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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 I2RS working group S. Hares 3 Internet-Draft Huawei 4 Intended status: Informational D. Migault 5 Expires: April 2, 2017 J. Halpern 6 Ericsson 7 September 29, 2016 9 I2RS Security Related Requirements 10 draft-ietf-i2rs-protocol-security-requirements-15 12 Abstract 14 This presents security-related requirements for the I2RS protocol 15 which provides a new interface to the routing system described in the 16 I2RS architecture document (RFC7921). The I2RS protocol is a re-use 17 protocol implemented by re-using portions of existing IETF protocols 18 and adding new features to these protocols. The I2RS protocol re- 19 uses security features of a secure transport (E.g. TLS, SSH, DTLS) 20 such as encryption, message integrity, mutual peer authentication, 21 and replay protection. The new I2RS features to consider from a 22 security perspective are: a priority mechanism to handle multi-headed 23 write transactions, an opaque secondary identifier which identifies 24 an application using the I2RS client, and an extremely constrained 25 read-only non-secure transport. This document provides the detailed 26 requirements for these security features. 28 Status of This Memo 30 This Internet-Draft is submitted in full conformance with the 31 provisions of BCP 78 and BCP 79. 33 Internet-Drafts are working documents of the Internet Engineering 34 Task Force (IETF). Note that other groups may also distribute 35 working documents as Internet-Drafts. The list of current Internet- 36 Drafts is at http://datatracker.ietf.org/drafts/current/. 38 Internet-Drafts are draft documents valid for a maximum of six months 39 and may be updated, replaced, or obsoleted by other documents at any 40 time. It is inappropriate to use Internet-Drafts as reference 41 material or to cite them other than as "work in progress." 43 This Internet-Draft will expire on April 2, 2017. 45 Copyright Notice 47 Copyright (c) 2016 IETF Trust and the persons identified as the 48 document authors. All rights reserved. 50 This document is subject to BCP 78 and the IETF Trust's Legal 51 Provisions Relating to IETF Documents 52 (http://trustee.ietf.org/license-info) in effect on the date of 53 publication of this document. Please review these documents 54 carefully, as they describe your rights and restrictions with respect 55 to this document. Code Components extracted from this document must 56 include Simplified BSD License text as described in Section 4.e of 57 the Trust Legal Provisions and are provided without warranty as 58 described in the Simplified BSD License. 60 Table of Contents 62 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 63 2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 4 64 2.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 65 2.2. Security Definitions . . . . . . . . . . . . . . . . . . 4 66 2.3. I2RS Specific Definitions . . . . . . . . . . . . . . . . 5 67 3. Security Features and Protocols: Re-used and New . . . . . . 7 68 3.1. Security Protocols Re-Used by the I2RS Protocol . . . . . 7 69 3.2. New Features Related to Security . . . . . . . . . . . . 8 70 3.3. I2RS Protocol Security Requirements vs. IETF Management 71 Protocols . . . . . . . . . . . . . . . . . . . . . . . . 9 72 4. Security-Related Requirements . . . . . . . . . . . . . . . . 10 73 4.1. I2RS Peers(agent and client) Identity Authentication . . 10 74 4.2. Identity Validation Before Role-Based Message Actions . . 11 75 4.3. Peer Identity, Priority, and Client Redundancy . . . . . 12 76 4.4. Multi-Channel Transport: Secure Transport and Insecure 77 Transport . . . . . . . . . . . . . . . . . . . . . . . . 13 78 4.5. Management Protocol Security . . . . . . . . . . . . . . 15 79 4.6. Role-Based Data Model Security . . . . . . . . . . . . . 16 80 4.7. Security of the environment . . . . . . . . . . . . . . . 17 81 5. Security Considerations . . . . . . . . . . . . . . . . . . . 17 82 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 83 7. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 18 84 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 18 85 8.1. Normative References . . . . . . . . . . . . . . . . . . 18 86 8.2. Informative References . . . . . . . . . . . . . . . . . 19 87 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20 89 1. Introduction 91 The Interface to the Routing System (I2RS) provides read and write 92 access to information and state within the routing system. An I2RS 93 client interacts with one or more I2RS agents to collect information 94 from network routing systems. [RFC7921] describes the architecture 95 of this interface, and this documents assumes the reader is familiar 96 with this architecture and its definitions. Section 2 highlights 97 some of the references the reader is required to be familiar with. 99 The I2RS interface is instantiated by the I2RS protocol connecting an 100 I2RS client and an I2RS agent associated with a routing system. The 101 I2RS protocol is a re-use protocol implemented by re-using portions 102 of existing IETF protocols, and adding new features to these 103 protocols. As a re-use protocol, it can be considered a higher-level 104 protocol since it can be instantiated in multiple management 105 protocols (e.g. NETCONF [RFC6241] or RESTCONF 106 [I-D.ietf-netconf-restconf]) operating over a secure transport. The 107 security for the I2RS protocol comes from the management protocols 108 operating over a a secure transport. 110 This document is part of the requirements for I2RS protocol which 111 also include: 113 o I2RS architecture [RFC7921], 115 o I2RS ephemeral state requirements [I-D.ietf-i2rs-ephemeral-state], 117 o publication/subscription requirements [RFC7922], and 119 o traceability [RFC7923]. 121 Since the I2RS "higher-level" protocol changes the interface to the 122 routing systems, it is important that implementers understand the new 123 security requirements for the environment the I2RS protocol operates 124 in. These security requirements for the I2RS environment are 125 specified in [I-D.ietf-i2rs-security-environment-reqs]; and the 126 summary of the I2RS protocol security environment is found in the 127 I2RS Architecture [RFC7920]. 129 I2RS reuses the secure transport protocols (TLS, SSH, DTLS) which 130 support encryption, message integrity, peer authentication, and key 131 distribution protocols. Optionally, implementers may utilize AAA 132 protocols (Radius over TLS or Diameter over TLS) to securely 133 distribute identity information. 135 Section 3 provides an overview of security features and protocols 136 being re-used (section 3.1) and the new security features being 137 required (section 3.2). Section 3 also explores how existing and new 138 security features and protocols would be paired with existing IETF 139 management protocols (section 3.3). 141 The new features I2RS extends to these protocols are a priority 142 mechanism to handle multi-headed writes, an opaque secondary 143 identifier to allow traceability of an application utilizing a 144 specific I2RS client to communicate with an I2RS agent, and insecure 145 transport constrained to be utilized only for read-only data, which 146 may include publically available data (e.g. public BGP Events, public 147 telemetry information, web service availability) and some legacy 148 data. 150 Section 4 provides the I2RS protocol security requirements by the 151 following security features: 153 o peer identity authentication (section 4.1), 155 o peer identity validation before role-based message actions 156 (section 4.2) 158 o peer identity and client redundancy (section 4.3), 160 o multi-channel transport requirements: Secure transport and 161 insecure Transport (section 4.4), 163 o management protocol security requirements (section 4.5), 165 o role-based security (section 4.6), 167 o security environment (section 4.7) 169 Protocols designed to be I2RS higher-layer protocols need to fulfill 170 these security requirements. 172 2. Definitions 174 2.1. Requirements Language 176 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 177 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 178 document are to be interpreted as described in RFC 2119 [RFC2119]. 180 2.2. Security Definitions 182 This document utilizes the definitions found in the following 183 documents: [RFC4949] and [RFC7921] 184 Specifically, this document utilizes the following definitions from 185 [RFC4949]: 187 o access control, 189 o authentication, 191 o data confidentiality, 193 o data integrity, 195 o data privacy, 197 o identity, 199 o identifier, 201 o mutual authentication, 203 o role, 205 o role-based access control, 207 o security audit trail, and 209 o trust. 211 [RFC7922] describes traceability for I2RS interface and the I2RS 212 protocol. Traceability is not equivalent to a security audit trail 213 or simple logging of information. A security audit trail may utilize 214 traceability information. 216 This document also requires that the user is familiar with the 217 pervasive security requirements in [RFC7258]. 219 2.3. I2RS Specific Definitions 221 The document utilizes the following concepts from the I2RS 222 architecture: [RFC7921]: 224 o I2RS client, I2RS agent, and I2RS protocol (section 2), 226 o I2RS higher-layer protocol (section 7.2) 228 o scope: read scope, notification scope, and write scope (section 229 2), 231 o identity and scope of the identity (section 2), 232 o roles or security rules (section 2), 234 o identity and scope, and secondary identity (section 2), 236 o routing system/subsytem (section 2), 238 o I2RS assumed security environment (section 4), 240 o I2RS identity and authorization (section 4.1), 242 o I2RS authorization, scope of Authorization in I2RS client and 243 agent (section 4.2), 245 o client redundancy with a single client identity (section 4.3), 247 o restrictions on I2RS in personal devices (section 4.4), 249 o communication channels and I2RS high-layer protocol (section 7.2), 251 o active communication versus connectivity (section 7.5), 253 o multi-headed control (section 7.8), and 255 o transaction, message, multi-message atomicity (section 7.9). 257 This document assumes the reader is familar with these terms. 259 This document discusses the security of the multiple I2RS 260 communication channels which operate over the higher-layer I2RS 261 protocol. The higher-layer I2RS protocol combines a secure transport 262 and I2RS contextual information, and re-uses IETF protocols and data 263 models to create the secure transport and the I2RS data-model driven 264 contextual information. To describe how the I2RS high-layer protocol 265 combines other protocols into the I2RS higher-layer protocol, the 266 following terms are used: 268 I2RS component protocols 270 Protocols which are re-used and combined to create the I2RS 271 protocol. 273 I2RS secure-transport component protocols 275 The I2RS secure transport protocols that support the I2RS higher- 276 layer protocol. 278 I2RS management component protocols 279 The I2RS management protocol which provide the management 280 information context. 282 I2RS AAA component protocols 284 The I2RS AAA protocols supporting the I2RS higher-layer protocol. 286 The I2RS higher-layer protocol requires implementation of a I2RS 287 secure-transport component protocol and the I2RS management component 288 protocol. The I2RS AAA component protocol is optional. 290 3. Security Features and Protocols: Re-used and New 292 3.1. Security Protocols Re-Used by the I2RS Protocol 294 I2RS requires a secure transport protocol and key distribution 295 protocols. The secure transport features required by I2RS are peer 296 authentication, confidentiality, data integrity, and replay 297 protection for I2RS messages. According to 298 [I-D.ietf-taps-transports], the secure transport protocols which 299 support peer authentication, confidentiality, data integrity, and 300 replay protection are the following: 302 1. TLS [RFC5246] over TCP or SCTP, 304 2. DTLS over UDP with replay detection and anti-DoS stateless cookie 305 mechanism required for the I2RS protocol, and the I2RS protocol 306 allow DTLS options of record size negotiation and and conveyance 307 of "don't" fragment bits to be optional in deployments. 309 3. HTTP over TLS (over TCP or SCTP), and 311 4. HTTP over DTLS (with the requirements and optional features 312 specified above in item 2). 314 The following protocols would need to be extended to provide 315 confidentiality, data integrity, peer authentication, and key 316 distribution protocols: IPFIX (over SCTP, TCP or UDP) and ForCES TML 317 layer (over SCTP). These protocols will need extensions to run over 318 a secure transport (TLS or DTLS) (see section 3.3 for details). 320 The specific type of key management protocols an I2RS secure 321 transport uses depends on the transport. Key management protocols 322 utilized for the I2RS protocols SHOULD support automatic rotation. 324 An I2RS implementer may use AAA protocols over secure transport to 325 distribute the identities for I2RS client and I2RS agent and role 326 authorization information. Two AAA protocols are: Diameter [RFC6733] 327 and Radius [RFC2865]. To provide the best security I2RS peer 328 identities, the AAA protocols MUST be run over a secure transport 329 (Diameter over secure transport (TLS over TCP) [RFC6733]), Radius 330 over a secure transport (TLS) [RFC6614]). 332 3.2. New Features Related to Security 334 The new features are priority, an opaque secondary identifier, and an 335 insecure protocol for read-only data constrained to specific standard 336 usages. The I2RS protocol allows multi-headed control by several 337 I2RS clients. This multi-headed control is based on the assumption 338 that the operator deploying the I2RS clients, I2RS agents, and the 339 I2rs protocol will coordinate the read, write, and notification scope 340 so the I2RS clients will not contend for the same write scope. 341 However, just in case there is an unforseen overlap of I2RS clients 342 attempting to write a particular piece of data, the I2RS architecture 343 [RFC7921] provides the concept of each I2RS client having a priority. 344 The I2RS client with the highest priority will have its write 345 succeed. This document specifies requirements for this new concept 346 of priority. 348 The opaque secondary identifier identifies an application which is 349 using the I2RS client to I2RS agent communication to manage the 350 routing system. The secondary identifier is opaque to the I2RS 351 protocol. In order to protect personal privacy, the secondary 352 identifier should not contain personal identifiable information. 354 The last new feature related to I2RS security is the ability to allow 355 non-confidential data to be transferred over a non-secure transport. 356 It is expected that most I2RS data models will describe information 357 that will be transferred with confidentiality. Therefore, any model 358 which transfers data over a non-secure transport is marked. The use 359 of a non-secure transport is optional, and an implementer SHOULD 360 create knobs that allow data marked as non-confidential to be sent 361 over a secure transport. 363 Non-confidential data can only be read or notification scope 364 transmission of events. Non-confidential data cannot be write scope 365 or notification scope configuration. An example of non-confidential 366 data is the telemetry information that is publically known (e.g. BGP 367 route-views data or web site status data) or some legacy data (e.g. 368 interface) which cannot be transported in secure transport. The IETF 369 I2RS Data models MUST indicate in the data model the specific data 370 which is non-confidential. 372 Most I2RS data models will expect that the information described in 373 the model will be transferred with confidentiality. 375 3.3. I2RS Protocol Security Requirements vs. IETF Management Protocols 377 Table 1 below provides a partial list of the candidate management 378 protocols and the secure transports each one of the support. One 379 column in the table indicates the transport protocol will need I2RS 380 security extensions. 382 Mangement 383 Protocol Transport Protocol I2RS Extensions 384 ========= ===================== ================= 385 NETCONF TLS over TCP (*1) None required (*2) 387 RESTCONF HTTP over TLS with None required (*2) 388 X.509v3 certificates, 389 certificate validation, 390 mutual authentication: 391 1) authenticated 392 server identity, 393 2) authenticated 394 client identity 395 (*1) 397 FORCES TML over SCTP Needs extension to 398 (*1) TML to run TML over 399 TLS over SCTP, or 400 DTLS with options for 401 replay protection 402 and anti-DoS stateless 403 cookie mechanism. 404 (DTLS record size 405 negotiation and conveyance 406 of "don't" fragment 407 bits are optional). 408 The IPSEC mechanism is 409 not sufficient for 410 I2RS traveling over 411 multiple hops 412 (router + link) (*2) 414 IPFIX SCTP, TCP, UDP Needs to extension 415 TLS or DTLS for to support TLS or 416 secure client (*1) DTLS with options for 417 replay protection 418 and anti-DoS stateless 419 cookie mechanism. 420 (DTLS record size 421 negotiation and conveyance 422 of "don't" fragment 423 bits are optional). 425 *1 - Key management protocols 426 MUST support appropriate key rotation. 428 *2 - Identity and Role authorization distributed 429 by Diameter or Radius MUST use Diameter over TLS 430 or Radius over TLS. 432 4. Security-Related Requirements 434 This section discusses security requirements based on the following 435 security functions: 437 o peer identity authentication (section 4.1), 439 o Peer Identity validation before Role-based Message Actions 440 (section 4.2) 442 o peer identity and client redundancy (section 4.3), 444 o multi-channel transport requirements: Secure transport and 445 insecure Transport (section 4.4), 447 o management protocol security requirements (section 4.5), 449 o role-based security (section 4.6), 451 o security environment (section 4.7) 453 The I2RS Protocol depends upon a secure transport layer for peer 454 authentication, data integrity, confidentiality, and replay 455 protection. The optional insecure transport can only be used 456 restricted set of publically data available (events or information) 457 or a select set of legacy data. Data passed over the insecure 458 transport channel MUST NOT contain any data which identifies a person 459 or any "write" transactions. 461 4.1. I2RS Peers(agent and client) Identity Authentication 463 The following requirements specify the security requirements for Peer 464 Identity Authentication for the I2RS protocol: 466 o SEC-REQ-01: All I2RS clients and I2RS agents MUST have an 467 identity, and at least one unique identifier that uniquely 468 identifies each party in the I2RS protocol context. 470 o SEC-REQ-02: The I2RS protocol MUST utilize these identifiers for 471 mutual identification of the I2RS client and I2RS agent. 473 o SEC-REQ-03: Identifier distribution and the loading of these 474 identifiers into I2RS agent and I2RS client SHOULD occur outside 475 the I2RS protocol prior to the I2RS protocol establishing a 476 connection between I2RS client and I2RS agent. AAA protocols MAY 477 be used to distribute these identifiers, but other mechanism can 478 be used. 480 Explanation: 482 These requirements specify the requirements for I2RS peer (I2RS agent 483 and I2RS client) authentication. A secure transport (E.g. TLS) will 484 authenticate based on these identities. The AAA protocol 485 distributing I2RS identity information SHOULD transport its 486 information over a secure transport. 488 4.2. Identity Validation Before Role-Based Message Actions 490 The requirements for I2RS clients with Secure Connections are the 491 following: 493 SEC-REQ-04: An I2RS agent receiving a request from an I2RS client 494 MUST confirm that the I2RS client has a valid identity. 496 SEC-REQ-05: An I2RS client receiving an I2RS message over a secure 497 transport MUST confirm that the I2RS agent has a valid identifier. 499 SEC-REQ-06: An I2RS agent receiving an I2RS message over an 500 insecure transport MUST confirm that the content is suitable for 501 transfer over such a transport. 503 Explanation: 505 Each I2RS client has a scope based on its identity and the security 506 roles (read, write, or events) associated with that identity, and 507 that scope must be considered in processing an I2RS messages sent on 508 a communication channel. An I2RS communication channel may utilize 509 multiple transport sessions, or establish a transport session and 510 then close the transport session. Therefore, it is important that 511 the I2RS peers are operating utilizing valid peer identities when a 512 message is processed rather than checking if a transport session 513 exists. 515 During the time period when a secure transport session is active, the 516 I2RS agent SHOULD assume that the I2RS client's identity remains 517 valid. Similarly, while a secure connection exists that included 518 validating the I2RS agent's identity and a message is received via 519 that connection, the I2RS client SHOULD assume that the I2RS agent's 520 identity remains valid. 522 4.3. Peer Identity, Priority, and Client Redundancy 524 Requirements: 526 SEC-REQ-07: Each I2RS Identifier MUST be associated with just one 527 priority. 529 SEC-REQ-08: Each Identifier is associated with one secondary 530 identifier during a particular I2RS transaction (e.g. read/write 531 sequence), but the secondary identifier may vary during the time a 532 connection between the I2RS client and I2RS agent is active. 534 Explanation: 536 The I2RS architecture also allows multiple I2RS clients with unique 537 identities to connect to an I2RS agent (section 7.8). The I2RS 538 deployment using multiple clients SHOULD coordinate this multi-headed 539 control of I2RS agents by I2RS clients so no conflict occurs in the 540 write scope. However, in the case of conflict on a write scope 541 variable, the error resolution mechanisms defined by the I2RS 542 architecture multi-headed control ([RFC7921], section 7.8) allow the 543 I2RS agent to deterministically choose one I2RS client. The I2RS 544 client with highest priority is given permission to write the 545 variable, and the second client receives an error message. 547 A single I2RS client may be associated with multiple applications 548 with different tasks (e.g. weekly configurations or emergency 549 configurations). The secondary identity is an opaque value that the 550 I2RS client passes to the I2RS agent so that this opaque value can be 551 placed in the tracing file or event stream to identify the 552 application using the I2RS client to I2RS agent communication. 554 One example of the use of the secondary identity is the situation 555 where an operator of a network has two applications that use an I2RS 556 client. The first application is a weekly configuration application 557 that uses the I2RS protocol to change configurations. The second 558 application is an application that allows operators to makes 559 emergency changes to routers in the network. Both of these 560 applications use the same I2RS client to write to an I2RS agent. In 561 order for traceability to determine which application (weekly 562 configuration or emergency) wrote some configuration changes to a 563 router, the I2RS client sends a different opaque value for each of 564 the applications. The weekly configuration secondary opaque value 565 could be "xzzy-splot" and the emergency secondary opaque value could 566 be "splish-splash". 568 A second example is if the I2RS client is used for monitoring of 569 critical infrastructure. The operator of a network using the I2RS 570 client may desire I2RS client redundancy where the monitoring 571 application wth the I2RS client is deployed on two different boxes 572 with the same I2RS client identity (see [RFC7921] section 4.3) These 573 two monitoring applications pass to the I2RS client whether the 574 application is the primary or back up application, and the I2RS 575 client passes this information in the I2RS secondary identitifier as 576 the figure below shows. The primary applications secondary 577 identifier is "primary-monitoring", and the backup application 578 secondary identifier is "backup-monitoring". The I2RS tracing 579 information will include the secondary identifier information along 580 with the transport information in the tracing file in the agent. 582 Example 2: Primary and Backup Application for Monitoring 583 Identification sent to agent 585 Application A--I2RS client--Secure transport(#1) 586 [I2RS identity 1, secondary identifier: "primary-monitoring"]--> 588 Application B--I2RS client--Secure transport(#2) 589 [I2RS identity 1, secondary identifier: "backup-monitoring"]--> 591 Figure 1 593 4.4. Multi-Channel Transport: Secure Transport and Insecure Transport 595 Requirements: 597 SEC-REQ-09: The I2RS protocol MUST be able to transfer data over a 598 secure transport and optionally MAY be able to transfer data over 599 a non-secure transport. The default transport is a secure 600 transport, and this means it is mandatory to implement (MTI) in 601 all I2RS agents, and in any I2RS client which: a) performs a Write 602 scope transaction which is sent to the I2RS agent or b): 603 configures an Event Scope transaction. It is mandatory to use 604 (MTU) on any I2RS client's Write transaction or the configuration 605 of an Event Scope transaction. 607 SEC-REQ-10: The secure transport MUST provide data 608 confidentiality, data integrity, and practical replay prevention. 610 SEC-REQ-11: The I2RS client and I2RS agent protocol SHOULD 611 implement mechanisms that mitigate DoS attacks. For the secure 612 transport, this means the secure transport must support DoS 613 prevention. For the insecure transport protocol, the I2RS higher- 614 layer protocol MUST contain a transport management layer that 615 considers the detection of DoS attacks and provides a warning over 616 a secure-transport channel. 618 SEC-REQ-12: A secure transport MUST be associated with a key 619 management solution that can guarantee that only the entities 620 having sufficient privileges can get the keys to encrypt/decrypt 621 the sensitive data. 623 SEC-REQ-13: A machine-readable mechanism to indicate that a data- 624 model contains non-confidential data MUST be provided. A non- 625 secure transport MAY be used to publish only read scope or 626 notification scope data if the associated data model indicates 627 that that data is non-confidential. 629 SEC-REQ-14: The I2RS protocol MUST be able to support multiple 630 secure transport sessions providing protocol and data 631 communication between an I2RS agent and an I2RS client. However, 632 a single I2RS agent to I2RS client connection MAY elect to use a 633 single secure transport session or a single non-secure transport 634 session conforming the requirements above. 636 SEC-REQ-15: Deployment configuration knobs SHOULD be created to 637 allow operators to send "non-confidential" Read scope (data or 638 Event streams) over a secure transport. 640 SEC-REQ-16: The I2RS protocol makes use of both secure and 641 insecure transports, but this use MUST NOT be done in any way that 642 weakens the secure transport protocol used in the I2RS protocol or 643 other contexts that do not have this requirement for mixing secure 644 and insecure modes of operation. 646 Explanation: 648 The I2RS architecture defines three scopes: read, write, and 649 notification scope. Insecure data can only be used for read scope 650 and notification scope of "non-confidential data". The configuration 651 of ephemeral data in the I2RS agent uses either write scope for data 652 or write scope for configuration of event notification streams. The 653 requirement to use secure transport for configuration prevents 654 accidental or malevolent entities from altering the I2RS routing 655 system through the I2RS agent. 657 It is anticipated that the passing of most I2RS ephemeral state 658 operational status SHOULD be done over a secure transport. 660 In most circumstances the secure transport protocol will be 661 associated with a key management system. Most deployments of the 662 I2RS protocol will allow for automatic key management systems. Since 663 the data models for the I2RS protocol will control key routing 664 functions, it is important that deployments of I2RS use automatic key 665 management systems. 667 Per BCP107 [RFC4107] while key management system SHOULD be automatic, 668 the systems MAY be manual in the following scenarios: 670 a) The environment has limited bandwidth or high round-trip times. 672 b) The information being protected has low value. 674 c) The total volume of traffic over the entire lifetime of the 675 long-term session key will be very low. 677 d) The scale of the deployment is limited. 679 Operators deploying the I2RS protocol selecting manual key management 680 SHOULD consider both short and medium term plans. Deploying 681 automatic systems initially may save effort over the long-term. 683 4.5. Management Protocol Security 685 Requirements: 687 SEC-REQ-17: In a critical infrastructure, certain data within 688 routing elements is sensitive and read/write operations on such 689 data SHOULD be controlled in order to protect its confidentiality. 690 To achieve this, higher-layer protocols MUST utilize a secure 691 transport, and SHOULD provide access control functions to protect 692 confidentiality of the data. 694 SEC-REQ-18: An integrity protection mechanism for I2RS MUST be 695 provided that will be able to ensure the following: 697 1) the data being protected is not modified without detection 698 during its transportation, 700 2) the data is actually from where it is expected to come from, 701 and 703 3) the data is not repeated from some earlier interaction the 704 higher layer protocol (best effort). 706 The I2RS higher-layer protocol operating over a secure transport 707 provides this integrity. The I2RS higher-layer protocol operating 708 over an insecure transport SHOULD provide some way for the client 709 receiving non-confidential read-scoped or event-scoped data over 710 the insecure connection to detect when the data integrity is 711 questionable; and in the event of a questionable data integrity 712 the I2RS client should disconnect the insecure transport 713 connection. 715 SEC-REQ-19: The I2RS higher-layer protocol MUST provide a 716 mechanism for message traceability (requirements in [RFC7922]) 717 that supports the tracking higher-layer functions run across 718 secure connection or a non-secure transport. 720 Explanation: 722 Most carriers do not want a router's configuration and data flow 723 statistics known by hackers or their competitors. While carriers may 724 share peering information, most carriers do not share configuration 725 and traffic statistics. To achieve this, the I2RS higher-layer 726 protocol (e.g NETCONF) requires access control (NACM [RFC6536]) for 727 sensitive data needs to be provided; and the confidentiality 728 protection on such data during transportation needs to be enforced. 730 Integrity of data is important even if the I2RS protocol is sending 731 non-confidential data over an insecure connection. The ability to 732 trace I2RS protocol messages that enact I2RS transactions provides a 733 minimal aid to helping operators check how messages enact 734 transactions on a secure or insecure transport. 736 4.6. Role-Based Data Model Security 738 The I2RS Architecture [RFC7921] specifies access control by "role" 739 where role is a method of making access control more manageable by 740 creating a grouping of users so that access control can be specified 741 for a role rather than for each of the individuals. Therefore, I2RS 742 role specifies the access control for a group as being read, write, 743 or notification. 745 SEC-REQ-20: The rules around what I2RS security role is permitted 746 to access and manipulate what information over a secure transport 747 (which protects the data in transit) SHOULD ensure that data of 748 any level of sensitivity is reasonably protected from being 749 observed by those without permission to view it, so that privacy 750 requirements are met. 752 SEC-REQ-21: Role security MUST work when multiple transport 753 connections are being used between the I2RS client and I2RS agent 754 as the I2RS architecture [RFC7921] describes. 756 Sec-REQ-22: If an I2RS agents or an I2RS client is tightly 757 correlated with a person, then the I2RS protocol and data models 758 SHOULD provide additional security that protects the person's 759 privacy. 761 Explanation: 763 I2RS higher-layer uses management protocol E.g. NETCONF, RESTCONF) 764 to pass messages in order to enact I2RS transactions. Role Security 765 must secure data (sensitivity and normal data) in a router even when 766 it is operating over multiple connections at the same time. NETCONF 767 can run over TLS (over TCP or SCTP) or SSH. RESTCONF runs over HTTP 768 over a secure transport (TLS). SCTP [RFC4960] provides security for 769 multiple streams plus end-to-end transport of data. Some I2RS 770 functions may wish to operate over DTLS which runs over UDP 771 ([RFC6347]), DDCP ([RFC6238]), and SCTP ([RFC5764]). 773 Please note the security of the application to I2RS client connection 774 is outside of the I2RS protocol or I2RS interface. 776 While I2RS clients are expected to be related to network devices and 777 not individual people, if an I2RS client ran on a person's phone, 778 then privacy protection to anonymize any data relating to a person's 779 identity or location would be needed. 781 A variety of forms of managemen may set policy on roles: "operator- 782 applied knobs", roles that restrict personal access, data-models with 783 specific "privacy roles", and access filters. 785 4.7. Security of the environment 787 The security for the implementation of a protocol also considers the 788 protocol environment. The environmental security requirements are 789 found in: [I-D.ietf-i2rs-security-environment-reqs]. 791 5. Security Considerations 793 This is a document about security requirements for the I2RS protocol 794 and data modules. Security considerations for the I2RS protocol 795 include both the protocol and the security environment. 797 6. IANA Considerations 799 This draft is requirements, and does not request anything of IANA. 801 7. Acknowledgement 803 The authors would like to thank Wes George, Ahmed Abro, Qin Wu, Eric 804 Yu, Joel Halpern, Scott Brim, Nancy Cam-Winget, DaCheng Zhang, Alia 805 Atlas, and Jeff Haas for their contributions to the I2RS security 806 requirements discussion and this document. The authors would like to 807 thank Bob Moskowitz, Kathleen Moriarty, Stephen Farrell, Radia 808 Perlman, Alvaro Retana, Ben Campbell, and Alissa Cooper for their 809 review of these requirements. 811 8. References 813 8.1. Normative References 815 [I-D.ietf-i2rs-security-environment-reqs] 816 Migault, D., Halpern, J., and S. Hares, "I2RS Environment 817 Security Requirements", draft-ietf-i2rs-security- 818 environment-reqs-01 (work in progress), April 2016. 820 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 821 Requirement Levels", BCP 14, RFC 2119, 822 DOI 10.17487/RFC2119, March 1997, 823 . 825 [RFC4107] Bellovin, S. and R. Housley, "Guidelines for Cryptographic 826 Key Management", BCP 107, RFC 4107, DOI 10.17487/RFC4107, 827 June 2005, . 829 [RFC4949] Shirey, R., "Internet Security Glossary, Version 2", 830 FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007, 831 . 833 [RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an 834 Attack", BCP 188, RFC 7258, DOI 10.17487/RFC7258, May 835 2014, . 837 [RFC7921] Atlas, A., Halpern, J., Hares, S., Ward, D., and T. 838 Nadeau, "An Architecture for the Interface to the Routing 839 System", RFC 7921, DOI 10.17487/RFC7921, June 2016, 840 . 842 [RFC7922] Clarke, J., Salgueiro, G., and C. Pignataro, "Interface to 843 the Routing System (I2RS) Traceability: Framework and 844 Information Model", RFC 7922, DOI 10.17487/RFC7922, June 845 2016, . 847 [RFC7923] Voit, E., Clemm, A., and A. Gonzalez Prieto, "Requirements 848 for Subscription to YANG Datastores", RFC 7923, 849 DOI 10.17487/RFC7923, June 2016, 850 . 852 8.2. Informative References 854 [I-D.ietf-i2rs-ephemeral-state] 855 Haas, J. and S. Hares, "I2RS Ephemeral State 856 Requirements", draft-ietf-i2rs-ephemeral-state-18 (work in 857 progress), September 2016. 859 [I-D.ietf-netconf-restconf] 860 Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF 861 Protocol", draft-ietf-netconf-restconf-17 (work in 862 progress), September 2016. 864 [I-D.ietf-taps-transports] 865 Fairhurst, G., Trammell, B., and M. Kuehlewind, "Services 866 provided by IETF transport protocols and congestion 867 control mechanisms", draft-ietf-taps-transports-11 (work 868 in progress), July 2016. 870 [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, 871 "Remote Authentication Dial In User Service (RADIUS)", 872 RFC 2865, DOI 10.17487/RFC2865, June 2000, 873 . 875 [RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol", 876 RFC 4960, DOI 10.17487/RFC4960, September 2007, 877 . 879 [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security 880 (TLS) Protocol Version 1.2", RFC 5246, 881 DOI 10.17487/RFC5246, August 2008, 882 . 884 [RFC5764] McGrew, D. and E. Rescorla, "Datagram Transport Layer 885 Security (DTLS) Extension to Establish Keys for the Secure 886 Real-time Transport Protocol (SRTP)", RFC 5764, 887 DOI 10.17487/RFC5764, May 2010, 888 . 890 [RFC6238] M'Raihi, D., Machani, S., Pei, M., and J. Rydell, "TOTP: 891 Time-Based One-Time Password Algorithm", RFC 6238, 892 DOI 10.17487/RFC6238, May 2011, 893 . 895 [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., 896 and A. Bierman, Ed., "Network Configuration Protocol 897 (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, 898 . 900 [RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer 901 Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347, 902 January 2012, . 904 [RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration 905 Protocol (NETCONF) Access Control Model", RFC 6536, 906 DOI 10.17487/RFC6536, March 2012, 907 . 909 [RFC6614] Winter, S., McCauley, M., Venaas, S., and K. Wierenga, 910 "Transport Layer Security (TLS) Encryption for RADIUS", 911 RFC 6614, DOI 10.17487/RFC6614, May 2012, 912 . 914 [RFC6733] Fajardo, V., Ed., Arkko, J., Loughney, J., and G. Zorn, 915 Ed., "Diameter Base Protocol", RFC 6733, 916 DOI 10.17487/RFC6733, October 2012, 917 . 919 [RFC7920] Atlas, A., Ed., Nadeau, T., Ed., and D. Ward, "Problem 920 Statement for the Interface to the Routing System", 921 RFC 7920, DOI 10.17487/RFC7920, June 2016, 922 . 924 Authors' Addresses 926 Susan Hares 927 Huawei 928 7453 Hickory Hill 929 Saline, MI 48176 930 USA 932 Email: shares@ndzh.com 933 Daniel Migault 934 Ericsson 935 8400 boulevard Decarie 936 Montreal, QC HAP 2N2 937 Canada 939 Email: daniel.migault@ericsson.com 941 Joel Halpern 942 Ericsson 943 US 945 Email: joel.halpern@ericsson.com