option identifies the request is for the 513 server certificate information, it replies with a Reply message to 514 the client. The Reply message MUST contain the requested Certificate 515 option, which MUST be constructed as explained in Section 10.1.1, and 516 Server Identifier option. In addition, the Reply message MUST 517 contain one and only one Signature option, which MUST be constructed 518 as explained in Section 10.1.2. Besides, the Reply message SHOULD 519 contain one and only one Increasing-number option, which MUST be 520 constructed as explained in Section 10.1.3. In addition, if client 521 authentication is needed, then the ORO option in the Reply message 522 contains the code of the certificate option to indicate the request 523 of the client certificate information. 525 Upon the receipt of Encrypted-Query message, the server MUST drop the 526 message if the other DHCPv6 option is contained except Server 527 Identifier option and Encrypted-message option. Then, the server 528 checks the Server Identifier option if the Encrypted-Query message 529 contains it. The DHCPv6 server drops the message that is not for it, 530 thus not paying cost to decrypt messages. It decrypts the Encrypted- 531 message option using its private key if it is the target server. If 532 the decryption fails, the server SHOULD send an encrypted Reply 533 message with a DecryptionFail error status code, defined in 534 Section 10.3, back to the client. 536 If secure DHCPv6 server needs client authentication and decrypted 537 message is a Solicit/Information-request message which contains the 538 information for client authentication, the secure DHCPv6 server 539 discards the received message that meets any of the following 540 conditions: 542 o the Signature option is missing, 544 o multiple Signature options are present, 546 o the Certificate option is missing. 548 In such failure, the server SHOULD send an encrypted Reply message 549 with an UnspecFail (value 1, [RFC3315]) error status code to the 550 client. 552 The server SHOULD first check the support of the hash function, 553 signature algorithm, encryption algorithm that the client supports. 554 If the hash algorithm field is zero, then the corresponding hash 555 algorithm is fixed according to the signature algorithm. If the 556 check fails, the server SHOULD reply with an AlgorithmNotSupported 557 error status code, defined in Section 10.3, back to the client. 558 Because the server does not support the acknowledged algorithm, the 559 Reply message with the AlgorithmNotSupported error status code is 560 encrypted with the mandatory algorithm. If all the algorithms are 561 supported, the server then checks the authority of this client. 563 The server validates the client's certificate through the local pre- 564 configured trusted certificates list. A certificate that finds a 565 match in the local trust certificates list is treated as verified. 566 The message that fails authentication validation MUST be dropped. In 567 such failure, the DHCPv6 server replies with an AuthenticationFail 568 error status code, defined in Section 10.3, back to the client. The 569 Reply message with the AuthenticationFail error status code is also 570 encrypted. At this point, the server has either recognized the 571 authentication of the client, or decided to drop the message. 573 If the decrypted message contains the Increasing-number option, the 574 server checks it according to the rule defined in Section 9.1. If 575 the check fails, an encrypted Reply message with a ReplayDetected 576 error status code, defined in Section 10.3, should be sent back to 577 the client. In addition, a Increasing-number option is carried to 578 indicate the server's stored number for the client to use. According 579 to the server's local policy, the message without an Increasing- 580 number option MAY be acceptable or rejected. If the server rejects 581 such a message, the server processes it as the increasing number 582 check fails. 584 The Signature field verification MUST show that the signature has 585 been calculated as specified in Section 10.1.2. If the signature 586 check fails, the DHCPv6 server SHOULD send an encrypted Reply message 587 with a SignatureFail error status code. Only the clients that get 588 through both the signature verification and increasing number check 589 (if there is a Increasing-number option) are accepted as 590 authenticated clients and continue to be handled their message as 591 defined in [RFC3315]. 593 Once the client has been authenticated, the DHCPv6 server sends the 594 Encrypted-response message to the DHCPv6 client. The Encrypted- 595 response message MUST only contain the Encrypted-message option, 596 which MUST be constructed as explained in Section 10.1.4. The 597 encryption text SHOULD be formatted as explain in [RFC5652]. The 598 Encrypted-message option contains the encrypted DHCPv6 message that 599 is encrypted using the authenticated client's public key. To provide 600 the replay protection, the Increasing-number option can be contained 601 in the encrypted DHCPv6 message. 603 8. Relay Agent Behavior 605 When a DHCPv6 relay agent receives an Encrypted-query or Encrypted- 606 response message, it may not recognize this message. The unknown 607 messages MUST be forwarded as described in [RFC7283]. 609 When a DHCPv6 relay agent recognizes the Encrypted-query and 610 Encrypted-response messages, it forwards the message according to 611 section 20 of [RFC3315]. There is nothing more the relay agents have 612 to do, it neither needs to verify the messages from client or server, 613 nor add any secure DHCPv6 options. Actually, by definition in this 614 document, relay agents MUST NOT add any secure DHCPv6 options. 616 Relay-forward and Relay-reply messages MUST NOT contain any 617 additional Certificate option or Increasing-number option, aside from 618 those present in the innermost encapsulated messages from the client 619 or server. 621 Relay agent is RECOMMENDED to cache server announcements to form the 622 list of the available DHCPv6 server certs. If the relay agent 623 receives the Information-request message, then it replies with a list 624 of server certs available locally. In this way, the client can be 625 confident of a quick response, and therefore treat the lack of a 626 quick response as an indication that no authenticated DHCP servers 627 exist. 629 9. Processing Rules 631 9.1. Increasing Number Check 633 In order to check the Increasing-number option, defined in 634 Section 10.1.3, the client/server has one stable stored number for 635 replay attack detection. The server should keep a record of the 636 increasing number forever. And the client keeps a record of the 637 increasing number during the transaction with the DHCPv6 server. In 638 addition, the client can forget the increasing number information 639 after the transaction is finished. 641 It is essential to remember that the increasing number is finite. 642 All arithmetic dealing with sequence numbers must be performed modulo 643 2^64. This unsigned arithmetic preserves the relationship of 644 sequence numbers as they cycle from 2^64 - 1 to 0 again. 646 In order to check the Increasing-number option, the following 647 comparison is needed. The symbol ">=" means "more or equal" (modulo 648 2^64). 650 NUM.STO = the stored number in the client/server 652 NUM.REC = the acknowledged number from the received message 654 The Increasing-number option in the received message passes the 655 increasing number check if it meets the following condition: 657 NUM.REC >= NUM.STO 659 And then, the value of NUM.STO is changed into the value of NUM.REC. 661 The increasing number check fails if NUM.REC is less than NUM.STO. 663 10. Extensions for Secure DHCPv6 665 This section describes the extensions to DHCPv6. Four new DHCPv6 666 options, two new DHCPv6 messages and five new status codes are 667 defined. 669 10.1. New DHCPv6 Options 671 10.1.1. Certificate Option 673 The Certificate option carries the certificate(s) of the client/ 674 server. The format of the Certificate option is described as 675 follows: 677 0 1 2 3 678 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 1 679 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 680 | OPTION_CERTIFICATE | option-len | 681 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 682 | EA-id | | 683 +-+-+-+-+-+-+-+-+ . 684 . Certificate (variable length) . 685 . . 686 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 688 option-code OPTION_CERTIFICATE (TBA1). 690 option-len 1 + Length of certificate in octets. 692 EA-id Encryption Algorithm id. The encryption algorithm 693 is used for the encrypted DHCPv6 configuration 694 process. This design is adopted in order to provide 695 encryption algorithm agility. The value is from the 696 Encryption Algorithm for Secure DHCPv6 registry in 697 IANA. A registry of the initial assigned values 698 is defined in Section 12. 700 Certificate A variable-length field containing certificates. The 701 encoding of certificate and certificate data MUST 702 be in format as defined in Section 3.6, [RFC7296]. 703 The support of X.509 certificate is mandatory. 705 10.1.2. Signature option 707 The Signature option allows a signature that is signed by the private 708 key to be attached to a DHCPv6 message. The Signature option could 709 be in any place within the DHCPv6 message while it is logically 710 created after the entire DHCPv6 header and options. It protects the 711 entire DHCPv6 header and options, including itself. The format of 712 the Signature option is described as follows: 714 0 1 2 3 715 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 1 716 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 717 | OPTION_SIGNATURE | option-len | 718 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 719 | SA-id | HA-id | | 720 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 721 | | 722 . Signature (variable length) . 723 . . 724 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 725 option-code OPTION_SIGNATURE (TBA2). 727 option-len 2 + Length of Signature field in octets. 729 SA-id Signature Algorithm id. The signature algorithm is 730 used for computing the signature result. This 731 design is adopted in order to provide signature 732 algorithm agility. The value is from the Signature 733 Algorithm for Secure DHCPv6 registry in IANA. The 734 support of RSASSA-PKCS1-v1_5 is mandatory. A 735 registry of the initial assigned values is defined 736 in Section 12. 738 HA-id Hash Algorithm id. The hash algorithm is used for 739 computing the signature result. This design is 740 adopted in order to provide hash algorithm agility. 741 The value is from the Hash Algorithm for Secure 742 DHCPv6 registry in IANA. The support of SHA-256 is 743 mandatory. A registry of the initial assigned values 744 is defined in Section 12. If the signature algorithm 745 and hash algorithm cannot be separated, the HA-id 746 field is zero. The hash algorithm is decided by the 747 corresponding signature algorithm. 749 Signature A variable-length field containing a digital 750 signature. The signature value is computed with 751 the hash algorithm and the signature algorithm, 752 as described in HA-id and SA-id. The signature 753 constructed by using the sender's private key 754 protects the following sequence of octets: 756 1. The DHCPv6 message header. 758 2. All DHCPv6 options including the Signature 759 option (fill the Signature field with zeroes). 761 The Signature field MUST be padded, with all 0, to 762 the next octet boundary if its size is not a 763 multiple of 8 bits. The padding length depends on 764 the signature algorithm, which is indicated in the 765 SA-id field. 767 Note: If Secure DHCPv6 is used, the DHCPv6 message is encrypted in a 768 way that the authentication mechanism defined in RFC3315 does not 769 understand. So the Authentication option SHOULD NOT be used if 770 Secure DHCPv6 is applied. 772 10.1.3. Increasing-number Option 774 The Increasing-number option carries the number which is higher than 775 the local stored number on the client/server. It adds the anti- 776 replay protection to the DHCPv6 messages. It is optional. 778 0 1 2 3 779 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 1 780 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 781 | OPTION_INCREASING_NUM | option-len | 782 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 783 | | 784 | InreasingNum (64-bit) | 785 | | 786 | | 787 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 789 option-code OPTION_INCREASING_NUM (TBA3). 791 option-len 8, in octets. 793 IncreasingNum A number for the replay attack detection which is more 794 or equal compared with the local stored number. 796 10.1.4. Encrypted-message Option 798 The Encrypted-message option carries the encrypted DHCPv6 message 799 with the recipient's public key. 801 The format of the Encrypted-message option is: 803 0 1 2 3 804 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 1 805 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 806 | option-code | option-len | 807 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 808 | | 809 . encrypted DHCPv6 message . 810 . (variable) . 811 . . 812 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 814 Figure 1: Encrypted-message Option Format 816 option-code OPTION_ENCRYPTED_MSG (TBA4). 818 option-len Length of the encrypted DHCPv6 message. 820 encrypted DHCPv6 message A variable length field containing the 821 encrypted DHCPv6 message sent by the client or the server. In 822 Encrypted-Query message, it contains encrypted DHCPv6 message sent 823 by a client. In Encrypted-response message, it contains encrypted 824 DHCPv6 message sent by a server. 826 10.2. New DHCPv6 Messages 828 Two new DHCPv6 messages are defined to achieve the DHCPv6 encryption: 829 Encrypted-Query and Encrypted-Response. Both the DHCPv6 messages 830 defined in this document share the following format: 832 0 1 2 3 833 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 1 834 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 835 | msg-type | transaction-id | 836 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 837 | | 838 . options . 839 . (variable) . 840 | | 841 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 843 Figure 2: The format of Encrypted-Query and Encrypted-Response 844 Messages 846 msg-type Identifier of the message type. It can be either 847 Encrypted-Query (TBA5) or DHCPv6-Response (TBA6). 849 transaction-id The transaction ID for this message exchange. 851 options The Encrypted-Query message MUST contain the 852 Encrypted-message option and MUST contain the Server 853 Identifier option if the message in the Encrypted- 854 message option has a Server Identifier option. The 855 Encrypted-Response message MUST only contain the 856 Encrypted-message option. 858 10.3. Status Codes 860 The following new status codes, see Section 5.4 of [RFC3315] are 861 defined. 863 o AlgorithmNotSupported (TBD7): indicates that the DHCPv6 server 864 does not support algorithms that sender used. 866 o AuthenticationFail (TBD8): indicates that the message from the 867 DHCPv6 client fails authentication check. 869 o ReplayDetected (TBD9): indicates the message from DHCPv6 client 870 fails the increasing number check. 872 o SignatureFail (TBD10): indicates the message from DHCPv6 client 873 fails the signature check. 875 o DecryptionFail (TBD11): indicates the message from DHCPv6 client 876 fails the DHCPv6 message decryption. 878 11. Security Considerations 880 This document provides the authentication and encryption mechanisms 881 for DHCPv6. 883 [RFC6273] has analyzed possible threats to the hash algorithms used 884 in SEND. Since Secure DHCPv6 defined in this document uses the same 885 hash algorithms in similar way to SEND, analysis results could be 886 applied as well: current attacks on hash functions do not constitute 887 any practical threat to the digital signatures used in the signature 888 algorithm in Secure DHCPv6. 890 A server, whose local policy accepts messages without a Increasing- 891 number option, may have to face the risk of replay attacks. 893 There are some mandatory algorithm for encryption algorithm in this 894 document. It may be at some point that the mandatory algorithm is no 895 longer safe to use. 897 If the client tries more than one cert for client authentication, the 898 server can easily get a client that implements this to enumerate its 899 entire cert list and probably learn a lot about a client that way. 901 12. IANA Considerations 903 This document defines four new DHCPv6 [RFC3315] options. The IANA is 904 requested to assign values for these four options from the DHCPv6 905 Option Codes table of the DHCPv6 Parameters registry maintained in 906 http://www.iana.org/assignments/dhcpv6-parameters. The four options 907 are: 909 The Certificate Option (TBA1), described in Section 10.1.1. 911 The Signature Option (TBA2), described in Section 10.1.2. 913 The Increasing-number Option (TBA3),described in Section 10.1.3. 915 The Encrypted-message Option (TBA4), described in Section 10.1.4. 917 The IANA is also requested to assign value for these two messages 918 from the DHCPv6 Message Types table of the DHCPv6 Parameters registry 919 maintained in http://www.iana.org/assignments/dhcpv6-parameters. The 920 two messages are: 922 The Encrypted-Query Message (TBA5), described in Section 10.2. 924 The Encrypted-Response Message (TBA6), described in Section 10.2. 926 The IANA is also requested to add three new registry tables to the 927 DHCPv6 Parameters registry maintained in 928 http://www.iana.org/assignments/dhcpv6-parameters. The three tables 929 are the Hash Algorithm for Secure DHCPv6 table, the Signature 930 Algorithm for Secure DHCPv6 table and the Encryption Algorithm for 931 Secure DHCPv6 table. 933 Initial values for these registries are given below. Future 934 assignments are to be made through Standards Action [RFC5226]. 935 Assignments for each registry consist of a name, a value and a RFC 936 number where the registry is defined. 938 Hash Algorithm for Secure DHCPv6. The values in this table are 8-bit 939 unsigned integers. The following initial values are assigned for 940 Hash Algorithm for Secure DHCPv6 in this document: 942 Name | Value | RFCs 943 -------------------+---------+-------------- 944 SigAlg-Combined | ox00 | this document 945 SHA-256 | 0x01 | this document 946 SHA-512 | 0x02 | this document 948 Signature Algorithm for Secure DHCPv6. The values in this table are 949 8-bit unsigned integers. The following initial values are assigned 950 for Signature Algorithm for Secure DHCPv6 in this document: 952 Name | Value | RFCs 953 -------------------+---------+-------------- 954 RSASSA-PKCS1-v1_5 | 0x01 | this document 956 Encryption algorithm for Secure DHCPv6. The values in this table are 957 8-bit unsigned integers. The following initial values are assigned 958 for encryption algorithm for Secure DHCPv6 in this document: 960 Name | Value | RFCs 961 -------------------+---------+-------------- 962 RSA | 0x01 | this document 964 IANA is requested to assign the following new DHCPv6 Status Codes, 965 defined in Section 10.3, in the DHCPv6 Parameters registry maintained 966 in http://www.iana.org/assignments/dhcpv6-parameters: 968 Code | Name | Reference 969 ---------+-----------------------+-------------- 970 TBD7 | AlgorithmNotSupported | this document 971 TBD8 | AuthenticationFail | this document 972 TBD9 | ReplayDetected | this document 973 TBD10 | SignatureFail | this document 974 TBD11 | DecryptionFail | this document 976 13. Acknowledgements 978 The authors would like to thank Tomek Mrugalski, Bernie Volz, 979 Jianping Wu, Randy Bush, Yiu Lee, Sean Shen, Ralph Droms, Jari Arkko, 980 Sean Turner, Stephen Farrell, Christian Huitema, Stephen Kent, Thomas 981 Huth, David Schumacher, Francis Dupont, Gang Chen, Suresh Krishnan, 982 Fred Templin, Robert Elz, Nico Williams, Erik Kline, Alan DeKok, 983 Bernard Aboba, Sam Hartman, Qi Sun, Zilong Liu and other members of 984 the IETF DHC working group for their valuable comments. 986 This document was produced using the xml2rfc tool [RFC2629]. 988 14. Change log [RFC Editor: Please remove] 990 draft-ietf-dhc-sedhcpv6-14: For the deployment part, Tofu is out of 991 scope and take Opportunistic security into consideration; Increasing 992 number option is changed into 64 bits; Increasing number check is a 993 separate section; IncreasingnumFail error status code is changed into 994 ReplayDetected error status code; Add the section of "caused change 995 to RFC3315"; 997 draft-ietf-dhc-sedhcpv6-13: Change the Timestamp option into 998 Increasing-number option and the corresponding check method; Delete 999 the OCSP stampling part for the certificate check; Add the scenario 1000 where the hash and signature algorithms cannot be separated; Add the 1001 comparison with RFC7824 and RFC7844; Add the encryption text format 1002 and reference of RFC5652. Add the consideration of scenario where 1003 multiple DHCPv6 servers share one common DHCPv6 server. Add the 1004 statement that Encrypted-Query and Encrypted-Response messages can 1005 only contain certain options: Server Identifier option and Encrypted- 1006 message option. Add opportunistic security for deployment 1007 consideration. Besides authentication+encyrption mode, encryption- 1008 only mode is added. 1010 draft-ietf-dhc-sedhcpv6-12: Add the Signature option and timestamp 1011 option during server/client authentication process. Add the hash 1012 function and signature algorithm. Add the requirement: The 1013 Information-request message cannot contain any other options except 1014 ORO option. Modify the use of "SHOULD"; Delete the reference of 1015 RFC5280 and modify the method of client/server cert verification; Add 1016 the relay agent cache function for the quick response when there is 1017 no authenticated server. 2016-4-24. 1019 draft-ietf-dhc-sedhcpv6-11: Delete the Signature option, because the 1020 encrypted DHCPv6 message and the Information-request message (only 1021 contain the Certificate option) don't need the Signature option for 1022 message integrity check; Rewrite the "Applicability" section; Add the 1023 encryption algorithm negotiation process; To support the encryption 1024 algorithm negotiation, the Certificate option contains the EA- 1025 id(encryption algorithm identifier) field; Reserve the Timestamp 1026 option to defend against the replay attacks for encrypted DHCPv6 1027 configuration process; Modify the client behavior when there is no 1028 authenticated DHCPv6 server; Add the DecryptionFail error code. 1029 2016-3-9. 1031 draft-ietf-dhc-sedhcpv6-10: merge DHCPv6 authentication and DHCPv6 1032 encryption. The public key option is removed, because the device can 1033 generate the self-signed certificate if it is pre-configured the 1034 public key not the certificate. 2015-12-10. 1036 draft-ietf-dhc-sedhcpv6-09: change some texts about the deployment 1037 part.2015-12-10. 1039 draft-ietf-dhc-sedhcpv6-08: clarified what the client and the server 1040 should do if it receives a message using unsupported algorithm; 1041 refined the error code treatment regarding to AuthenticationFail and 1042 TimestampFail; added consideration on how to reduce the DoS attack 1043 when using TOFU; other general editorial cleanups. 2015-06-10. 1045 draft-ietf-dhc-sedhcpv6-07: removed the deployment consideration 1046 section; instead, described more straightforward use cases with TOFU 1047 in the overview section, and clarified how the public keys would be 1048 stored at the recipient when TOFU is used. The overview section also 1049 clarified the integration of PKI or other similar infrastructure is 1050 an open issue. 2015-03-23. 1052 draft-ietf-dhc-sedhcpv6-06: remove the limitation that only clients 1053 use PKI- certificates and only servers use public keys. The new text 1054 would allow clients use public keys and servers use PKI-certificates. 1055 2015-02-18. 1057 draft-ietf-dhc-sedhcpv6-05: addressed comments from mail list that 1058 responsed to the second WGLC. 2014-12-08. 1060 draft-ietf-dhc-sedhcpv6-04: addressed comments from mail list. 1061 Making timestamp an independent and optional option. Reduce the 1062 serverside authentication to base on only client's certificate. 1063 Reduce the clientside authentication to only Leaf of Faith base on 1064 server's public key. 2014-09-26. 1066 draft-ietf-dhc-sedhcpv6-03: addressed comments from WGLC. Added a 1067 new section "Deployment Consideration". Corrected the Public Key 1068 Field in the Public Key Option. Added consideration for large DHCPv6 1069 message transmission. Added TimestampFail error code. Refined the 1070 retransmission rules on clients. 2014-06-18. 1072 draft-ietf-dhc-sedhcpv6-02: addressed comments (applicability 1073 statement, redesign the error codes and their logic) from IETF89 DHC 1074 WG meeting and volunteer reviewers. 2014-04-14. 1076 draft-ietf-dhc-sedhcpv6-01: addressed comments from IETF88 DHC WG 1077 meeting. Moved Dacheng Zhang from acknowledgement to be co-author. 1078 2014-02-14. 1080 draft-ietf-dhc-sedhcpv6-00: adopted by DHC WG. 2013-11-19. 1082 draft-jiang-dhc-sedhcpv6-02: removed protection between relay agent 1083 and server due to complexity, following the comments from Ted Lemon, 1084 Bernie Volz. 2013-10-16. 1086 draft-jiang-dhc-sedhcpv6-01: update according to review comments from 1087 Ted Lemon, Bernie Volz, Ralph Droms. Separated Public Key/ 1088 Certificate option into two options. Refined many detailed 1089 processes. 2013-10-08. 1091 draft-jiang-dhc-sedhcpv6-00: original version, this draft is a 1092 replacement of draft-ietf-dhc-secure-dhcpv6, which reached IESG and 1093 dead because of consideration regarding to CGA. The authors followed 1094 the suggestion from IESG making a general public key based mechanism. 1095 2013-06-29. 1097 15. References 1099 15.1. Normative References 1101 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1102 Requirement Levels", BCP 14, RFC 2119, 1103 DOI 10.17487/RFC2119, March 1997, 1104 . 1106 [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 1107 (IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460, 1108 December 1998, . 1110 [RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins, 1111 C., and M. Carney, "Dynamic Host Configuration Protocol 1112 for IPv6 (DHCPv6)", RFC 3315, DOI 10.17487/RFC3315, July 1113 2003, . 1115 [RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander, 1116 "SEcure Neighbor Discovery (SEND)", RFC 3971, 1117 DOI 10.17487/RFC3971, March 2005, 1118 . 1120 [RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet 1121 Control Message Protocol (ICMPv6) for the Internet 1122 Protocol Version 6 (IPv6) Specification", RFC 4443, 1123 DOI 10.17487/RFC4443, March 2006, 1124 . 1126 [RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70, 1127 RFC 5652, DOI 10.17487/RFC5652, September 2009, 1128 . 1130 [RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, 1131 "Network Time Protocol Version 4: Protocol and Algorithms 1132 Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010, 1133 . 1135 [RFC7283] Cui, Y., Sun, Q., and T. Lemon, "Handling Unknown DHCPv6 1136 Messages", RFC 7283, DOI 10.17487/RFC7283, July 2014, 1137 . 1139 [RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T. 1140 Kivinen, "Internet Key Exchange Protocol Version 2 1141 (IKEv2)", STD 79, RFC 7296, DOI 10.17487/RFC7296, October 1142 2014, . 1144 [RFC7435] Dukhovni, V., "Opportunistic Security: Some Protection 1145 Most of the Time", RFC 7435, DOI 10.17487/RFC7435, 1146 December 2014, . 1148 [RFC7824] Krishnan, S., Mrugalski, T., and S. Jiang, "Privacy 1149 Considerations for DHCPv6", RFC 7824, 1150 DOI 10.17487/RFC7824, May 2016, 1151 . 1153 [RFC7844] Huitema, C., Mrugalski, T., and S. Krishnan, "Anonymity 1154 Profiles for DHCP Clients", RFC 7844, 1155 DOI 10.17487/RFC7844, May 2016, 1156 . 1158 15.2. Informative References 1160 [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, 1161 DOI 10.17487/RFC2629, June 1999, 1162 . 1164 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 1165 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 1166 DOI 10.17487/RFC5226, May 2008, 1167 . 1169 [RFC6273] Kukec, A., Krishnan, S., and S. Jiang, "The Secure 1170 Neighbor Discovery (SEND) Hash Threat Analysis", RFC 6273, 1171 DOI 10.17487/RFC6273, June 2011, 1172 . 1174 [RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an 1175 Attack", BCP 188, RFC 7258, DOI 10.17487/RFC7258, May 1176 2014, . 1178 [RSA] RSA Laboratories, "RSA Encryption Standard, Version 2.1, 1179 PKCS 1", November 2002. 1181 Authors' Addresses 1183 Sheng Jiang 1184 Huawei Technologies Co., Ltd 1185 Q14, Huawei Campus, No.156 Beiqing Road 1186 Hai-Dian District, Beijing, 100095 1187 CN 1189 Email: jiangsheng@huawei.com 1191 Lishan Li 1192 Tsinghua University 1193 Beijing 100084 1194 P.R.China 1196 Phone: +86-15201441862 1197 Email: lilishan48@gmail.com 1198 Yong Cui 1199 Tsinghua University 1200 Beijing 100084 1201 P.R.China 1203 Phone: +86-10-6260-3059 1204 Email: yong@csnet1.cs.tsinghua.edu.cn 1206 Tatuya Jinmei 1207 Infoblox Inc. 1208 3111 Coronado Drive 1209 Santa Clara, CA 1210 US 1212 Email: jinmei@wide.ad.jp 1214 Ted Lemon 1215 Nominum, Inc. 1216 2000 Seaport Blvd 1217 Redwood City, CA 94063 1218 USA 1220 Phone: +1-650-381-6000 1221 Email: Ted.Lemon@nominum.com 1223 Dacheng Zhang 1224 Beijing 1225 CN 1227 Email: dacheng.zhang@gmail.com