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Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-10) exists of draft-ietf-karp-crypto-key-table-07 Summary: 0 errors (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 OSPF Working Group M. Bhatia 3 Internet-Draft Alcatel-Lucent 4 Intended status: Standards Track S. Hartman 5 Expires: May 29, 2014 Painless Security 6 D. Zhang 7 Huawei Technologies co., LTD. 8 A. Lindem 9 Ericsson 10 November 25, 2013 12 Security Extension for OSPFv2 when using Manual Key Management 13 draft-ietf-ospf-security-extension-manual-keying-06 15 Abstract 17 The current OSPFv2 cryptographic authentication mechanism as defined 18 in RFC 2328 and RFC 5709 is vulnerable to both inter-session and 19 intra-session replay attacks when using manual keying. Additionally, 20 the existing cryptographic authentication schemes do not cover the IP 21 header. This omission can be exploited to carry out various types of 22 attacks. 24 This draft proposes changes to the authentication sequence number 25 mechanism that will protect OSPFv2 from both inter-session and intra- 26 session replay attacks when using manual keys for securing OSPFv2 27 protocol packets. Additionally, we also describe some changes in the 28 cryptographic hash computation so that we eliminate most attacks that 29 result from OSPFv2 not protecting the IP header. 31 Status of this Memo 33 This Internet-Draft is submitted in full conformance with the 34 provisions of BCP 78 and BCP 79. 36 Internet-Drafts are working documents of the Internet Engineering 37 Task Force (IETF). Note that other groups may also distribute 38 working documents as Internet-Drafts. The list of current Internet- 39 Drafts is at http://datatracker.ietf.org/drafts/current/. 41 Internet-Drafts are draft documents valid for a maximum of six months 42 and may be updated, replaced, or obsoleted by other documents at any 43 time. It is inappropriate to use Internet-Drafts as reference 44 material or to cite them other than as "work in progress." 46 This Internet-Draft will expire on May 29, 2014. 48 Copyright Notice 49 Copyright (c) 2013 IETF Trust and the persons identified as the 50 document authors. All rights reserved. 52 This document is subject to BCP 78 and the IETF Trust's Legal 53 Provisions Relating to IETF Documents 54 (http://trustee.ietf.org/license-info) in effect on the date of 55 publication of this document. Please review these documents 56 carefully, as they describe your rights and restrictions with respect 57 to this document. Code Components extracted from this document must 58 include Simplified BSD License text as described in Section 4.e of 59 the Trust Legal Provisions and are provided without warranty as 60 described in the Simplified BSD License. 62 Table of Contents 64 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 65 1.1. Requirements Section . . . . . . . . . . . . . . . . . . . 3 66 1.2. Acknowledgments . . . . . . . . . . . . . . . . . . . . . 4 67 2. Replay Protection using Extended Sequence Numbers . . . . . . 4 68 3. OSPF Packet Extensions . . . . . . . . . . . . . . . . . . . . 5 69 4. OSPF Packet Key Selection . . . . . . . . . . . . . . . . . . 6 70 4.1. Key Selection for Unicast OSPF Packet Transmission . . . . 7 71 4.2. Key Selection for Multicast OSPF Packet Transmission . . . 8 72 4.3. Key Selection for OSPF Packet Reception . . . . . . . . . 8 73 5. Securing the IP header . . . . . . . . . . . . . . . . . . . . 9 74 6. Mitigating Cross-Protocol Attacks . . . . . . . . . . . . . . 9 75 7. Security Considerations . . . . . . . . . . . . . . . . . . . 10 76 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 77 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11 78 9.1. Normative References . . . . . . . . . . . . . . . . . . . 11 79 9.2. Informative References . . . . . . . . . . . . . . . . . . 11 80 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12 82 1. Introduction 84 The OSPFv2 cryptographic authentication mechanism as described in 85 [RFC2328] uses per-packet sequence numbers to provide protection 86 against replay attacks. The sequence numbers increase monotonically 87 so that attempts to replay the stale packets can be thwarted. The 88 sequence number values are maintained as a part of adjacency states. 89 Therefore, if an adjacency is taken down, the associated sequence 90 numbers get reinitialized and the neighbors start all over again. 91 Additionally, the cryptographic authentication mechanism does not 92 specify how to deal with the rollover of a sequence number when its 93 value wraps. These omissions can be taken advantage of by attackers 94 to implement various replay attacks ([RFC6039]). In order to address 95 these issues, we propose extensions to the authentication sequence 96 number mechanism. 98 The cryptographic authentication as described in [RFC2328] and later 99 updated in [RFC5709] does not include the IP header. This also can 100 be exploited to launch several attacks as the source address in the 101 IP header is no longer protected. The OSPF specification, for 102 broadcast and NBMA (Non-Broadcast Multi-Access Networks), requires 103 implementations to look at the source address in the IP header to 104 determine the neighbor from which the packet was received. Changing 105 the IP source address of a packet that confuses the receiver and can 106 be exploited to produce a number of denial of service attacks 107 [RFC6039]. If the packet is interpreted as coming from a different 108 neighbor, the sequence number received from the neighbor may be 109 updated. This may disrupt communication with the legitimate 110 neighbor. Hello packets may be reflected to cause a neighbor to 111 appear to have one-way communication. Additionally, Database 112 Description packets may be reflected in cases where the per-packet 113 sequence numbers are sufficiently divergent in order to disrupt an 114 adjacency [RFC6863]. This is referred to as the IP layer issue in 115 [RFC6862]. 117 [RFC2328] states that implementations MUST offer keyed MD5 118 authentication. It is likely that this will be deprecated in favor 119 of the stronger algorithms described in [RFC5709] and required in 120 [RFC6094]. 122 This draft proposes a few simple changes to the cryptographic 123 authentication mechanism, as currently described in [RFC5709], to 124 prevent such IP layer attacks. 126 1.1. Requirements Section 128 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 129 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 130 document are to be interpreted as described in RFC2119 [RFC2119]. 132 When used in lowercase, these words convey their typical use in 133 common language, and are not to be interpreted as described in 134 RFC2119 [RFC2119]. 136 1.2. Acknowledgments 138 Thanks to Ran Atkinson for help in the analysis of RFC 6506 errata 139 leading to clarifications in this document. 141 2. Replay Protection using Extended Sequence Numbers 143 In order to provide replay protection against both inter-session and 144 intra-session replay attacks, the OSPFv2 sequence number is expanded 145 to 64-bits with the least significant 32-bit value containing a 146 strictly increasing sequence number and the most significant 32-bit 147 value containing the boot count. OSPFv2 implementations are required 148 to retain the boot count in non-volatile storage for the deployment 149 life the OSPF router. The requirement to preserve the boot count is 150 also placed on SNMP agents by the SNMPv3 security architecture (refer 151 to snmpEngineBoots in [RFC4222]). 153 Since there is no room in the OSPFv2 packet for a 64-bit sequence 154 number, it will occupy the 8 octets following the OSPFv2 packet and 155 MUST be included when calculating the OSPFv2 packet digest. These 156 additional 8 bytes are not included in the OSPFv2 packet header 157 length but are included in the OSPFv2 header Authentication Data 158 length and the IPv4 packet header length. 160 The lower order 32-bit sequence number MUST be incremented for every 161 OSPF packet sent by the OSPF router. Upon reception, the sequence 162 number MUST be greater than the sequence number in the last OSPF 163 packet of that type accepted from the sending OSPF neighbor. 164 Otherwise, the OSPF packet is considered a replayed packet and 165 dropped. OSPF packets of different types may arrive out of order if 166 they are prioritized as recommended in [RFC3414]. 168 OSPF routers implementing this specification MUST use available 169 mechanisms to preserve the sequence number's strictly increasing 170 property for the deployed life of the OSPFv3 router (including cold 171 restarts). This is achieved by maintaining a boot count in non- 172 volatile storage and incrementing it each time the OSPF router loses 173 its prior sequence number state. The SNMPv3 snmpEngineBoots variable 174 [RFC4222] MAY be used for this purpose. However, maintaining a 175 separate boot count solely for OSPF sequence numbers has the 176 advantage of decoupling SNMP reinitialization and OSPF 177 reinitialization. Also, in the rare event that the lower order 32- 178 bit sequence number wraps, the boot count can be incremented to 179 preserve the strictly increasing property of the aggregate sequence 180 number. Hence, a separate OSPF boot count is RECOMMENDED. 182 3. OSPF Packet Extensions 184 The OSPF packet header includes an authentication type field, and 64- 185 bits of data for use by the appropriate authentication scheme 186 (determined by the type field). Authentication types 0, 1 and 2 are 187 defined [RFC2328]. This section of this defines Authentication type 188 TBD (3 is recommended). 190 When using this authentication scheme, the 64-bit Authentication 191 field in the OSPF packet header as defined in section D.3 of 192 [RFC2328] is changed as shown below. The sequence number is removed 193 and the Key ID is extended to 32 bits and moved to the former 194 position of the sequence number. 196 Additionally, the 64-bit sequence number is moved to the first 64- 197 bits following the OSPFv2 packet and is protected by the 198 authentication digest. These additional 64 bits or 8 octets are 199 included in the IP header length but not the OSPF header packet 200 length. 202 0 1 2 3 203 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 1 204 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 205 | Version # | Type | Packet length | 206 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 207 | Router ID | 208 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 209 | Area ID | 210 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 211 | Checksum | AuType | 212 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 213 | 0 | Auth Data Len | 214 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 215 | Key ID | 216 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 217 | | 218 | OSPF Protocol Packet | 219 ~ ~ 220 | | 221 | | 222 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 223 | Sequence Number (Boot Count) | 224 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 225 | Sequence Number (Strictly Increasing Packet Counter) | 226 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 227 | | 228 ~ Authentication Data ~ 229 | | 230 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 232 Figure 1 - Extended Sequence Number Packet Extensions 234 4. OSPF Packet Key Selection 236 This section describes how the proposed security solution selects 237 long-lived keys from key tables. [I-D.ietf-karp-crypto-key-table]. 238 Generally, a key used for OSPFv2 packet authentication should satisfy 239 the following requirements: 241 o For packet transmission, the key validity interval as defined by 242 SendLifetimeStart and SendLifetimeEnd must include the current 243 time. 245 o For packet reception, the key validity interval as defined by 246 AcceptLifetimeStart and AcceptLifetimeEnd must include the current 247 time. 249 o The key must be valid for the desired security algorithm. 251 In the remainder of this section, additional requirements for keys 252 are enumerated for different scenarios. 254 4.1. Key Selection for Unicast OSPF Packet Transmission 256 Assume that a router R1 tries to send a unicast OSPF packet from its 257 interface I1 to the interface R2 of a remote router R2 using security 258 protocol P via interface I at time T. First, consider the 259 circumstances where R1 and R2 are not connected with a virtual link. 260 R1 then needs to select a long long-lived symmetric key from its key 261 table. Because the key should be shared by the by both R1 and R2 to 262 protect the communication between I1 and I2, the key should satisfy 263 the following requirements: 265 o The Peers field is unused. OSPF authentication is interface 266 based. 268 o The Interfaces field includes the local IP address of the 269 interface for numbered interfaces or the MIB-II [RFC1213], ifIndex 270 for unnumbered interfaces. 272 o The Direction field is either "out" or "both". 274 o If multiple keys match the Interface, the key with the most recent 275 SendLifetimeStart time will be selected. This will facilitate 276 graceful key rollover. 278 o The Key ID field in the OSPFv2 header (refer to figure 1) will be 279 set to the selected key's LocalKeyName. 281 When R1 and R2 are connected to a virtual link, the interfaces field 282 must identify the virtual endpoint rather than the virtual link. 283 Since there may be virtual links to the same router, the transit area 284 ID must be part of the identifier. Hence, the key should satisfy the 285 following requirements: 287 o The Peers field is unused. OSPF authentication is interface 288 based. 290 o The Interfaces field includes both the virtual endpoint's OSPF 291 router ID and the transit area ID for the virtual link. 293 o The Direction field is either "out" or "both". 295 o If multiple keys match the Interface, the key with the most recent 296 SendLifetimeStart time will be selected. This will facilitate 297 graceful key rollover. 299 o The Key ID field in the OSPFv2 header (refer to figure 1) will be 300 set to the selected key's LocalKeyName. 302 4.2. Key Selection for Multicast OSPF Packet Transmission 304 If a router R1 sends an OSPF packet from its interface I1 to a 305 multicast address (e.g., AllSPFRouters, AllDRouters), it needs to 306 select a key according to the following requirements: 308 o The Peers field is unused. OSPF authentication is interface 309 based. 311 o The Interfaces field includes the local IP address of the 312 interface for numbered interfaces or the MIB-II [RFC1213], ifIndex 313 for unnumbered interfaces. 315 o The Direction field is either "out" or "both". 317 o If multiple keys match the Interface, the key with the most recent 318 SendLifetimeStart time will be selected. This will facilitate 319 graceful key rollover. 321 o The Key ID field in the OSPFv2 header (refer to figure 1) will be 322 set to the selected key's LocalKeyName. 324 4.3. Key Selection for OSPF Packet Reception 326 When Cryptographic Authentication is used, the ID of the 327 authentication key is included in the authentication field of the 328 OSPF packet header. Using this key ID, it is relatively easy for a 329 receiver to locate the key. The simple requirements are: 331 o The interface on which the key was received is associated with the 332 key's interface. 334 o The Key ID obtained from the OSPFv2 packet header corresponds to 335 the neighbor's PeerKeyName. Since OSPFv2 keys are symmetric, the 336 LocalKeyName and PeerKeyName for OSPFv2 keys will be identical. 337 Hence, the Key ID will be used to select the correct local key. 339 o The Direction field is either "in" or "both". 341 5. Securing the IP header 343 This document updates the definition of Apad which is currently a 344 constant defined in [RFC5709] to the source address from the IP 345 header of the OSPFv2 protocol packet. The overall cryptographic 346 authentication process defined in [RFC5709] remains unchanged. To 347 reduce the potential for confusion, this section minimizes the 348 repetition of text from RFC 5709 and is incorporated here by 349 reference [RFC5709]. 351 RFC 5709, Section 3.3, describes how the cryptographic authentication 352 must be computed. It requires OSPFv2 packet's Authentication Trailer 353 (which is the appendage described in RFC 2328, Section D.4.3, Page 354 233, items (6)(a) and (6)(d)) to be filled with the value Apad where 355 Apad is a hexadecimal constant value 0x878FE1F3 repeated (L/4) times, 356 where L is the length of the hash being used and is measured in 357 octets rather than bits. 359 Routers at the sending side must initialize Apad to a value of the 360 source address that would be used when sending out the OSPFv2 packet, 361 repeated L/4 times, where L is the length of the hash, measured in 362 octets. The basic idea is to incorporate the source address from the 363 IP header in the cryptographic authentication computation so that any 364 change of IP source address in a replayed packet can be detected. 366 At the receiving end, implementations MUST initialize Apad as the 367 source address from IP Header of the incoming OSPFv2 packet, repeated 368 L/4 times, instead of the constant that's currently defined in 369 [RFC5709]. Besides changing the value of Apad, this document does 370 not introduce any other changes to the authentication mechanism 371 described in [RFC5709]. This would prevent all attacks where a rogue 372 OSPF router changes the IP source address of an OSPFv2 packet and 373 replays it on the same multi-access interface or another interface 374 since the IP source address is now protected and modification would 375 result in the OSPFv2 packet being dropped due to an authentication 376 failure. 378 6. Mitigating Cross-Protocol Attacks 380 In order to prevent cross protocol replay attacks for protocols 381 sharing common keys, the two octet OSPFv2 Cryptographic Protocol ID 382 is appended to the authentication key prior to use. Refer to IANA 383 Considerations (Section 8). 385 [RFC5709], Section 3.3 describes the mechanism to prepare the key 386 used in the hash computation. This document updates the sub section 387 "PREPARATION OF KEY" as follows: 389 The OSPFv2 Cryptographic Protocol ID is appended to the 390 Authentication Key (K) yielding a Protocol-Specific Authentication 391 Key (Ks). In this application, Ko is always L octets long. While 392 [RFC2104] supports a key that is up to B octets long, this 393 application uses L as the Ks length consistent with [RFC4822], 394 [RFC5310], and [RFC5709]. According to [FIPS-198], Section 3, keys 395 greater than L octets do not significantly increase the function 396 strength. Ks is computed as follows: 398 If the Protocol-Specific Authentication Key (Ks) is L octets long, 399 then Ko is equal to Ks. If the Protocol-Specific Authentication Key 400 (Ks) is more than L octets long, then Ko is set to H(Ks). If the 401 Protocol-Specific Authentication Key (Ks) is less than L octets long, 402 then Ko is set to the Protocol-Specific Authentication Key (Ks) with 403 zeros appended to the end of the Protocol-Specific Authentication Key 404 (Ks) such that Ko is L octets long. 406 Once the cryptographic key (Ko) used with the hash algorithm is 407 derived the rest of the authentication mechanism described in 408 [RFC5709] remains unchanged other than one detail that was 409 unspecified. When XORing Ko and Ipad of Opad, Ko MUST be padded with 410 zeros to the length of Ipad or Opad. It is expected that RFC 5709 411 [RFC5709] implementations perform this padding implicitly. 413 7. Security Considerations 415 This document rectifies the manual key management procedure that 416 currently exists within OSPFv2, as part of the Phase 1 of the KARP 417 Working Group. Therefore, only the OSPFv2 manual key management 418 mechanism is considered. Any solution that takes advantage of the 419 automatic key management mechanism is beyond the scope of this 420 document. 422 The proposed sequence number extension offers most of the benefits of 423 more complicated mechanisms involving challenges. There are, 424 however, a couple drawbacks to this approach. First, it requires the 425 OSPF implementation to be able to save its boot count in non-volatile 426 storage. If the non-volatile storage is ever repaired or upgraded 427 such that the contents are lost or the OSPFv2 router is replaced, the 428 keys MUST be changed to prevent replay attacks. 430 Second, if a router is taken out of service completely (either 431 intentionally or due to a persistent failure), the potential exists 432 for reestablishment of an OSPFv2 adjacency by replaying the entire 433 OSPFv2 session establishment. This scenario is however, extremely 434 unlikely, since it would imply an identical OSPFv2 adjacency 435 formation packet exchange. Without adjacency formation, the replay 436 of OSPFv2 hello packets alone for an OSPFv2 router that has been 437 taken out of service should not result in any serious attack as the 438 only consequence is superfluous processing. Of course, this attack 439 could also be thwarted by changing the relevant manual keys. 441 This document also provides a solution to prevent certain denial of 442 service attacks that can be launched by changing the source address 443 in the IP header of an OSPFv2 protocol packet. 445 8. IANA Considerations 447 This document requests a new code point from the "OSPF Shortest Path 448 First (OSPF) Authentication Codes" registry: 450 o 3 - Cryptographic Authentication with Extended Sequence Numbers. 452 This document also requests a new code point from the "Authentication 453 Cryptographic Protocol ID" registry defined under "Keying and 454 Authentication for Routing Protocols (KARP) Parameters": 456 o 2 - OSPFv2. 458 9. References 460 9.1. Normative References 462 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 463 Requirement Levels", BCP 14, RFC 2119, March 1997. 465 [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. 467 [RFC5709] Bhatia, M., Manral, V., Fanto, M., White, R., Barnes, M., 468 Li, T., and R. Atkinson, "OSPFv2 HMAC-SHA Cryptographic 469 Authentication", RFC 5709, October 2009. 471 9.2. Informative References 473 [FIPS-198] 474 US National Institute of Standards & Technology, "The 475 Keyed-Hash Message Authentication Code (HMAC)", FIPS PUB 476 198 , March 2002. 478 [I-D.ietf-karp-crypto-key-table] 479 Housley, R., Polk, T., Hartman, S., and D. Zhang, 480 "Database of Long-Lived Symmetric Cryptographic Keys", 481 draft-ietf-karp-crypto-key-table-07 (work in progress), 482 March 2013. 484 [RFC1213] McCloghrie, K. and M. Rose, "Management Information Base 485 for Network Management of TCP/IP-based internets:MIB-II", 486 STD 17, RFC 1213, March 1991. 488 [RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed- 489 Hashing for Message Authentication", RFC 2104, 490 February 1997. 492 [RFC3414] Blumenthal, U. and B. Wijnen, "User-based Security Model 493 (USM) for version 3 of the Simple Network Management 494 Protocol (SNMPv3)", STD 62, RFC 3414, December 2002. 496 [RFC4222] Choudhury, G., "Prioritized Treatment of Specific OSPF 497 Version 2 Packets and Congestion Avoidance", BCP 112, 498 RFC 4222, October 2005. 500 [RFC4822] Atkinson, R. and M. Fanto, "RIPv2 Cryptographic 501 Authentication", RFC 4822, February 2007. 503 [RFC5310] Bhatia, M., Manral, V., Li, T., Atkinson, R., White, R., 504 and M. Fanto, "IS-IS Generic Cryptographic 505 Authentication", RFC 5310, February 2009. 507 [RFC6039] Manral, V., Bhatia, M., Jaeggli, J., and R. White, "Issues 508 with Existing Cryptographic Protection Methods for Routing 509 Protocols", RFC 6039, October 2010. 511 [RFC6094] Bhatia, M. and V. Manral, "Summary of Cryptographic 512 Authentication Algorithm Implementation Requirements for 513 Routing Protocols", RFC 6094, February 2011. 515 [RFC6862] Lebovitz, G., Bhatia, M., and B. Weis, "Keying and 516 Authentication for Routing Protocols (KARP) Overview, 517 Threats, and Requirements", RFC 6862, March 2013. 519 [RFC6863] Hartman, S. and D. Zhang, "Analysis of OSPF Security 520 According to the Keying and Authentication for Routing 521 Protocols (KARP) Design Guide", RFC 6863, March 2013. 523 Authors' Addresses 525 Manav Bhatia 526 Alcatel-Lucent 527 Bangalore, 528 India 530 Phone: 531 Email: manav.bhatia@alcatel-lucent.com 533 Sam Hartman 534 Painless Security 536 Email: hartmans@painless-security.com 538 Dacheng Zhang 539 Huawei Technologies co., LTD. 540 Beijing, 541 China 543 Phone: 544 Fax: 545 Email: zhangdacheng@huawei.com 546 URI: 548 Acee Lindem 549 Ericsson 550 301 Midenhall Way 551 Cary, NC 27513 552 USA 554 Phone: 555 Email: acee.lindem@ericsson.com