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This document may contain material 15 from IETF Documents or IETF Contributions published or made publicly 16 available before November 10, 2008. The person(s) controlling the 17 copyright in some of this material may not have granted the IETF 18 Trust the right to allow modifications of such material outside the 19 IETF Standards Process. Without obtaining an adequate license from 20 the person(s) controlling the copyright in such materials, this 21 document may not be modified outside the IETF Standards Process, and 22 derivative works of it may not be created outside the IETF Standards 23 Process, except to format it for publication as an RFC or to 24 translate it into languages other than English. 26 Internet-Drafts are working documents of the Internet Engineering 27 Task Force (IETF), its areas, and its working groups. Note that 28 other groups may also distribute working documents as Internet- 29 Drafts. 31 Internet-Drafts are draft documents valid for a maximum of six months 32 and may be updated, replaced, or obsoleted by other documents at any 33 time. It is inappropriate to use Internet-Drafts as reference 34 material or to cite them other than as "work in progress." 36 The list of current Internet-Drafts can be accessed at 37 http://www.ietf.org/ietf/1id-abstracts.txt. 39 The list of Internet-Draft Shadow Directories can be accessed at 40 http://www.ietf.org/shadow.html. 42 This Internet-Draft will expire on September 5, 2009. 44 Copyright Notice 46 Copyright (c) 2009 IETF Trust and the persons identified as the 47 document authors. All rights reserved. 49 This document is subject to BCP 78 and the IETF Trust's Legal 50 Provisions Relating to IETF Documents in effect on the date of 51 publication of this document (http://trustee.ietf.org/license-info). 52 Please review these documents carefully, as they describe your rights 53 and restrictions with respect to this document. 55 Abstract 57 A trust anchor represents an authoritative entity via a public key 58 and associated data. The public key is used to verify digital 59 signatures and the associated data is used to constrain the types of 60 information for which the trust anchor is authoritative. A relying 61 party uses trust anchors to determine if a digitally signed object is 62 valid by verifying a digital signature using the trust anchor's 63 public key, and by enforcing the constraints expressed in the 64 associated data for the trust anchor. This document describes some 65 of the problems associated with the lack of a standard trust anchor 66 management mechanism and defines requirements for data formats and 67 push-based protocols designed to address these problems. 69 Table of Contents 71 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 72 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 6 73 1.2. Requirements Notation . . . . . . . . . . . . . . . . . . 6 74 2. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 7 75 3. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 9 76 3.1. Transport independence . . . . . . . . . . . . . . . . . . 9 77 3.1.1. Functional Requirements . . . . . . . . . . . . . . . 9 78 3.1.2. Rationale . . . . . . . . . . . . . . . . . . . . . . 9 79 3.2. Basic management operations . . . . . . . . . . . . . . . 9 80 3.2.1. Functional Requirements . . . . . . . . . . . . . . . 9 81 3.2.2. Rationale . . . . . . . . . . . . . . . . . . . . . . 10 82 3.3. Management targets . . . . . . . . . . . . . . . . . . . . 10 83 3.3.1. Functional Requirements . . . . . . . . . . . . . . . 10 84 3.3.2. Rationale . . . . . . . . . . . . . . . . . . . . . . 10 85 3.4. Delegation of TA Manager Authority . . . . . . . . . . . . 11 86 3.4.1. Functional Requirements . . . . . . . . . . . . . . . 11 87 3.4.2. Rationale . . . . . . . . . . . . . . . . . . . . . . 11 88 3.5. RFC 5280 Support . . . . . . . . . . . . . . . . . . . . . 11 89 3.5.1. Functional Requirements . . . . . . . . . . . . . . . 11 90 3.5.2. Rationale . . . . . . . . . . . . . . . . . . . . . . 12 91 3.6. Support Purposes Other Than Certification Path 92 Validation . . . . . . . . . . . . . . . . . . . . . . . . 12 93 3.6.1. Functional Requirements . . . . . . . . . . . . . . . 12 94 3.6.2. Rationale . . . . . . . . . . . . . . . . . . . . . . 12 95 3.7. Trust Anchor Format . . . . . . . . . . . . . . . . . . . 12 96 3.7.1. Functional Requirements . . . . . . . . . . . . . . . 12 97 3.7.2. Rationale . . . . . . . . . . . . . . . . . . . . . . 13 98 3.8. Source Authentication . . . . . . . . . . . . . . . . . . 13 99 3.8.1. Functional Requirements . . . . . . . . . . . . . . . 13 100 3.8.2. Rationale . . . . . . . . . . . . . . . . . . . . . . 13 101 3.9. Reduce Reliance on Out-of-Band Trust Mechanisms . . . . . 13 102 3.9.1. Functional Requirements . . . . . . . . . . . . . . . 13 103 3.9.2. Rationale . . . . . . . . . . . . . . . . . . . . . . 13 104 3.10. Replay Detection . . . . . . . . . . . . . . . . . . . . . 14 105 3.10.1. Functional Requirements . . . . . . . . . . . . . . . 14 106 3.10.2. Rationale . . . . . . . . . . . . . . . . . . . . . . 14 107 3.11. Compromise or Disaster Recovery . . . . . . . . . . . . . 14 108 3.11.1. Functional Requirements . . . . . . . . . . . . . . . 14 109 3.11.2. Rationale . . . . . . . . . . . . . . . . . . . . . . 14 110 4. Security Considerations . . . . . . . . . . . . . . . . . . . 16 111 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 112 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18 113 6.1. Normative References . . . . . . . . . . . . . . . . . . . 18 114 6.2. Informative References . . . . . . . . . . . . . . . . . . 18 115 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19 117 1. Introduction 119 Digital signatures are used in many applications. For digital 120 signatures to provide integrity and authentication, the public key 121 used to verify the digital signature must be "trusted", i.e., 122 accepted by a relying party (RP) as appropriate for use in the given 123 context. A public key used to verify a signature must be configured 124 as a trust anchor (TA) or contained in a certificate that can be 125 transitively verified by a certification path terminating at a trust 126 anchor. A Trust Anchor is a public key and associated data used by a 127 relying party to validate a signature on a signed object where the 128 object is either: 130 o a public key certificate that begins a certification path 131 terminated by a signature certificate or encryption certificate 133 o an object, other than a public key certificate or certificate 134 revocation list (CRL), that cannot be validated via use of a 135 certification path 137 Trust anchors have only local significance, i.e., each RP is 138 configured with a set of trust anchors, either by the RP or by an 139 entity that manages TAs in the context in which the RP operates. The 140 associated data defines the scope of a trust anchor by imposing 141 constraints on the signatures the trust anchor may be used to verify. 142 For example, if a trust anchor is used to verify signatures on X.509 143 certificates, these constraints may include a combination of name 144 spaces, certificate policies, or application/usage types. 146 One use of digital signatures is the verification of signatures on 147 firmware packages loaded into hardware modules, such as cryptographic 148 modules, cable boxes, routers, etc. Since such devices are often 149 managed remotely, the devices must be able to authenticate the source 150 of management interactions and can use trust anchors to perform this 151 authentication. However, trust anchors require management as well. 152 Other applications requiring trust anchor management include web 153 browsers, which use trust anchors when authenticating web servers, 154 and email clients, which use trust anchors when validating signed 155 email and when authenticating recipients of encrypted email. 157 All applications that rely upon digital signatures rely upon some 158 means of managing one or more sets of trust anchors. Each set of 159 trust anchors is referred to in this document as a trust anchor 160 store. Often, the means of managing trust anchor stores are 161 application-specific and rely upon out-of-band means to establish and 162 maintain trustworthiness. An application may use multiple trust 163 anchor stores and a given trust anchor store may be used by multiple 164 applications. Each trust anchor store is managed by at least one TA 165 manager; a TA manager may manage multiple TA stores. 167 This section provides an introduction and defines basic terminology. 168 Section 2 describes problems with current trust anchor management 169 methods. Sections 3 and 4 describe requirements and security 170 considerations for a trust anchor management solution. 172 1.1. Terminology 174 The following terms are defined in order to provide a vocabulary for 175 describing requirements for trust anchor management. 177 Trust Anchor: A trust anchor represents an authoritative entity via 178 a public key and associated data. The public key is used to 179 verify digital signatures and the associated data is used to 180 constrain the types of information for which the trust anchor is 181 authoritative. A relying party uses trust anchors to determine if 182 a digitally signed object is valid by verifying a digital 183 signature using the trust anchor's public key, and by enforcing 184 the constraints expressed in the associated data for the trust 185 anchor. 187 Trust Anchor Manager: Trust anchor manager is an entity responsible 188 for managing the contents of a trust anchor store. Throughout 189 this document, each trust anchor manager is assumed to be 190 represented as or delegated by a distinct trust anchor. 192 Trust Anchor Store: A trust anchor store is a set of one or more 193 trust anchors stored in a device. A trust anchor store may be 194 managed by one or more trust anchor managers. A device may have 195 more than one trust anchor store, each of which may be used by one 196 or more applications. 198 1.2. Requirements Notation 200 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 201 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 202 document are to be interpreted as described in RFC 2119 [RFC2119]. 204 2. Problem Statement 206 Trust anchors are used to support many application scenarios. Most 207 Internet browsers and email clients use trust anchors when 208 authenticating TLS sessions, verifying signed email and generating 209 encrypted email by validating a certification path to a server's 210 certificate, an e-mail originator's certificate or an e-mail 211 recipient's certificate, respectively. Many software distributions 212 are digitally signed to enable authentication of the software source 213 prior to installation. Trust anchors that support these applications 214 are typically installed as part of the operating system (OS) or 215 application, installed using an enterprise configuration management 216 system, or installed directly by an OS or application user. 218 Trust anchors are typically stored in application-specific or 219 operating system-specific trust anchor stores. Often, a single 220 machine may have a number of different trust anchor stores that may 221 not be synchronized. Reviewing the contents of a particular trust 222 anchor store typically involves use of a proprietary tool that 223 interacts with a particular type of trust store. 225 The presence of a trust anchor in a particular store often conveys 226 implicit authorization to validate signatures for any contexts from 227 which the store is accessed. For example, the public key of a 228 timestamp authority (TSA) may be installed in a trust anchor store to 229 validate signatures on timestamps [RFC3161]. However, if the store 230 containing this TA is used by multiple applications that serve 231 different purposes, the same key may be used (inappropriately) to 232 validate other types of objects such as certificates or OCSP 233 responses. Currently, there is no standard general purpose mechanism 234 for limiting the applicability (scope) of a trust anchor. Placing 235 different TAs in different stores and limiting the set of 236 applications that access a given TA store is a common practice to 237 address this problem. 239 Trust relationships between PKIs are negotiated by policy 240 authorities. Negotiations frequently require significant time to 241 ensure all participating parties' requirements are satisfied. These 242 requirements are expressed, to some extent, in public key 243 certificates via policy constraints, name constraints, etc. In order 244 for these requirements to be enforced, trust anchor stores must be 245 managed in accord with policy authority intentions. Otherwise, the 246 constraints defined in a cross-certificate could be circumvented by 247 recognizing the subject of the cross certificate as a trust anchor, 248 which would enable path processing implementations to avoid the 249 cross-certificate. 251 Trust anchors are often represented as self-signed certificates, 252 which provide no useful means of establishing the validity of the 253 information contained in the certificate. Confidence in the 254 integrity of a trust anchor is typically established through out-of- 255 band means, often by checking the "fingerprint" (one-way hash) of the 256 self-signed certificate with an authoritative source. Routine trust 257 anchor re-key operations typically require similar out-of-band 258 checks, though in-band rekey of a trust anchor is supported by the 259 Certificate Management Protocol (CMP) [RFC4210]. Ideally, only the 260 initial set of trust anchors are installed in a particular trust 261 anchor store should require out-of-band verification, particularly 262 when the costs of performing out-of-band checks commensurate with the 263 security requirements of applications using the trust anchor store 264 are high. 266 Despite the prevalent use of trust anchors, there is neither a 267 standard means for discovering the set of trust anchors installed in 268 a particular trust anchor store nor a standard means of managing 269 those trust anchors. The remainder of this document describes 270 requirements for a solution to this problem along with some security 271 considerations. 273 3. Requirements 275 This section describes the requirements for a trust anchor management 276 protocol. Requirements are provided for trust anchor contents as 277 well as for trust anchor store management operations. 279 3.1. Transport independence 281 3.1.1. Functional Requirements 283 A general-purpose solution for the management of trust anchors MUST 284 be transport independent in order to apply to a range of device 285 communications environments. It MUST work in both session-oriented 286 and store-and-forward communications environments as well as in both 287 push and pull distribution models. To accommodate both communication 288 models in a uniform fashion, connectionless integrity and data origin 289 authentication for TA transactions MUST be provided at the 290 application layer. Confidentiality MAY be provided for such 291 transactions. 293 3.1.2. Rationale 295 Not all devices that use trust anchors are available for online 296 management operations; some devices may require manual interaction 297 for trust anchor management. Data origin authentication and 298 integrity are required to ensure that the transaction has not been 299 modified en route. Only connectionless integrity is required, for 300 compatibility with store-and-forward contexts. 302 3.2. Basic management operations 304 3.2.1. Functional Requirements 306 At a minimum, a protocol used for trust anchor management MUST enable 307 a trust anchor manager to perform the following operations: 309 o Determine which trust anchors are installed in a particular trust 310 anchor store 312 o Add one or more trust anchors to a trust anchor store 314 o Remove one or more trust anchors from a trust anchor store 316 o Replace an entire trust anchor store 318 A trust anchor management protocol MUST provide support for these 319 basic operations, however, not all implementations must support each 320 option. For example, some implementations may support only 321 replacement of trust anchor stores. 323 3.2.2. Rationale 325 These requirements describe the core operations required to manage 326 the contents of a trust anchor store. An edit operation was omitted 327 for sake of simplicity, with consecutive remove and add operations 328 used for this purpose. A single add or remove operation can act upon 329 more than one trust anchor to avoid unnecessary round trips and are 330 provided to avoid the need to always replace an entire trust anchor 331 store. Trust anchor store replacement may be useful as a simple, 332 higher bandwidth alternative to add and remove operations. 334 3.3. Management targets 336 3.3.1. Functional Requirements 338 A protocol for TA management MUST allow a TA management transaction 339 to be directed to: 341 All TA stores for which the manager is responsible 343 An enumerated list of one or more named groups of trust anchor 344 stores 346 An individual trust anchor store 348 3.3.2. Rationale 350 Connections between PKIs can be accomplished using different means. 351 Unilateral or bilateral cross-certification can be performed, or a 352 community may simply elect to explicitly accept a trust anchor from 353 another community. Typically, these decisions occur at the 354 enterprise level. In some scenarios, it can be useful to establish 355 these connections for a small community within an enterprise. 356 Enterprise-wide mechanisms such as cross-certificates are ill-suited 357 for this purpose since certificate revocation or expiration affects 358 the entire enterprise. 360 A trust anchor management protocol can address this issue by 361 supporting limited installation of trust anchors (i.e., installation 362 of TAs in subsets of the enterprise user community), and by 363 supporting expression of constraints on trust anchor use by relying 364 parties. Limited installation requires the ability to identify the 365 members of the community that are intended to rely upon a particular 366 trust anchor, as well as the ability to query and report on the 367 contents of trust anchor stores. Trust anchor constraints can be 368 used to represent the limitations that might otherwise be expressed 369 in a cross-certificate, and limited installation ensures the 370 recognition of the trust anchor does not necessarily encompass an 371 entire enterprise. 373 Trust anchor configurations may be uniform across an enterprise, or 374 they may be unique to a single application or small set of 375 applications. Many devices and some applications utilize multiple 376 trust anchor stores. By providing means of addressing a specific 377 store or collections of stores, a trust anchor management protocol 378 can enable efficient management of all stores under a trust anchor 379 manager's control. 381 3.4. Delegation of TA Manager Authority 383 3.4.1. Functional Requirements 385 A trust anchor management protocol MUST enable secure transfer of 386 control of a trust anchor store from one trust anchor manager to 387 another. It also SHOULD enable delegation for specific operations 388 without requiring delegation of the overall trust anchor management 389 capability itself. 391 3.4.2. Rationale 393 Trust anchor manager re-key is one type of transfer that must be 394 supported. In this case, the new key will be assigned the same 395 privileges as the old key. 397 Creation of trust anchors for specific purposes, such as firmware 398 signing, is another example of delegation. For example, a trust 399 anchor manager may delegate only the authority to sign firmware to an 400 entity, but disallow further delegation of that privilege, or the 401 trust anchor manager may allow its delegate to further delegate 402 firmware signing authority to other entities. 404 3.5. RFC 5280 Support 406 3.5.1. Functional Requirements 408 A trust anchor management protocol MUST enable management of trust 409 anchors that will be used to validate certification paths and CRLs in 410 accordance with [RFC5280] and [RFC5055]. A trust anchor format MUST 411 enable the representation of constraints that influence certification 412 path validation or otherwise establish the scope of usage of the 413 trust anchor public key. Examples of such constraints are name 414 constraints, certificate policies, and key usage. 416 3.5.2. Rationale 418 Certification path validation is one of the most common applications 419 of trust anchors. The rules for using trust anchors for path 420 validation are established in [RFC5280]. [RFC5055] describes the use 421 of trust anchors for delegated path validation. Trust anchors used 422 to validate certification paths are responsible for providing, 423 possibly through a delegate, the revocation status information of 424 certificates it issues; this is often accomplished by signing a CRL. 426 3.6. Support Purposes Other Than Certification Path Validation 428 3.6.1. Functional Requirements 430 A trust anchor management protocol MUST enable management of trust 431 anchors that can be used for purposes other than certification path 432 validation, including trust anchors that cannot be used for 433 certification path validation. It SHOULD be possible to authorize a 434 trust anchor to delegate authority (to other TAs or certificate 435 holders) and to prevent a trust anchor from delegating authority. 437 3.6.2. Rationale 439 Trust anchors are used to validate a variety of signed objects, not 440 just public key certificates and CRLs. For example, a trust anchor 441 may be used to verify firmware packages [RFC4108], OCSP responses 442 [RFC2560], SCVP responses [RFC5055] or timestamps [RFC3161]. TAs 443 that are authorized for use with some or all of these other types of 444 operations may not be authorized to verify public key certificates or 445 CRLs. Thus it is important to be able to impose constraints on the 446 ways in which a given TA is employed. 448 3.7. Trust Anchor Format 450 3.7.1. Functional Requirements 452 Minimally, a trust anchor management protocol MUST support management 453 of trust anchors represented as self-signed certificates and trust 454 anchors represented as a distinguished name, public key information 455 and, optionally, associated data. The definition of a trust anchor 456 MUST include a public key, a public key algorithm and, if necessary, 457 public key parameters. When the public key is used to validate 458 certification paths or CRLs, a distinguished name also MUST be 459 included per [RFC5280]. A trust anchor format SHOULD enable 460 specification of a public key identifier to enable other applications 461 of the trust anchor, for example, verification of data signed using 462 the Cryptographic Message Syntax (CMS) SignedData structure 463 [RFC3852]. A trust anchor format also SHOULD enable the 464 representation of constraints that can be applied to restrict the use 465 of a trust anchor. 467 3.7.2. Rationale 469 There is no standardized format for trust anchors. Self-signed X.509 470 certificates are typically used but [RFC5280] does not mandate a 471 particular trust anchor representation. It requires only that a 472 trust anchor's public key information and distinguished name be 473 available during certification path validation. CMS is widely used 474 to protect a variety of types of content using digital signatures, 475 including contents that may verified directly using a trust anchor, 476 such as firmware packages [RFC4108]. Constraints may include a 477 validity period, constraints on certification path validation, etc. 479 3.8. Source Authentication 481 3.8.1. Functional Requirements 483 An entity receiving trust anchor management data MUST be able to 484 authenticate the identity of the party providing the information and 485 MUST be able to confirm the party is authorized to provide that trust 486 anchor information. 488 A trust anchor manager MUST be able to authenticate which trust 489 anchor store corresponds to a report listing the contents of the 490 trust anchor store and be able to confirm the contents of the report 491 have not been subsequently altered. 493 3.8.2. Rationale 495 Data origin authentication and integrity are required to support 496 remote management operations, even when TA management transactions 497 are effected via store-and-forward communications. 499 3.9. Reduce Reliance on Out-of-Band Trust Mechanisms 501 3.9.1. Functional Requirements 503 When performing add operations, a trust anchor management protocol 504 SHOULD enable TA integrity to be checked automatically by a relying 505 party without relying on out-of-band trust mechanisms. 507 3.9.2. Rationale 509 Traditionally, a trust anchor is distributed out-of-band with its 510 integrity checked manually prior to installation. Installation 511 typically is performed by anyone with sufficient administrative 512 privilege on the system receiving the trust anchor. Reliance on out- 513 of-band trust mechanisms is one problem with current trust anchor 514 management approaches and reduction of the need to use out-of-band 515 trust mechanisms is a primary motivation for developing a trust 516 anchor management protocol. Ideally, out-of-band trust mechanisms 517 will be required only during trust anchor store initialization. 519 3.10. Replay Detection 521 3.10.1. Functional Requirements 523 A trust anchor management protocol MUST enable participants engaged 524 in a trust anchor management protocol exchange to detect replay 525 attacks. A replay detection mechanism that does not introduce a 526 requirement for a reliable source of time MUST be available. 527 Mechanisms that do require a reliable source of time MAY be 528 available. 530 3.10.2. Rationale 532 Detection of replays of trust anchor management transaction is 533 required to support remote management operations. Replay of old 534 trust anchor management transaction could result in the 535 reintroduction of compromised trust anchors to a trust anchor store, 536 potentially exposing applications to malicious signed objects or 537 certification paths. 539 Some devices that utilize trust anchors have no access to a reliable 540 source of time, so a replay detection mechanism that requires a 541 reliable time source is insufficient. 543 3.11. Compromise or Disaster Recovery 545 3.11.1. Functional Requirements 547 A trust anchor management protocol MUST enable recovery from the 548 compromise or loss of a trust anchor private key, including the 549 private key authorized to serve as a trust anchor manager, without 550 requiring reinitialization of the trust store. 552 3.11.2. Rationale 554 Compromise or loss of a private key corresponding to a trust anchor 555 can have significant negative consequences. Currently, in some 556 cases, re-initialization of all effected trust anchor stores is 557 required to recover from a lost or compromised trust anchor key. Due 558 to the costs associated with re-initialization, a trust anchor 559 management protocol should support recovery options that do not 560 require trust anchor store re-initialization. 562 4. Security Considerations 564 The public key used to authenticate a TA management transaction may 565 have been placed in the client as the result of an earlier TA 566 management transaction or during an initial bootstrap configuration 567 operation. In most scenarios, at least one public key authorized for 568 trust anchor management must be placed in each trust anchor store to 569 be managed during the initial configuration of the trust anchor 570 store. This public key may be transported and checked using out-of- 571 band means. In all scenarios, regardless of the authentication 572 mechanism, at least one trust anchor manager must be established for 573 each trust anchor store during the initial configuration of the trust 574 anchor store. 576 Compromise of a trust anchor's private key can result in many 577 security problems including issuance of bogus certificates or 578 installation of rogue trust anchors. 580 Usage of trust anchor-based constraints requires great care when 581 defining trust anchors. Errors on the part of a trust anchor manager 582 could result in denial of service or have serious security 583 consequences. For example, if a name constraint for a trust anchor 584 that serves as the root of a PKI includes a typo, denial of service 585 results for certificate holders and relying parties. If a trust 586 anchor manager inadvertently delegates all of its privileges and the 587 delegate subsequently removes the trust anchor manager from trust 588 anchor stores now under its control, recovery may require 589 reinitialization of all effected trust anchor stores. 591 RFC 5280 requires that certificate path validation be initialized 592 with a TA subject name and public key, but does not require 593 processing of other information, such as name constraints extensions. 594 Inclusion of constraints in trust anchors is optional. When 595 constraints are explicitly included by a trust anchor manager using a 596 trust anchor management protocol, there exists an expectation that 597 the certificate path validation algorithm will make use of the 598 constraints. Application owners must confirm the path processing 599 implementations support the processing of TA-based constraints, where 600 required. 602 Many of the security considerations from [RFC5280] are also 603 applicable to trust anchor management. 605 5. IANA Considerations 607 None. Please remove this section prior to publication as an RFC. 609 6. References 611 6.1. Normative References 613 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 614 Requirement Levels", BCP 14, RFC 2119, March 1997. 616 [RFC5055] Freeman, T., Housley, R., Malpani, A., Cooper, D., and W. 617 Polk, "Server-Based Certificate Validation Protocol 618 (SCVP)", RFC 5055, December 2007. 620 [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., 621 Housley, R., and W. Polk, "Internet X.509 Public Key 622 Infrastructure Certificate and Certificate Revocation List 623 (CRL) Profile", RFC 5280, May 2008. 625 6.2. Informative References 627 [RFC2560] Myers, M., Ankney, R., Malpani, A., Galperin, S., and C. 628 Adams, "X.509 Internet Public Key Infrastructure Online 629 Certificate Status Protocol - OCSP", RFC 2560, June 1999. 631 [RFC3161] Adams, C., Cain, P., Pinkas, D., and R. Zuccherato, 632 "Internet X.509 Public Key Infrastructure Time-Stamp 633 Protocol (TSP)", RFC 3161, August 2001. 635 [RFC3852] Housley, R., "Cryptographic Message Syntax (CMS)", 636 RFC 3852, July 2004. 638 [RFC4108] Housley, R., "Using Cryptographic Message Syntax (CMS) to 639 Protect Firmware Packages", RFC 4108, August 2005. 641 [RFC4210] Adams, C., Farrell, S., Kause, T., and T. Mononen, 642 "Internet X.509 Public Key Infrastructure Certificate 643 Management Protocol (CMP)", RFC 4210, September 2005. 645 Authors' Addresses 647 Raksha Reddy 648 National Security Agency 649 Suite 6599 650 9800 Savage Road 651 Fort Meade, MD 20755 653 Email: r.reddy@radium.ncsc.mil 655 Carl Wallace 656 Cygnacom Solutions 657 Suite 5200 658 7925 Jones Branch Drive 659 McLean, VA 22102 661 Email: cwallace@cygnacom.com