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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: August 8, 2020 Microsoft 6 M. Scurtescu 7 Coinbase 8 M. Ansari 9 Cisco 10 A. Nadalin 11 Microsoft 12 February 5, 2020 14 Push-Based Security Event Token (SET) Delivery Using HTTP 15 draft-ietf-secevent-http-push-08 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 August 8, 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 . . . . . . . . 7 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 . . . . . . . . . . . . . . . . . . . . . . . 20 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. 109 1.1. Notational Conventions 111 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 112 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 113 "OPTIONAL" in this document are to be interpreted as described in BCP 114 14 [RFC2119] [RFC8174] when, and only when, they appear in all 115 capitals, as shown here. 117 Throughout this document, all figures may contain spaces and extra 118 line wrapping for readability and due to space limitations. 120 1.2. Definitions 122 This specification utilizes the following terms defined in [RFC8417]: 123 "Security Event Token (SET)", "SET Issuer", "SET Recipient", and 124 "Event Payload". 126 This specification utilizes terminology defined in [RFC8417], as well 127 as the terms defined below: 129 SET Transmitter An entity that delivers SETs in its possession to 130 one or more SET Recipients. 132 2. SET Delivery 134 To deliver a SET to a given SET Recipient, the SET Transmitter makes 135 a SET transmission request to the SET Recipient, with the SET itself 136 contained within the request. The SET Recipient replies to this 137 request with a response either acknowledging successful transmission 138 of the SET or indicating that an error occurred while receiving, 139 parsing, and/or validating the SET. 141 Upon receipt of a SET, the SET Recipient SHALL validate that all of 142 the following are true: 144 o The SET Recipient can parse the SET. 146 o The SET is authentic (i.e., it was issued by the issuer specified 147 within the SET, and if signed, was signed by a key belonging to 148 the issuer). 150 o The SET Recipient is identified as an intended audience of the 151 SET. 153 o The SET Issuer is recognized as an issuer that the SET Recipient 154 is willing to receive SETs from (e.g., the issuer is whitelisted 155 by the SET Recipient). 157 o The SET Recipient is willing to accept the SET when transmitted by 158 the SET Transmitter (e.g., the SET Transmitter is expected to send 159 SETs with the subject of the SET in question). 161 The mechanisms by which the SET Recipient performs this validation 162 are out of scope for this document. SET parsing and issuer and 163 audience identification are defined in [RFC8417]. The mechanism for 164 validating the authenticity of a SET is deployment specific, and may 165 vary depending on the authentication mechanisms in use, and whether 166 the SET is signed and/or encrypted (See Section 3). 168 SET Transmitters MAY transmit SETs issued by another entity. The SET 169 Recipient may accept or reject (i.e., return an error response such 170 as "access_denied") a SET at its own discretion. 172 The SET Recipient SHOULD ensure that the SET is persisted in a way 173 that is sufficient to meet the SET Recipient's own reliability 174 requirements, and MUST NOT expect or depend on a SET Transmitter to 175 re-transmit or otherwise make available to the SET Recipient a SET 176 once the SET Recipient acknowledges that it was received 177 successfully. 179 Once the SET has been validated and persisted, the SET Recipient 180 SHOULD immediately return a response indicating that the SET was 181 successfully delivered. The SET Recipient SHOULD NOT perform 182 extensive business logic that processes the event expressed by the 183 SET prior to sending this response. Such logic SHOULD be executed 184 asynchronously from delivery, in order to minimize the expense and 185 impact of SET delivery on the SET Transmitter. 187 The SET Transmitter MAY re-transmit a SET if the responses from 188 previous transmissions timed out or indicated potentially recoverable 189 error (such as server unavailability that may be transient). In all 190 other cases, the SET Transmitter SHOULD NOT re-transmit a SET. The 191 SET Transmitter SHOULD delay retransmission for an appropriate amount 192 of time to avoid overwhelming the SET Recipient (see Section 4). 194 2.1. Transmitting a SET 196 To transmit a SET to a SET Recipient, the SET Transmitter makes an 197 HTTP POST request to an HTTP endpoint provided by the SET Recipient. 198 The "Content-Type" header of this request MUST be "application/ 199 secevent+jwt" as defined in Sections 2.3 and 7.2 of [RFC8417], and 200 the "Accept" header MUST be "application/json". The request body 201 MUST consist of the SET itself, represented as a JWT [RFC7519]. 203 The SET Transmitter MAY include in the request an "Accept-Language" 204 header to indicate to the SET Recipient the preferred language(s) in 205 which to receive error messages. 207 The mechanisms by which the SET Transmitter determines the HTTP 208 endpoint to use when transmitting a SET to a given SET Recipient are 209 not defined by this specification and are deployment specific. 211 The following is a non-normative example of a SET transmission 212 request: 214 POST /Events HTTP/1.1 215 Host: notify.rp.example.com 216 Accept: application/json 217 Accept-Language: en-US, en;q=0.5 218 Content-Type: application/secevent+jwt 220 eyJ0eXAiOiJzZWNldmVudCtqd3QiLCJhbGciOiJIUzI1NiJ9Cg 221 . 222 eyJpc3MiOiJodHRwczovL2lkcC5leGFtcGxlLmNvbS8iLCJqdGkiOiI3NTZFNjk 223 3MTc1NjUyMDY5NjQ2NTZFNzQ2OTY2Njk2NTcyIiwiaWF0IjoxNTA4MTg0ODQ1LC 224 JhdWQiOiI2MzZDNjk2NTZFNzQ1RjY5NjQiLCJldmVudHMiOnsiaHR0cHM6Ly9zY 225 2hlbWFzLm9wZW5pZC5uZXQvc2VjZXZlbnQvcmlzYy9ldmVudC10eXBlL2FjY291 226 bnQtZGlzYWJsZWQiOnsic3ViamVjdCI6eyJzdWJqZWN0X3R5cGUiOiJpc3Mtc3V 227 iIiwiaXNzIjoiaHR0cHM6Ly9pZHAuZXhhbXBsZS5jb20vIiwic3ViIjoiNzM3NT 228 YyNkE2NTYzNzQifSwicmVhc29uIjoiaGlqYWNraW5nIn19fQ 229 . 230 Y4rXxMD406P2edv00cr9Wf3_XwNtLjB9n-jTqN1_lLc 232 Figure 1: Example SET Transmission Request 234 2.2. Success Response 236 If the SET is determined to be valid, the SET Recipient SHALL 237 acknowledge successful transmission by responding with HTTP Response 238 Status Code 202 (Accepted) (see Section 6.3.3 of [RFC7231]). The 239 body of the response MUST be empty. 241 The following is a non-normative example of a successful receipt of a 242 SET. 244 HTTP/1.1 202 Accepted 246 Figure 2: Example Successful Delivery Response 248 Note that the purpose of the acknowledgement response is to let the 249 SET Transmitter know that a SET has been delivered and the 250 information no longer needs to be retained by the SET Transmitter. 251 Before acknowledgement, SET Recipients SHOULD ensure they have 252 validated received SETs and retained them in a manner appropriate to 253 information retention requirements appropriate to the SET event types 254 signaled. The level and method of retention of SETs by SET 255 Recipients is out of scope of this specification. 257 2.3. Failure Response 259 In the event of a general HTTP error condition, the SET Recipient 260 SHOULD respond with an appropriate HTTP Status Code as defined in 261 Section 6 of [RFC7231]. 263 When the SET Recipient detects an error parsing, validating or 264 authenticating a SET transmitted in a SET Transmission Request, the 265 SET Recipient SHALL respond with an HTTP Response Status Code of 400 266 (Bad Request). The "Content-Type" header of this response MUST be 267 "application/json", and the body MUST be a UTF-8 encoded JSON 268 [RFC8259] object containing the following name/value pairs: 270 err A Security Event Token Error Code (see Section 2.4). 272 description A UTF-8 string containing a human-readable description 273 of the error that MAY provide additional diagnostic information. 274 The exact content of this field is implementation-specific. 276 The response MUST include a "Content-Language" header, whose value 277 indicates the language of the error descriptions included in the 278 response body. If the SET Recipient can provide error descriptions 279 in multiple languages, they SHOULD choose the language to use 280 according to the value of the "Accept-Language" header sent by the 281 SET Transmitter in the transmission request, as described in 282 Section 5.3.5 of [RFC7231]. If the SET Transmitter did not send an 283 "Accept-Language" header, or if the SET Recipient does not support 284 any of the languages included in the header, the SET Recipient MUST 285 respond with messages that are understandable by an English-speaking 286 person, as described in Section 4.5 of [RFC2277]. 288 The following is an example non-normative error response indicating 289 that the key used to encrypt the SET has been revoked. 291 HTTP/1.1 400 Bad Request 292 Content-Language: en-US 293 Content-Type: application/json 295 { 296 "err": "invalid_key", 297 "description": "Key ID 12345 has been revoked." 298 } 300 Figure 3: Example Error Response (invalid_key) 302 The following is an example non-normative error response indicating 303 that the access token included in the request is expired. 305 HTTP/1.1 400 Bad Request 306 Content-Language: en-US 307 Content-Type: application/json 309 { 310 "err": "authentication_failed", 311 "description": "Access token is expired." 312 } 314 Figure 4: Example Error Response (authentication_failed) 316 The following is an example non-normative error response indicating 317 that the SET Receiver is not willing to accept SETs issued by the 318 specified issuer from this particular SET Transmitter. 320 HTTP/1.1 400 Bad Request 321 Content-Language: en-US 322 Content-Type: application/json 324 { 325 "err": "access_denied", 326 "description": "Not authorized for issuer http://iss.example.com/." 327 } 329 Figure 5: Example Error Response (access_denied) 331 2.4. Security Event Token Delivery Error Codes 333 Security Event Token Delivery Error Codes are strings that identify a 334 specific category of error that may occur when parsing or validating 335 a SET. Every Security Event Token Delivery Error Code MUST have a 336 unique name registered in the IANA "Security Event Token Delivery 337 Error Codes" registry established by Section 7.1. 339 The following table presents the initial set of Error Codes that are 340 registered in the IANA "Security Event Token Delivery Error Codes" 341 registry: 343 +-----------------------+-------------------------------------------+ 344 | Error Code | Description | 345 +-----------------------+-------------------------------------------+ 346 | invalid_request | The request body cannot be parsed as a | 347 | | SET, or the Event Payload within the SET | 348 | | does not conform to the event's | 349 | | definition. | 350 | invalid_key | One or more keys used to encrypt or sign | 351 | | the SET is invalid or otherwise | 352 | | unacceptable to the SET Recipient. (e.g., | 353 | | expired, revoked, failed certificate | 354 | | validation, etc.) | 355 | authentication_failed | The SET Recipient could not authenticate | 356 | | the SET Transmitter. | 357 | access_denied | The SET Transmitter is not authorized to | 358 | | transmit the SET to the SET Recipient. | 359 +-----------------------+-------------------------------------------+ 361 Table 1: SET Delivery Error Codes 363 Implementations SHOULD expect that other Error Codes MAY also be 364 received, as the set of Error Codes is extensible via the IANA 365 "Security Event Token Delivery Error Codes" registry established in 366 Section 7.1. 368 3. Authentication and Authorization 370 The SET delivery method described in this specification is based upon 371 HTTP and and HTTP over TLS [RFC2818] and/or standard HTTP 372 authentication and authorization schemes, as per [RFC7235]. The TLS 373 server certificate MUST be validated, per [RFC6125]. 375 Authorization for the eligibility to provide actionable SETs can be 376 determined by using the identity of the SET Issuer, the identity of 377 the SET Transmitter, perhaps using mutual TLS, or via other employed 378 authentication methods. Because SETs are not commands, SET 379 Recipients are free to ignore SETs that are not of interest. 381 4. Delivery Reliability 383 Delivery reliability requirements may vary depending upon the use 384 cases. This specification defines the response from the SET 385 Recipient in such a way as to provide the SET Transmitter with the 386 information necessary to determine what further action is required, 387 if any, in order to meet their requirements. SET Transmitters with 388 high reliability requirements may be tempted to always retry failed 389 transmissions, however, it should be noted that for many types of SET 390 delivery errors, a retry is extremely unlikely to be successful. For 391 example, "invalid_request" indicates a structural error in the 392 content of the request body that is likely to remain when re- 393 transmitting the same SET. Others such as "access_denied" may be 394 transient, for example if the SET Transmitter refreshes expired 395 credentials prior to re-transmission. 397 Implementers SHOULD evaluate the reliability requirements of their 398 use cases and the impact of various retry mechanisms on the 399 performance of their systems to determine an appropriate strategy for 400 handling various error conditions. 402 5. Security Considerations 404 5.1. Authentication Using Signed SETs 406 In scenarios where HTTP authorization or TLS mutual authentication 407 are not used or are considered weak, JWS signed SETs SHOULD be used 408 (see [RFC7515] and Section 5 of [RFC8417]). This enables the SET 409 Recipient to validate that the SET Transmitter is authorized to 410 deliver the SET. 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 As stated in Section 2.7.1 of [RFC7230], an HTTP requestor MUST NOT 419 generate the "userinfo" (i.e., username and password) component (and 420 its "@" delimiter) when an "http" URI reference is generated with a 421 message, as they are now disallowed in HTTP. 423 5.3. Confidentiality of SETs 425 SETs may contain sensitive information that is considered Personally 426 Identifiable Information (e.g., subject claims). In such cases, SET 427 Transmitters and SET Recipients MUST protect the confidentiality of 428 the SET contents by encrypting the SET as described in JWE [RFC7516], 429 using a transport-layer security mechanism such as TLS, or both. If 430 an Event delivery endpoint supports TLS, it MUST support at least TLS 431 version 1.2 [RFC5246] and SHOULD support the newest version of TLS 432 that meets its security requirements, which as of the time of this 433 publication is TLS 1.3 [RFC8446]. When using TLS, the client MUST 434 perform a TLS/SSL server certificate check using DNS-ID [RFC6125]. 435 Implementation security considerations for TLS can be found in 436 "Recommendations for Secure Use of TLS and DTLS" [RFC7525]. 438 5.4. Denial of Service 440 The SET Recipient may be vulnerable to a denial-of-service attack 441 where a malicious party makes a high volume of requests containing 442 invalid SETs, causing the endpoint to expend significant resources on 443 cryptographic operations that are bound to fail. This may be 444 mitigated by authenticating SET Transmitters with a mechanism with 445 low runtime overhead, such as mutual TLS. 447 5.5. Authenticating Persisted SETs 449 At the time of receipt, the SET Recipient can rely upon transport 450 layer mechanisms, HTTP authentication methods, and/or other context 451 from the transmission request to authenticate the SET Transmitter and 452 validate the authenticity of the SET. However, this context is 453 typically unavailable to systems that the SET Recipient forwards the 454 SET onto, or to systems that retrieve the SET from storage. If the 455 SET Recipient requires the ability to validate SET authenticity 456 outside of the context of the transmission request, then the SET 457 Recipient SHOULD ensure that such SETs have been signed in accordance 458 with [RFC7515]. 460 6. Privacy Considerations 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 Transmitters should consider 473 the ramifications of sharing a particular subject identifier with a 474 SET Recipient (e.g., whether doing so could enable correlation and/or 475 de-anonymization of data), and choose appropriate subject identifiers 476 for their use cases. 478 7. IANA Considerations 480 7.1. Security Event Token Delivery Error Codes 482 This document defines Security Event Token Delivery Error Codes, for 483 which IANA is asked to create and maintain a new registry titled 484 "Security Event Token Delivery Error Codes". Initial values for the 485 Security Event Token Delivery Error Codes registry are defined in 486 Table 1 and registered below. Future assignments are to be made 487 through the Specification Required registration policy ([RFC8126]) 488 and shall follow the template presented in Section 7.1.1. 490 Error Codes are intended to be interpreted by automated systems, and 491 therefore SHOULD identify classes of errors to which an automated 492 system could respond in a meaningfully distinct way (e.g., by 493 refreshing authentication credentials and retrying the request). 495 7.1.1. Registration Template 497 Error Code 498 The name of the Security Event Token Delivery Error Code, as 499 described in Section 2.4. The name MUST be a case-sensitive ASCII 500 string consisting only of letters, digits and underscore, these 501 are the characters whose codes fall within the inclusive ranges 502 0x30-39, 0x41-5A, 0x5F and 0x61-7A. 504 Description 505 A brief human-readable description of the Security Event Token 506 Delivery Error Code. 508 Change Controller 509 For error codes registered by the IETF or its working groups, list 510 "IETF SecEvent Working Group". For all other error codes, list 511 the name of the party responsible for the registration. Contact 512 information such as mailing address, email address, or phone 513 number may also be provided. 515 Defining Document(s) 516 A reference to the document or documents that define the Security 517 Event Token Delivery Error Code. The definition MUST specify the 518 name and description of the error code, and explain under what 519 circumstances the error code may be used. URIs that can be used 520 to retrieve copies of each document at no cost SHOULD be included. 522 7.1.2. Initial Registry Contents 524 Error Code: invalid_request 525 Description: The request body cannot be parsed as a SET or the 526 event payload within the SET does not conform to the event's 527 definition. 528 Change Controller: IETF 529 Defining Document(s): Section 2.4 of [[ this specification ]] 531 Error Code: invalid_key 532 Description: One or more keys used to encrypt or sign the SET is 533 invalid or otherwise unacceptable to the SET Recipient. (e.g., 534 expired, revoked, failed certificate validation, etc.) 535 Change Controller: IETF 536 Defining Document(s): Section 2.4 of [[ this specification ]] 538 Error Code: authentication_failed 539 Description: The SET Recipient could not authenticate the SET 540 Transmitter. 541 Change Controller: IETF 542 Defining Document(s): Section 2.4 of [[ this specification ]] 544 Error Code: access_denied 545 Description: The SET Transmitter is not authorized to transmit the 546 SET to the SET Recipient. 547 Change Controller: IETF 548 Defining Document(s): Section 2.4 of [[ this specification ]] 550 8. References 552 8.1. Normative References 554 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 555 Requirement Levels", BCP 14, RFC 2119, 556 DOI 10.17487/RFC2119, March 1997, 557 . 559 [RFC2277] Alvestrand, H., "IETF Policy on Character Sets and 560 Languages", BCP 18, RFC 2277, DOI 10.17487/RFC2277, 561 January 1998, . 563 [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, 564 DOI 10.17487/RFC2818, May 2000, 565 . 567 [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security 568 (TLS) Protocol Version 1.2", RFC 5246, 569 DOI 10.17487/RFC5246, August 2008, 570 . 572 [RFC6125] Saint-Andre, P. and J. Hodges, "Representation and 573 Verification of Domain-Based Application Service Identity 574 within Internet Public Key Infrastructure Using X.509 575 (PKIX) Certificates in the Context of Transport Layer 576 Security (TLS)", RFC 6125, DOI 10.17487/RFC6125, March 577 2011, . 579 [RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer 580 Protocol (HTTP/1.1): Message Syntax and Routing", 581 RFC 7230, DOI 10.17487/RFC7230, June 2014, 582 . 584 [RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer 585 Protocol (HTTP/1.1): Semantics and Content", RFC 7231, 586 DOI 10.17487/RFC7231, June 2014, 587 . 589 [RFC7515] Jones, M., Bradley, J., and N. Sakimura, "JSON Web 590 Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, May 591 2015, . 593 [RFC7516] Jones, M. and J. Hildebrand, "JSON Web Encryption (JWE)", 594 RFC 7516, DOI 10.17487/RFC7516, May 2015, 595 . 597 [RFC7519] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token 598 (JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015, 599 . 601 [RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre, 602 "Recommendations for Secure Use of Transport Layer 603 Security (TLS) and Datagram Transport Layer Security 604 (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May 605 2015, . 607 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 608 Writing an IANA Considerations Section in RFCs", BCP 26, 609 RFC 8126, DOI 10.17487/RFC8126, June 2017, 610 . 612 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 613 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 614 May 2017, . 616 [RFC8259] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data 617 Interchange Format", STD 90, RFC 8259, 618 DOI 10.17487/RFC8259, December 2017, 619 . 621 [RFC8417] Hunt, P., Ed., Jones, M., Denniss, W., and M. Ansari, 622 "Security Event Token (SET)", RFC 8417, 623 DOI 10.17487/RFC8417, July 2018, 624 . 626 [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol 627 Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, 628 . 630 8.2. Informative References 632 [RFC7235] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer 633 Protocol (HTTP/1.1): Authentication", RFC 7235, 634 DOI 10.17487/RFC7235, June 2014, 635 . 637 Appendix A. Other Streaming Specifications 639 [[ NOTE TO THE RFC EDITOR: This section to be removed prior to 640 publication ]] 642 The following pub/sub, queuing, streaming systems were reviewed as 643 possible solutions or as input to the current draft: 645 Poll-Based Security Event Token (SET) Delivery Using HTTP 647 In addition to this specification, the WG is defining a polling-based 648 SET delivery protocol. That protocol's draft (draft-ietf-secevent- 649 http-poll) describes it as: 651 This specification defines how a series of Security Event Tokens 652 (SETs) may be delivered to an intended recipient using HTTP POST over 653 TLS initiated as a poll by the recipient. The specification also 654 defines how delivery can be assured, subject to the SET Recipient's 655 need for assurance. 657 XMPP Events 659 The WG considered the XMPP events ands its ability to provide a 660 single messaging solution without the need for both polling and push 661 modes. The feeling was the size and methodology of XMPP was to far 662 apart from the current capabilities of the SECEVENTs community which 663 focuses in on HTTP based service delivery and authorization. 665 Amazon Simple Notification Service 667 Simple Notification Service, is a pub/sub messaging product from AWS. 668 SNS supports a variety of subscriber types: HTTP/HTTPS endpoints, AWS 669 Lambda functions, email addresses (as JSON or plain text), phone 670 numbers (via SMS), and AWS SQS standard queues. It doesn't directly 671 support pull, but subscribers can get the pull model by creating an 672 SQS queue and subscribing it to the topic. Note that this puts the 673 cost of pull support back onto the subscriber, just as it is in the 674 push model. It is not clear that one way is strictly better than the 675 other; larger, sophisticated developers may be happy to own message 676 persistence so they can have their own internal delivery guarantees. 677 The long tail of OIDC clients may not care about that, or may fail to 678 get it right. Regardless, I think we can learn something from the 679 Delivery Policies supported by SNS, as well as the delivery controls 680 that SQS offers (e.g., Visibility Timeout, Dead-Letter Queues). I'm 681 not suggesting that we need all of these things in the spec, but they 682 give an idea of what features people have found useful. 684 Other information: 686 o API Reference: 687 http://docs.aws.amazon.com/AWSSimpleQueueService/latest/ 688 APIReference/Welcome.html 690 o Visibility Timeouts: 691 http://docs.aws.amazon.com/AWSSimpleQueueService/latest/ 692 SQSDeveloperGuide/sqs-visibility-timeout.html 694 Apache Kafka 696 Apache Kafka is an Apache open source project based upon TCP for 697 distributed streaming. It prescribes some interesting general 698 purpose features that seem to extend far beyond the simpler streaming 699 model SECEVENTs is after. A comment from MS has been that Kafka does 700 an acknowledge with poll combination event which seems to be a 701 performance advantage. See: https://kafka.apache.org/intro 703 Google Pub/Sub 705 Google Pub Sub system favours a model whereby polling and 706 acknowledgement of events is done as separate endpoints as separate 707 functions. 709 Information: 711 o Cloud Overview - https://cloud.google.com/pubsub/ 712 o Subscriber Overview - https://cloud.google.com/pubsub/docs/ 713 subscriber 715 o Subscriber Pull(poll) - https://cloud.google.com/pubsub/docs/pull 717 Appendix B. Acknowledgments 719 The editors would like to thank the members of the SCIM working 720 group, which began discussions of provisioning events starting with 721 draft-hunt-scim-notify-00 in 2015. 723 The editors would like to thank Phil Hunt and the other authors of 724 draft-ietf-secevent-delivery-02, on which this draft is based. 726 The editors would like to thank the participants in the the SecEvents 727 working group for their contributions to this specification. 729 Appendix C. Change Log 731 [[ NOTE TO THE RFC EDITOR: This section to be removed prior to 732 publication ]] 734 Draft 00 - AB - Based on draft-ietf-secevent-delivery-02 with the 735 following changes: 737 o Renamed to "Push-Based SET Token Delivery Using HTTP" 739 o Removed references to the HTTP Polling delivery method. 741 o Removed informative reference to RFC6202. 743 Draft 01 - AB: 745 o Fixed area and workgroup to match secevent. 747 o Removed unused definitions and definitions already covered by SET. 749 o Renamed Event Transmitter and Event Receiver to SET Transmitter 750 and SET Receiver, respectively. 752 o Added IANA registry for SET Delivery Error Codes. 754 o Removed enumeration of HTTP authentication methods. 756 o Removed generally applicable guidance for HTTP, authorization 757 tokens, and bearer tokens. 759 o Moved guidance for using authentication methods as DoS protection 760 to Security Considerations. 762 o Removed redundant instruction to use WWW-Authenticate header. 764 o Removed further generally applicable guidance for authorization 765 tokens. 767 o Removed bearer token from example delivery request, and text 768 referencing it. 770 o Broke delivery method description into separate request/response 771 sections. 773 o Added missing empty line between headers and body in example 774 request. 776 o Removed unapplicable notes about example formatting. 778 o Removed text about SET creation and handling. 780 o Removed duplication in protocol description. 782 o Added "non-normative example" text to example transmission 783 request. 785 o Fixed inconsistencies in use of Error Code term. 787 Draft 02 - AB: 789 o Rewrote abstract and introduction. 791 o Rewrote definitions for SET Transmitter, SET Receiver. 793 o Renamed Event Delivery section to SET Delivery. 795 o Readability edits to Success Response and Failure Response 796 sections. 798 o Consolidated definition of error response under Failure Response 799 section. 801 o Removed Event Delivery Process section and moved its content to 802 parent section. 804 o Readability edits to SET Delivery section and its subsections. 806 o Added callout that SET Receiver HTTP endpoint configuration is 807 out-of-scope. 809 o Added callout that SET verification mechanisms are out-of-scope. 811 o Added retry guidance, notes regarding delivery reliability 812 requirements. 814 o Added guidance around using JWS and/or JWE to authenticate 815 persisted SETs. 817 Draft 03 - mbj: 819 o Addressed problems identified in my 18-Jul-18 review message 820 titled "Issues for both the Push and Poll Specs". 822 o Changes to align terminology with RFC 8417, for instance, by using 823 the already defined term SET Recipient rather than SET Receiver. 825 o Applied editorial and minor normative corrections. 827 o Updated Marius' contact information. 829 Draft 04 - AB: 831 o Replaced Error Codes with smaller set of meaningfully 832 differentiated codes. 834 o Added more error response examples. 836 o Removed un-referenced normative references. 838 o Added normative reference to JSON in error response definition. 840 o Added text clarifying that the value of the "description" 841 attribute in error responses is implementation specific. 843 o Added requirement that error descriptions and responses are UTF-8 844 encoded. 846 o Added error description language preferences and specification via 847 "Accept-Language" and "Content-Language" headers. 849 o Added "recognized issuer" validation requirement in section 2. 851 o Added time outs as an acceptable reason to resend a SET in section 852 2. 854 o Edited text in section 1 to clarify that configuration is out of 855 scope. 857 o Made minor editorial corrections. 859 Draft 05 - AB: 861 o Made minor editorial corrections. 863 o Updated example request with a correct SET header and signature. 865 o Revised TLS guidance to allow implementers to provide 866 confidentiality protection via JWE. 868 o Revised TLS guidance to require *at least* TLS 1.2. 870 o Revised TLS guidance to recommend supporting the newest version of 871 TLS that meets security requirements. 873 o Revised SET Delivery Error Code format to allow the same set of 874 characters as is allowed in error codes in RFC6749. 876 o Added mention of HTTP Poll spec to list of other streaming specs 877 in appendix. 879 o Added validation step requiring SET Recipient to verify that the 880 SET is one which the SET Transmitter is expected to send to the 881 SET Recipient. 883 o Changed responding to errors with an appropriate HTTP status code 884 from optional to recommended. 886 o Changed Error Codes registry change policy from Expert Review to 887 First Come First Served; added guidance that error codes are meant 888 to be consumed by automated systems. 890 o Added text making clear that it is up to SET Recipients whether or 891 not they will accept SETs where the SET Issuer is different from 892 the SET Transmitter. 894 o Reworded guidance around signing and/or encrypting SETs for 895 integrity protection. 897 o Renamed TLS "Support Considerations" section to "Confidentiality 898 of SETs". 900 o Reworded guidance around subject identifier selection and privacy 901 concerns. 903 Draft 06 - mbj, MS: 905 o Made minor editorial corrections. 907 o Updated to indicate that failure response should be returned if 908 errors occur in authenticating the SET. 910 o Updated reference for JSON from RFC 7159 to RFC 8259. 912 o Fixed Authentication Using Signed SETs to indicate the SET 913 Transmitter must be authorized to deliver the SET, not the SET 914 Issuer. 916 o Fixed Authenticating Persisted SETs to put the responsibility for 917 ensuring the SET is signed on the SET Recipient. 919 o Fixed error code format definition to match error codes defined in 920 doc. 922 Draft 07 - AB: 924 o Made minor editorial corrections. 926 o Removed "SET Recipient" definition and added explicit list of 927 terms used from RFC8417. 929 Draft 08 - mbj 931 o Addressed area director review comments by Benjamin Kaduk. 933 Authors' Addresses 935 Annabelle Backman (editor) 936 Amazon 938 Email: richanna@amazon.com 940 Michael B. Jones (editor) 941 Microsoft 943 Email: mbj@microsoft.com 944 URI: http://self-issued.info/ 945 Marius Scurtescu 946 Coinbase 948 Email: marius.scurtescu@coinbase.com 950 Morteza Ansari 951 Cisco 953 Email: morteza.ansari@cisco.com 955 Anthony Nadalin 956 Microsoft 958 Email: tonynad@microsoft.com