Network Working Group A. Lindem, Ed.
Internet-Draft Cisco Systems
Intended status: Standards Track Y. Qu
Expires: July 23, 2017 Huawei
D. Yeung
Arrcus, Inc
I. Chen
Ericsson
J. Zhang
Juniper Networks
Y. Yang
SockRate
January 19, 2017
Routing Key Chain YANG Data Model
draft-ietf-rtgwg-yang-key-chain-13.txt
Abstract
This document describes the key chain YANG data model. A key chain
is a list of elements each containing a key, send lifetime, accept
lifetime, and algorithm (authentication or encryption). By properly
overlapping the send and accept lifetimes of multiple key chain
elements, keys and algorithms may be gracefully updated. By
representing them in a YANG data model, key distribution can be
automated. Key chains are commonly used for routing protocol
authentication and other applications. 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 the TCP
Authentication Option.
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."
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This Internet-Draft will expire on July 23, 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 . . . . . . . . . . . . . . . 5
3.2. Key Chain Model Features . . . . . . . . . . . . . . . . 6
3.3. Key Chain Model Tree . . . . . . . . . . . . . . . . . . 6
4. Key Chain YANG Model . . . . . . . . . . . . . . . . . . . . 10
5. Security Considerations . . . . . . . . . . . . . . . . . . . 20
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 21
7.1. Normative References . . . . . . . . . . . . . . . . . . 21
7.2. Informative References . . . . . . . . . . . . . . . . . 22
Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23
1. Introduction
This document describes the key chain YANG data model. A key chain
is a list of elements each containing a key, send lifetime, accept
lifetime, and algorithm (authentication or encryption). By properly
overlapping the send and accept lifetimes of multiple key chain
elements, keys and algorithms may be gracefully updated. By
representing them in a YANG data model, key distribution can be
automated. Key chains are commonly used for routing protocol
authentication and other applications. In some applications, the
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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", "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 list 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] 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
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, 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. In essence, the
key-chain is a reusable key policy that can be referenced where ever
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it is required. The key-chain construct has been implemented by most
networking vendors and deployed in many networks.
The module name was change from ietf-key-chain to ietf-routing-key-
chain to avoid disambiguate it from the ietf-system-keychain module
defined in [NETCONF-SERVER-CONF]. However, due to popular demand,
the module name has been restored to simply ietf-key-chain.
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 facilate 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 and/or algorithm
used by an application for authentication or encryption. This MAY be
accomplished by accepting all the keys that have a valid accept
lifetime and sending 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.
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
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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 start sending the new
key.
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).
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 entry to be used. In
addition to the Key-ID, each key chain entry includes a key-string
and a cryptographic algorithm. Optionally, the key chain entries
include send/accept lifetimes. If the send/accept lifetime is
unspecified, the key is always considered valid.
Note that asymmetric keys, i.e., a different key value used for
transmission versus acceptance, may be supported with multiple key
chain elements where the accept-lifetime or send-lifetime is not
valid (e.g., has an end-time equal to the start-time).
Due to the differences in key chain implementations across various
vendors, some of the data elements are optional. Additionally, the
key-chain is made a grouping so that an implementation could support
scoping other than at the global level. Finally, the crypto-
algorithm-types grouping is provided for reuse when configuring
legacy authentication and encryption not using key-chains.
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 maintained in a separate tree.
The key string itself is omitted from the operational state to
minimize visibility similar to what was done with keys in SNMP MIBs.
The timestamp of the last key-chain modification is also maintained
in the operational state. Additionally, the operational state
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includes an indication of whether or not a key chain entry 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
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 implemented by
vendors or only a single vendor.
3.3. Key Chain Model Tree
+--rw key-chain
| +--rw key-chain-list* [name]
| | +--rw name string
| | +--rw description? string
| | +--rw accept-tolerance {accept-tolerance}?
| | | +--rw duration? uint32
| | +--rw key-chain-entries* [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?
| | | | | 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?
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| | | | 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
| | | +--rw (algorithm)?
| | | +--:(hmac-sha-1-12) {crypto-hmac-sha-1-12}?
| | | | +--rw hmac-sha1-12? empty
| | | +--:(aes-cmac-prf-128) {aes-cmac-prf-128}?
| | | | +--rw aes-cmac-prf-128? empty
| | | +--:(md5)
| | | | +--rw md5? empty
| | | +--:(sha-1)
| | | | +--rw sha-1? empty
| | | +--:(hmac-sha-1)
| | | | +--rw hmac-sha-1? empty
| | | +--:(hmac-sha-256)
| | | | +--rw hmac-sha-256? empty
| | | +--:(hmac-sha-384)
| | | | +--rw hmac-sha-384? empty
| | | +--:(hmac-sha-512)
| | | | +--rw hmac-sha-512? empty
| | | +--:(clear-text) {clear-text}?
| | | | +--rw clear-text? empty
| | | +--:(replay-protection-only)
| | | {replay-protection-only}?
| | | +--rw replay-protection-only? empty
| | +--rw key-string
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| | +--rw (key-string-style)?
| | +--:(keystring)
| | | +--rw keystring? string
| | +--:(hexadecimal) {hex-key-string}?
| | +--rw hexadecimal-string? yang:hex-string
| +--rw aes-key-wrap {aes-key-wrap}?
| +--rw enable? boolean
+--ro key-chain-state
+--ro key-chain-list* [name]
| +--ro name string
| +--ro description? string
| +--ro accept-tolerance {accept-tolerance}?
| | +--ro duration? uint32
| +--ro last-modified-timestamp? yang:date-and-time
| +--ro key-chain-entries* [key-id]
| +--ro key-id uint64
| +--ro lifetime
| | +--ro (lifetime)?
| | +--:(send-and-accept-lifetime)
| | | +--ro send-accept-lifetime
| | | +--ro (lifetime)?
| | | +--:(always)
| | | | +--ro always? empty
| | | +--:(start-end-time)
| | | +--ro start-date-time?
| | | yang:date-and-time
| | | +--ro (end-time)?
| | | +--:(infinite)
| | | | +--ro no-end-time? empty
| | | +--:(duration)
| | | | +--ro duration? uint32
| | | +--:(end-date-time)
| | | +--ro end-date-time?
| | | yang:date-and-time
| | +--:(independent-send-accept-lifetime)
| | | {independent-send-accept-lifetime}?
| | +--ro send-lifetime
| | | +--ro (lifetime)?
| | | +--:(always)
| | | | +--ro always? empty
| | | +--:(start-end-time)
| | | +--ro start-date-time?
| | | yang:date-and-time
| | | +--ro (end-time)?
| | | +--:(infinite)
| | | | +--ro no-end-time? empty
| | | +--:(duration)
| | | | +--ro duration? uint32
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| | | +--:(end-date-time)
| | | +--ro end-date-time?
| | | yang:date-and-time
| | +--ro accept-lifetime
| | +--ro (lifetime)?
| | +--:(always)
| | | +--ro always? empty
| | +--:(start-end-time)
| | +--ro start-date-time? yang:date-and-time
| | +--ro (end-time)?
| | +--:(infinite)
| | | +--ro no-end-time? empty
| | +--:(duration)
| | | +--ro duration? uint32
| | +--:(end-date-time)
| | +--ro end-date-time?
| | yang:date-and-time
| +--ro crypto-algorithm
| | +--ro (algorithm)?
| | +--:(hmac-sha-1-12) {crypto-hmac-sha-1-12}?
| | | +--ro hmac-sha1-12? empty
| | +--:(aes-cmac-prf-128) {aes-cmac-prf-128}?
| | | +--ro aes-cmac-prf-128? empty
| | +--:(md5)
| | | +--ro md5? empty
| | +--:(sha-1)
| | | +--ro sha-1? empty
| | +--:(hmac-sha-1)
| | | +--ro hmac-sha-1? empty
| | +--:(hmac-sha-256)
| | | +--ro hmac-sha-256? empty
| | +--:(hmac-sha-384)
| | | +--ro hmac-sha-384? empty
| | +--:(hmac-sha-512)
| | | +--ro hmac-sha-512? empty
| | +--:(clear-text) {clear-text}?
| | | +--ro clear-text? empty
| | +--:(replay-protection-only)
| | | {replay-protection-only}?
| | +--ro replay-protection-only? empty
| +--ro key-string
| +--ro (key-string-style)?
| +--:(keystring)
| | +--ro keystring? string
| +--:(hexadecimal) {hex-key-string}?
| +--ro hexadecimal-string? yang:hex-string
| +--ro send-lifetime-active? boolean
| +--ro accept-lifetime-active? boolean
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+--ro aes-key-wrap {aes-key-wrap}?
+--ro enable? boolean
4. Key Chain YANG Model
<CODE BEGINS> file "ietf-key-chain@2017-01-20.yang"
module ietf-key-chain {
namespace "urn:ietf:params:xml:ns:yang:ietf-key-chain";
// replace with IANA namespace when assigned
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) 2015 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 2017-01-20 {
description
"Add support of using NETCONF Access Control for
key-string.";
reference
"RFC XXXX: A YANG Data Model for key-chain";
}
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revision 2016-11-14 {
description
"Restore last-modified timestamp leaf.";
reference
"RFC XXXX: A YANG Data Model for key-chain";
}
revision 2016-10-27 {
description
"Restructure into separate config and state trees to
match YANG structure.";
reference
"RFC XXXX: A YANG Data Model for key-chain";
}
revision 2016-08-17 {
description
"Add description and last-modified timestamp leaves.";
reference
"RFC XXXX: A YANG Data Model for key-chain";
}
revision 2016-07-01 {
description
"Rename module back to ietf-key-chain.
Added replay-protection-only feature and algorithm.";
reference
"RFC XXXX: A YANG Data Model for key-chain";
}
revision 2016-03-15 {
description
"Rename module from ietf-key-chain to
ietf-routing-key-chain.";
reference
"RFC XXXX: A YANG Data Model for Routing key-chain";
}
revision 2016-02-16 {
description
"Updated version. Added clear-text algorithm as a
feature.";
reference
"RFC XXXX: A YANG Data Model for key-chain";
}
revision 2015-10-15 {
description
"Updated version, organization, and copyright.
Added aes-cmac-prf-128 and aes-key-wrap features.";
reference
"RFC XXXX: A YANG Data Model for key-chain";
}
revision 2015-06-29 {
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description
"Updated version. Added Operation State following
draft-openconfig-netmod-opstate-00.";
reference
"RFC XXXX: A YANG Data Model for key-chain";
}
revision 2015-02-24 {
description
"Initial revision.";
reference
"RFC XXXX: A YANG Data Model for key-chain";
}
typedef key-chain-ref {
type leafref {
path "/key-chain:key-chain/key-chain:key-chain-list/"
+ "key-chain:name";
}
description
"This type is used by data models that need to reference
configured key-chains.";
}
/* feature list */
feature hex-key-string {
description
"Support hexadecimal key string.";
}
feature accept-tolerance {
description
"To specify 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.";
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}
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).";
}
/* groupings */
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.";
}
choice end-time {
default infinite;
description
"End-time setting.";
case infinite {
leaf no-end-time {
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type empty;
description
"Indicates key lifetime end-time in
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 crypto-algorithm-types {
description "Cryptographic algorithm types.";
choice algorithm {
description
"Options for cryptographic algorithm specification.";
case hmac-sha-1-12 {
if-feature crypto-hmac-sha-1-12;
leaf hmac-sha1-12 {
type empty;
description "The HMAC-SHA1-12 algorithm.";
}
}
case aes-cmac-prf-128 {
if-feature aes-cmac-prf-128;
leaf aes-cmac-prf-128 {
type empty;
description "The AES-CMAC-PRF-128 algorithm -
required by RFC 5926 for TCP-AO key
derivation functions.";
}
}
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case md5 {
leaf md5 {
type empty;
description "The MD5 algorithm.";
}
}
case sha-1 {
leaf sha-1 {
type empty;
description "The SHA-1 algorithm.";
}
}
case hmac-sha-1 {
leaf hmac-sha-1 {
type empty;
description
"HMAC-SHA-1 authentication algorithm.";
}
}
case hmac-sha-256 {
leaf hmac-sha-256 {
type empty;
description
"HMAC-SHA-256 authentication algorithm.";
}
}
case hmac-sha-384 {
leaf hmac-sha-384 {
type empty;
description
"HMAC-SHA-384 authentication algorithm.";
}
}
case hmac-sha-512 {
leaf hmac-sha-512 {
type empty;
description
"HMAC-SHA-512 authentication algorithm.";
}
}
case clear-text {
if-feature clear-text;
leaf clear-text {
type empty;
description "Clear text.";
}
}
case replay-protection-only {
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if-feature replay-protection-only;
leaf replay-protection-only {
type empty;
description
"Provide replay-protection without any
authentication as required by protocols
such as Bidirectional Forwarding
Detection (BFD).";
}
}
}
}
grouping key-chain-common-entry {
description "Key-chain entry data nodes common to
configuration and state.";
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 {
uses lifetime;
description
"Single lifetime specification for both
send and accept lifetimes.";
}
}
case independent-send-accept-lifetime {
if-feature independent-send-accept-lifetime;
description
"Independent send and accept key lifetimes.";
container send-lifetime {
uses lifetime;
description
"Separate lifetime specification for send
lifetime.";
}
container accept-lifetime {
uses lifetime;
description
"Separate lifetime specification for
accept lifetime.";
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}
}
}
}
container crypto-algorithm {
uses crypto-algorithm-types;
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 {
type yang:hex-string;
description
"Key in hexadecimal string format.";
}
}
}
}
}
grouping key-chain-config-entry {
description "Key-chain configuration entry.";
uses key-chain-common-entry;
}
grouping key-chain-state-entry {
description "Key-chain state entry.";
uses key-chain-common-entry;
leaf send-lifetime-active {
type boolean;
config false;
description
"Indicates if the send lifetime of the
key-chain entry is currently active.";
}
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leaf accept-lifetime-active {
type boolean;
config false;
description
"Indicates if the accept lifetime of the
key-chain entry is currently active.";
}
}
grouping key-chain-common {
description
"key-chain common grouping.";
leaf name {
type string;
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.";
}
}
}
grouping key-chain-config {
description
"key-chain configuration grouping.";
uses key-chain-common;
list key-chain-entries {
key "key-id";
description "One key.";
leaf key-id {
type uint64;
description "Key ID.";
}
uses key-chain-config-entry;
}
}
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grouping key-chain-state {
description
"key-chain state grouping.";
uses key-chain-common;
leaf last-modified-timestamp {
type yang:date-and-time;
description "Timestamp of the most recent update
to the key-chain";
}
list key-chain-entries {
key "key-id";
description "One key.";
leaf key-id {
type uint64;
description "Key ID.";
}
uses key-chain-state-entry;
}
}
container key-chain {
list key-chain-list {
key "name";
description
"List of key-chains.";
uses key-chain-config;
}
container aes-key-wrap {
if-feature aes-key-wrap;
description
"AES Key Wrap password encryption.";
leaf enable {
type boolean;
default false;
description
"Enable AES Key Wrap encryption.";
}
}
description "All configured key-chains
on the device.";
}
container key-chain-state {
config false;
list key-chain-list {
key "name";
description
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"List of key-chains and operational state.";
uses key-chain-state;
}
container aes-key-wrap {
if-feature aes-key-wrap;
description
"AES Key Wrap password encryption.";
leaf enable {
type boolean;
description
"Indicates whether AES Key Wrap encryption
is enabled.";
}
}
description "State for all configured key-chains
on the device.";
}
}
<CODE ENDS>
5. Security Considerations
This document enables the automated distribution of industry standard
key chains using the NETCONF [NETCONF] protocol. As such, the
security considerations for the NETCONF protocol are applicable.
Given that the key chains themselves are sensitive data, it is
RECOMMENDED that the NETCONF communication channel be encrypted. One
way to do accomplish this would be to invoke and run NETCONF over SSH
as described in [NETCONF-SSH].
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.
The key strings are not accessible by default and NETCONF Access
Control Mode [NETCONF-ACM] rules are required to configure or
retrieve them.
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.
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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].
name: ietf-key-chain namespace: urn:ietf:params:xml:ns:yang:ietf-
key-chain prefix: ietf-key-chain reference: RFC XXXX
7. References
7.1. 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.
[NETCONF-SSH]
Wasserman, M., "Using NETCONF Protocol over Secure Shell
(SSH)", RFC 6242, June 2011.
[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.
[YANG] Bjorklund, M., "YANG - A Data Modeling Language for the
Network Configuration Protocol (NETCONF)", RFC 6020,
October 2010.
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7.2. Informative References
[AES-KEY-WRAP]
Housley, R. and M. Dworkin, "Advanced Encryption Standard
(AES) Key Wrap with Padding 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.
[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-SERVER-CONF]
Watsen, K. and J. Schoenwaelder, "NETCONF Server and
RESTCONF Server Configuration Models", draft-ietf-netconf-
server-model-08.txt (work in progress), October 2015.
[NTP-PROTO]
Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network
Time Protocol Version 4: Protocol and Algorithms
Specification", RFC 5905, June 2010.
[OSPFV3-AUTH]
Bhatia, M., Manral, V., and A. Lindem, "Supporting
Authentication Trailer for OSPFv3", RFC 7166, March 2014.
[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.
[YANG-CRYPTO-KEYTABLE]
Chen, I., "YANG Data Model for RFC 7210 Key Table", draft-
chen-rtg-key-table-yang-02.txt (work in progress),
November 2015.
Appendix A. Acknowledgments
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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.
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
Ing-Wher Chen
Ericsson
Email: ichen@kuatrotech.com
Jeffrey Zhang
Juniper Networks
10 Technology Park Drive
Westford, MA 01886
USA
Email: zzhang@juniper.net
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Yi Yang
SockRate
Email: yi.yang@sockrate.com
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