idnits 2.17.1 draft-tschofenig-rats-psa-token-03.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 : ---------------------------------------------------------------------------- ** The document seems to lack a Security Considerations section. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The document seems to contain a disclaimer for pre-RFC5378 work, but was first submitted on or after 10 November 2008. The disclaimer is usually necessary only for documents that revise or obsolete older RFCs, and that take significant amounts of text from those RFCs. If you can contact all authors of the source material and they are willing to grant the BCP78 rights to the IETF Trust, you can and should remove the disclaimer. Otherwise, the disclaimer is needed and you can ignore this comment. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (November 18, 2019) is 1615 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) ** Obsolete normative reference: RFC 7049 (Obsoleted by RFC 8949) ** Obsolete normative reference: RFC 8152 (Obsoleted by RFC 9052, RFC 9053) == Outdated reference: A later version (-25) exists of draft-ietf-rats-eat-01 Summary: 3 errors (**), 0 flaws (~~), 3 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 RATS H. Tschofenig, Ed. 3 Internet-Draft S. Frost 4 Intended status: Standards Track M. Brossard 5 Expires: May 21, 2020 A. Shaw 6 T. Fossati 7 Arm Limited 8 November 18, 2019 10 Arm's Platform Security Architecture (PSA) Attestation Token 11 draft-tschofenig-rats-psa-token-03 13 Abstract 15 The insecurity of IoT systems is a widely known and discussed 16 problem. The Arm Platform Security Architecture (PSA) is being 17 developed to address this challenge by making it easier to build 18 secure IoT systems. 20 This document specifies token format and claims used in the 21 attestation API of the Arm Platform Security Architecture (PSA). 23 At its core, the CWT (COSE Web Token) format is used and populated 24 with a set of claims, in a way similar to EAT (Entity Attestation 25 Token). This specification describes what claims are used by PSA 26 compliant systems and what has been implemented within Arm Trusted 27 Firmware-M. 29 Status of This Memo 31 This Internet-Draft is submitted in full conformance with the 32 provisions of BCP 78 and BCP 79. 34 Internet-Drafts are working documents of the Internet Engineering 35 Task Force (IETF). Note that other groups may also distribute 36 working documents as Internet-Drafts. The list of current Internet- 37 Drafts is at https://datatracker.ietf.org/drafts/current/. 39 Internet-Drafts are draft documents valid for a maximum of six months 40 and may be updated, replaced, or obsoleted by other documents at any 41 time. It is inappropriate to use Internet-Drafts as reference 42 material or to cite them other than as "work in progress." 44 This Internet-Draft will expire on May 21, 2020. 46 Copyright Notice 48 Copyright (c) 2019 IETF Trust and the persons identified as the 49 document authors. All rights reserved. 51 This document is subject to BCP 78 and the IETF Trust's Legal 52 Provisions Relating to IETF Documents 53 (https://trustee.ietf.org/license-info) in effect on the date of 54 publication of this document. Please review these documents 55 carefully, as they describe your rights and restrictions with respect 56 to this document. Code Components extracted from this document must 57 include Simplified BSD License text as described in Section 4.e of 58 the Trust Legal Provisions and are provided without warranty as 59 described in the Simplified BSD License. 61 This document may contain material from IETF Documents or IETF 62 Contributions published or made publicly available before November 63 10, 2008. The person(s) controlling the copyright in some of this 64 material may not have granted the IETF Trust the right to allow 65 modifications of such material outside the IETF Standards Process. 66 Without obtaining an adequate license from the person(s) controlling 67 the copyright in such materials, this document may not be modified 68 outside the IETF Standards Process, and derivative works of it may 69 not be created outside the IETF Standards Process, except to format 70 it for publication as an RFC or to translate it into languages other 71 than English. 73 Table of Contents 75 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 76 2. Conventions and Terminology . . . . . . . . . . . . . . . . . 4 77 2.1. Glossary . . . . . . . . . . . . . . . . . . . . . . . . 4 78 3. Information Model . . . . . . . . . . . . . . . . . . . . . . 5 79 3.1. PSA Lifecycle States . . . . . . . . . . . . . . . . . . 7 80 3.2. PSA Software Components . . . . . . . . . . . . . . . . . 7 81 4. Token Encoding . . . . . . . . . . . . . . . . . . . . . . . 9 82 5. Claims . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 83 6. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 84 7. Security and Privacy Considerations . . . . . . . . . . . . . 14 85 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 86 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 87 9.1. Normative References . . . . . . . . . . . . . . . . . . 14 88 9.2. Informative References . . . . . . . . . . . . . . . . . 15 89 Appendix A. Contributors . . . . . . . . . . . . . . . . . . . . 16 90 Appendix B. Reference Implementation . . . . . . . . . . . . . . 16 91 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16 93 1. Introduction 95 Modern hardware for Internet of Things devices contain trusted 96 execution environments and in case of the Arm v8-M architecture 97 TrustZone support. On these low end microcontrollers, TrustZone 98 enables the separation between a "normal world" and a "secure world" 99 where security sensitive code resides in the "secure world" and 100 applications running in the "normal world" request secure services 101 using a well-defined API. Various APIs have been developed by Arm as 102 part of the Platform Security Architecture [PSA] programme; this 103 document focuses on the functionality provided by the attestation 104 API. Since the tokens exposed via the attestation API are also 105 consumed by services outside the device, there is an actual need for 106 making them interoperable. In this specification these 107 interoperability needs are addressed by describing the exact syntax 108 and semantics of the attestation claims, and defining the way these 109 claims are encoded and cryptographically protected. 111 Further details on concepts expressed below can be found in the PSA 112 Security Model documentation [PSA-SM]. 114 Figure 1 provides a view of the architectural components and how they 115 interact. Applications on the IoT device communicate with services 116 residing in the "secure world" by means of a well-defined API. The 117 attestation API produces tokens, as described in this document, and 118 those tokens may be presented to network or application services. 120 .-----------------+------------------. 121 | Normal World | Secure World | 122 | | .-. | 123 | | |A| | 124 | | |T| | 125 | | |T| | 126 | | |E| .-. | 127 | | .-. |S| |S| | 128 | | |C| |T| |T| | 129 .----------. | | |R| |A| |O| | 130 | Network | | .----------. | |Y| |T| |R| | 131 | and App |<-------------+ Apps | .--+--. |P| |I| |A| | 132 | Services | | '----------' |P | | |T| |O| |G| | 133 '----------' | .----------. |S | | |O| |N| |E| | 134 | |Middleware| |A | | '-' '-' '-' | 135 | '----------' | | | .----------. | 136 | .----------. |A | | | | | 137 | | | |P | | | SPM | | 138 | | RTOS and | |I | | '----------' | 139 | | Drivers | '--+--' .----------. | 140 | | | | | Boot | | 141 | '----------' | | Loader | | 142 | | '----------' | 143 +-----------------+------------------+ 144 | H A R D|W A R E | 145 '-----------------+------------------' 147 Internet of Things Device 149 Figure 1: Software Architecture 151 2. Conventions and Terminology 153 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 154 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 155 "OPTIONAL" in this document are to be interpreted as described in 156 BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all 157 capitals, as shown here. 159 2.1. Glossary 161 RoT Root of Trust, the minimal set of software, hardware and data 162 that has to be implicitly trusted in the platform - there is no 163 software or hardware at a deeper level that can verify that the 164 Root of Trust is authentic and unmodified. 166 SPE Secure Processing Environment, a platform's processing 167 environment for software that provides confidentiality and 168 integrity for its runtime state, from software and hardware, 169 outside of the SPE. Contains the Secure Partition Manager (SPM), 170 the Secure Partitions and the trusted hardware. 172 NSPE Non Secure Processing Environment, the security domain outside 173 of the SPE, the Application domain, typically containing the 174 application firmware and hardware. 176 3. Information Model 178 Table 1 describes the mandatory and optional claims in the report. 180 +----------------+--------------+-----------------------------------+ 181 | Claim | Mandatory | Description | 182 +----------------+--------------+-----------------------------------+ 183 | Auth Challenge | Yes | Input object from the caller. For | 184 | | | example, this can be a | 185 | | | cryptographic nonce, a hash of | 186 | | | locally attested data. The length | 187 | | | must be 32, 48, or 64 bytes. | 188 | | | | 189 | Instance ID | Yes | Represents the unique identifier | 190 | | | of the instance. It is a hash of | 191 | | | the public key corresponding to | 192 | | | the Initial Attestation Key. The | 193 | | | full definition is in [PSA-SM]. | 194 | | | | 195 | Verification | No | A hint used by a relying party to | 196 | Service | | locate a validation service for | 197 | Indicator | | the token. The value is a text | 198 | | | string that can be used to locate | 199 | | | the service or a URL specifying | 200 | | | the address of the service. A | 201 | | | verifier may choose to ignore | 202 | | | this claim in favor of other | 203 | | | information. | 204 | | | | 205 | Profile | No | Contains the name of a document | 206 | Definition | | that describes the 'profile' of | 207 | | | the report. The document name may | 208 | | | include versioning. The value for | 209 | | | this specification is | 210 | | | PSA_IOT_PROFILE_1. | 211 | | | | 212 | Implementation | Yes | Uniquely identifies the | 213 | ID | | underlying immutable PSA RoT. A | 214 | | | verification service can use this | 215 | | | claim to locate the details of | 216 | | | the verification process. Such | 217 | | | details include the | 218 | | | implementation's origin and | 219 | | | associated certification state. | 220 | | | | 221 | Client ID | Yes | Represents the Partition ID of | 222 | | | the caller. It is a signed | 223 | | | integer whereby negative values | 224 | | | represent callers from the NSPE | 225 | | | and where positive IDs represent | 226 | | | callers from the SPE. The full | 227 | | | definition of the partition ID is | 228 | | | given in [PSA-FF]. | 229 | | | | 230 | Security | Yes | Represents the current lifecycle | 231 | Lifecycle | | state of the PSA RoT. The state | 232 | | | is represented by an integer that | 233 | | | is divided to convey a major | 234 | | | state and a minor state. A major | 235 | | | state is mandatory and defined by | 236 | | | [PSA-SM]. A minor state is | 237 | | | optional and 'IMPLEMENTATION | 238 | | | DEFINED'. The encoding is: | 239 | | | version[15:8] - PSA security | 240 | | | lifecycle state, and version[7:0] | 241 | | | - IMPLEMENTATION DEFINED state. | 242 | | | The PSA lifecycle states are | 243 | | | listed in Section 3.1. For PSA, a | 244 | | | remote verifier can only trust | 245 | | | reports from the PSA RoT when it | 246 | | | is in SECURED or | 247 | | | NON_PSA_ROT_DEBUG major states. | 248 | | | | 249 | Hardware | No | Provides metadata linking the | 250 | version | | token to the GDSII that went to | 251 | | | fabrication for this instance. It | 252 | | | can be used to link the class of | 253 | | | chip and PSA RoT to the data on a | 254 | | | certification website. It must be | 255 | | | represented as a thirteen-digit | 256 | | | [EAN-13] | 257 | | | | 258 | Boot Seed | Yes | Represents a random value created | 259 | | | at system boot time that will | 260 | | | allow differentiation of reports | 261 | | | from different boot sessions. | 262 | | | | 263 | Software | Yes (unless | A list of software components | 264 | Components | the No | that represent all the software | 265 | | Software | loaded by the PSA Root of Trust. | 266 | | Measurements | This claim is needed for the | 267 | | claim is | rules outlined in [PSA-SM]. The | 268 | | specified) | software components are further | 269 | | | detailed in Section 3.2. | 270 | | | | 271 | No Software | Yes (if no | In the event that the | 272 | Measurements | software | implementation does not contain | 273 | | components | any software measurements then | 274 | | specified) | the Software Components claim | 275 | | | above can be omitted but instead | 276 | | | it will be mandatory to include | 277 | | | this claim to indicate this is a | 278 | | | deliberate state. This claim is | 279 | | | intended for devices that are not | 280 | | | compliant with [PSA-SM]. | 281 +----------------+--------------+-----------------------------------+ 283 Table 1: Information Model of PSA Attestation Claims. 285 3.1. PSA Lifecycle States 287 The PSA lifecycle states consist of the following values: 289 - PSA_LIFECYCLE_UNKNOWN (0x0000u) 291 - PSA_LIFECYCLE_ASSEMBLY_AND_TEST (0x1000u) 293 - PSA_LIFECYCLE_PSA_ROT_PROVISIONING (0x2000u) 295 - PSA_LIFECYCLE_SECURED (0x3000u) 297 - PSA_LIFECYCLE_NON_PSA_ROT_DEBUG (0x4000u) 299 - PSA_LIFECYCLE_RECOVERABLE_PSA_ROT_DEBUG (0x5000u) 301 - PSA_LIFECYCLE_DECOMMISSIONED (0x6000u) 303 3.2. PSA Software Components 305 Each software component in the Software Components claim MUST include 306 the required properties of Table 2. 308 +-----+-------------+-----------+-----------------------------------+ 309 | Key | Type | Mandatory | Description | 310 | ID | | | | 311 +-----+-------------+-----------+-----------------------------------+ 312 | 1 | Measurement | No | A short string representing the | 313 | | Type | | role of this software component | 314 | | | | (e.g. 'BL' for Boot Loader). | 315 | | | | | 316 | 2 | Measurement | Yes | Represents a hash of the | 317 | | value | | invariant software component in | 318 | | | | memory at startup time. The value | 319 | | | | must be a cryptographic hash of | 320 | | | | 256 bits or stronger. | 321 | | | | | 322 | 3 | Reserved | No | Reserved | 323 | | | | | 324 | 4 | Version | No | The issued software version in | 325 | | | | the form of a text string. The | 326 | | | | value of this claim will | 327 | | | | correspond to the entry in the | 328 | | | | original signed manifest of the | 329 | | | | component. | 330 | | | | | 331 | 5 | Signer ID | No | The hash of a signing authority | 332 | | | | public key for the software | 333 | | | | component. The value of this | 334 | | | | claim will correspond to the | 335 | | | | entry in the original manifest | 336 | | | | for the component. This can be | 337 | | | | used by a verifier to ensure the | 338 | | | | components were signed by an | 339 | | | | expected trusted source. This | 340 | | | | field must be present to be | 341 | | | | compliant with [PSA-SM]. | 342 | | | | | 343 | 6 | Measurement | No | Description of the way in which | 344 | | description | | the measurement value of the | 345 | | | | software component is computed. | 346 | | | | The value will be a text string | 347 | | | | containing an abbreviated | 348 | | | | description (or name) of the | 349 | | | | measurement method which can be | 350 | | | | used to lookup the details of the | 351 | | | | method in a profile document. | 352 | | | | This claim will normally be | 353 | | | | excluded, unless there was an | 354 | | | | exception to the default | 355 | | | | measurement described in the | 356 | | | | profile for a specific component. | 357 +-----+-------------+-----------+-----------------------------------+ 359 Table 2: Software Components Claims. 361 The following measurement types are current defined: 363 - 'BL': a Boot Loader 365 - 'PRoT': a component of the PSA Root of Trust 367 - 'ARoT': a component of the Application Root of Trust 369 - 'App': a component of the NSPE application 371 - 'TS': a component of a Trusted Subsystem 373 4. Token Encoding 375 The report is encoded as a COSE Web Token (CWT) [RFC8392], similar to 376 the Entity Attestation Token (EAT) [I-D.ietf-rats-eat]. The token 377 consists of a series of claims declaring evidence as to the nature of 378 the instance of hardware and software. The claims are encoded in 379 CBOR [RFC7049] format. 381 5. Claims 383 The token is modelled to include custom values that correspond to the 384 following claims suggested in the EAT specification: 386 - nonce (mandatory); arm_psa_nonce is used instead 388 - UEID (mandatory); arm_psa_UEID is used instead 390 - origination (recommended); arm_psa_origination is used instead 392 Later revisions of this documents might phase out those custom claims 393 to be replaced by the EAT standard claims. 395 As noted, some fields must be at least 32 bytes long to provide 396 sufficient cryptographic strength. 398 +-------+----------------+----------------------------+-------------+ 399 | Claim | Claim | Claim Name | CBOR Value | 400 | Key | Description | | Type | 401 +-------+----------------+----------------------------+-------------+ 402 | -7500 | Profile | arm_psa_profile_id | Text string | 403 | 0 | Definition | | | 404 | | | | | 405 | -7500 | Client ID | arm_psa_partition_id | Unsigned | 406 | 1 | | | integer or | 407 | | | | Negative | 408 | | | | integer | 409 | | | | | 410 | -7500 | Security | arm_psa_security_lifecycle | Unsigned | 411 | 2 | Lifecycle | | integer | 412 | | | | | 413 | -7500 | Implementation | arm_psa_implementation_id | Byte string | 414 | 3 | ID | | (>=32 | 415 | | | | bytes) | 416 | | | | | 417 | -7500 | Boot Seed | arm_psa_boot_seed | Byte string | 418 | 4 | | | (>=32 | 419 | | | | bytes) | 420 | | | | | 421 | -7500 | Hardware | arm_psa_hw_version | Text string | 422 | 5 | Version | | | 423 | | | | | 424 | -7500 | Software | arm_psa_sw_components | Array of | 425 | 6 | Components | | map entries | 426 | | | | (compound | 427 | | | | map claim). | 428 | | | | See below | 429 | | | | for allowed | 430 | | | | key-values. | 431 | | | | | 432 | -7500 | No Software | arm_psa_no_sw_measurements | Unsigned | 433 | 7 | Measurements | | integer | 434 | | | | | 435 | -7500 | Auth Challenge | arm_psa_nonce | Byte string | 436 | 8 | | | | 437 | | | | | 438 | -7500 | Instance ID | arm_psa_UEID | Byte string | 439 | 9 | | | | 440 | | | | | 441 | -7501 | Verification | arm_psa_origination | Byte string | 442 | 0 | Service | | | 443 | | Indicator | | | 444 +-------+----------------+----------------------------+-------------+ 445 When using the Software Components claim each key value MUST 446 correspond to the following types: 448 1. Text string (type) 450 2. Byte string (measurement, >=32 bytes) 452 3. Reserved 454 4. Text string (version) 456 5. Byte string (signer ID, >=32 bytes) 458 6. Text string (measurement description) 460 6. Example 462 The following example shows an attestation token that was produced 463 for a device that has a single-stage bootloader, and an RTOS with a 464 device management client. From a code point of view, the RTOS and 465 the device management client form a single binary. 467 EC key using curve P-256 with: 469 - x: 470 0xdcf0d0f4bcd5e26a54ee36cad660d283d12abc5f7307de58689e77cd60452e75 472 - y: 473 0x8cbadb5fe9f89a7107e5a2e8ea44ec1b09b7da2a1a82a0252a4c1c26ee1ed7cf 475 - d: 476 0xc74670bcb7e85b3803efb428940492e73e3fe9d4f7b5a8ad5e480cbdbcb554c2 478 Key using COSE format (base64-encoded): 480 pSJYIIy621/p+JpxB+Wi6OpE7BsJt9oqGoKgJSpMHCbuHtfPI1ggx0ZwvLfoWzgD77Q 481 olASS5z4/6dT3taitXkgMvby1VMIBAiFYINzw0PS81eJqVO42ytZg0oPRKrxfcwfeWG 482 ied81gRS51IAE= 484 Example of EAT token (base64-encoded): 486 0oRDoQEmoFkCIqk6AAEk+1ggAAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8 487 6AAEk+lggAAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh86AAEk/YSkAlggAA 488 ECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8EZTMuMS40BVggAAECAwQFBgcIC 489 QoLDA0ODxAREhMUFRYXGBkaGxwdHh8BYkJMpAJYIAABAgMEBQYHCAkKCwwNDg8QERIT 490 FBUWFxgZGhscHR4fBGMxLjEFWCAAAQIDBAUGBwgJCgsMDQ4PEBESExQVFhcYGRobHB0 491 eHwFkUFJvVKQCWCAAAQIDBAUGBwgJCgsMDQ4PEBESExQVFhcYGRobHB0eHwRjMS4wBV 492 ggAAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8BZEFSb1SkAlggAAECAwQFB 493 gcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8EYzIuMgVYIAABAgMEBQYHCAkKCwwNDg8Q 494 ERITFBUWFxgZGhscHR4fAWNBcHA6AAEk+RkwADoAAST/WCAAAQIDBAUGBwgJCgsMDQ4 495 PEBESExQVFhcYGRobHB0eHzoAASUBbHBzYV92ZXJpZmllcjoAAST4IDoAASUAWCEBAA 496 ECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh86AAEk93FQU0FfSW9UX1BST0ZJT 497 EVfMVhAWIYFCO5+jMSOuoctu11pSlQrEyKtDVECPBlw30KfBlAcaDqVEIoMztCm6A4J 498 ZvIr1j0cAFaXShG6My14d4f7Tw== 500 Same token using extended CBOR diagnostic format: 502 18( 503 [ 504 / protected / h'a10126' / { 505 \ alg \ 1: -7 \ ECDSA 256 \ 506 } / , 507 / unprotected / {}, 508 / payload / h'a93a000124fb5820000102030405060708090a0b0c0d0e0f1011121 509 31415161718191a1b1c1d1e1f3a000124fa5820000102030405060708090a0b0c0d0e 510 0f101112131415161718191a1b1c1d1e1f3a000124fd84a4025820000102030405060 511 708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f0465332e312e34055820 512 000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f01624 513 24ca4025820000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c 514 1d1e1f0463312e31055820000102030405060708090a0b0c0d0e0f101112131415161 515 718191a1b1c1d1e1f016450526f54a4025820000102030405060708090a0b0c0d0e0f 516 101112131415161718191a1b1c1d1e1f0463312e30055820000102030405060708090 517 a0b0c0d0e0f101112131415161718191a1b1c1d1e1f016441526f54a4025820000102 518 030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f0463322e320 519 55820000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f 520 01634170703a000124f91930003a000124ff5820000102030405060708090a0b0c0d0 521 e0f101112131415161718191a1b1c1d1e1f3a000125016c7073615f76657269666965 522 723a000124f8203a00012500582101000102030405060708090a0b0c0d0e0f1011121 523 31415161718191a1b1c1d1e1f3a000124f7715053415f496f545f50524f46494c455f 524 31' / { 525 / arm_psa_boot_seed / -75004: h'000102030405060708090a0b0c0d0e0f10 526 1112131415161718191a1b1c1d1e1f', 527 / arm_psa_implementation_id / -75003: h'000102030405060708090a0b0c 528 0d0e0f101112131415161718191a1b1c1d1e1f', 529 / arm_psa_sw_components / -75006: [ 530 { 531 / measurement / 2: h'000102030405060708090a0b0c0d0e0f101112 532 131415161718191a1b1c1d1e1f', 533 / version / 4: "3.1.4", 534 / signerID / 5: h'000102030405060708090a0b0c0d0e0f101112131 535 415161718191a1b1c1d1e1f', 536 / type / 1: "BL" 537 }, 538 { 539 / measurement / 2: h'000102030405060708090a0b0c0d0e0f101112 540 131415161718191a1b1c1d1e1f', 541 / version / 4: "1.1", 542 / signerID / 5: h'000102030405060708090a0b0c0d0e0f101112131 543 415161718191a1b1c1d1e1f', 544 / type / 1: "PRoT" 545 }, 546 { 547 / measurement / 2: h'000102030405060708090a0b0c0d0e0f101112 548 131415161718191a1b1c1d1e1f', 549 / version / 4: "1.0", 550 / signerID / 5: h'000102030405060708090a0b0c0d0e0f101112131 551 415161718191a1b1c1d1e1f', 552 / type / 1: "ARoT" 553 }, 554 { 555 / measurement / 2: h'000102030405060708090a0b0c0d0e0f101112 556 131415161718191a1b1c1d1e1f', 557 / version / 4: "2.2", 558 / signerID / 5: h'000102030405060708090a0b0c0d0e0f101112131 559 415161718191a1b1c1d1e1f', 560 / type / 1: "App" 561 } 562 ], 563 / arm_psa_security_lifecycle / -75002: 12288 / SECURED /, 564 / arm_psa_nonce / -75008: h'000102030405060708090a0b0c0d0e0f10111 565 2131415161718191a1b1c1d1e1f', 566 / arm_psa_origination / -75010: "psa_verifier", 567 / arm_psa_partition_id / -75001: -1, 568 / arm_psa_UEID / -75009: h'01000102030405060708090a0b0c0d0e0f1011 569 12131415161718191a1b1c1d1e1f', 570 / arm_psa_profile_id / -75000: "PSA_IoT_PROFILE_1" 571 }), 572 } / , 573 / signature / h'58860508ee7e8cc48eba872dbb5d694a542b1322ad0d51023c197 574 0df429f06501c683a95108a0cced0a6e80e0966f22bd63d1c0056974a11ba332d7877 575 87fb4f' 576 ] 577 ) 579 7. Security and Privacy Considerations 581 This specification re-uses the CWT and the EAT specification. Hence, 582 the security and privacy considerations of those specifications apply 583 here as well. 585 Since CWTs offer different ways to protect the token this 586 specification profiles those options and only uses public key 587 cryptography. The token MUST be signed following the structure of 588 the COSE specification [RFC8152]. The COSE type MUST be COSE-Sign1. 590 Attestation tokens contain information that may be unique to a device 591 and therefore they may allow to single out an individual device for 592 tracking purposes. Implementation must take appropriate measures to 593 ensure that only those claims are included that fulfil the purpose of 594 the application and that users of those devices consent to the data 595 sharing. 597 8. IANA Considerations 599 IANA is requested to allocate the claims defined in Section 5 to the 600 CBOR Web Token (CWT) Claims registry [IANA-CWT]. The change 601 controller are the authors and the reference is this document. 603 9. References 605 9.1. Normative References 607 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 608 Requirement Levels", BCP 14, RFC 2119, 609 DOI 10.17487/RFC2119, March 1997, 610 . 612 [RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object 613 Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049, 614 October 2013, . 616 [RFC8152] Schaad, J., "CBOR Object Signing and Encryption (COSE)", 617 RFC 8152, DOI 10.17487/RFC8152, July 2017, 618 . 620 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 621 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 622 May 2017, . 624 [RFC8392] Jones, M., Wahlstroem, E., Erdtman, S., and H. Tschofenig, 625 "CBOR Web Token (CWT)", RFC 8392, DOI 10.17487/RFC8392, 626 May 2018, . 628 9.2. Informative References 630 [EAN-13] GS1, "International Article Number - EAN/UPC barcodes", 631 2019, . 633 [I-D.ietf-rats-eat] 634 Mandyam, G., Lundblade, L., Ballesteros, M., and J. 635 O'Donoghue, "The Entity Attestation Token (EAT)", draft- 636 ietf-rats-eat-01 (work in progress), July 2019. 638 [IANA-CWT] 639 IANA, "CBOR Web Token (CWT) Claims", 2019, 640 . 642 [PSA] Arm, "Platform Security Architecture Resources", 2019, 643 . 646 [PSA-FF] Arm, "Platform Security Architecture Firmware Framework 647 1.0 (PSA-FF)", February 2019, 648 . 650 [PSA-SM] Arm, "Platform Security Architecture Security Model 1.0 651 (PSA-SM)", February 2019, 652 . 654 [TF-M] Linaro, "Trusted Firmware", 2019, 655 . 657 Appendix A. Contributors 659 We would like to thank the following supporters for their 660 contributions: 662 * Laurence Lundblade 663 Security Theory LLC 664 lgl@securitytheory.com 666 * Tamas Ban 667 Arm Limited 668 Tamas.Ban@arm.com 670 Appendix B. Reference Implementation 672 Trusted Firmware M (TF-M) [TF-M] is the name of the open source 673 project that provides a reference implementation of PSA APIs and an 674 SPM, created for the latest Arm v8-M microcontrollers with TrustZone 675 technology. TF-M provides foundational firmware components that 676 silicon manufacturers and OEMs can build on (including trusted boot, 677 secure device initialisation and secure function invocation). 679 Authors' Addresses 681 Hannes Tschofenig (editor) 682 Arm Limited 684 EMail: hannes.tschofenig@arm.com 686 Simon Frost 687 Arm Limited 689 EMail: Simon.Frost@arm.com 691 Mathias Brossard 692 Arm Limited 694 EMail: Mathias.Brossard@arm.com 696 Adrian Shaw 697 Arm Limited 699 EMail: Adrian.Shaw@arm.com 700 Thomas Fossati 701 Arm Limited 703 EMail: thomas.fossati@arm.com