Internet DRAFT - draft-ietf-rtgwg-yang-key-chain
draft-ietf-rtgwg-yang-key-chain
Network Working Group A. Lindem, Ed.
Internet-Draft Cisco Systems
Intended status: Standards Track Y. Qu
Expires: October 31, 2017 Huawei
D. Yeung
Arrcus, Inc
I. Chen
Jabil
J. Zhang
Juniper Networks
April 29, 2017
Routing Key Chain YANG Data Model
draft-ietf-rtgwg-yang-key-chain-24.txt
Abstract
This document describes the key chain YANG data model. Key chains
are commonly used for routing protocol authentication and other
applications requiring symmetric keys. A key chain is a list of
elements each containing a key string, send lifetime, accept
lifetime, and algorithm (authentication or encryption). By properly
overlapping the send and accept lifetimes of multiple key chain
elements, key strings and algorithms may be gracefully updated. By
representing them in a YANG data model, key distribution can be
automated.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on October 31, 2017.
Lindem, et al. Expires October 31, 2017 [Page 1]
Internet-Draft YANG Key Chain April 2017
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Notation . . . . . . . . . . . . . . . . . . 3
1.2. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 3
2. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Applicability . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Graceful Key Rollover using Key Chains . . . . . . . . . 4
3. Design of the Key Chain Model . . . . . . . . . . . . . . . . 5
3.1. Key Chain Operational State . . . . . . . . . . . . . . . 6
3.2. Key Chain Model Features . . . . . . . . . . . . . . . . 6
3.3. Key Chain Model Tree . . . . . . . . . . . . . . . . . . 6
4. Key Chain YANG Model . . . . . . . . . . . . . . . . . . . . 8
5. Security Considerations . . . . . . . . . . . . . . . . . . . 16
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 17
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
8.1. Normative References . . . . . . . . . . . . . . . . . . 17
8.2. Informative References . . . . . . . . . . . . . . . . . 18
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 19
A.1. Simple Key Chain with Always Valid Single Key . . . . . . 19
A.2. Key Chain with Keys having Different Lifetimes . . . . . 20
A.3. Key Chain with Independent Send and Accept Lifetimes . . 22
Appendix B. Acknowledgments . . . . . . . . . . . . . . . . . . 23
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23
1. Introduction
This document describes the key chain YANG [YANG-1.1] data model.
Key chains are commonly used for routing protocol authentication and
other applications requiring symmetric keys. A key chain is a list
of elements each containing a key string, send lifetime, accept
lifetime, and algorithm (authentication or encryption). By properly
Lindem, et al. Expires October 31, 2017 [Page 2]
Internet-Draft YANG Key Chain April 2017
overlapping the send and accept lifetimes of multiple key chain
elements, key strings and algorithms may be gracefully updated. By
representing them in a YANG data model, key distribution can be
automated.
In some applications, the protocols do not use the key chain element
key directly, but rather a key derivation function is used to derive
a short-lived key from the key chain element key (e.g., the Master
Keys used in [TCP-AO]).
1.1. Requirements Notation
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
[RFC-KEYWORDS].
1.2. Tree Diagrams
A simplified graphical representation of the complete data tree is
presented in Section 3.3. The following tree notation is used.
o Brackets "[" and "]" enclose YANG list keys. These YANG list keys
should not be confused with the key-chain keys.
o Curly braces "{" and "}" contain names of optional features that
make the corresponding node conditional.
o Abbreviations before data node names: "rw" means configuration
(read-write), "ro" state data (read-only), "-x" RPC operations,
and "-n" notifications.
o Symbols after data node names: "?" means an optional node, "!" a
container with presence, and "*" denotes a "list" or "leaf-list".
o Parentheses enclose choice and case nodes, and case nodes are also
marked with a colon (":").
o Ellipsis ("...") stands for contents of subtrees that are not
shown.
2. Problem Statement
This document describes a YANG [YANG-1.1] data model for key chains.
Key chains have been implemented and deployed by a large percentage
of network equipment vendors. Providing a standard YANG model will
facilitate automated key distribution and non-disruptive key
Lindem, et al. Expires October 31, 2017 [Page 3]
Internet-Draft YANG Key Chain April 2017
rollover. This will aid in tightening the security of the core
routing infrastructure as recommended in [IAB-REPORT].
A key chain is a list containing one or more elements containing a
Key ID, key string, send/accept lifetimes, and the associated
authentication or encryption algorithm. A key chain can be used by
any service or application requiring authentication or encryption
using symmetric keys. In essence, the key-chain is a reusable key
policy that can be referenced wherever it is required. The key-chain
construct has been implemented by most networking vendors and
deployed in many networks.
A conceptual representation of a crypto key table is described in
[CRYPTO-KEYTABLE]. The crypto key table also includes keys as well
as their corresponding lifetimes and algorithms. Additionally, the
key table includes key selection criteria and envisions a deployment
model where the details of the applications or services requiring
authentication or encryption permeate into the key database. The
YANG key-chain model described herein doesn't include key selection
criteria or support this deployment model. At the same time, it does
not preclude it. The draft [YANG-CRYPTO-KEYTABLE] describes
augmentations to the key chain YANG model in support of key selection
criteria.
2.1. Applicability
Other YANG modules may reference ietf-key-chain YANG module key-chain
names for authentication and encryption applications. A YANG type
has been provided to facilitate reference to the key-chain name
without having to specify the complete YANG XML Path Language (XPath)
selector.
2.2. Graceful Key Rollover using Key Chains
Key chains may be used to gracefully update the key string and/or
algorithm used by an application for authentication or encryption.
To achieve graceful key rollover, the receiver MAY accept all the
keys that have a valid accept lifetime and the sender MAY send the
key with the most recent send lifetime. One scenario for
facilitating key rollover is to:
1. Distribute a key chain with a new key to all the routers or other
network devices in the domain of that key chain. The new key's
accept lifetime should be such that it is accepted during the key
rollover period. The send lifetime should be a time in the
future when it can be assured that all the routers in the domain
of that key are upgraded. This will have no immediate impact on
the keys used for transmission.
Lindem, et al. Expires October 31, 2017 [Page 4]
Internet-Draft YANG Key Chain April 2017
2. Assure that all the network devices have been updated with the
updated key chain and that their system times are roughly
synchronized. The system times of devices within an
administrative domain are commonly synchronized (e.g., using
Network Time Protocol (NTP) [NTP-PROTO]). This also may be
automated.
3. When the send lifetime of the new key becomes valid, the network
devices within the domain of key chain will using the new key for
transmissions.
4. At some point in the future, a new key chain with the old key
removed may be distributed to the network devices within the
domain of the key chain. However, this may be deferred until the
next key rollover. If this is done, the key chain will always
include two keys; either the current and future key (during key
rollovers) or the current and previous keys (between key
rollovers).
Since the most recent send lifetime is defined as the one with the
latest start-time, specification of "always" will prevent using the
graceful key rollover technique described above. Other key
configuration and usage scenarios are possible but these are beyond
the scope of this document.
3. Design of the Key Chain Model
The ietf-key-chain module contains a list of one or more keys indexed
by a Key ID. For some applications (e.g., OSPFv3 [OSPFV3-AUTH]), the
Key ID is used to identify the key chain key to be used. In addition
to the Key ID, each key chain key includes a key-string and a
cryptographic algorithm. Optionally, the key chain keys include
send/accept lifetimes. If the send/accept lifetime is unspecified,
the key is always considered valid.
Note that different key values for transmission versus acceptance may
be supported with multiple key chain elements. The key used for
transmission will have a valid send-lifetime and invalid accept-
lifetime (e.g., has an end-time equal to the start-time). The key
used for acceptance will have a valid accept-lifetime and invalid
send-lifetime.
Due to the differences in key chain implementations across various
vendors, some of the data elements are optional. Finally, the crypto
algorithm identities are provided for reuse when configuring legacy
authentication and encryption not using key-chains.
Lindem, et al. Expires October 31, 2017 [Page 5]
Internet-Draft YANG Key Chain April 2017
A key-chain is identified by a unique name within the scope of the
network device. The "key-chain-ref" typedef SHOULD be used by other
YANG modules when they need to reference a configured key-chain.
3.1. Key Chain Operational State
The key chain operational state is included in the same tree as key
chain configuration consistent with Network Management Datastore
Architecture [NMDA]. The timestamp of the last key chain
modification is also maintained in the operational state.
Additionally, the operational state includes an indication of whether
or not a key chain key is valid for sending or acceptance.
3.2. Key Chain Model Features
Features are used to handle differences between vendor
implementations. For example, not all vendors support configuration
of an acceptance tolerance or configuration of key strings in
hexadecimal. They are also used to support of security requirements
(e.g., TCP-AO Algorithms [TCP-AO-ALGORITHMS]) not yet implemented by
vendors or only a single vendor.
It is common for an entity with sufficient permissions to read and
store a device's configuration which would include the contents of
this model. To avoid unnecessarily seeing and storing the keys in
clear-text, this model provides the aes-key-wrap feature. More
details are described in Security Considerations Section 5.
3.3. Key Chain Model Tree
+--rw key-chains
+--rw key-chain* [name]
| +--rw name string
| +--rw description? string
| +--rw accept-tolerance {accept-tolerance}?
| | +--rw duration? uint32
| +--ro last-modified-timestamp? yang:date-and-time
| +--rw key* [key-id]
| +--rw key-id uint64
| +--rw lifetime
| | +--rw (lifetime)?
| | +--:(send-and-accept-lifetime)
| | | +--rw send-accept-lifetime
| | | +--rw (lifetime)?
| | | +--:(always)
| | | | +--rw always? empty
| | | +--:(start-end-time)
| | | +--rw start-date-time?
Lindem, et al. Expires October 31, 2017 [Page 6]
Internet-Draft YANG Key Chain April 2017
| | | | yang:date-and-time
| | | +--rw (end-time)?
| | | +--:(infinite)
| | | | +--rw no-end-time? empty
| | | +--:(duration)
| | | | +--rw duration? uint32
| | | +--:(end-date-time)
| | | +--rw end-date-time?
| | | yang:date-and-time
| | +--:(independent-send-accept-lifetime)
| | | {independent-send-accept-lifetime}?
| | +--rw send-lifetime
| | | +--rw (lifetime)?
| | | +--:(always)
| | | | +--rw always? empty
| | | +--:(start-end-time)
| | | +--rw start-date-time?
| | | | yang:date-and-time
| | | +--rw (end-time)?
| | | +--:(infinite)
| | | | +--rw no-end-time? empty
| | | +--:(duration)
| | | | +--rw duration? uint32
| | | +--:(end-date-time)
| | | +--rw end-date-time?
| | | yang:date-and-time
| | +--rw accept-lifetime
| | +--rw (lifetime)?
| | +--:(always)
| | | +--rw always? empty
| | +--:(start-end-time)
| | +--rw start-date-time?
| | | yang:date-and-time
| | +--rw (end-time)?
| | +--:(infinite)
| | | +--rw no-end-time? empty
| | +--:(duration)
| | | +--rw duration? uint32
| | +--:(end-date-time)
| | +--rw end-date-time?
| | yang:date-and-time
| +--rw crypto-algorithm identityref
| +--rw key-string
| | +--rw (key-string-style)?
| | +--:(keystring)
| | | +--rw keystring? string
| | +--:(hexadecimal) {hex-key-string}?
| | +--rw hexadecimal-string? yang:hex-string
Lindem, et al. Expires October 31, 2017 [Page 7]
Internet-Draft YANG Key Chain April 2017
| +--ro send-lifetime-active? boolean
| +--ro accept-lifetime-active? boolean
+--rw aes-key-wrap {aes-key-wrap}?
+--rw enable? boolean
4. Key Chain YANG Model
<CODE BEGINS> file "ietf-key-chain@2017-04-18.yang"
module ietf-key-chain {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-key-chain";
prefix key-chain;
import ietf-yang-types {
prefix yang;
}
import ietf-netconf-acm {
prefix nacm;
}
organization
"IETF RTG (Routing) Working Group";
contact
"Acee Lindem - acee@cisco.com";
description
"This YANG module defines the generic configuration
data for key-chain. It is intended that the module
will be extended by vendors to define vendor-specific
key-chain configuration parameters.
Copyright (c) 2017 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision 2017-04-18 {
description
"Initial RFC Revision";
reference "RFC XXXX: A YANG Data Model for key-chain";
}
Lindem, et al. Expires October 31, 2017 [Page 8]
Internet-Draft YANG Key Chain April 2017
feature hex-key-string {
description
"Support hexadecimal key string.";
}
feature accept-tolerance {
description
"Support the tolerance or acceptance limit.";
}
feature independent-send-accept-lifetime {
description
"Support for independent send and accept key lifetimes.";
}
feature crypto-hmac-sha-1-12 {
description
"Support for TCP HMAC-SHA-1 12 byte digest hack.";
}
feature clear-text {
description
"Support for clear-text algorithm. Usage is
NOT RECOMMENDED.";
}
feature aes-cmac-prf-128 {
description
"Support for AES Cipher based Message Authentication
Code Pseudo Random Function.";
}
feature aes-key-wrap {
description
"Support for Advanced Encryption Standard (AES) Key Wrap.";
}
feature replay-protection-only {
description
"Provide replay-protection without any authentication
as required by protocols such as Bidirectional
Forwarding Detection (BFD).";
}
identity crypto-algorithm {
description
"Base identity of cryptographic algorithm options.";
}
Lindem, et al. Expires October 31, 2017 [Page 9]
Internet-Draft YANG Key Chain April 2017
identity hmac-sha-1-12 {
base crypto-algorithm;
if-feature "crypto-hmac-sha-1-12";
description
"The HMAC-SHA1-12 algorithm.";
}
identity aes-cmac-prf-128 {
base crypto-algorithm;
if-feature "aes-cmac-prf-128";
description
"The AES-CMAC-PRF-128 algorithm - required by
RFC 5926 for TCP-AO key derivation functions.";
}
identity md5 {
base crypto-algorithm;
description
"The MD5 algorithm.";
}
identity sha-1 {
base crypto-algorithm;
description
"The SHA-1 algorithm.";
}
identity hmac-sha-1 {
base crypto-algorithm;
description
"HMAC-SHA-1 authentication algorithm.";
}
identity hmac-sha-256 {
base crypto-algorithm;
description
"HMAC-SHA-256 authentication algorithm.";
}
identity hmac-sha-384 {
base crypto-algorithm;
description
"HMAC-SHA-384 authentication algorithm.";
}
identity hmac-sha-512 {
base crypto-algorithm;
description
Lindem, et al. Expires October 31, 2017 [Page 10]
Internet-Draft YANG Key Chain April 2017
"HMAC-SHA-512 authentication algorithm.";
}
identity clear-text {
base crypto-algorithm;
if-feature "clear-text";
description
"Clear text.";
}
identity replay-protection-only {
base crypto-algorithm;
if-feature "replay-protection-only";
description
"Provide replay-protection without any authentication as
required by protocols such as Bidirectional Forwarding
Detection (BFD).";
}
typedef key-chain-ref {
type leafref {
path
"/key-chain:key-chains/key-chain:key-chain/key-chain:name";
}
description
"This type is used by data models that need to reference
configured key-chains.";
}
grouping lifetime {
description
"Key lifetime specification.";
choice lifetime {
default "always";
description
"Options for specifying key accept or send lifetimes";
case always {
leaf always {
type empty;
description
"Indicates key lifetime is always valid.";
}
}
case start-end-time {
leaf start-date-time {
type yang:date-and-time;
description
"Start time.";
Lindem, et al. Expires October 31, 2017 [Page 11]
Internet-Draft YANG Key Chain April 2017
}
choice end-time {
default "infinite";
description
"End-time setting.";
case infinite {
leaf no-end-time {
type empty;
description
"Indicates key lifetime end-time is infinite.";
}
}
case duration {
leaf duration {
type uint32 {
range "1..2147483646";
}
units "seconds";
description
"Key lifetime duration, in seconds";
}
}
case end-date-time {
leaf end-date-time {
type yang:date-and-time;
description
"End time.";
}
}
}
}
}
}
grouping key-common {
description
"Key-chain key data nodes common to
configuration and state.";
}
container key-chains {
description
"All configured key-chains on the device.";
list key-chain {
key "name";
description
"List of key-chains.";
leaf name {
type string;
Lindem, et al. Expires October 31, 2017 [Page 12]
Internet-Draft YANG Key Chain April 2017
description
"Name of the key-chain.";
}
leaf description {
type string;
description
"A description of the key-chain";
}
container accept-tolerance {
if-feature "accept-tolerance";
description
"Tolerance for key lifetime acceptance (seconds).";
leaf duration {
type uint32;
units "seconds";
default "0";
description
"Tolerance range, in seconds.";
}
}
leaf last-modified-timestamp {
type yang:date-and-time;
config false;
description
"Timestamp of the most recent update to the key-chain";
}
list key {
key "key-id";
description
"Single key in key chain.";
leaf key-id {
type uint64;
description
"Numeric value uniquely identifying the key";
}
container lifetime {
description
"Specify a key's lifetime.";
choice lifetime {
description
"Options for specification of send and accept
lifetimes.";
case send-and-accept-lifetime {
description
"Send and accept key have the same lifetime.";
container send-accept-lifetime {
description
"Single lifetime specification for both
Lindem, et al. Expires October 31, 2017 [Page 13]
Internet-Draft YANG Key Chain April 2017
send and accept lifetimes.";
uses lifetime;
}
}
case independent-send-accept-lifetime {
if-feature "independent-send-accept-lifetime";
description
"Independent send and accept key lifetimes.";
container send-lifetime {
description
"Separate lifetime specification for send
lifetime.";
uses lifetime;
}
container accept-lifetime {
description
"Separate lifetime specification for accept
lifetime.";
uses lifetime;
}
}
}
}
leaf crypto-algorithm {
type identityref {
base crypto-algorithm;
}
mandatory true;
description
"Cryptographic algorithm associated with key.";
}
container key-string {
description
"The key string.";
nacm:default-deny-all;
choice key-string-style {
description
"Key string styles";
case keystring {
leaf keystring {
type string;
description
"Key string in ASCII format.";
}
}
case hexadecimal {
if-feature "hex-key-string";
leaf hexadecimal-string {
Lindem, et al. Expires October 31, 2017 [Page 14]
Internet-Draft YANG Key Chain April 2017
type yang:hex-string;
description
"Key in hexadecimal string format. When compared
to ASCII, specification in hexadecimal affords
greater key entropy with the same number of
internal key-string octets. Additionally, it
discourages usage of well-known words or
numbers.";
}
}
}
}
leaf send-lifetime-active {
type boolean;
config false;
description
"Indicates if the send lifetime of the
key-chain key is currently active.";
}
leaf accept-lifetime-active {
type boolean;
config false;
description
"Indicates if the accept lifetime of the
key-chain key is currently active.";
}
}
}
container aes-key-wrap {
if-feature "aes-key-wrap";
description
"AES Key Wrap encryption for key-chain key-strings. The
encrypted key-strings are encoded as hexadecimal key
strings using the hex-key-string leaf.";
leaf enable {
type boolean;
default "false";
description
"Enable AES Key Wrap encryption.";
}
}
}
}
<CODE ENDS>
Lindem, et al. Expires October 31, 2017 [Page 15]
Internet-Draft YANG Key Chain April 2017
5. Security Considerations
The YANG module defined in this document is designed to be accessed
via network management protocols such as NETCONF [NETCONF] or
RESTCONF [RESTCONF]. The lowest NETCONF layer is the secure
transport layer, and the mandatory-to-implement secure transport is
Secure Shell (SSH) [NETCONF-SSH]. The lowest RESTCONF layer is
HTTPS, and the mandatory-to-implement secure transport is TLS [TLS].
The NETCONF access control model [NETCONF-ACM] provides the means to
restrict access for particular NETCONF or RESTCONF users to a pre-
configured subset of all available NETCONF or RESTCONF protocol
operations and content. The key strings are not accessible by
default and NETCONF Access Control Mode [NETCONF-ACM] rules are
required to configure or retrieve them.
When configured, the key-strings can be encrypted using the AES Key
Wrap algorithm [AES-KEY-WRAP]. The AES key-encryption key (KEK) is
not included in the YANG model and must be set or derived independent
of key-chain configuration. When AES key-encryption is used, the
hex-key-string feature is also required since the encrypted keys will
contain characters that are not representable in the YANG string
built-in type [YANG-1.1]. It is RECOMMENDED that key-strings be
encrypted using AES key-encryption to prevent key-chains from being
retrieved and stored with the key-strings in clear text. This
recommendation is independent of the access protection that is
availed from the NETCONF Access Control Model (NACM) [NETCONF-ACM].
The clear-text algorithm is included as a YANG feature. Usage is NOT
RECOMMENDED except in cases where the application and device have no
other alternative (e.g., a legacy network device that must
authenticate packets at intervals of 10 milliseconds or less for many
peers using Bidirectional Forwarding Detection [BFD]). Keys used
with the clear-text algorithm are considered insecure and SHOULD NOT
be reused with more secure algorithms.
Similarly, the MD5 and SHA-1 algorithms have been proven to be
insecure ([Dobb96a], [Dobb96b], and [SHA-SEC-CON]) and usage is NOT
RECOMMENDED. Usage should be confined to deployments where it is
required for backward compatibility.
Implementations with keys provided via this model should store them
using best current security practices.
Lindem, et al. Expires October 31, 2017 [Page 16]
Internet-Draft YANG Key Chain April 2017
6. IANA Considerations
This document registers a URI in the IETF XML registry
[XML-REGISTRY]. Following the format in [XML-REGISTRY], the
following registration is requested to be made:
URI: urn:ietf:params:xml:ns:yang:ietf-key-chain
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace.
This document registers a YANG module in the YANG Module Names
registry [YANG-1.0].
name: ietf-key-chain
namespace: urn:ietf:params:xml:ns:yang:ietf-key-chain
prefix: key-chain
reference: RFC XXXX
7. Contributors
Contributors' Addresses
Yi Yang
SockRate
Email: yi.yang@sockrate.com
8. References
8.1. Normative References
[NETCONF] Enns, R., Bjorklund, M., Schoenwaelder, J., and A.
Bierman, "Network Configuration Protocol (NETCONF)", RFC
6241, June 2011.
[NETCONF-ACM]
Bierman, A. and M. Bjorklund, "Network Configuration
Protocol (NETCONF) Access Control Model", RFC 6536, March
2012.
[RFC-KEYWORDS]
Bradner, S., "Key words for use in RFC's to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[XML-REGISTRY]
Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004.
Lindem, et al. Expires October 31, 2017 [Page 17]
Internet-Draft YANG Key Chain April 2017
[YANG-1.0]
Bjorklund, M., "YANG - A Data Modeling Language for
Network Configuration Protocol (NETCONF)", RFC 6020,
October 2010.
[YANG-1.1]
Bjorklund, M., "The YANG 1.1 Data Modeling Language", RFC
7950, August 2016.
8.2. Informative References
[AES-KEY-WRAP]
Schaad, J. and R. Housley, "Advanced Encryption Standard
(AES) Key Wrap Algorithm", RFC 5649, August 2009.
[BFD] Katz, D. and D. Ward, "Bidirectional Forwarding Detection
(BFD)", RFC 5880, June 2010.
[CRYPTO-KEYTABLE]
Housley, R., Polk, T., Hartman, S., and D. Zhang,
"Table of Cryptographic Keys", RFC 7210, April 2014.
[Dobb96a] Dobbertin, H., "Cryptanalysis of MD5 Compress", Technical
Report (Presented at the RUMP Session of EuroCrypt 1996),
2 May 1996.
[Dobb96b] Dobbertin, H., "The Status of MD5 After a Recent Attack",
CryptoBytes Vol. 2, No. 2, Summer 1996.
[IAB-REPORT]
Andersson, L., Davies, E., and L. Zhang, "Report from the
IAB workshop on Unwanted Traffic March 9-10, 2006", RFC
4948, August 2007.
[NETCONF-SSH]
Wasserman, M., "NETCONF over SSH", RFC 6242, June 2011.
[NMDA] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watson, K.,
and R. Wilton, "Network Management Datastore
Architecture", draft-ietf-netmod-revised-datastores-01.txt
(work in progress), March 2017.
[NTP-PROTO]
Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network
Time Protocol Version 4: Protocol and Algorithms
Specification", RFC 5905, June 2010.
Lindem, et al. Expires October 31, 2017 [Page 18]
Internet-Draft YANG Key Chain April 2017
[OSPFV3-AUTH]
Bhatia, M., Manral, V., and A. Lindem, "Supporting
Authentication Trailer for OSPFv3", RFC 7166, March 2014.
[RESTCONF]
Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, January 2017.
[SHA-SEC-CON]
Polk, T., Chen, L., Turner, S., and P. Hoffman, "Security
Considerations for the SHA-0 and SHA-1 Message-Digest
Algorithms", RFC 6194, February 2011.
[TCP-AO] Touch, J., Mankin, A., and R. Bonica, "The TCP
Authentication Option", RFC 5925, June 2010.
[TCP-AO-ALGORITHMS]
Lebovitz, G. and E. Rescorla, "Cryptographic Algorithms
for the TCP Authentication Option (TCP-AO)", RFC 5926,
June 2010.
[TLS] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol", RFC 5246, August 2008.
[YANG-CRYPTO-KEYTABLE]
Chen, I., "YANG Data Model for RFC 7210 Key Table", draft-
chen-rtg-key-table-yang-00.txt (work in progress),
November 2015.
Appendix A. Examples
A.1. Simple Key Chain with Always Valid Single Key
Lindem, et al. Expires October 31, 2017 [Page 19]
Internet-Draft YANG Key Chain April 2017
<?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<key-chains xmlns="urn:ietf:params:xml:ns:yang:ietf-key-chain">
<key-chain>
<name>keychain-no-end-time</name>
<description>
A key chain with a single key that is always valid for
transmission and reception.
</description>
<key>
<key-id>100</key-id>
<lifetime>
<send-accept-lifetime>
<always/>
</send-accept-lifetime>
</lifetime>
<crypto-algorithm>hmac-sha-256</crypto-algorithm>
<key-string>
<keystring>keystring_in_ascii_100</keystring>
</key-string>
</key>
</key-chain>
</key-chains>
</data>
A.2. Key Chain with Keys having Different Lifetimes
Lindem, et al. Expires October 31, 2017 [Page 20]
Internet-Draft YANG Key Chain April 2017
<?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<key-chains xmlns="urn:ietf:params:xml:ns:yang:ietf-key-chain">
<key-chain>
<name>keychain2</name>
<description>
A key chain where each key contains different send time
and accept time and a different algorithm illustrating
algorithm agility.
</description>
<key>
<key-id>35</key-id>
<lifetime>
<send-lifetime>
<start-date-time>2017-01-01T00:00:00Z</start-date-time>
<end-date-time>2017-02-01T00:00:00Z</end-date-time>
</send-lifetime>
<accept-lifetime>
<start-date-time>2016-12-31T23:59:55Z</start-date-time>
<end-date-time>2017-02-01T00:00:05Z</end-date-time>
</accept-lifetime>
</lifetime>
<crypto-algorithm>hmac-sha-256</crypto-algorithm>
<key-string>
<keystring>keystring_in_ascii_35</keystring>
</key-string>
</key>
<key>
<key-id>36</key-id>
<lifetime>
<send-lifetime>
<start-date-time>2017-02-01T00:00:00Z</start-date-time>
<end-date-time>2017-03-01T00:00:00Z</end-date-time>
</send-lifetime>
<accept-lifetime>
<start-date-time>2017-01-31T23:59:55Z</start-date-time>
<end-date-time>2017-03-01T00:00:05Z</end-date-time>
</accept-lifetime>
</lifetime>
<crypto-algorithm>hmac-sha-512</crypto-algorithm>
<key-string>
<hexadecimal-string>fe:ed:be:af:36</hexadecimal-string>
</key-string>
</key>
</key-chain>
</key-chains>
</data>
Lindem, et al. Expires October 31, 2017 [Page 21]
Internet-Draft YANG Key Chain April 2017
A.3. Key Chain with Independent Send and Accept Lifetimes
<?xml version="1.0" encoding="utf-8"?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<key-chains xmlns="urn:ietf:params:xml:ns:yang:ietf-key-chain">
<key-chain>
<name>keychain2</name>
<description>
A key chain where each key contains different send time
and accept times.
</description>
<key>
<key-id>35</key-id>
<lifetime>
<send-lifetime>
<start-date-time>2017-01-01T00:00:00Z</start-date-time>
<end-date-time>2017-02-01T00:00:00Z</end-date-time>
</send-lifetime>
<accept-lifetime>
<start-date-time>2016-12-31T23:59:55Z</start-date-time>
<end-date-time>2017-02-01T00:00:05Z</end-date-time>
</accept-lifetime>
</lifetime>
<crypto-algorithm>hmac-sha-256</crypto-algorithm>
<key-string>
<keystring>keystring_in_ascii_35</keystring>
</key-string>
</key>
<key>
<key-id>36</key-id>
<lifetime>
<send-lifetime>
<start-date-time>2017-02-01T00:00:00Z</start-date-time>
<end-date-time>2017-03-01T00:00:00Z</end-date-time>
</send-lifetime>
<accept-lifetime>
<start-date-time>2017-01-31T23:59:55Z</start-date-time>
<end-date-time>2017-03-01T00:00:05Z</end-date-time>
</accept-lifetime>
</lifetime>
<crypto-algorithm>hmac-sha-256</crypto-algorithm>
<key-string>
<hexadecimal-string>fe:ed:be:af:36</hexadecimal-string>
</key-string>
</key>
</key-chain>
</key-chains>
</data>
Lindem, et al. Expires October 31, 2017 [Page 22]
Internet-Draft YANG Key Chain April 2017
Appendix B. Acknowledgments
The RFC text was produced using Marshall Rose's xml2rfc tool.
Thanks to Brian Weis for fruitful discussions on security
requirements.
Thanks to Ines Robles for Routing Directorate QA review comments.
Thanks to Ladislav Lhotka for YANG Doctor comments.
Thanks to Martin Bjorklund for additional YANG Doctor comments.
Thanks to Tom Petch for comments during IETF last call.
Thanks to Matthew Miller for comments made during the Gen-ART review.
Thanks to Vincent Roca for comments made during the Security
Directorate review.
Thanks to Warren Kumari, Ben Campbell, Adam Roach, and Benoit Claise
for comments received during the IESG review.
Authors' Addresses
Acee Lindem (editor)
Cisco Systems
301 Midenhall Way
Cary, NC 27513
USA
Email: acee@cisco.com
Yingzhen Qu
Huawei
Email: yingzhen.qu@huawei.com
Derek Yeung
Arrcus, Inc
Email: derek@arrcus.com
Lindem, et al. Expires October 31, 2017 [Page 23]
Internet-Draft YANG Key Chain April 2017
Ing-Wher Chen
Jabil
Email: ing-wher_chen@jabil.com
Jeffrey Zhang
Juniper Networks
10 Technology Park Drive
Westford, MA 01886
USA
Email: zzhang@juniper.net
Lindem, et al. Expires October 31, 2017 [Page 24]
