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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Security Events Working Group A. Backman, Ed. 3 Internet-Draft Amazon 4 Intended status: Standards Track M. Jones, Ed. 5 Expires: December 6, 2020 Microsoft 6 M. Scurtescu 7 Coinbase 8 M. Ansari 9 Cisco 10 A. Nadalin 11 Microsoft 12 June 4, 2020 14 Push-Based Security Event Token (SET) Delivery Using HTTP 15 draft-ietf-secevent-http-push-11 17 Abstract 19 This specification defines how a Security Event Token (SET) may be 20 delivered to an intended recipient using HTTP POST. The SET is 21 transmitted in the body of an HTTP POST request to an endpoint 22 operated by the recipient, and the recipient indicates successful or 23 failed transmission via the HTTP response. 25 Status of This Memo 27 This Internet-Draft is submitted in full conformance with the 28 provisions of BCP 78 and BCP 79. 30 Internet-Drafts are working documents of the Internet Engineering 31 Task Force (IETF). Note that other groups may also distribute 32 working documents as Internet-Drafts. The list of current Internet- 33 Drafts is at https://datatracker.ietf.org/drafts/current/. 35 Internet-Drafts are draft documents valid for a maximum of six months 36 and may be updated, replaced, or obsoleted by other documents at any 37 time. It is inappropriate to use Internet-Drafts as reference 38 material or to cite them other than as "work in progress." 40 This Internet-Draft will expire on December 6, 2020. 42 Copyright Notice 44 Copyright (c) 2020 IETF Trust and the persons identified as the 45 document authors. All rights reserved. 47 This document is subject to BCP 78 and the IETF Trust's Legal 48 Provisions Relating to IETF Documents 49 (https://trustee.ietf.org/license-info) in effect on the date of 50 publication of this document. Please review these documents 51 carefully, as they describe your rights and restrictions with respect 52 to this document. Code Components extracted from this document must 53 include Simplified BSD License text as described in Section 4.e of 54 the Trust Legal Provisions and are provided without warranty as 55 described in the Simplified BSD License. 57 Table of Contents 59 1. Introduction and Overview . . . . . . . . . . . . . . . . . . 2 60 1.1. Notational Conventions . . . . . . . . . . . . . . . . . 3 61 1.2. Definitions . . . . . . . . . . . . . . . . . . . . . . . 3 62 2. SET Delivery . . . . . . . . . . . . . . . . . . . . . . . . 3 63 2.1. Transmitting a SET . . . . . . . . . . . . . . . . . . . 5 64 2.2. Success Response . . . . . . . . . . . . . . . . . . . . 5 65 2.3. Failure Response . . . . . . . . . . . . . . . . . . . . 6 66 2.4. Security Event Token Delivery Error Codes . . . . . . . . 8 67 3. Authentication and Authorization . . . . . . . . . . . . . . 8 68 4. Delivery Reliability . . . . . . . . . . . . . . . . . . . . 9 69 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9 70 5.1. Authentication Using Signed SETs . . . . . . . . . . . . 9 71 5.2. HTTP Considerations . . . . . . . . . . . . . . . . . . . 9 72 5.3. Confidentiality of SETs . . . . . . . . . . . . . . . . . 9 73 5.4. Denial of Service . . . . . . . . . . . . . . . . . . . . 10 74 5.5. Authenticating Persisted SETs . . . . . . . . . . . . . . 10 75 6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 10 76 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 77 7.1. Security Event Token Delivery Error Codes . . . . . . . . 11 78 7.1.1. Registration Template . . . . . . . . . . . . . . . . 11 79 7.1.2. Initial Registry Contents . . . . . . . . . . . . . . 12 80 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 81 8.1. Normative References . . . . . . . . . . . . . . . . . . 12 82 8.2. Informative References . . . . . . . . . . . . . . . . . 14 83 Appendix A. Other Streaming Specifications . . . . . . . . . . . 14 84 Appendix B. Acknowledgments . . . . . . . . . . . . . . . . . . 16 85 Appendix C. Change Log . . . . . . . . . . . . . . . . . . . . . 16 86 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21 88 1. Introduction and Overview 90 This specification defines a mechanism by which a transmitter of a 91 Security Event Token (SET) [RFC8417] may deliver the SET to an 92 intended recipient via HTTP POST [RFC7231]. 94 Push-Based SET Delivery over HTTP POST is intended for scenarios 95 where all of the following apply: 97 o The transmitter of the SET is capable of making outbound HTTP 98 requests. 100 o The recipient is capable of hosting an HTTP endpoint that is 101 accessible to the transmitter. 103 o The transmitter and recipient are known to one another. 105 A mechanism for exchanging configuration metadata such as endpoint 106 URLs and cryptographic keys between the transmitter and recipient is 107 out of scope for this specification. How SETs are defined and the 108 process by which security events are identified for SET Recipients 109 are specified in [RFC8417]. 111 1.1. Notational Conventions 113 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 114 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 115 "OPTIONAL" in this document are to be interpreted as described in BCP 116 14 [RFC2119] [RFC8174] when, and only when, they appear in all 117 capitals, as shown here. 119 Throughout this document, all figures may contain spaces and extra 120 line wrapping for readability and due to space limitations. 122 1.2. Definitions 124 This specification utilizes the following terms defined in [RFC8417]: 125 "Security Event Token (SET)", "SET Issuer", "SET Recipient", and 126 "Event Payload". 128 This specification utilizes terminology defined in [RFC8417], as well 129 as the terms defined below: 131 SET Transmitter An entity that delivers SETs in its possession to 132 one or more SET Recipients. 134 2. SET Delivery 136 To deliver a SET to a given SET Recipient, the SET Transmitter makes 137 a SET transmission request to the SET Recipient, with the SET itself 138 contained within the request. The SET Recipient replies to this 139 request with a response either acknowledging successful transmission 140 of the SET or indicating that an error occurred while receiving, 141 parsing, and/or validating the SET. 143 Upon receipt of a SET, the SET Recipient SHALL validate that all of 144 the following are true: 146 o The SET Recipient can parse the SET. 148 o The SET is authentic (i.e., it was issued by the issuer specified 149 within the SET, and if signed, was signed by a key belonging to 150 the issuer). 152 o The SET Recipient is identified as an intended audience of the 153 SET. 155 o The SET Issuer is recognized as an issuer that the SET Recipient 156 is willing to receive SETs from (e.g., the issuer is whitelisted 157 by the SET Recipient). 159 o The SET Recipient is willing to accept the SET when transmitted by 160 the SET Transmitter (e.g., the SET Transmitter is expected to send 161 SETs with the subject of the SET in question). 163 The mechanisms by which the SET Recipient performs this validation 164 are out of scope for this document. SET parsing and issuer and 165 audience identification are defined in [RFC8417]. The mechanism for 166 validating the authenticity of a SET is deployment specific, and may 167 vary depending on the authentication mechanisms in use, and whether 168 the SET is signed and/or encrypted (See Section 3). 170 SET Transmitters MAY transmit SETs issued by another entity. The SET 171 Recipient may accept or reject (i.e., return an error response such 172 as "access_denied") a SET at its own discretion. 174 The SET Recipient SHOULD ensure that the SET is persisted in a way 175 that is sufficient to meet the SET Recipient's own reliability 176 requirements, and MUST NOT expect or depend on a SET Transmitter to 177 re-transmit or otherwise make available to the SET Recipient a SET 178 once the SET Recipient acknowledges that it was received 179 successfully. 181 Once the SET has been validated and persisted, the SET Recipient 182 SHOULD immediately return a response indicating that the SET was 183 successfully delivered. The SET Recipient SHOULD NOT perform 184 anything beyond the required validation steps prior to sending this 185 response. Any additional steps SHOULD be executed asynchronously 186 from delivery, in order to minimize the expense and impact of SET 187 delivery on the SET Transmitter. 189 The SET Transmitter MAY re-transmit a SET if the responses from 190 previous transmissions timed out or indicated potentially recoverable 191 error (such as server unavailability that may be transient). In all 192 other cases, the SET Transmitter SHOULD NOT re-transmit a SET. The 193 SET Transmitter SHOULD delay retransmission for an appropriate amount 194 of time to avoid overwhelming the SET Recipient (see Section 4). 196 2.1. Transmitting a SET 198 To transmit a SET to a SET Recipient, the SET Transmitter makes an 199 HTTP POST request to an HTTP endpoint provided by the SET Recipient. 200 The "Content-Type" header of this request MUST be "application/ 201 secevent+jwt" as defined in Sections 2.3 and 7.2 of [RFC8417], and 202 the "Accept" header MUST be "application/json". The request body 203 MUST consist of the SET itself, represented as a JWT [RFC7519]. 205 The SET Transmitter MAY include in the request an "Accept-Language" 206 header to indicate to the SET Recipient the preferred language(s) in 207 which to receive error messages. 209 The mechanisms by which the SET Transmitter determines the HTTP 210 endpoint to use when transmitting a SET to a given SET Recipient are 211 not defined by this specification and are deployment specific. 213 The following is a non-normative example of a SET transmission 214 request: 216 POST /Events HTTP/1.1 217 Host: notify.rp.example.com 218 Accept: application/json 219 Accept-Language: en-US, en;q=0.5 220 Content-Type: application/secevent+jwt 222 eyJ0eXAiOiJzZWNldmVudCtqd3QiLCJhbGciOiJIUzI1NiJ9Cg 223 . 224 eyJpc3MiOiJodHRwczovL2lkcC5leGFtcGxlLmNvbS8iLCJqdGkiOiI3NTZFNjk 225 3MTc1NjUyMDY5NjQ2NTZFNzQ2OTY2Njk2NTcyIiwiaWF0IjoxNTA4MTg0ODQ1LC 226 JhdWQiOiI2MzZDNjk2NTZFNzQ1RjY5NjQiLCJldmVudHMiOnsiaHR0cHM6Ly9zY 227 2hlbWFzLm9wZW5pZC5uZXQvc2VjZXZlbnQvcmlzYy9ldmVudC10eXBlL2FjY291 228 bnQtZGlzYWJsZWQiOnsic3ViamVjdCI6eyJzdWJqZWN0X3R5cGUiOiJpc3Mtc3V 229 iIiwiaXNzIjoiaHR0cHM6Ly9pZHAuZXhhbXBsZS5jb20vIiwic3ViIjoiNzM3NT 230 YyNkE2NTYzNzQifSwicmVhc29uIjoiaGlqYWNraW5nIn19fQ 231 . 232 Y4rXxMD406P2edv00cr9Wf3_XwNtLjB9n-jTqN1_lLc 234 Figure 1: Example SET Transmission Request 236 2.2. Success Response 238 If the SET is determined to be valid, the SET Recipient SHALL 239 acknowledge successful transmission by responding with HTTP Response 240 Status Code 202 (Accepted) (see Section 6.3.3 of [RFC7231]). The 241 body of the response MUST be empty. 243 The following is a non-normative example of a successful receipt of a 244 SET. 246 HTTP/1.1 202 Accepted 248 Figure 2: Example Successful Delivery Response 250 Note that the purpose of the acknowledgement response is to let the 251 SET Transmitter know that a SET has been delivered and the 252 information no longer needs to be retained by the SET Transmitter. 253 Before acknowledgement, SET Recipients SHOULD ensure they have 254 validated received SETs and retained them in a manner appropriate to 255 information retention requirements appropriate to the SET event types 256 signaled. The level and method of retention of SETs by SET 257 Recipients is out of scope of this specification. 259 2.3. Failure Response 261 In the event of a general HTTP error condition, the SET Recipient 262 SHOULD respond with an appropriate HTTP Status Code as defined in 263 Section 6 of [RFC7231]. 265 When the SET Recipient detects an error parsing, validating, or 266 authenticating a SET transmitted in a SET Transmission Request, the 267 SET Recipient SHALL respond with an HTTP Response Status Code of 400 268 (Bad Request). The "Content-Type" header of this response MUST be 269 "application/json", and the body MUST be a UTF-8 encoded JSON 270 [RFC8259] object containing the following name/value pairs: 272 err A Security Event Token Error Code (see Section 2.4). 274 description A UTF-8 string containing a human-readable description 275 of the error that MAY provide additional diagnostic information. 276 The exact content of this field is implementation specific. 278 The response MUST include a "Content-Language" header, whose value 279 indicates the language of the error descriptions included in the 280 response body. If the SET Recipient can provide error descriptions 281 in multiple languages, they SHOULD choose the language to use 282 according to the value of the "Accept-Language" header sent by the 283 SET Transmitter in the transmission request, as described in 284 Section 5.3.5 of [RFC7231]. If the SET Transmitter did not send an 285 "Accept-Language" header, or if the SET Recipient does not support 286 any of the languages included in the header, the SET Recipient MUST 287 respond with messages that are understandable by an English-speaking 288 person, as described in Section 4.5 of [RFC2277]. 290 The following is an example non-normative error response indicating 291 that the key used to encrypt the SET has been revoked. 293 HTTP/1.1 400 Bad Request 294 Content-Language: en-US 295 Content-Type: application/json 297 { 298 "err": "invalid_key", 299 "description": "Key ID 12345 has been revoked." 300 } 302 Figure 3: Example Error Response (invalid_key) 304 The following is an example non-normative error response indicating 305 that the access token included in the request is expired. 307 HTTP/1.1 400 Bad Request 308 Content-Language: en-US 309 Content-Type: application/json 311 { 312 "err": "authentication_failed", 313 "description": "Access token has expired." 314 } 316 Figure 4: Example Error Response (authentication_failed) 318 The following is an example non-normative error response indicating 319 that the SET Receiver is not willing to accept SETs issued by the 320 specified issuer from this particular SET Transmitter. 322 HTTP/1.1 400 Bad Request 323 Content-Language: en-US 324 Content-Type: application/json 326 { 327 "err": "access_denied", 328 "description": "Not authorized for issuer http://iss.example.com/." 329 } 331 Figure 5: Example Error Response (access_denied) 333 2.4. Security Event Token Delivery Error Codes 335 Security Event Token Delivery Error Codes are strings that identify a 336 specific category of error that may occur when parsing or validating 337 a SET. Every Security Event Token Delivery Error Code MUST have a 338 unique name registered in the IANA "Security Event Token Delivery 339 Error Codes" registry established by Section 7.1. 341 The following table presents the initial set of Error Codes that are 342 registered in the IANA "Security Event Token Delivery Error Codes" 343 registry: 345 +-----------------------+-------------------------------------------+ 346 | Error Code | Description | 347 +-----------------------+-------------------------------------------+ 348 | invalid_request | The request body cannot be parsed as a | 349 | | SET, or the Event Payload within the SET | 350 | | does not conform to the event's | 351 | | definition. | 352 | invalid_key | One or more keys used to encrypt or sign | 353 | | the SET is invalid or otherwise | 354 | | unacceptable to the SET Recipient. (e.g., | 355 | | expired, revoked, failed certificate | 356 | | validation, etc.) | 357 | authentication_failed | The SET Recipient could not authenticate | 358 | | the SET Transmitter. | 359 | access_denied | The SET Transmitter is not authorized to | 360 | | transmit the SET to the SET Recipient. | 361 +-----------------------+-------------------------------------------+ 363 Table 1: SET Delivery Error Codes 365 Implementations SHOULD expect that other Error Codes may also be 366 received, as the set of Error Codes is extensible via the IANA 367 "Security Event Token Delivery Error Codes" registry established in 368 Section 7.1. 370 3. Authentication and Authorization 372 The SET delivery method described in this specification is based upon 373 HTTP and HTTP over TLS [RFC2818] and/or standard HTTP authentication 374 and authorization schemes, as per [RFC7235]. The TLS server 375 certificate MUST be validated, per [RFC6125]. 377 Authorization for the eligibility to provide actionable SETs can be 378 determined by using the identity of the SET Issuer, the identity of 379 the SET Transmitter, perhaps using mutual TLS, or via other employed 380 authentication methods. Because SETs are not commands, SET 381 Recipients are free to ignore SETs that are not of interest. 383 4. Delivery Reliability 385 Delivery reliability requirements may vary depending upon the use 386 cases. This specification defines the response from the SET 387 Recipient in such a way as to provide the SET Transmitter with the 388 information necessary to determine what further action is required, 389 if any, in order to meet their requirements. SET Transmitters with 390 high reliability requirements may be tempted to always retry failed 391 transmissions, however, it should be noted that for many types of SET 392 delivery errors, a retry is extremely unlikely to be successful. For 393 example, "invalid_request" indicates a structural error in the 394 content of the request body that is likely to remain when re- 395 transmitting the same SET. Others such as "access_denied" may be 396 transient, for example if the SET Transmitter refreshes expired 397 credentials prior to re-transmission. 399 Implementers SHOULD evaluate the reliability requirements of their 400 use cases and the impact of various retry mechanisms on the 401 performance of their systems to determine an appropriate strategy for 402 handling various error conditions. 404 5. Security Considerations 406 5.1. Authentication Using Signed SETs 408 JWS signed SETs can be used (see [RFC7515] and Section 5 of 409 [RFC8417]) to enable the SET Recipient to validate that the SET 410 Issuer is authorized to provide actionable SETs. 412 5.2. HTTP Considerations 414 SET delivery depends on the use of Hypertext Transfer Protocol and is 415 thus subject to the security considerations of HTTP Section 9 of 416 [RFC7230] and its related specifications. 418 5.3. Confidentiality of SETs 420 SETs may contain sensitive information that is considered Personally 421 Identifiable Information (PII). In such cases, SET Transmitters and 422 SET Recipients MUST protect the confidentiality of the SET contents 423 by encrypting the SET as described in JWE [RFC7516], using a 424 transport-layer security mechanism such as TLS, or both. If an Event 425 delivery endpoint supports TLS, it MUST support at least TLS version 426 1.2 [RFC5246] and SHOULD support the newest version of TLS that meets 427 its security requirements, which as of the time of this publication 428 is TLS 1.3 [RFC8446]. When using TLS, the client MUST perform a TLS/ 429 SSL server certificate check using DNS-ID [RFC6125]. How a SET 430 Transmitter determines the expected service identity to match the SET 431 Recipient's server certificate against is out of scope for this 432 document. Implementation security considerations for TLS can be 433 found in "Recommendations for Secure Use of TLS and DTLS" [RFC7525]. 435 5.4. Denial of Service 437 The SET Recipient may be vulnerable to a denial-of-service attack 438 where a malicious party makes a high volume of requests containing 439 invalid SETs, causing the endpoint to expend significant resources on 440 cryptographic operations that are bound to fail. This may be 441 mitigated by authenticating SET Transmitters with a mechanism such as 442 mutual TLS. 444 5.5. Authenticating Persisted SETs 446 At the time of receipt, the SET Recipient can rely upon transport 447 layer mechanisms, HTTP authentication methods, and/or other context 448 from the transmission request to authenticate the SET Transmitter and 449 validate the authenticity of the SET. However, this context is 450 typically unavailable to systems that the SET Recipient forwards the 451 SET onto, or to systems that retrieve the SET from storage. If the 452 SET Recipient requires the ability to validate SET authenticity 453 outside of the context of the transmission request, then the SET 454 Recipient SHOULD ensure that such SETs have been signed in accordance 455 with [RFC7515]. 457 6. Privacy Considerations 459 SET Transmitters SHOULD attempt to deliver SETs that are targeted to 460 the specific business and protocol needs of subscribers. 462 When sharing personally identifiable information or information that 463 is otherwise considered confidential to affected users, SET 464 Transmitters and Recipients MUST have the appropriate legal 465 agreements and user consent or terms of service in place. 466 Furthermore, data that needs confidentiality protection MUST be 467 encrypted, either via TLS or using JSON Web Encryption (JWE) 468 [RFC7516], or both. 470 In some cases, subject identifiers themselves may be considered 471 sensitive information, such that their inclusion within a SET may be 472 considered a violation of privacy. SET Issuers should consider the 473 ramifications of sharing a particular subject identifier with a SET 474 Recipient (e.g., whether doing so could enable correlation and/or de- 475 anonymization of data) and choose appropriate subject identifiers for 476 their use cases. 478 If SETs are transmitted over unencrypted channels, some privacy- 479 sensitive information about them might leak, even though the SETs 480 themselves are encrypted. For instance, an attacker may be able to 481 determine whether or not a SET was accepted and the reason for its 482 rejection or may be able to derive information from being able to 483 observe the size of the encrypted SET. 485 7. IANA Considerations 487 7.1. Security Event Token Delivery Error Codes 489 This document defines Security Event Token Delivery Error Codes, for 490 which IANA is asked to create and maintain a new registry titled 491 "Security Event Token Delivery Error Codes". Initial values for the 492 Security Event Token Delivery Error Codes registry are defined in 493 Table 1 and registered below. Future assignments are to be made 494 through the Specification Required registration policy ([RFC8126]) 495 and shall follow the template presented in Section 7.1.1. 497 Error Codes are intended to be interpreted by automated systems, and 498 therefore SHOULD identify classes of errors to which an automated 499 system could respond in a meaningfully distinct way (e.g., by 500 refreshing authentication credentials and retrying the request). 502 7.1.1. Registration Template 504 Error Code 505 The name of the Security Event Token Delivery Error Code, as 506 described in Section 2.4. The name MUST be a case-sensitive ASCII 507 string consisting only of letters, digits, and underscore; these 508 are the characters whose codes fall within the inclusive ranges 509 0x30-39, 0x41-5A, 0x5F and 0x61-7A. 511 Description 512 A brief human-readable description of the Security Event Token 513 Delivery Error Code. 515 Change Controller 516 For error codes registered by the IETF or its working groups, list 517 "IETF SecEvent Working Group". For all other error codes, list 518 the name of the party responsible for the registration. Contact 519 information such as mailing address, email address, or phone 520 number may also be provided. 522 Defining Document(s) 523 A reference to the document or documents that define the Security 524 Event Token Delivery Error Code. The definition MUST specify the 525 name and description of the error code and explain under what 526 circumstances the error code may be used. URIs that can be used 527 to retrieve copies of each document at no cost SHOULD be included. 529 7.1.2. Initial Registry Contents 531 Error Code: invalid_request 532 Description: The request body cannot be parsed as a SET or the 533 event payload within the SET does not conform to the event's 534 definition. 535 Change Controller: IETF 536 Defining Document(s): Section 2.4 of [[ this specification ]] 538 Error Code: invalid_key 539 Description: One or more keys used to encrypt or sign the SET is 540 invalid or otherwise unacceptable to the SET Recipient. (e.g., 541 expired, revoked, failed certificate validation, etc.) 542 Change Controller: IETF 543 Defining Document(s): Section 2.4 of [[ this specification ]] 545 Error Code: authentication_failed 546 Description: The SET Recipient could not authenticate the SET 547 Transmitter. 548 Change Controller: IETF 549 Defining Document(s): Section 2.4 of [[ this specification ]] 551 Error Code: access_denied 552 Description: The SET Transmitter is not authorized to transmit the 553 SET to the SET Recipient. 554 Change Controller: IETF 555 Defining Document(s): Section 2.4 of [[ this specification ]] 557 8. References 559 8.1. Normative References 561 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 562 Requirement Levels", BCP 14, RFC 2119, 563 DOI 10.17487/RFC2119, March 1997, 564 . 566 [RFC2277] Alvestrand, H., "IETF Policy on Character Sets and 567 Languages", BCP 18, RFC 2277, DOI 10.17487/RFC2277, 568 January 1998, . 570 [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, 571 DOI 10.17487/RFC2818, May 2000, 572 . 574 [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security 575 (TLS) Protocol Version 1.2", RFC 5246, 576 DOI 10.17487/RFC5246, August 2008, 577 . 579 [RFC6125] Saint-Andre, P. and J. Hodges, "Representation and 580 Verification of Domain-Based Application Service Identity 581 within Internet Public Key Infrastructure Using X.509 582 (PKIX) Certificates in the Context of Transport Layer 583 Security (TLS)", RFC 6125, DOI 10.17487/RFC6125, March 584 2011, . 586 [RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer 587 Protocol (HTTP/1.1): Message Syntax and Routing", 588 RFC 7230, DOI 10.17487/RFC7230, June 2014, 589 . 591 [RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer 592 Protocol (HTTP/1.1): Semantics and Content", RFC 7231, 593 DOI 10.17487/RFC7231, June 2014, 594 . 596 [RFC7515] Jones, M., Bradley, J., and N. Sakimura, "JSON Web 597 Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, May 598 2015, . 600 [RFC7516] Jones, M. and J. Hildebrand, "JSON Web Encryption (JWE)", 601 RFC 7516, DOI 10.17487/RFC7516, May 2015, 602 . 604 [RFC7519] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token 605 (JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015, 606 . 608 [RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre, 609 "Recommendations for Secure Use of Transport Layer 610 Security (TLS) and Datagram Transport Layer Security 611 (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May 612 2015, . 614 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 615 Writing an IANA Considerations Section in RFCs", BCP 26, 616 RFC 8126, DOI 10.17487/RFC8126, June 2017, 617 . 619 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 620 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 621 May 2017, . 623 [RFC8259] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data 624 Interchange Format", STD 90, RFC 8259, 625 DOI 10.17487/RFC8259, December 2017, 626 . 628 [RFC8417] Hunt, P., Ed., Jones, M., Denniss, W., and M. Ansari, 629 "Security Event Token (SET)", RFC 8417, 630 DOI 10.17487/RFC8417, July 2018, 631 . 633 [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol 634 Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, 635 . 637 8.2. Informative References 639 [RFC7235] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer 640 Protocol (HTTP/1.1): Authentication", RFC 7235, 641 DOI 10.17487/RFC7235, June 2014, 642 . 644 Appendix A. Other Streaming Specifications 646 [[ NOTE TO THE RFC EDITOR: This section to be removed prior to 647 publication ]] 649 The following pub/sub, queuing, streaming systems were reviewed as 650 possible solutions or as input to the current draft: 652 Poll-Based Security Event Token (SET) Delivery Using HTTP 654 In addition to this specification, the WG is defining a polling-based 655 SET delivery protocol. That protocol's draft (draft-ietf-secevent- 656 http-poll) describes it as: 658 This specification defines how a series of Security Event Tokens 659 (SETs) may be delivered to an intended recipient using HTTP POST over 660 TLS initiated as a poll by the recipient. The specification also 661 defines how delivery can be assured, subject to the SET Recipient's 662 need for assurance. 664 XMPP Events 665 The WG considered XMPP Events and their ability to provide a single 666 messaging solution without the need for both polling and push modes. 667 The feeling was the size and methodology of XMPP was too far apart 668 from the current capabilities of the SECEVENTs community, which 669 focuses in on HTTP based service delivery and authorization. 671 Amazon Simple Notification Service 673 Simple Notification Service is a pub/sub messaging product from AWS. 674 SNS supports a variety of subscriber types: HTTP/HTTPS endpoints, AWS 675 Lambda functions, email addresses (as JSON or plain text), phone 676 numbers (via SMS), and AWS SQS standard queues. It does not directly 677 support pull, but subscribers can get the pull model by creating an 678 SQS queue and subscribing it to the topic. Note that this puts the 679 cost of pull support back onto the subscriber, just as it is in the 680 push model. It is not clear that one way is strictly better than the 681 other; larger, sophisticated developers may be happy to own message 682 persistence so they can have their own internal delivery guarantees. 683 The long tail of OIDC clients may not care about that or may fail to 684 get it right. Regardless, I think we can learn something from the 685 Delivery Policies supported by SNS, as well as the delivery controls 686 that SQS offers (e.g., Visibility Timeout, Dead-Letter Queues). I am 687 not suggesting that we need all of these things in the spec, but they 688 give an idea of what features people have found useful. 690 Other information: 692 o API Reference: 693 http://docs.aws.amazon.com/AWSSimpleQueueService/latest/ 694 APIReference/Welcome.html 696 o Visibility Timeouts: 697 http://docs.aws.amazon.com/AWSSimpleQueueService/latest/ 698 SQSDeveloperGuide/sqs-visibility-timeout.html 700 Apache Kafka 702 Apache Kafka is an Apache open source project based upon TCP for 703 distributed streaming. It prescribes some interesting general- 704 purpose features that seem to extend far beyond the simpler streaming 705 model that SECEVENTs is after. A comment from MS has been that Kafka 706 does an acknowledge with poll combination event which seems to be a 707 performance advantage. See: https://kafka.apache.org/intro 709 Google Pub/Sub 710 The Google Pub Sub system favors a model whereby polling and 711 acknowledgement of events is done with separate endpoints and as 712 separate functions. 714 Information: 716 o Cloud Overview - https://cloud.google.com/pubsub/ 718 o Subscriber Overview - https://cloud.google.com/pubsub/docs/ 719 subscriber 721 o Subscriber Pull(poll) - https://cloud.google.com/pubsub/docs/pull 723 Appendix B. Acknowledgments 725 The editors would like to thank the members of the SCIM working 726 group, which began discussions of provisioning events starting with 727 draft-hunt-scim-notify-00 in 2015. We would like to thank Phil Hunt 728 and the other authors of draft-ietf-secevent-delivery-02, upon which 729 this specification is based. We would like to thank the participants 730 in the SecEvents working group for their contributions to this 731 specification. 733 Additionally, we would like to thank the following individuals for 734 their reviews of the specification: Joe Clarke, Vijay Gurbani, 735 Benjamin Kaduk, Yaron Sheffer, and Valery Smyslov. 737 Appendix C. Change Log 739 [[ NOTE TO THE RFC EDITOR: This section to be removed prior to 740 publication ]] 742 Draft 00 - AB - Based on draft-ietf-secevent-delivery-02 with the 743 following changes: 745 o Renamed to "Push-Based SET Token Delivery Using HTTP" 747 o Removed references to the HTTP Polling delivery method. 749 o Removed informative reference to RFC6202. 751 Draft 01 - AB: 753 o Fixed area and workgroup to match secevent. 755 o Removed unused definitions and definitions already covered by SET. 757 o Renamed Event Transmitter and Event Receiver to SET Transmitter 758 and SET Receiver, respectively. 760 o Added IANA registry for SET Delivery Error Codes. 762 o Removed enumeration of HTTP authentication methods. 764 o Removed generally applicable guidance for HTTP, authorization 765 tokens, and bearer tokens. 767 o Moved guidance for using authentication methods as DoS protection 768 to Security Considerations. 770 o Removed redundant instruction to use WWW-Authenticate header. 772 o Removed further generally applicable guidance for authorization 773 tokens. 775 o Removed bearer token from example delivery request, and text 776 referencing it. 778 o Broke delivery method description into separate request/response 779 sections. 781 o Added missing empty line between headers and body in example 782 request. 784 o Removed inapplicable notes about example formatting. 786 o Removed text about SET creation and handling. 788 o Removed duplication in protocol description. 790 o Added "non-normative example" text to example transmission 791 request. 793 o Fixed inconsistencies in use of Error Code term. 795 Draft 02 - AB: 797 o Rewrote abstract and introduction. 799 o Rewrote definitions for SET Transmitter, SET Receiver. 801 o Renamed Event Delivery section to SET Delivery. 803 o Readability edits to Success Response and Failure Response 804 sections. 806 o Consolidated definition of error response under Failure Response 807 section. 809 o Removed Event Delivery Process section and moved its content to 810 parent section. 812 o Readability edits to SET Delivery section and its subsections. 814 o Added callout that SET Receiver HTTP endpoint configuration is 815 out-of-scope. 817 o Added callout that SET verification mechanisms are out-of-scope. 819 o Added retry guidance, notes regarding delivery reliability 820 requirements. 822 o Added guidance around using JWS and/or JWE to authenticate 823 persisted SETs. 825 Draft 03 - mbj: 827 o Addressed problems identified in my 18-Jul-18 review message 828 titled "Issues for both the Push and Poll Specs". 830 o Changes to align terminology with RFC 8417, for instance, by using 831 the already defined term SET Recipient rather than SET Receiver. 833 o Applied editorial and minor normative corrections. 835 o Updated Marius' contact information. 837 Draft 04 - AB: 839 o Replaced Error Codes with smaller set of meaningfully 840 differentiated codes. 842 o Added more error response examples. 844 o Removed un-referenced normative references. 846 o Added normative reference to JSON in error response definition. 848 o Added text clarifying that the value of the "description" 849 attribute in error responses is implementation specific. 851 o Added requirement that error descriptions and responses are UTF-8 852 encoded. 854 o Added error description language preferences and specification via 855 "Accept-Language" and "Content-Language" headers. 857 o Added "recognized issuer" validation requirement in section 2. 859 o Added timeouts as an acceptable reason to resend a SET in section 860 2. 862 o Edited text in section 1 to clarify that configuration is out of 863 scope. 865 o Made minor editorial corrections. 867 Draft 05 - AB: 869 o Made minor editorial corrections. 871 o Updated example request with a correct SET header and signature. 873 o Revised TLS guidance to allow implementers to provide 874 confidentiality protection via JWE. 876 o Revised TLS guidance to require *at least* TLS 1.2. 878 o Revised TLS guidance to recommend supporting the newest version of 879 TLS that meets security requirements. 881 o Revised SET Delivery Error Code format to allow the same set of 882 characters as is allowed in error codes in RFC6749. 884 o Added mention of HTTP Poll spec to list of other streaming specs 885 in appendix. 887 o Added validation step requiring SET Recipient to verify that the 888 SET is one which the SET Transmitter is expected to send to the 889 SET Recipient. 891 o Changed responding to errors with an appropriate HTTP status code 892 from optional to recommended. 894 o Changed Error Codes registry change policy from Expert Review to 895 First Come First Served; added guidance that error codes are meant 896 to be consumed by automated systems. 898 o Added text making clear that it is up to SET Recipients whether or 899 not they will accept SETs where the SET Issuer is different from 900 the SET Transmitter. 902 o Reworded guidance around signing and/or encrypting SETs for 903 integrity protection. 905 o Renamed TLS "Support Considerations" section to "Confidentiality 906 of SETs". 908 o Reworded guidance around subject identifier selection and privacy 909 concerns. 911 Draft 06 - mbj, MS: 913 o Made minor editorial corrections. 915 o Updated to indicate that failure response should be returned if 916 errors occur in authenticating the SET. 918 o Updated reference for JSON from RFC 7159 to RFC 8259. 920 o Fixed Authentication Using Signed SETs to indicate the SET 921 Transmitter must be authorized to deliver the SET, not the SET 922 Issuer. 924 o Fixed Authenticating Persisted SETs to put the responsibility for 925 ensuring the SET is signed on the SET Recipient. 927 o Fixed error code format definition to match error codes defined in 928 doc. 930 Draft 07 - AB: 932 o Made minor editorial corrections. 934 o Removed "SET Recipient" definition and added explicit list of 935 terms used from RFC8417. 937 Draft 08 - mbj 939 o Addressed area director review comments by Benjamin Kaduk. 941 Draft 09 - mbj + AB 943 o Corrected editorial nits. 945 Draft 10 - AB 947 o Addressed area director review comments by Benjamin Kaduk: 949 * Added reference to 8417 as definition document for SETs. 951 * Added text clarifying that determining the SET Recipient's 952 service identity is out of scope. 954 * Added normative recommendation for transmitters to target SETs 955 to specific business needs of subscribers. 957 * Minor editorial corrections. 959 Draft 11 - mbj 961 o Addressed SecDir review comments by Valery Smyslov. 963 o Addressed OpsDir review comments by Joe Clarke. 965 o Addressed GenArt review comments by Vijay Gurbani. 967 Authors' Addresses 969 Annabelle Backman (editor) 970 Amazon 972 Email: richanna@amazon.com 974 Michael B. Jones (editor) 975 Microsoft 977 Email: mbj@microsoft.com 978 URI: http://self-issued.info/ 980 Marius Scurtescu 981 Coinbase 983 Email: marius.scurtescu@coinbase.com 985 Morteza Ansari 986 Cisco 988 Email: morteza.ansari@cisco.com 990 Anthony Nadalin 991 Microsoft 993 Email: tonynad@microsoft.com