idnits 2.17.1 draft-ietf-regext-secure-authinfo-transfer-00.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 an IANA Considerations section. (See Section 2.2 of https://www.ietf.org/id-info/checklist for how to handle the case when there are no actions for IANA.) Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (February 14, 2020) is 1533 days in the past. Is this intentional? Checking references for intended status: Best Current Practice ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Looks like a reference, but probably isn't: '1' on line 996 ** Obsolete normative reference: RFC 8499 (Obsoleted by RFC 9499) Summary: 2 errors (**), 0 flaws (~~), 1 warning (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group J. Gould 3 Internet-Draft R. Wilhelm 4 Intended status: Best Current Practice VeriSign, Inc. 5 Expires: August 17, 2020 February 14, 2020 7 Extensible Provisioning Protocol (EPP) Secure Authorization Information 8 for Transfer 9 draft-ietf-regext-secure-authinfo-transfer-00 11 Abstract 13 The Extensible Provisioning Protocol (EPP), in RFC 5730, defines the 14 use of authorization information to authorize a transfer. The 15 authorization information is object-specific and has been defined in 16 the EPP Domain Name Mapping, in RFC 5731, and the EPP Contact 17 Mapping, in RFC 5733, as password-based authorization information. 18 Other authorization mechanisms can be used, but in practice the 19 password-based authorization information has been used at the time of 20 object create, managed with the object update, and used to authorize 21 an object transfer request. What has not been fully considered is 22 the security of the authorization information that includes the 23 complexity of the authorization information, the time-to-live (TTL) 24 of the authorization information, and where and how the authorization 25 information is stored. This document defines an operational 26 practice, using the EPP RFCs, that leverages the use of strong random 27 authorization information values that are short-lived, that are not 28 stored by the client, and that are stored using a cryptographic hash 29 by the server to provide for secure authorization information used 30 for transfers. 32 Status of This Memo 34 This Internet-Draft is submitted in full conformance with the 35 provisions of BCP 78 and BCP 79. 37 Internet-Drafts are working documents of the Internet Engineering 38 Task Force (IETF). Note that other groups may also distribute 39 working documents as Internet-Drafts. The list of current Internet- 40 Drafts is at https://datatracker.ietf.org/drafts/current/. 42 Internet-Drafts are draft documents valid for a maximum of six months 43 and may be updated, replaced, or obsoleted by other documents at any 44 time. It is inappropriate to use Internet-Drafts as reference 45 material or to cite them other than as "work in progress." 47 This Internet-Draft will expire on August 17, 2020. 49 Copyright Notice 51 Copyright (c) 2020 IETF Trust and the persons identified as the 52 document authors. All rights reserved. 54 This document is subject to BCP 78 and the IETF Trust's Legal 55 Provisions Relating to IETF Documents 56 (https://trustee.ietf.org/license-info) in effect on the date of 57 publication of this document. Please review these documents 58 carefully, as they describe your rights and restrictions with respect 59 to this document. Code Components extracted from this document must 60 include Simplified BSD License text as described in Section 4.e of 61 the Trust Legal Provisions and are provided without warranty as 62 described in the Simplified BSD License. 64 Table of Contents 66 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 67 1.1. Conventions Used in This Document . . . . . . . . . . . . 4 68 2. Registrant, Registrar, Registry . . . . . . . . . . . . . . . 5 69 3. Secure Authorization Information . . . . . . . . . . . . . . 6 70 3.1. Secure Random Authorization Information . . . . . . . . . 6 71 3.2. Authorization Information Time-To-Live (TTL) . . . . . . 7 72 3.3. Authorization Information Storage and Transport . . . . . 7 73 3.4. Authorization Information Matching . . . . . . . . . . . 8 74 4. Create, Transfer, and Secure Authorization Information . . . 8 75 4.1. Create Command . . . . . . . . . . . . . . . . . . . . . 9 76 4.2. Update Command . . . . . . . . . . . . . . . . . . . . . 11 77 4.3. Info Command and Response . . . . . . . . . . . . . . . . 14 78 4.4. Transfer Request Command . . . . . . . . . . . . . . . . 15 79 5. Transition Considerations . . . . . . . . . . . . . . . . . . 16 80 5.1. Transition Phase 1 - Features . . . . . . . . . . . . . . 18 81 5.2. Transition Phase 2 - Storage . . . . . . . . . . . . . . 18 82 5.3. Transition Phase 3 - Enforcement . . . . . . . . . . . . 19 83 6. Implementation Status . . . . . . . . . . . . . . . . . . . . 19 84 6.1. Verisign EPP SDK . . . . . . . . . . . . . . . . . . . . 20 85 6.2. RegistryEngine EPP Service . . . . . . . . . . . . . . . 20 86 7. Security Considerations . . . . . . . . . . . . . . . . . . . 21 87 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21 88 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 21 89 9.1. Normative References . . . . . . . . . . . . . . . . . . 21 90 9.2. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 22 91 Appendix A. Change History . . . . . . . . . . . . . . . . . . . 22 92 A.1. Change from 00 to 01 . . . . . . . . . . . . . . . . . . 22 93 A.2. Change from 01 to 02 . . . . . . . . . . . . . . . . . . 22 94 A.3. Change from 02 to 03 . . . . . . . . . . . . . . . . . . 22 95 A.4. Change from 03 to REGEXT 00 . . . . . . . . . . . . . . . 24 96 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24 98 1. Introduction 100 The Extensible Provisioning Protocol (EPP), in [RFC5730], defines the 101 use of authorization information to authorize a transfer. The 102 authorization information is object-specific and has been defined in 103 the EPP Domain Name Mapping, in [RFC5731], and the EPP Contact 104 Mapping, in [RFC5733], as password-based authorization information. 105 Other authorization mechanisms can be used, but in practice the 106 password-based authorization information has been used at the time of 107 object create, managed with the object update, and used to authorize 108 an object transfer request. What has not been considered is the 109 security of the authorization information that includes the 110 complexity of the authorization information, the time-to-live (TTL) 111 of the authorization information, and where and how the authorization 112 information is stored. This document defines an operational 113 practice, using the EPP RFCs, that leverages the use of strong, 114 random authorization information values that are short-lived, that 115 are not stored by the client, and that are stored by the server using 116 a cryptographic hash to provide, for secure authorization information 117 used for transfers. This operational practice can be used to support 118 transfers of any EPP object, where the domain name object defined in 119 [RFC5731] is used in this document for illustration purposes. 120 Elements of the practice may be used to support the secure use of the 121 authorization information for purposes other than transfer, but any 122 other purposes and the applicable elements are out-of-scope for this 123 document. 125 The overall goal is to have strong, random authorization information 126 values, that are short-lived, and that are either not stored or 127 stored as a cryptographic hash values by the non-responsible parties. 128 In a registrant, registrar, and registry model, the registrant 129 registers the object through the registrar to the registry. The 130 registrant is the responsible party and the registrar and the 131 registry are the non-responsible parties. EPP is a protocol between 132 the registrar and the registry, where the registrar is referred to as 133 the client and the registry is referred to as the server. The 134 following are the elements of the operational practice and how the 135 existing features of the EPP RFCs can be leveraged to satisfy them: 137 "Strong Random Authorization Information": The EPP RFCs define the 138 password-based authorization information value using an XML 139 schema "normalizedString" type, so they don't restrict what can 140 be used in any way. This operational practice defines the 141 recommended mechanism for creating a strong random authorization 142 value, that would be generated by the client. 143 "Short-Lived Authorization Information": The EPP RFCs don't 144 explicitly support short-lived authorization information or a 145 time-to-live (TTL) for authorization information, but there are 146 EPP RFC features that can be leveraged to support short-lived 147 authorization information. If authorization information is set 148 only when there is a transfer in process, the server needs to 149 support empty authorization information on create, support 150 setting and unsetting authorization information, and support 151 automatically unsetting the authorization information upon a 152 successful transfer. All of these features can be supported by 153 the EPP RFCs. 154 "Storing Authorization Information Securely": The EPP RFCs don't 155 specify where and how the authorization information is stored in 156 the client or the server, so there are no restrictions to define 157 an operational practice for storing the authorization information 158 securely. The operational practice will not require the client 159 to store the authorization information and will require the 160 server to store the authorization information using a 161 cryptographic hash, with at least a 256-bit hash function, such 162 as SHA-256. Returning the authorization information set in an 163 EPP info response will not be supported. 165 1.1. Conventions Used in This Document 167 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 168 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 169 document are to be interpreted as described in RFC 2119 [RFC2119]. 171 XML is case sensitive. Unless stated otherwise, XML specifications 172 and examples provided in this document MUST be interpreted in the 173 character case presented in order to develop a conforming 174 implementation. 176 In examples, "C:" represents lines sent by a protocol client and "S:" 177 represents lines returned by a protocol server. Indentation and 178 white space in examples are provided only to illustrate element 179 relationships and are not a required feature of this protocol. 181 The examples reference XML namespace prefixes that are used for the 182 associated XML namespaces. Implementations MUST NOT depend on the 183 example XML namespaces and instead employ a proper namespace-aware 184 XML parser and serializer to interpret and output the XML documents. 185 The example namespace prefixes used and their associated XML 186 namespaces include: 188 "domain": urn:ietf:params:xml:ns:domain-1.0 189 "contact": urn:ietf:params:xml:ns:contact-1.0 191 2. Registrant, Registrar, Registry 193 The EPP RFCs refer to client and server, but when it comes to 194 transfers, there are three types of actors that are involved. This 195 document will refer to the actors as registrant, registrar, and 196 registry. [RFC8499] defines these terms formally for the Domain Name 197 System (DNS). The terms are further described below to cover their 198 roles as actors of using the authorization information in the 199 transfer process of any object in the registry, such as a domain name 200 or a contact: 202 "registrant": [RFC8499] defines the registrant as "an individual or 203 organization on whose behalf a name in a zone is registered by 204 the registry". The registrant can be the owner of any object in 205 the registry, such as a domain name or a contact. The registrant 206 interfaces with the registrar for provisioning the objects. A 207 transfer is coordinated by the registrant to transfer the 208 sponsorship of the object from one registrar to another. The 209 authorization information is meant to authenticate the registrant 210 as the owner of the object to the non-sponsoring registrar and to 211 authorize the transfer. 212 "registrar": [RFC8499] defines the registrar as "a service provider 213 that acts as a go-between for registrants and registries". The 214 registrar interfaces with the registrant for the provisioning of 215 objects, such as domain names and contacts, and with the 216 registries to satisfy the registrant's provisioning requests. A 217 registrar may directly interface with the registrant or may 218 indirectly interface with the registrant, typically through one 219 or more resellers. Implementing a transfer using secure 220 authorization information extends through the registrar's 221 reseller channel up to the direct interface with the registrant. 222 The registrar's interface with the registries uses EPP. The 223 registrar's interface with its reseller channel or the registrant 224 is registrar-specific. In the EPP RFCs, the registrar is 225 referred to as the "client", since EPP is the protocol used 226 between the registrar and the registry. The sponsoring registrar 227 is the authorized registrar to manage objects on behalf of the 228 registrant. A non-sponsoring registrar is not authorized to 229 manage objects on behalf of the registrant. A transfer of an 230 object's sponsorship is from one registrar, referred to as the 231 losing registrar, to another registrar, referred to as the 232 gaining registrar. 233 "registry": [RFC8499] defines the registry as "the administrative 234 operation of a zone that allows registration of names within the 235 zone". The registry typically interfaces with the registrars 236 over EPP and generally does not interact directly with the 237 registrant. In the EPP RFCs, the registry is referred to as the 238 "server", since EPP is the protocol used between the registrar 239 and the registry. The registry has a record of the sponsoring 240 registrar for each object and provides the mechanism (over EPP) 241 to coordinate a transfer of an object's sponsorship between 242 registrars. 244 3. Secure Authorization Information 246 The authorization information in the EPP RFCs ([RFC5731] and 247 [RFC5733]) that support transfer use password-based authorization 248 information. Other EPP objects that support password-based 249 authorization information for transfer can use the Secure 250 Authorization Information defined in this document. For the 251 authorization information to be secure it must be a strong random 252 value and must have a short time-to-live (TTL). The security of the 253 authorization information is defined in the following sections. 255 3.1. Secure Random Authorization Information 257 For authorization information to be secure, it MUST be generated 258 using a secure random value. The authorization information is 259 treated as a password, where according to [RFC4086] a high-security 260 password must have at least 49 bits of randomness or entropy. The 261 required length L of a password, rounded up to the largest whole 262 number, is based on the set of characters N and the desired entropy 263 H, in the equation L = ROUNDUP(H / log2 N). With a target entropy of 264 49, the required length can be calculated after deciding on the set 265 of characters that will be randomized. The following are a set of 266 possible character sets and the calculation of the required length. 268 Calculation of the required length with 49 bits of entropy and with 269 the set of all printable ASCII characters except space (0x20), which 270 consists of the 94 characters 0x21-0x7E. 272 ROUNDUP(49 / log2 94) =~ ROUNDUP(49 / 6.55) =~ ROUNDUP(7.48) = 8 274 Calculation of the required length with 49 bits of entropy and with 275 the set of case-insensitive alphanumeric characters, which consists 276 of 36 characters (a-z A-Z 0-9). 278 ROUNDUP(49 / log2 36) =~ ROUNDUP(49 / 5.17) =~ ROUNDUP(9.48) = 10 280 Considering the age of [RFC4086], the evolution of security 281 practices, and that the authorization information is a machine- 282 generated value, the recommendation is to use at least 128 bits of 283 entropy. The lengths are recalculated below using 128 bits of 284 entropy. 286 Calculation of the required length with 128 bits of entropy and with 287 the set of all printable ASCII characters except space (0x20), which 288 consists of the 94 characters 0x21-0x7E. 290 ROUNDUP(128 / log2 94) =~ ROUNDUP(128 / 6.55) =~ ROUNDUP(19.54) = 20 292 Calculation of the required length with 128 bits of entropy and with 293 the set of case insensitive alphanumeric characters, which consists 294 of 36 characters (a-z A-Z 0-9). 296 ROUNDUP(128 / log2 36) =~ ROUNDUP(128 / 5.17) =~ ROUNDUP(24.76) = 25 298 The strength of the random authorization information is dependent on 299 the actual entropy of the underlying random number generator. For 300 the random number generator, the practices defined in [RFC4086] and 301 section 4.7.1 of the NIST Federal Information Processing Standards 302 (FIPS) Publication 140-2 [1] SHOULD be followed to produce random 303 values that will be resistant to attack. A random number generator 304 (RNG) is preferable over the use of a pseudorandom number generator 305 (PRNG) to reduce the predictability of the authorization information. 306 The more predictable the random number generator is, the lower the 307 true entropy, and the longer the required length for the 308 authorization information. 310 3.2. Authorization Information Time-To-Live (TTL) 312 The authorization information SHOULD only be set when there is a 313 transfer in process. This implies that the authorization information 314 has a Time-To-Live (TTL) by which the authorization information is 315 cleared when the TTL expires. The EPP RFCs have no definition of 316 TTL, but since the server supports the setting and unsetting of the 317 authorization information by the sponsoring registrar, then the 318 sponsoring registrar can apply a TTL based on client policy. The TTL 319 client policy may be based on proprietary registrar-specific criteria 320 which provides for a transfer-specific TTL tuned for the particular 321 circumstances of the transaction. The sponsoring registrar will be 322 aware of the TTL and the sponsoring registrar MUST inform the 323 registrant of the TTL when the authorization information is provided 324 to the registrant. 326 3.3. Authorization Information Storage and Transport 328 To protect the disclosure of the authorization information, the 329 following requirements apply: 331 1. The authorization information MUST be stored by the registry 332 using a strong one-way cryptographic hash, with at least a 333 256-bit hash function, such as SHA-256. 335 2. An empty authorization information MUST be stored with a NULL 336 (undefined) value. 337 3. The authorization information MUST NOT be stored by the losing 338 registrar. 339 4. The authorization information MUST only be stored by the gaining 340 registrar as a "transient" value in support of the transfer 341 process. 342 5. The plain text version of the authorization information MUST NOT 343 be written to any logs by the registrar or the registry. 344 6. All communication that includes the authorization information 345 MUST be over an encrypted channel, such as defined in [RFC5734] 346 for EPP. 347 7. The registrar's interface for communicating the authorization 348 information with the registrant MUST be over an authenticated and 349 encrypted channel. 351 3.4. Authorization Information Matching 353 To support the authorization information TTL, as defined in 354 Section 3.2, the authorization information must have either a set or 355 unset state. The unset authorization information is stored with a 356 NULL (undefined) value. Based on the requirement to store the 357 authorization information using a strong one-way cryptographic hash, 358 as defined in Section 3.3, a set authorization information is stored 359 with a non-NULL hashed value. The empty authorization information is 360 used as input in both the create command (Section 4.1) and the update 361 command (Section 4.2) to define the unset state. The matching of the 362 authorization information in the info command (Section 4.3) and the 363 transfer request command (Section 4.4) is based on the following 364 rules: 366 1. Any input authorization information value MUST NOT match an unset 367 authorization information value. 368 2. An empty input authorization information value MUST NOT match any 369 authorization information value. 370 3. A non-empty input authorization information value MUST be hashed 371 and matched against the set authorization information value, 372 which is stored using the same hash algorithm. 374 4. Create, Transfer, and Secure Authorization Information 376 To make the transfer process secure using secure authorization 377 information, as defined in Section 3, the client and server need to 378 implement steps where the authorization information is set only when 379 a transfer is actively in process and ensure that the authorization 380 information is stored securely and transported only over secure 381 channels. The steps in management of the authorization information 382 for transfers include: 384 1. Registrant requests to register the object with the registrar. 385 Registrar sends the create command, with empty authorization 386 information, to the registry, as defined in Section 4.1. 387 2. Registrant requests from the losing registrar the authorization 388 information to provide to the gaining registrar. 389 3. Losing registrar generates a secure random authorization 390 information value, sends it to the registry as defined in 391 Section 4.2, and provides it to the registrant. 392 4. Registrant provides the authorization information value to the 393 gaining registrar. 394 5. Gaining registrar optionally verifies the authorization 395 information with the info command to the registry, as defined in 396 Section 4.3. 397 6. Gaining registrar sends the transfer request with the 398 authorization information to the registry, as defined in 399 Section 4.4. 400 7. If the transfer successfully completes, the registry 401 automatically unsets the authorization information; otherwise the 402 losing registrar unsets the authorization information when the 403 TTL expires, as defined in Section 4.2. 405 The following sections outline the practices of the EPP commands and 406 responses between the registrar and the registry that supports secure 407 authorization information for transfer. 409 4.1. Create Command 411 For a create command, the registry MUST allow for the passing of an 412 empty authorization information and MAY disallow for the passing of a 413 non-empty authorization information. By having an empty 414 authorization information on create, the object is initially not in 415 the transfer process. Any EPP object extension that supports setting 416 the authorization information with a "eppcom:pwAuthInfoType" element, 417 can have an empty authorization information passed, such as [RFC5731] 418 and [RFC5733]. 420 Example of passing empty authorization information in an [RFC5731] 421 domain name create command. 423 C: 424 C: 425 C: 426 C: 427 C: 429 C: example.com 430 C: 431 C: 432 C: 433 C: 434 C: 435 C: ABC-12345 436 C: 437 C: 439 Example of passing empty authorization information in an [RFC5733] 440 contact create command. 442 C: 443 C: 444 C: 445 C: 446 C: 448 C: sh8013 449 C: 450 C: John Doe 451 C: 452 C: Dulles 453 C: US 454 C: 455 C: 456 C: jdoe@example.com 457 C: 458 C: 459 C: 460 C: 461 C: 462 C: ABC-12345 463 C: 464 C: 466 4.2. Update Command 468 For an update command, the registry MUST allow for the setting and 469 unsetting of the authorization information. The registrar sets the 470 authorization information by first generating a strong, random 471 authorization information value, based on Section 3.1, and setting it 472 in the registry in the update command. The registry SHOULD validate 473 the randomness of the authorization information based on the length 474 and character set required by the registry. For example, a registry 475 that requires 20 random printable ASCII characters except space 476 (0x20), should validate that the authorization information contains 477 at least one upper case alpha character, one lower case alpha 478 character, and one non-alpha numeric character. If the authorization 479 information fails the randomness validation, the registry MUST return 480 an EPP error result code of 2202. 482 Often the registrar has the "clientTransferProhibited" status set, so 483 to start the transfer process, the "clientTransferProhibited" status 484 needs to be removed, and the strong, random authorization information 485 value needs to be set. The registrar MUST define a time-to-live 486 (TTL), as defined in Section 3.2, where if the TTL expires the 487 registrar will unset the authorization information. 489 Example of removing the "clientTransferProhibited" status and setting 490 the authorization information in an [RFC5731] domain name update 491 command. 493 C: 494 C: 495 C: 496 C: 497 C: 499 C: example.com 500 C: 501 C: 502 C: 503 C: 504 C: 505 C: LuQ7Bu@w9?%+_HK3cayg$55$LSft3MPP 506 C: 507 C: 508 C: 509 C: 510 C: 511 C: ABC-12345-XYZ 512 C: 513 C: 514 When the registrar-defined TTL expires, the sponsoring registrar 515 cancels the transfer process by unsetting the authorization 516 information value and may add back statuses like the 517 "clientTransferProbited" status. Any EPP object extension that 518 supports setting the authorization information with a 519 "eppcom:pwAuthInfoType" element, can have an empty authorization 520 information passed, such as [RFC5731] and [RFC5733]. Setting an 521 empty authorization information unsets the value. [RFC5731] supports 522 an explicit mechanism of unsetting the authorization information, by 523 passing the authorization information value. The 524 registry MUST support unsetting the authorization information by 525 accepting an empty authorization information value and accepting an 526 explicit unset element if it is supported by the object extension. 528 Example of adding the "clientTransferProhibited" status and unsetting 529 the authorization information explicitly in an [RFC5731] domain name 530 update command. 532 C: 533 C: 534 C: 535 C: 536 C: 538 C: example.com 539 C: 540 C: 541 C: 542 C: 543 C: 544 C: 545 C: 546 C: 547 C: 548 C: 549 C: ABC-12345-XYZ 550 C: 551 C: 552 Example of unsetting the authorization information with an empty 553 authorization information in an [RFC5731] domain name update command. 555 C: 556 C: 557 C: 558 C: 559 C: 561 C: example.com 562 C: 563 C: 564 C: 565 C: 566 C: 567 C: 568 C: 569 C: 570 C: 571 C: 572 C: ABC-12345-XYZ 573 C: 574 C: 576 Example of unsetting the authorization information with an empty 577 authorization information in an [RFC5733] contact update command. 579 C: 580 C: 581 C: 582 C: 583 C: 585 C: sh8013 586 C: 587 C: 588 C: 589 C: 590 C: 591 C: 592 C: 593 C: ABC-12345-XYZ 594 C: 595 C: 597 4.3. Info Command and Response 599 For an info command, the registry MUST allow for the passing of a 600 non-empty authorization information for verification. The gaining 601 registrar can pre-verify the authorization information provided by 602 the registrant prior to submitting the transfer request with the use 603 of the info command. The registry compares the hash of the passed 604 authorization information with the hashed authorization information 605 value stored for the object. When the authorization information is 606 not set or the passed authorization information does not match the 607 previously set value, the registry MUST return an EPP error result 608 code of 2202 [RFC5730]. 610 Example of passing a non-empty authorization information in an 611 [RFC5731] domain name info command to verify the authorization 612 information value. 614 C: 615 C: 616 C: 617 C: 618 C: 620 C: example.com 621 C: 622 C: LuQ7Bu@w9?%+_HK3cayg$55$LSft3MPP 623 C: 624 C: 625 C: 626 C: 627 C: ABC-12345 628 C: 629 C: 631 The info response in object extensions, such as [RFC5731] and 632 [RFC5733], MUST NOT include the optional authorization information 633 element with a non-empty authorization value. The authorization 634 information is stored as a hash in the registry, so returning the 635 plain text authorization information is not possible, unless a valid 636 plain text authorization information is passed in the info command. 637 The registry MUST NOT return any indication of whether the 638 authorization information is set or unset to the non-sponsoring 639 registrar by not returning the authorization information element in 640 the response. The registry MAY return an indication to the 641 sponsoring registrar that the authorization information is set by 642 using an empty authorization information value. The registry MAY 643 return an indication to the sponsoring registrar that the 644 authorization information is unset by not returning the authorization 645 information element. 647 Example of returning an empty authorization information in an 648 [RFC5731] domain name info response to indicate to the sponsoring 649 registrar that the authorization information is set. 651 S: 652 S: 653 S: 654 S: 655 S: Command completed successfully 656 S: 657 S: 658 S: 660 S: example.com 661 S: EXAMPLE1-REP 662 S: 663 S: ClientX 664 S: 665 S: 666 S: 667 S: 668 S: 669 S: 670 S: ABC-12345 671 S: 54322-XYZ 672 S: 673 S: 674 S: 676 4.4. Transfer Request Command 678 For a Transfer Request Command, the registry MUST allow for the 679 passing of a non-empty authorization information to authorize a 680 transfer. The registry compares the hash of the passed authorization 681 information with the hashed authorization information value stored 682 for the object. When the authorization information is not set or the 683 passed authorization information does not match the previously set 684 value, the registry MUST return an EPP error result code of 2202 685 [RFC5730]. Whether the transfer occurs immediately or is pending is 686 up to server policy. When the transfer occurs immediately, the 687 registry MUST return the EPP success result code of 1000 and when the 688 transfer is pending, the registry MUST return the EPP success result 689 code of 1001. The losing registrar MUST be informed of a successful 690 transfer request using an EPP poll message. 692 Example of passing a non-empty authorization information in an 693 [RFC5731] domain name transfer request command to authorize the 694 transfer. 696 C: 697 C: 698 C: 699 C: 700 C: 702 C: example1.com 703 C: 704 C: LuQ7Bu@w9?%+_HK3cayg$55$LSft3MPP 705 C: 706 C: 707 C: 708 C: 709 C: ABC-12345 710 C: 711 C: 713 Upon successful completion of the transfer, the registry MUST 714 automatically unset the authorization information. If the transfer 715 request is not submitted within the time-to-live (TTL) (Section 3.2) 716 or the transfer is cancelled or rejected, the registrar MUST unset 717 the authorization information as defined in Section 4.2. 719 5. Transition Considerations 721 The goal of the transition considerations to the practice defined in 722 this document, referred to as the Secure Authorization Information 723 Model, is to minimize the impact to the registrars by supporting 724 incremental steps of adoption. The transtion steps are dependent on 725 the starting point of the registry. Registries may have different 726 starting points, since some of the elements of the Secure 727 Authorization Information Model may have already been implemented. 728 The considerations assume a starting point, referred to as the 729 Classic Authorization Information Model, that have the following 730 steps in the management of the authorization information for 731 transfers: 733 1. Registrant requests to register the object with the registrar. 734 Registrar sends the create command, with a non-empty 735 authorization information, to the registry. The registry stores 736 the authorization information as an encrypted value and requires 737 a non-empty authorization information for the life of the object. 738 The registrar may store the long-lived authorization information. 740 2. At the time of transfer, Registrant requests from the losing 741 registrar the authorization information to provide to the gaining 742 registrar. 743 3. Losing registrar retrieves the stored authorization information 744 locally or queries the registry for authorization information 745 using the info command, and provides it to the registrant. If 746 the registry is queried, the authorization information is 747 decrypted and the plain text authorization information is 748 returned in the info response to the registrar. 749 4. Registrant provides the authorization information value to the 750 gaining registrar. 751 5. Gaining registrar optionally verifies the authorization 752 information with the info command to the registry, by passing the 753 authorization information in the info command to the registry. 754 6. Gaining registrar sends the transfer request with the 755 authorization information to the registry. The registry will 756 decrypt the stored authorization information to compare to the 757 passed authorization information. 758 7. If the transfer successfully completes, the authorization 759 information is not touched by the registry and may be updated by 760 the gaining registrar using the update command. If the transfer 761 is cancelled or rejected, the losing registrar may reset the 762 authorization information using the update command. 764 The gaps between the Classic Authorization Information Model and the 765 Secure Authorization Information Model include: 767 1. Registry requirement for a non-empty authorization information on 768 create and for the life of the object versus the authorization 769 information not being set on create and only being set when a 770 transfer is in process. 771 2. Registry not allowing the authorization information to be unset 772 versus supporting the authorization to be unset in the update 773 command. 774 3. Registry storing the authorization information as an encrypted 775 value versus as a hashed value. 776 4. Registry support for returning the authorization information 777 versus not returning the authorization information in the info 778 response. 779 5. Registry not touching the authorization information versus the 780 registry automatically unsetting the authorization information 781 upon a successful transfer. 782 6. Registry may validate a shorter authorization information value 783 using password complexity rules versus validating the randomness 784 of a longer authorization information value that meets the 785 required bits of entropy. 787 The transition can be handled in the three phases defined in the sub- 788 sections Section 5.1, Section 5.2, Section 5.3. 790 5.1. Transition Phase 1 - Features 792 The goal of the "Transition Phase 1 - Features" is to implement the 793 needed features in EPP so that the registrar can optionally implement 794 the Secure Authorization Information Model. The features to 795 implement are broken out by the command and responses below: 797 Create Command: Change the create command to make the authorization 798 information optional, by allowing both a non-empty value and an 799 empty value. This enables a registrar to optionally create 800 objects without an authorization information value, as defined in 801 Section 4.1. 802 Update Command: Change the update command to allow unsetting the 803 authorization information, as defined in Section 4.2. This 804 enables the registrar to optionally unset the authorization 805 information when the TTL expires or when the transfer is cancelled 806 or rejected. 807 Transfer Approve Command and Transfer Auto-Approve: Change the 808 transfer approve command and the transfer auto-approve to 809 automatically unset the authorization information. This sets the 810 default state of the object to not have the authorization 811 information set. The registrar implementing the Secure 812 Authorization Information Model will not set the authorization 813 information for an inbound transfer and the registrar implementing 814 the Classic Authorization Information Model will set the new 815 authorization information upon the successful transfer. 816 Info Response: Change the info command to not return the 817 authorization information in the info response, as defined in 818 Section 4.3. This sets up the implementation of "Transition Phase 819 2 - Storage", since the dependency in returning the authorization 820 information in the info response will be removed. This feature is 821 the only one that is not an optional change to the registrar. 822 Info Command and Transfer Request: Change the info command and the 823 transfer request to ensure that a registrar cannot get an 824 indication that the authorization information is set or not set by 825 returning the EPP error result code of 2202 when comparing a 826 passed authorization to a non-matching set authorization 827 information value or an unset value. 829 5.2. Transition Phase 2 - Storage 831 The goal of the "Transition Phase 2 - Storage" is to transition the 832 registry to use hashed authorization information instead of encrypted 833 authorization information. There is no direct impact to the 834 registrars, since the only visible indication that the authorization 835 information has been hashed is by not returning the set authorization 836 information in the info response, which is addressed in Transition 837 Phase 1 - Features (Section 5.1). There are three steps to 838 transition the authorization information storage, which includes: 840 Hash New Authorization Information Values: Change the create command 841 and the update command to hash instead of encyrpting the 842 authorization information. 843 Supporting Comparing Against Encrypted and Hashed Authorization 844 Information: 845 Change the info command and the transfer request command to be 846 able to compare a passed authorization information value with 847 either a hashed or encyrpted authorization information value. 848 Hash Existing Encrypted Authorization Information Values: Convert 849 the encrypted authorization information values stored in the 850 registry database to hashed values. The update is not a visible 851 change to the registrar. The conversion can be done over a period 852 of time depending on registry policy. 854 5.3. Transition Phase 3 - Enforcement 856 The goal of the "Transition Phase 3 - Enforcement" is to complete the 857 implementation of the "Secure Authorization Information Model", by 858 enforcing the following: 860 Disallow Authorization Information on Create Command: Change the 861 create command to not allow for the passing of a non-empty 862 authorization information value. 863 Validate the Strong Random Authorization Information: Change the 864 validation of the authorization information in the update command 865 to ensure at least 128 bits of entropy. 867 6. Implementation Status 869 Note to RFC Editor: Please remove this section and the reference to 870 RFC 7942 [RFC7942] before publication. 872 This section records the status of known implementations of the 873 protocol defined by this specification at the time of posting of this 874 Internet-Draft, and is based on a proposal described in RFC 7942 875 [RFC7942]. The description of implementations in this section is 876 intended to assist the IETF in its decision processes in progressing 877 drafts to RFCs. Please note that the listing of any individual 878 implementation here does not imply endorsement by the IETF. 879 Furthermore, no effort has been spent to verify the information 880 presented here that was supplied by IETF contributors. This is not 881 intended as, and must not be construed to be, a catalog of available 882 implementations or their features. Readers are advised to note that 883 other implementations may exist. 885 According to RFC 7942 [RFC7942], "this will allow reviewers and 886 working groups to assign due consideration to documents that have the 887 benefit of running code, which may serve as evidence of valuable 888 experimentation and feedback that have made the implemented protocols 889 more mature. It is up to the individual working groups to use this 890 information as they see fit". 892 6.1. Verisign EPP SDK 894 Organization: Verisign Inc. 896 Name: Verisign EPP SDK 898 Description: The Verisign EPP SDK includes both a full client 899 implementation and a full server stub implementation of draft-ietf- 900 regext-secure-authinfo-transfer. 902 Level of maturity: Development 904 Coverage: All aspects of the protocol are implemented. 906 Licensing: GNU Lesser General Public License 908 Contact: jgould@verisign.com 910 URL: https://www.verisign.com/en_US/channel-resources/domain- 911 registry-products/epp-sdks 913 6.2. RegistryEngine EPP Service 915 Organization: CentralNic 917 Name: RegistryEngine EPP Service 919 Description: Generic high-volume EPP service for gTLDs, ccTLDs and 920 SLDs 922 Level of maturity: Deployed in CentralNic's production environment as 923 well as two other gTLD registry systems, and two ccTLD registry 924 systems. 926 Coverage: Auhtorization Information is "write only" in that the 927 registrars can set the Auhtorization Information, but not get the 928 Auhtorization Information in the Info Response. 930 Licensing: Proprietary In-House software 932 Contact: epp@centralnic.com 934 URL: https://www.centralnic.com 936 7. Security Considerations 938 TBD 940 8. Acknowledgements 942 The authors wish to thank the following persons for their feedback 943 and suggestions: 945 o Michael Bauland 946 o Martin Casanova 947 o Scott Hollenbeck 948 o Jody Kolker 949 o Patrick Mevzek 950 o Matthew Pozun 951 o Srikanth Veeramachaneni 953 9. References 955 9.1. Normative References 957 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 958 Requirement Levels", BCP 14, RFC 2119, 959 DOI 10.17487/RFC2119, March 1997, 960 . 962 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 963 "Randomness Requirements for Security", BCP 106, RFC 4086, 964 DOI 10.17487/RFC4086, June 2005, 965 . 967 [RFC5730] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)", 968 STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009, 969 . 971 [RFC5731] Hollenbeck, S., "Extensible Provisioning Protocol (EPP) 972 Domain Name Mapping", STD 69, RFC 5731, 973 DOI 10.17487/RFC5731, August 2009, 974 . 976 [RFC5733] Hollenbeck, S., "Extensible Provisioning Protocol (EPP) 977 Contact Mapping", STD 69, RFC 5733, DOI 10.17487/RFC5733, 978 August 2009, . 980 [RFC5734] Hollenbeck, S., "Extensible Provisioning Protocol (EPP) 981 Transport over TCP", STD 69, RFC 5734, 982 DOI 10.17487/RFC5734, August 2009, 983 . 985 [RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running 986 Code: The Implementation Status Section", BCP 205, 987 RFC 7942, DOI 10.17487/RFC7942, July 2016, 988 . 990 [RFC8499] Hoffman, P., Sullivan, A., and K. Fujiwara, "DNS 991 Terminology", BCP 219, RFC 8499, DOI 10.17487/RFC8499, 992 January 2019, . 994 9.2. URIs 996 [1] https://csrc.nist.gov/publications/detail/fips/140/2/final 998 Appendix A. Change History 1000 A.1. Change from 00 to 01 1002 1. Filled in the "Implementation Status" section with the inclusion 1003 of the "Verisign EPP SDK" and "RegistryEngine EPP Service" 1004 implementations. 1005 2. Made small wording corrections based on private feedback. 1006 3. Added content to the "Acknowledgements" section. 1008 A.2. Change from 01 to 02 1010 1. Revised the language used for the storage of the authorization 1011 information based on the feedback from Patrick Mevzek and Jody 1012 Kolker. 1014 A.3. Change from 02 to 03 1016 1. Updates based on the feedback from the interim REGEXT meeting 1017 held at ICANN-66: 1019 1. Section 3.3, include a reference to the hash algorithm to 1020 use. Broke the requirements into a list and included a the 1021 reference the text ', with at least a 256-bit hash function, 1022 such as SHA-256'. 1024 2. Add a Transition Considerations section to cover the 1025 transition from the classic authorization information 1026 security model in the EPP RFCs to the model defined in the 1027 document. 1028 3. Add a statement to the Introduction that elements of the 1029 practice can be used for purposes other than transfer, but 1030 with a caveat. 1031 2. Updates based on the review by Michael Bauland, that include: 1033 1. In section 2, change 'there are three actors' to 'there are 1034 three types of actors' to cover the case with transfers that 1035 has two registrar actors (losing and gaining). 1036 2. In section 3.1, change the equations equals to be 1037 approximately equal by using '=~' instead of '=', where 1038 applicable. 1039 3. In section 3.3, change 'MUST be over an encrypted channel, 1040 such as [RFC5734]'' to 'MUST be over an encrypted channel, 1041 such as defined in [RFC5734]''. 1042 4. In section 4.1, remove the optional RFC 5733 elements from 1043 the contact create, which includes the , 1044 , , , 1045 , , and elements. 1046 5. In section 4.2, changed 'Example of unsetting the 1047 authorization information explicitly in an [RFC5731] domain 1048 name update command.' to 'Example of adding the 1049 "clientTransferProhibited" status and unsetting the 1050 authorization information explicitly in an [RFC5731] domain 1051 name update command.' 1052 6. In section 4.3, cover a corner case of the ability to return 1053 the authorization information when it's passed in the info 1054 command. 1055 7. In section 4.4, change 'If the transfer does not complete 1056 within the time-to-live (TTL)' to 'If the transfer is not 1057 initiated within the time-to-live (TTL)', since the TTL is 1058 the time between setting the authorization information and 1059 when it's successfully used in a transfer request. Added the 1060 case of unsetting the authorization information when the 1061 transfer is cancelled or rejected. 1062 3. Updates based on the authorization information messages by Martin 1063 Casanova on the REGEXT mailing list, that include: 1065 1. Added section 3.4 'Authorization Information Matching' to 1066 clarify how the authorization information is matched, when 1067 there is set and unset authorization information in the 1068 database and empty and non-empty authorization information 1069 passed in the info and transfer commands. 1070 2. Added support for signaling that the authorization 1071 information is set or unset to the sponsoring registrar with 1072 the inclusion of an empty authorization information element 1073 in the response to indicate that the authorization 1074 information is set and the exclusion of the authorization 1075 information element in the response to indicate that the 1076 authorization information is unset. 1077 4. Made the capitalization of command and response references 1078 consistent by uppercasing section and item titles and lowercasing 1079 references elsewhere. 1081 A.4. Change from 03 to REGEXT 00 1083 1. Changed to regext working group draft by changing draft-gould- 1084 regext-secure-authinfo-transfer to draft-ietf-regext-secure- 1085 authinfo-transfer. 1087 Authors' Addresses 1089 James Gould 1090 VeriSign, Inc. 1091 12061 Bluemont Way 1092 Reston, VA 20190 1093 US 1095 Email: jgould@verisign.com 1096 URI: http://www.verisign.com 1098 Richard Wilhelm 1099 VeriSign, Inc. 1100 12061 Bluemont Way 1101 Reston, VA 20190 1102 US 1104 Email: rwilhelm@verisign.com 1105 URI: http://www.verisign.com