| NETCONF Working Group | K. Watsen |
| Internet-Draft | Watsen Networks |
| Intended status: Standards Track | G. Wu |
| Expires: September 9, 2020 | Cisco Systems |
| L. Xia | |
| Huawei | |
| March 8, 2020 |
YANG Groupings for TLS Clients and TLS Servers
draft-ietf-netconf-tls-client-server-18
This document defines three YANG modules: the first defines groupings for a generic TLS client, the second defines groupings for a generic TLS server, and the third defines common identities and groupings used by both the client and the server. It is intended that these groupings will be used by applications using the TLS protocol.
This draft contains many placeholder values that need to be replaced with finalized values at the time of publication. This note summarizes all of the substitutions that are needed. No other RFC Editor instructions are specified elsewhere in this document.
This document contains references to other drafts in progress, both in the Normative References section, as well as in body text throughout. Please update the following references to reflect their final RFC assignments:
Artwork in this document contains shorthand references to drafts in progress. Please apply the following replacements:
Artwork in this document contains placeholder values for the date of publication of this draft. Please apply the following replacement:
The following Appendix section is to be removed prior to publication:
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 https://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 September 9, 2020.
Copyright (c) 2020 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 (https://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.
This document defines three YANG 1.1 [RFC7950] modules: the first defines a grouping for a generic TLS client, the second defines a grouping for a generic TLS server, and the third defines identities and groupings common to both the client and the server (TLS is defined in [RFC5246]). It is intended that these groupings will be used by applications using the TLS protocol. For instance, these groupings could be used to help define the data model for an HTTPS [RFC2818] server or a NETCONF over TLS [RFC7589] based server.
The client and server YANG modules in this document each define one grouping, which is focused on just TLS-specific configuration, and specifically avoids any transport-level configuration, such as what ports to listen-on or connect-to. This affords applications the opportunity to define their own strategy for how the underlying TCP connection is established. For instance, applications supporting NETCONF Call Home [RFC8071] could use the "ssh-server-grouping" grouping for the TLS parts it provides, while adding data nodes for the TCP-level call-home configuration.
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 BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
This section provides a tree diagram [RFC8340] for the "ietf-tls-client" module that does not have groupings expanded.
========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) ===========
module: ietf-tls-client
grouping tls-client-grouping
+-- client-identity
| +-- (auth-type)?
| +--:(certificate) {x509-certificate-auth}?
| | +-- certificate
| | +---u ks:local-or-keystore-end-entity-cert-with-key-\
grouping
| +--:(raw-public-key) {raw-public-key-auth}?
| | +-- raw-private-key
| | +---u ks:local-or-keystore-asymmetric-key-grouping
| +--:(psk) {psk-auth}?
| +-- psk
| +---u ks:local-or-keystore-symmetric-key-grouping
+-- server-authentication
| +-- ca-certs! {x509-certificate-auth}?
| | +---u ts:local-or-truststore-certs-grouping
| +-- server-certs! {x509-certificate-auth}?
| | +---u ts:local-or-truststore-certs-grouping
| +-- raw-public-keys! {raw-public-key-auth}?
| | +---u ts:local-or-truststore-public-keys-grouping
| +-- psks! {psk-auth}?
+-- hello-params {tls-client-hello-params-config}?
| +---u tlscmn:hello-params-grouping
+-- keepalives! {tls-client-keepalives}?
+-- max-wait? uint16
+-- max-attempts? uint8
This section presents two examples showing the tls-client-grouping populated with some data. These examples are effectively the same except the first configures the client identity using a local key while the second uses a key configured in a keystore. Both examples are consistent with the examples presented in Section 2 of [I-D.ietf-netconf-trust-anchors] and Section 3.2 of [I-D.ietf-netconf-keystore].
========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) ===========
<tls-client
xmlns="urn:ietf:params:xml:ns:yang:ietf-tls-client"
xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
<!-- how this client will authenticate itself to the server -->
<client-identity>
<certificate>
<local-definition>
<algorithm>rsa2048</algorithm>
<public-key-format>ct:subject-public-key-info-format</public\
-key-format>
<public-key>base64encodedvalue==</public-key>
<private-key-format>ct:rsa-private-key-format</private-key-f\
ormat>
<private-key>base64encodedvalue==</private-key>
<cert>base64encodedvalue==</cert>
</local-definition>
</certificate>
<!-- TESTED, BUT COMMENTED OUT DUE TO ONLY ONE ALLOWED AT A TIME
<raw-private-key>
<local-definition>
<algorithm>rsa2048</algorithm>
<public-key-format>ct:subject-public-key-info-format</public\
-key-format>
<public-key>base64encodedvalue==</public-key>
<private-key-format>ct:rsa-private-key-format</private-key-f\
ormat>
<private-key>base64encodedvalue==</private-key>
</local-definition>
</raw-private-key>
<psk>
<local-definition>
<algorithm>aes-256-cbc</algorithm>
<key-format>ct:octet-string-key-format</key-format>
<key>base64encodedvalue==</key>
</local-definition>
</psk>
-->
</client-identity>
<!-- which certificates will this client trust -->
<server-authentication>
<ca-certs>
<local-definition>
<cert>base64encodedvalue==</cert>
<cert>base64encodedvalue==</cert>
<cert>base64encodedvalue==</cert>
</local-definition>
</ca-certs>
<server-certs>
<local-definition>
<cert>base64encodedvalue==</cert>
<cert>base64encodedvalue==</cert>
<cert>base64encodedvalue==</cert>
</local-definition>
</server-certs>
<raw-public-keys>
<local-definition>
<public-key>
<name>corp-fw1</name>
<algorithm>secp256r1</algorithm>
<public-key-format>ct:subject-public-key-info-format</publ\
ic-key-format>
<public-key>base64encodedvalue==</public-key>
</public-key>
<public-key>
<name>corp-fw1</name>
<algorithm>secp256r1</algorithm>
<public-key-format>ct:subject-public-key-info-format</publ\
ic-key-format>
<public-key>base64encodedvalue==</public-key>
</public-key>
</local-definition>
</raw-public-keys>
<psks/>
</server-authentication>
<keepalives>
<max-wait>30</max-wait>
<max-attempts>3</max-attempts>
</keepalives>
</tls-client>
The following example configures the client identity using a local key:
========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) ===========
<tls-client xmlns="urn:ietf:params:xml:ns:yang:ietf-tls-client">
<!-- how this client will authenticate itself to the server -->
<client-identity>
<certificate>
<keystore-reference>
<asymmetric-key>rsa-asymmetric-key</asymmetric-key>
<certificate>ex-rsa-cert</certificate>
</keystore-reference>
</certificate>
<!-- TESTED, BUT COMMENTED OUT DUE TO ONLY ONE ALLOWED AT A TIME
<raw-private-key>
<keystore-reference>raw-private-key</keystore-reference>
</raw-private-key>
<psk>
<keystore-reference>encrypted-symmetric-key</keystore-referenc\
e>
</psk>
-->
</client-identity>
<!-- which certificates will this client trust -->
<server-authentication>
<ca-certs>
<truststore-reference>trusted-server-ca-certs</truststore-refe\
rence>
</ca-certs>
<server-certs>
<truststore-reference>trusted-server-ee-certs</truststore-refe\
rence>
</server-certs>
<raw-public-keys>
<truststore-reference>Raw Public Keys for Servers</truststore-\
reference>
</raw-public-keys>
<psks/>
</server-authentication>
<keepalives>
<max-wait>30</max-wait>
<max-attempts>3</max-attempts>
</keepalives>
</tls-client>
The following example configures the client identity using a key from the keystore:
This YANG module has normative references to [I-D.ietf-netconf-trust-anchors] and [I-D.ietf-netconf-keystore].
<CODE BEGINS> file "ietf-tls-client@2020-03-08.yang"
module ietf-tls-client {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-tls-client";
prefix tlsc;
import ietf-tls-common {
prefix tlscmn;
revision-date 2020-03-08; // stable grouping definitions
reference
"RFC XXXX: YANG Groupings for TLS Clients and TLS Servers";
}
import ietf-crypto-types {
prefix ct;
reference
"RFC AAAA: Common YANG Data Types for Cryptography";
}
import ietf-truststore {
prefix ts;
reference
"RFC BBBB: A YANG Data Model for a Truststore";
}
import ietf-keystore {
prefix ks;
reference
"RFC CCCC: A YANG Data Model for a Keystore";
}
import ietf-netconf-acm {
prefix nacm;
reference
"RFC 8341: Network Configuration Access Control Model";
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://datatracker.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
Author: Kent Watsen <mailto:kent+ietf@watsen.net>
Author: Gary Wu <mailto:garywu@cisco.com>";
description
"This module defines reusable groupings for TLS clients that
can be used as a basis for specific TLS client instances.
Copyright (c) 2019 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
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(https://www.rfc-editor.org/info/rfcXXXX); see the RFC
itself for full legal notices.
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 BCP 14 (RFC 2119)
(RFC 8174) when, and only when, they appear in all
capitals, as shown here.";
revision 2020-03-08 {
description
"Initial version";
reference
"RFC XXXX: YANG Groupings for TLS Clients and TLS Servers";
}
// Features
feature tls-client-hello-params-config {
description
"TLS hello message parameters are configurable on a TLS
client.";
}
feature tls-client-keepalives {
description
"Per socket TLS keepalive parameters are configurable for
TLS clients on the server implementing this feature.";
}
feature x509-certificate-auth {
description
"Indicates that the client supports authenticating servers
using X.509 certificates.";
}
feature raw-public-key-auth {
description
"Indicates that the client supports authenticating servers
using ray public keys.";
}
feature psk-auth {
description
"Indicates that the client supports authenticating servers
using PSKs (pre-shared or pairwise-symmetric keys).";
}
// Groupings
grouping tls-client-grouping {
description
"A reusable grouping for configuring a TLS client without
any consideration for how an underlying TCP session is
established.
Note that this grouping uses fairly typical descendent
node names such that a stack of 'uses' statements will
have name conflicts. It is intended that the consuming
data model will resolve the issue (e.g., by wrapping
the 'uses' statement in a container called
'tls-client-parameters'). This model purposely does
not do this itself so as to provide maximum flexibility
to consuming models.";
container client-identity {
nacm:default-deny-write;
description
"Identity credentials the TLS client MAY present when
establishing a connection to a TLS server. If not
configured, then client authentication is presumed to
occur a protocol layer above TLS. When configured,
and requested by the TLS server when establishing a
TLS session, these credentials are passed in the
Certificate message defined in Section 7.4.2 of
RFC 5246.";
reference
"RFC 5246:
The Transport Layer Security (TLS) Protocol Version 1.2
RFC ZZZZ:
YANG Data Model for a 'Keystore' Mechanism";
choice auth-type {
description
"A choice amongst available authentication types.";
case certificate {
if-feature x509-certificate-auth;
container certificate {
description
"Specifies the client identity using a certificate.";
uses
ks:local-or-keystore-end-entity-cert-with-key-grouping{
refine "local-or-keystore/local/local-definition" {
must 'public-key-format'
+ ' = "ct:subject-public-key-info-format"';
}
refine "local-or-keystore/keystore/keystore-reference"
+ "/asymmetric-key" {
must 'deref(.)/../ks:public-key-format'
+ ' = "ct:subject-public-key-info-format"';
}
}
}
}
case raw-public-key {
if-feature raw-public-key-auth;
container raw-private-key {
description
"Specifies the client identity using a raw
private key.";
uses ks:local-or-keystore-asymmetric-key-grouping {
refine "local-or-keystore/local/local-definition" {
must 'public-key-format'
+ ' = "ct:subject-public-key-info-format"';
}
refine "local-or-keystore/keystore"
+ "/keystore-reference" {
must 'deref(.)/../ks:public-key-format'
+ ' = "ct:subject-public-key-info-format"';
}
}
}
}
case psk {
if-feature psk-auth;
container psk {
description
"Specifies the client identity using a PSK (pre-shared
or pairwise-symmetric key). Note that, when the PSK is
configured as a Keystore reference, the key's 'name'
node MAY be used as the PSK's ID when used by the TLS
protocol.";
uses ks:local-or-keystore-symmetric-key-grouping {
augment "local-or-keystore/local/local-definition" {
if-feature "ks:local-definitions-supported";
description
"Adds an 'id' value when the PSK is used by TLS.";
leaf id {
type string; // is this the right type?
description
"The key id used in the TLS protocol for PSKs.";
}
}
}
}
}
}
} // container client-identity
container server-authentication {
nacm:default-deny-write;
must 'ca-certs or server-certs';
description
"Specifies how the TLS client can authenticate TLS servers.
Any combination of credentials is additive and unordered.
Note that no configuration is required for PSK (pre-shared
or pairwise-symmetric key) based authentication as the key
is necessarily the same as configured in the '../client-
identity' node.";
container ca-certs {
if-feature "x509-certificate-auth";
presence
"Indicates that the TLS client can authenticate TLS servers
using configured certificate authority certificates.";
description
"A set of certificate authority (CA) certificates used by
the TLS client to authenticate TLS server certificates.
A server certificate is authenticated if it has a valid
chain of trust to a configured CA certificate.";
reference
"RFC YYYY: YANG Data Model for a Truststore";
uses ts:local-or-truststore-certs-grouping;
// Note: TS certs don't have a key-format...no test needed
}
container server-certs {
// FIXME: plural too much? rename to ee-certs?
if-feature "x509-certificate-auth";
presence
"Indicates that the TLS client can authenticate TLS
servers using configured server certificates.";
description
"A set of server certificates (i.e., end entity
certificates) used by the TLS client to authenticate
certificates presented by TLS servers. A server
certificate is authenticated if it is an exact
match to a configured server certificate.";
reference
"RFC YYYY: YANG Data Model for a Truststore";
uses ts:local-or-truststore-certs-grouping;
// Note: TS certs don't have a key-format...no test needed
}
container raw-public-keys {
if-feature "raw-public-key-auth";
presence
"Indicates that the TLS client can authenticate TLS
servers using configured server certificates.";
description
"A set of raw public keys used by the TLS client to
authenticate raw public keys presented by the TLS
server. A raw public key is authenticated if it
is an exact match to a configured raw public key.";
reference
"RFC YYYY: YANG Data Model for a Truststore";
uses ts:local-or-truststore-public-keys-grouping {
refine "local-or-truststore/local/local-definition"
+ "/public-key" {
must 'public-key-format'
+ ' = "ct:subject-public-key-info-format"';
}
refine "local-or-truststore/truststore"
+ "/truststore-reference" {
must 'deref(.)/../*/ts:public-key-format'
+ ' = "ct:subject-public-key-info-format"';
}
}
}
container psks {
if-feature "psk-auth";
presence
"Indicates that the TLS client can authenticate TLS servers
using a configure PSK (pre-shared or pairwise-symmetric
key).";
description
"No configuration is required since the PSK value is the
same as PSK value configured in the 'client-identity'
node.";
}
} // container server-authentication
container hello-params {
nacm:default-deny-write;
if-feature "tls-client-hello-params-config";
uses tlscmn:hello-params-grouping;
description
"Configurable parameters for the TLS hello message.";
} // container hello-params
container keepalives {
nacm:default-deny-write;
if-feature "tls-client-keepalives";
presence "Indicates that keepalives are enabled.";
description
"Configures the keep-alive policy, to proactively test
the aliveness of the TLS server. An unresponsive
TLS server is dropped after approximately max-wait
* max-attempts seconds.";
leaf max-wait {
type uint16 {
range "1..max";
}
units "seconds";
default "30";
description
"Sets the amount of time in seconds after which if
no data has been received from the TLS server, a
TLS-level message will be sent to test the
aliveness of the TLS server.";
}
leaf max-attempts {
type uint8;
default "3";
description
"Sets the maximum number of sequential keep-alive
messages that can fail to obtain a response from
the TLS server before assuming the TLS server is
no longer alive.";
}
}
} // grouping tls-client-grouping
} // module ietf-tls-client
<CODE ENDS>
This section provides a tree diagram [RFC8340] for the "ietf-tls-server" module that does not have groupings expanded.
========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) ===========
module: ietf-tls-server
grouping tls-server-grouping
+-- server-identity
| +-- (auth-type)
| +--:(certificate) {x509-certificate-auth}?
| | +-- certificate
| | +---u ks:local-or-keystore-end-entity-cert-with-key-\
grouping
| +--:(raw-private-key) {raw-public-key-auth}?
| | +-- raw-private-key
| | +---u ks:local-or-keystore-asymmetric-key-grouping
| +--:(psk) {psk-auth}?
| +-- psk
| +---u ks:local-or-keystore-symmetric-key-grouping
+-- client-authentication! {client-auth-config-supported}?
| +-- ca-certs! {x509-certificate-auth}?
| | +---u ts:local-or-truststore-certs-grouping
| +-- client-certs! {x509-certificate-auth}?
| | +---u ts:local-or-truststore-certs-grouping
| +-- raw-public-keys! {raw-public-key-auth}?
| | +---u ts:local-or-truststore-public-keys-grouping
| +-- psks! {psk-auth}?
+-- hello-params {tls-server-hello-params-config}?
| +---u tlscmn:hello-params-grouping
+-- keepalives! {tls-server-keepalives}?
+-- max-wait? uint16
+-- max-attempts? uint8
This section presents two examples showing the tls-server-grouping populated with some data. These examples are effectively the same except the first configures the server identity using a local key while the second uses a key configured in a keystore. Both examples are consistent with the examples presented in Section 2 of [I-D.ietf-netconf-trust-anchors] and Section 3.2 of [I-D.ietf-netconf-keystore].
========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) ===========
<tls-server
xmlns="urn:ietf:params:xml:ns:yang:ietf-tls-server"
xmlns:ct="urn:ietf:params:xml:ns:yang:ietf-crypto-types">
<!-- how this server will authenticate itself to the client -->
<server-identity>
<certificate>
<local-definition>
<algorithm>rsa2048</algorithm>
<public-key-format>ct:subject-public-key-info-format</public\
-key-format>
<public-key>base64encodedvalue==</public-key>
<private-key-format>ct:rsa-private-key-format</private-key-f\
ormat>
<private-key>base64encodedvalue==</private-key>
<cert>base64encodedvalue==</cert>
</local-definition>
</certificate>
<!-- TESTED, BUT COMMENTED OUT DUE TO ONLY ONE ALLOWED AT A TIME
<raw-private-key>
<local-definition>
<algorithm>rsa2048</algorithm>
<public-key-format>ct:subject-public-key-info-format</public\
-key-format>
<public-key>base64encodedvalue==</public-key>
<private-key-format>ct:rsa-private-key-format</private-key-f\
ormat>
<private-key>base64encodedvalue==</private-key>
</local-definition>
</raw-private-key>
<psk>
<local-definition>
<algorithm>aes-256-cbc</algorithm>
<key-format>ct:octet-string-key-format</key-format>
<key>base64encodedvalue==</key>
</local-definition>
</psk>
-->
</server-identity>
<!-- which certificates will this server trust -->
<client-authentication>
<ca-certs>
<local-definition>
<cert>base64encodedvalue==</cert>
<cert>base64encodedvalue==</cert>
<cert>base64encodedvalue==</cert>
</local-definition>
</ca-certs>
<client-certs>
<local-definition>
<cert>base64encodedvalue==</cert>
<cert>base64encodedvalue==</cert>
<cert>base64encodedvalue==</cert>
</local-definition>
</client-certs>
<raw-public-keys>
<local-definition>
<public-key>
<name>User A</name>
<algorithm>secp256r1</algorithm>
<public-key-format>ct:subject-public-key-info-format</publ\
ic-key-format>
<public-key>base64encodedvalue==</public-key>
</public-key>
<public-key>
<name>User B</name>
<algorithm>secp256r1</algorithm>
<public-key-format>ct:subject-public-key-info-format</publ\
ic-key-format>
<public-key>base64encodedvalue==</public-key>
</public-key>
</local-definition>
</raw-public-keys>
<psks/>
</client-authentication>
</tls-server>
The following example configures the server identity using a local key:
========== NOTE: '\' line wrapping per BCP XXX (RFC XXXX) ===========
<tls-server xmlns="urn:ietf:params:xml:ns:yang:ietf-tls-server">
<!-- how this server will authenticate itself to the client -->
<server-identity>
<certificate>
<keystore-reference>
<asymmetric-key>rsa-asymmetric-key</asymmetric-key>
<certificate>ex-rsa-cert</certificate>
</keystore-reference>
</certificate>
<!-- TESTED, BUT COMMENTED OUT DUE TO ONLY ONE ALLOWED AT A TIME
<raw-private-key>
<keystore-reference>raw-private-key</keystore-reference>
</raw-private-key>
<psk>
<keystore-reference>encrypted-symmetric-key</keystore-referenc\
e>
</psk>
-->
</server-identity>
<!-- which certificates will this server trust -->
<client-authentication>
<ca-certs>
<truststore-reference>trusted-client-ca-certs</truststore-refe\
rence>
</ca-certs>
<client-certs>
<truststore-reference>trusted-client-ee-certs</truststore-refe\
rence>
</client-certs>
<raw-public-keys>
<truststore-reference>Raw Public Keys for Clients</truststore-\
reference>
</raw-public-keys>
<psks/>
</client-authentication>
</tls-server>
The following example configures the server identity using a key from the keystore:
This YANG module has a normative references to [RFC5246], [I-D.ietf-netconf-trust-anchors] and [I-D.ietf-netconf-keystore].
<CODE BEGINS> file "ietf-tls-server@2020-03-08.yang"
module ietf-tls-server {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-tls-server";
prefix tlss;
import ietf-tls-common {
prefix tlscmn;
revision-date 2020-03-08; // stable grouping definitions
reference
"RFC XXXX: YANG Groupings for TLS Clients and TLS Servers";
}
import ietf-crypto-types {
prefix ct;
reference
"RFC AAAA: Common YANG Data Types for Cryptography";
}
import ietf-truststore {
prefix ts;
reference
"RFC BBBB: A YANG Data Model for a Truststore";
}
import ietf-keystore {
prefix ks;
reference
"RFC CCCC: A YANG Data Model for a Keystore";
}
import ietf-netconf-acm {
prefix nacm;
reference
"RFC 8341: Network Configuration Access Control Model";
}
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://datatracker.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
Author: Kent Watsen <mailto:kent+ietf@watsen.net>
Author: Gary Wu <mailto:garywu@cisco.com>";
description
"This module defines reusable groupings for TLS servers that
can be used as a basis for specific TLS server instances.
Copyright (c) 2019 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
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(https://www.rfc-editor.org/info/rfcXXXX); see the RFC
itself for full legal notices.
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 BCP 14 (RFC 2119)
(RFC 8174) when, and only when, they appear in all
capitals, as shown here.";
revision 2020-03-08 {
description
"Initial version";
reference
"RFC XXXX: YANG Groupings for TLS Clients and TLS Servers";
}
// Features
feature tls-server-hello-params-config {
description
"TLS hello message parameters are configurable on a TLS
server.";
}
feature tls-server-keepalives {
description
"Per socket TLS keepalive parameters are configurable for
TLS servers on the server implementing this feature.";
}
feature client-auth-config-supported {
description
"Indicates that the configuration for how to authenticate
clients can be configured herein, as opposed to in an
application specific location. That is, to support the
consuming data models that prefer to place client
authentication with client definitions, rather then
in a data model principally concerned with configuring
the transport.";
}
feature x509-certificate-auth {
description
"Indicates that the server supports authenticating clients
using X.509 certificates.";
}
feature raw-public-key-auth {
description
"Indicates that the server supports authenticating clients
using ray public keys.";
}
feature psk-auth {
description
"Indicates that the server supports authenticating clients
using PSKs (pre-shared or pairwise-symmetric keys).";
}
// Groupings
grouping tls-server-grouping {
description
"A reusable grouping for configuring a TLS server without
any consideration for how underlying TCP sessions are
established.
Note that this grouping uses fairly typical descendent
node names such that a stack of 'uses' statements will
have name conflicts. It is intended that the consuming
data model will resolve the issue (e.g., by wrapping
the 'uses' statement in a container called
'tls-server-parameters'). This model purposely does
not do this itself so as to provide maximum flexibility
to consuming models.";
container server-identity {
nacm:default-deny-write;
description
"A locally-defined or referenced end-entity certificate,
including any configured intermediate certificates, the
TLS server will present when establishing a TLS connection
in its Certificate message, as defined in Section 7.4.2
in RFC 5246.";
reference
"RFC 5246:
The Transport Layer Security (TLS) Protocol Version 1.2
RFC ZZZZ:
YANG Data Model for a 'Keystore' Mechanism";
choice auth-type {
mandatory true;
description
"A choice amongst authentication types.";
case certificate {
if-feature x509-certificate-auth;
container certificate {
description
"Specifies the server identity using a certificate.";
uses
ks:local-or-keystore-end-entity-cert-with-key-grouping{
refine "local-or-keystore/local/local-definition" {
must 'public-key-format'
+ ' = "ct:subject-public-key-info-format"';
}
refine "local-or-keystore/keystore/keystore-reference"
+ "/asymmetric-key" {
must 'deref(.)/../ks:public-key-format'
+ ' = "ct:subject-public-key-info-format"';
}
}
}
}
case raw-private-key {
if-feature raw-public-key-auth;
container raw-private-key {
description
"Specifies the server identity using a raw
private key.";
uses ks:local-or-keystore-asymmetric-key-grouping {
refine "local-or-keystore/local/local-definition" {
must 'public-key-format'
+ ' = "ct:subject-public-key-info-format"';
}
refine "local-or-keystore/keystore/keystore-reference"{
must 'deref(.)/../ks:public-key-format'
+ ' = "ct:subject-public-key-info-format"';
}
}
}
}
case psk {
if-feature psk-auth;
container psk {
description
"Specifies the server identity using a PSK (pre-shared
or pairwise-symmetric key). Note that, when the PSK is
configured as a Keystore reference, the key's 'name'
node MAY be used as the PSK's ID when used by the TLS
protocol.";
uses ks:local-or-keystore-symmetric-key-grouping {
augment "local-or-keystore/local/local-definition" {
if-feature "ks:local-definitions-supported";
description
"An 'id' value for when the PSK is used by TLS.";
leaf id {
type string; // is this the right type?
description
"The key id used in the TLS protocol for PSKs.";
}
}
}
}
}
}
} // container server-identity
container client-authentication {
if-feature "client-auth-config-supported";
nacm:default-deny-write;
presence
"Indicates that client authentication is supported (i.e.,
that the server will request clients send certificates).
If not configured, the TLS server SHOULD NOT request the
TLS clients provide authentication credentials.";
description
"Specifies how the TLS server can authenticate TLS clients.
Any combination of credentials is additive and unordered.
Note that no configuration is required for PSK (pre-shared
or pairwise-symmetric key) based authentication as the key
is necessarily the same as configured in the '../server-
identity' node.";
container ca-certs {
if-feature "x509-certificate-auth";
presence
"Indicates that the TLS server can authenticate TLS clients
using configured certificate authority certificates.";
description
"A set of certificate authority (CA) certificates used by
the TLS server to authenticate TLS client certificates. A
client certificate is authenticated if it has a valid
chain of trust to a configured CA certificate.";
reference
"RFC CCCC: YANG Data Model for a Truststore";
uses ts:local-or-truststore-certs-grouping;
// Note: TS certs don't have a key-format...no test needed
}
container client-certs { // FIXME: plural too much?
if-feature "x509-certificate-auth";
presence
"Indicates that the TLS server can authenticate TLS
clients using configured client certificates.";
description
"A set of client certificates (i.e., end entity
certificates) used by the TLS server to authenticate
certificates presented by TLS clients. A client
certificate is authenticated if it is an exact
match to a configured client certificate.";
reference
"RFC CCCC: YANG Data Model for a Truststore";
uses ts:local-or-truststore-certs-grouping;
// Note: TS certs don't have a key-format...no test needed
}
container raw-public-keys {
if-feature "raw-public-key-auth";
presence
"Indicates that the TLS server can authenticate TLS
clients using raw public keys.";
description
"A set of raw public keys used by the TLS server to
authenticate raw public keys presented by the TLS
client. A raw public key is authenticated if it
is an exact match to a configured raw public key.";
reference
"RFC CCCC: YANG Data Model for a Truststore";
uses ts:local-or-truststore-public-keys-grouping {
refine "local-or-truststore/local/local-definition"
+ "/public-key" {
must 'public-key-format'
+ ' = "ct:subject-public-key-info-format"';
}
refine "local-or-truststore/truststore"
+ "/truststore-reference" {
must 'deref(.)/../*/ts:public-key-format'
+ ' = "ct:subject-public-key-info-format"';
}
}
}
container psks {
if-feature "psk-auth";
presence
"Indicates that the TLS server can authenticate the TLS
client using its PSK (pre-shared or pairwise-symmetric
key).";
description
"No configuration is required since the PSK value is the
same as PSK value configured in the 'client-identity'
node.";
}
} // container client-authentication
container hello-params {
nacm:default-deny-write;
if-feature "tls-server-hello-params-config";
uses tlscmn:hello-params-grouping;
description
"Configurable parameters for the TLS hello message.";
} // container hello-params
container keepalives {
nacm:default-deny-write;
if-feature "tls-server-keepalives";
presence "Indicates that keepalives are enabled.";
description
"Configures the keep-alive policy, to proactively test
the aliveness of the TLS client. An unresponsive
TLS client is dropped after approximately max-wait
* max-attempts seconds.";
leaf max-wait {
type uint16 {
range "1..max";
}
units "seconds";
default "30";
description
"Sets the amount of time in seconds after which if
no data has been received from the TLS client, a
TLS-level message will be sent to test the
aliveness of the TLS client.";
}
leaf max-attempts {
type uint8;
default "3";
description
"Sets the maximum number of sequential keep-alive
messages that can fail to obtain a response from
the TLS client before assuming the TLS client is
no longer alive.";
}
} // container keepalives
} // grouping tls-server-grouping
} // module ietf-tls-server
<CODE ENDS>
The TLS common model presented in this section contains identities and groupings common to both TLS clients and TLS servers. The hello-params-grouping can be used to configure the list of TLS algorithms permitted by the TLS client or TLS server. The lists of algorithms are ordered such that, if multiple algorithms are permitted by the client, the algorithm that appears first in its list that is also permitted by the server is used for the TLS transport layer connection. The ability to restrict the algorithms allowed is provided in this grouping for TLS clients and TLS servers that are capable of doing so and may serve to make TLS clients and TLS servers compliant with local security policies. This model supports both TLS1.2 [RFC5246] and TLS 1.3 [RFC8446].
TLS 1.2 and TLS 1.3 have different ways defining their own supported cryptographic algorithms, see TLS and DTLS IANA registries page (https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml):
Thus, in order to support both TLS1.2 and TLS1.3, the cipher-suites part of the hello-params-grouping should include three parameters for configuring its permitted TLS algorithms, which are: TLS Cipher Suites, TLS SignatureScheme, TLS Supported Groups. Note that TLS1.2 only uses TLS Cipher Suites.
+-----------------------------------------------+---------+ | ciper-suites in hello-params-grouping | HASH | +-----------------------------------------------+---------+ | TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 | sha-256 | | TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 | sha-384 | | TLS_DHE_PSK_WITH_AES_128_GCM_SHA256 | sha-256 | | TLS_DHE_PSK_WITH_AES_256_GCM_SHA384 | sha-384 | | TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 | sha-256 | | TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 | sha-384 | | TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 | sha-256 | | TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 | sha-384 | | TLS_DHE_RSA_WITH_AES_128_CCM | sha-256 | | TLS_DHE_RSA_WITH_AES_256_CCM | sha-256 | | TLS_DHE_PSK_WITH_AES_128_CCM | sha-256 | | TLS_DHE_PSK_WITH_AES_256_CCM | sha-256 | | TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 | sha-256 | | TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 | sha-256 | | TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 | sha-256 | | TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256 | sha-256 | | TLS_DHE_PSK_WITH_CHACHA20_POLY1305_SHA256 | sha-256 | | TLS_ECDHE_PSK_WITH_AES_128_GCM_SHA256 | sha-256 | | TLS_ECDHE_PSK_WITH_AES_256_GCM_SHA384 | sha-384 | | TLS_ECDHE_PSK_WITH_AES_128_CCM_SHA256 | sha-256 | +-----------------------------------------------+---------+
Table 1-1 TLS 1.2 Compatibility Matrix Part 1: ciper-suites mapping to hash-algorithm
+--------------------------------------------- +---------------------+ | ciper-suites in hello-params-grouping | symmetric | | | | +--------------------------------------------- +---------------------+ | TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 | enc-aes-128-gcm | | TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 | enc-aes-256-gcm | | TLS_DHE_PSK_WITH_AES_128_GCM_SHA256 | enc-aes-128-gcm | | TLS_DHE_PSK_WITH_AES_256_GCM_SHA384 | enc-aes-256-gcm | | TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 | enc-aes-128-gcm | | TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 | enc-aes-256-gcm | | TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 | enc-aes-128-gcm | | TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 | enc-aes-256-gcm | | TLS_DHE_RSA_WITH_AES_128_CCM | enc-aes-128-ccm | | TLS_DHE_RSA_WITH_AES_256_CCM | enc-aes-256-ccm | | TLS_DHE_PSK_WITH_AES_128_CCM | enc-aes-128-ccm | | TLS_DHE_PSK_WITH_AES_256_CCM | enc-aes-256-ccm | | TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 |enc-chacha20-poly1305| | TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256|enc-chacha20-poly1305| | TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 |enc-chacha20-poly1305| | TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256 |enc-chacha20-poly1305| | TLS_DHE_PSK_WITH_CHACHA20_POLY1305_SHA256 |enc-chacha20-poly1305| | TLS_ECDHE_PSK_WITH_AES_128_GCM_SHA256 | enc-aes-128-gcm | | TLS_ECDHE_PSK_WITH_AES_256_GCM_SHA384 | enc-aes-256-gcm | | TLS_ECDHE_PSK_WITH_AES_128_CCM_SHA256 | enc-aes-128-ccm | +--------------------------------------------- +---------------------+
Table 1-2 TLS 1.2 Compatibility Matrix Part 2: ciper-suites mapping to symmetric-key-encryption-algorithm
+--------------------------------------------- +---------------------+ | ciper-suites in hello-params-grouping | MAC | | | | +--------------------------------------------- +---------------------+ | TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 | mac-aes-128-gcm | | TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 | mac-aes-256-gcm | | TLS_DHE_PSK_WITH_AES_128_GCM_SHA256 | mac-aes-128-gcm | | TLS_DHE_PSK_WITH_AES_256_GCM_SHA384 | mac-aes-256-gcm | | TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 | mac-aes-128-gcm | | TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 | mac-aes-256-gcm | | TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 | mac-aes-128-gcm | | TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 | mac-aes-256-gcm | | TLS_DHE_RSA_WITH_AES_128_CCM | mac-aes-128-ccm | | TLS_DHE_RSA_WITH_AES_256_CCM | mac-aes-256-ccm | | TLS_DHE_PSK_WITH_AES_128_CCM | mac-aes-128-ccm | | TLS_DHE_PSK_WITH_AES_256_CCM | mac-aes-256-ccm | | TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 |mac-chacha20-poly1305| | TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256|mac-chacha20-poly1305| | TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 |mac-chacha20-poly1305| | TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256 |mac-chacha20-poly1305| | TLS_DHE_PSK_WITH_CHACHA20_POLY1305_SHA256 |mac-chacha20-poly1305| | TLS_ECDHE_PSK_WITH_AES_128_GCM_SHA256 | mac-aes-128-gcm | | TLS_ECDHE_PSK_WITH_AES_256_GCM_SHA384 | mac-aes-256-gcm | | TLS_ECDHE_PSK_WITH_AES_128_CCM_SHA256 | mac-aes-128-ccm | +--------------------------------------------- +---------------------+
Table 1-3 TLS 1.2 Compatibility Matrix Part 3: ciper-suites mapping to MAC-algorithm
+----------------------------------------------+----------------------+ |ciper-suites in hello-params-grouping | signature | +--------------------------------------------- +----------------------+ | TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 | rsa-pkcs1-sha256 | | TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 | rsa-pkcs1-sha384 | | TLS_DHE_PSK_WITH_AES_128_GCM_SHA256 | N/A | | TLS_DHE_PSK_WITH_AES_256_GCM_SHA384 | N/A | | TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 |ecdsa-secp256r1-sha256| | TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 |ecdsa-secp384r1-sha384| | TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 | rsa-pkcs1-sha256 | | TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 | rsa-pkcs1-sha384 | | TLS_DHE_RSA_WITH_AES_128_CCM | rsa-pkcs1-sha256 | | TLS_DHE_RSA_WITH_AES_256_CCM | rsa-pkcs1-sha256 | | TLS_DHE_PSK_WITH_AES_128_CCM | N/A | | TLS_DHE_PSK_WITH_AES_256_CCM | N/A | | TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 | rsa-pkcs1-sha256 | | TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256|ecdsa-secp256r1-sha256| | TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 | rsa-pkcs1-sha256 | | TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256 | N/A | | TLS_DHE_PSK_WITH_CHACHA20_POLY1305_SHA256 | N/A | | TLS_ECDHE_PSK_WITH_AES_128_GCM_SHA256 | N/A | | TLS_ECDHE_PSK_WITH_AES_256_GCM_SHA384 | N/A | | TLS_ECDHE_PSK_WITH_AES_128_CCM_SHA256 | N/A | +----------------------------------------------+----------------------+
Table 1-4 TLS 1.2 Compatibility Matrix Part 4: ciper-suites mapping to signature-algorithm
+----------------------------------------------+-----------------------+ |ciper-suites in hello-params-grouping | key-negotiation | +----------------------------------------------+-----------------------+ | TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 | dhe-ffdhe2048, ... | | TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 | dhe-ffdhe2048, ... | | TLS_DHE_PSK_WITH_AES_128_GCM_SHA256 | psk-dhe-ffdhe2048, ...| | TLS_DHE_PSK_WITH_AES_256_GCM_SHA384 | psk-dhe-ffdhe2048, ...| | TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 | ecdhe-secp256r1, ... | | TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 | ecdhe-secp256r1, ... | | TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 | ecdhe-secp256r1, ... | | TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 | ecdhe-secp256r1, ... | | TLS_DHE_RSA_WITH_AES_128_CCM | dhe-ffdhe2048, ... | | TLS_DHE_RSA_WITH_AES_256_CCM | dhe-ffdhe2048, ... | | TLS_DHE_PSK_WITH_AES_128_CCM | psk-dhe-ffdhe2048, ...| | TLS_DHE_PSK_WITH_AES_256_CCM | psk-dhe-ffdhe2048, ...| | TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 | ecdhe-secp256r1, ... | | TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256| ecdhe-secp256r1, ... | | TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 | dhe-ffdhe2048, ... | | TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256 |psk-ecdhe-secp256r1,...| | TLS_DHE_PSK_WITH_CHACHA20_POLY1305_SHA256 | psk-dhe-ffdhe2048, ...| | TLS_ECDHE_PSK_WITH_AES_128_GCM_SHA256 |psk-ecdhe-secp256r1,...| | TLS_ECDHE_PSK_WITH_AES_256_GCM_SHA384 |psk-ecdhe-secp256r1,...| | TLS_ECDHE_PSK_WITH_AES_128_CCM_SHA256 |psk-ecdhe-secp256r1,...| +----------------------------------------------+-----------------------+
Table 1-5 TLS 1.2 Compatibility Matrix Part 5: ciper-suites mapping to key-negotiation-algorithm
+------------------------------+---------+ | ciper-suites in hello | HASH | | -params-grouping | | +------------------------------+---------+ | TLS_AES_128_GCM_SHA256 | sha-256 | | TLS_AES_256_GCM_SHA384 | sha-384 | | TLS_CHACHA20_POLY1305_SHA256 | sha-256 | | TLS_AES_128_CCM_SHA256 | sha-256 | +------------------------------+---------+
Table 2-1 TLS 1.3 Compatibility Matrix Part 1: ciper-suites mapping to hash-algorithm
+------------------------------+-----------------------+ | ciper-suites in hello | symmetric | | -params-grouping | | +------------------------------+-----------------------+ | TLS_AES_128_GCM_SHA256 | enc-aes-128-gcm | | TLS_AES_256_GCM_SHA384 | enc-aes-128-gcm | | TLS_CHACHA20_POLY1305_SHA256 | enc-chacha20-poly1305 | | TLS_AES_128_CCM_SHA256 | enc-aes-128-ccm | +------------------------------+-----------------------+
Table 2-2 TLS 1.3 Compatibility Matrix Part 2: ciper-suites mapping to symmetric-key--encryption-algorithm
+------------------------------+-----------------------+ | ciper-suites in hello | symmetric | | -params-grouping | | +------------------------------+-----------------------+ | TLS_AES_128_GCM_SHA256 | mac-aes-128-gcm | | TLS_AES_256_GCM_SHA384 | mac-aes-128-gcm | | TLS_CHACHA20_POLY1305_SHA256 | mac-chacha20-poly1305 | | TLS_AES_128_CCM_SHA256 | mac-aes-128-ccm | +------------------------------+-----------------------+
Table 2-3 TLS 1.3 Compatibility Matrix Part 3: ciper-suites mapping to MAC-algorithm
+----------------------------+-------------------------+ |signatureScheme in hello | signature | | -params-grouping | | +----------------------------+-------------------------+ | rsa-pkcs1-sha256 | rsa-pkcs1-sha256 | | rsa-pkcs1-sha384 | rsa-pkcs1-sha384 | | rsa-pkcs1-sha512 | rsa-pkcs1-sha512 | | rsa-pss-rsae-sha256 | rsa-pss-rsae-sha256 | | rsa-pss-rsae-sha384 | rsa-pss-rsae-sha384 | | rsa-pss-rsae-sha512 | rsa-pss-rsae-sha512 | | rsa-pss-pss-sha256 | rsa-pss-pss-sha256 | | rsa-pss-pss-sha384 | rsa-pss-pss-sha384 | | rsa-pss-pss-sha512 | rsa-pss-pss-sha512 | | ecdsa-secp256r1-sha256 | ecdsa-secp256r1-sha256 | | ecdsa-secp384r1-sha384 | ecdsa-secp384r1-sha384 | | ecdsa-secp521r1-sha512 | ecdsa-secp521r1-sha512 | | ed25519 | ed25519 | | ed448 | ed448 | +----------------------------+-------------------------+
Table 2-4 TLS 1.3 Compatibility Matrix Part 4: SignatureScheme mapping to signature-algorithm
+----------------------------+-------------------------+ |supported Groups in hello | key-negotiation | | -params-grouping | | +----------------------------+-------------------------+ | dhe-ffdhe2048 | dhe-ffdhe2048 | | dhe-ffdhe3072 | dhe-ffdhe3072 | | dhe-ffdhe4096 | dhe-ffdhe4096 | | dhe-ffdhe6144 | dhe-ffdhe6144 | | dhe-ffdhe8192 | dhe-ffdhe8192 | | psk-dhe-ffdhe2048 | psk-dhe-ffdhe2048 | | psk-dhe-ffdhe3072 | psk-dhe-ffdhe3072 | | psk-dhe-ffdhe4096 | psk-dhe-ffdhe4096 | | psk-dhe-ffdhe6144 | psk-dhe-ffdhe6144 | | psk-dhe-ffdhe8192 | psk-dhe-ffdhe8192 | | ecdhe-secp256r1 | ecdhe-secp256r1 | | ecdhe-secp384r1 | ecdhe-secp384r1 | | ecdhe-secp521r1 | ecdhe-secp521r1 | | ecdhe-x25519 | ecdhe-x25519 | | ecdhe-x448 | ecdhe-x448 | | psk-ecdhe-secp256r1 | psk-ecdhe-secp256r1 | | psk-ecdhe-secp384r1 | psk-ecdhe-secp384r1 | | psk-ecdhe-secp521r1 | psk-ecdhe-secp521r1 | | psk-ecdhe-x25519 | psk-ecdhe-x25519 | | psk-ecdhe-x448 | psk-ecdhe-x448 | +----------------------------+-------------------------+
Table 2-5 TLS 1.3 Compatibility Matrix Part 5: Supported Groups mapping to key-negotiation-algorithm
[I-D.ietf-netconf-crypto-types] defines six categories of cryptographic algorithms (hash-algorithm, symmetric-key-encryption-algorithm, mac-algorithm, asymmetric-key-encryption-algorithm, signature-algorithm, key-negotiation-algorithm) and lists several widely accepted algorithms for each of them. The TLS client and server models use one or more of these algorithms. The following tables are provided, in part to define the subset of algorithms defined in the crypto-types model used by TLS, and in part to ensure compatibility of configured TLS cryptographic parameters for configuring its permitted TLS algorithms:
Note that in Table 1-5:
Features are defined for algorithms that are OPTIONAL or are not widely supported by popular implementations. Note that the list of algorithms is not exhaustive.
The following tree diagram [RFC8340] provides an overview of the data model for the "ietf-tls-common" module.
module: ietf-tls-common
grouping hello-params-grouping
+-- tls-versions
| +-- tls-version* identityref
+-- cipher-suites
+-- cipher-suite* identityref
This section shows how it would appear if the transport-params-grouping were populated with some data.
<hello-params
xmlns="urn:ietf:params:xml:ns:yang:ietf-tls-common"
xmlns:tlscmn="urn:ietf:params:xml:ns:yang:ietf-tls-common">
<tls-versions>
<tls-version>tlscmn:tls-1.1</tls-version>
<tls-version>tlscmn:tls-1.2</tls-version>
</tls-versions>
<cipher-suites>
<cipher-suite>tlscmn:dhe-rsa-with-aes-128-cbc-sha</cipher-suite>
<cipher-suite>tlscmn:rsa-with-aes-128-cbc-sha</cipher-suite>
<cipher-suite>tlscmn:rsa-with-3des-ede-cbc-sha</cipher-suite>
</cipher-suites>
</hello-params>
This YANG module has a normative references to [RFC4346], [RFC5246], [RFC5288], [RFC5289], and [RFC8422].
This YANG module has a informative references to [RFC2246], [RFC4346], [RFC5246], and [RFC8446].
<CODE BEGINS> file "ietf-tls-common@2020-03-08.yang"
module ietf-tls-common {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-tls-common";
prefix tlscmn;
organization
"IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http://datatracker.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
Author: Kent Watsen <mailto:kent+ietf@watsen.net>
Author: Gary Wu <mailto:garywu@cisco.com>";
description
"This module defines a common features, identities, and
groupings for Transport Layer Security (TLS).
Copyright (c) 2019 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
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(https://www.rfc-editor.org/info/rfcXXXX); see the RFC
itself for full legal notices.
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 BCP 14 (RFC 2119)
(RFC 8174) when, and only when, they appear in all
capitals, as shown here.";
revision 2020-03-08 {
description
"Initial version";
reference
"RFC XXXX: YANG Groupings for TLS Clients and TLS Servers";
}
// Features
feature tls-1_0 {
description
"TLS Protocol Version 1.0 is supported.";
reference
"RFC 2246: The TLS Protocol Version 1.0";
}
feature tls-1_1 {
description
"TLS Protocol Version 1.1 is supported.";
reference
"RFC 4346: The Transport Layer Security (TLS) Protocol
Version 1.1";
}
feature tls-1_2 {
description
"TLS Protocol Version 1.2 is supported.";
reference
"RFC 5246: The Transport Layer Security (TLS) Protocol
Version 1.2";
}
feature tls-1_3 {
description
"TLS Protocol Version 1.2 is supported.";
reference
"RFC 8446: The Transport Layer Security (TLS) Protocol
Version 1.3";
}
feature tls-ecc {
description
"Elliptic Curve Cryptography (ECC) is supported for TLS.";
reference
"RFC 8422: Elliptic Curve Cryptography (ECC) Cipher Suites
for Transport Layer Security (TLS)";
}
feature tls-dhe {
description
"Ephemeral Diffie-Hellman key exchange is supported for TLS.";
reference
"RFC 5246: The Transport Layer Security (TLS) Protocol
Version 1.2";
}
feature tls-3des {
description
"The Triple-DES block cipher is supported for TLS.";
reference
"RFC 5246: The Transport Layer Security (TLS) Protocol
Version 1.2";
}
feature tls-gcm {
description
"The Galois/Counter Mode authenticated encryption mode is
supported for TLS.";
reference
"RFC 5288: AES Galois Counter Mode (GCM) Cipher Suites for
TLS";
}
feature tls-sha2 {
description
"The SHA2 family of cryptographic hash functions is supported
for TLS.";
reference
"FIPS PUB 180-4: Secure Hash Standard (SHS)";
}
// Identities
identity tls-version-base {
description
"Base identity used to identify TLS protocol versions.";
}
identity tls-1.0 {
if-feature "tls-1_0";
base tls-version-base;
description
"TLS Protocol Version 1.0.";
reference
"RFC 2246: The TLS Protocol Version 1.0";
}
identity tls-1.1 {
if-feature "tls-1_1";
base tls-version-base;
description
"TLS Protocol Version 1.1.";
reference
"RFC 4346: The Transport Layer Security (TLS) Protocol
Version 1.1";
}
identity tls-1.2 {
if-feature "tls-1_2";
base tls-version-base;
description
"TLS Protocol Version 1.2.";
reference
"RFC 5246: The Transport Layer Security (TLS) Protocol
Version 1.2";
}
identity cipher-suite-base {
description
"Base identity used to identify TLS cipher suites.";
}
identity rsa-with-aes-128-cbc-sha {
base cipher-suite-base;
description
"Cipher suite TLS_RSA_WITH_AES_128_CBC_SHA.";
reference
"RFC 5246: The Transport Layer Security (TLS) Protocol
Version 1.2";
}
identity rsa-with-aes-256-cbc-sha {
base cipher-suite-base;
description
"Cipher suite TLS_RSA_WITH_AES_256_CBC_SHA.";
reference
"RFC 5246: The Transport Layer Security (TLS) Protocol
Version 1.2";
}
identity rsa-with-aes-128-cbc-sha256 {
if-feature "tls-sha2";
base cipher-suite-base;
description
"Cipher suite TLS_RSA_WITH_AES_128_CBC_SHA256.";
reference
"RFC 5246: The Transport Layer Security (TLS) Protocol
Version 1.2";
}
identity rsa-with-aes-256-cbc-sha256 {
if-feature "tls-sha2";
base cipher-suite-base;
description
"Cipher suite TLS_RSA_WITH_AES_256_CBC_SHA256.";
reference
"RFC 5246: The Transport Layer Security (TLS) Protocol
Version 1.2";
}
identity dhe-rsa-with-aes-128-cbc-sha {
if-feature "tls-dhe";
base cipher-suite-base;
description
"Cipher suite TLS_DHE_RSA_WITH_AES_128_CBC_SHA.";
reference
"RFC 5246: The Transport Layer Security (TLS) Protocol
Version 1.2";
}
identity dhe-rsa-with-aes-256-cbc-sha {
if-feature "tls-dhe";
base cipher-suite-base;
description
"Cipher suite TLS_DHE_RSA_WITH_AES_256_CBC_SHA.";
reference
"RFC 5246: The Transport Layer Security (TLS) Protocol
Version 1.2";
}
identity dhe-rsa-with-aes-128-cbc-sha256 {
if-feature "tls-dhe and tls-sha2";
base cipher-suite-base;
description
"Cipher suite TLS_DHE_RSA_WITH_AES_128_CBC_SHA256.";
reference
"RFC 5246: The Transport Layer Security (TLS) Protocol
Version 1.2";
}
identity dhe-rsa-with-aes-256-cbc-sha256 {
if-feature "tls-dhe and tls-sha2";
base cipher-suite-base;
description
"Cipher suite TLS_DHE_RSA_WITH_AES_256_CBC_SHA256.";
reference
"RFC 5246: The Transport Layer Security (TLS) Protocol
Version 1.2";
}
identity ecdhe-ecdsa-with-aes-128-cbc-sha256 {
if-feature "tls-ecc and tls-sha2";
base cipher-suite-base;
description
"Cipher suite TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256.";
reference
"RFC 5289: TLS Elliptic Curve Cipher Suites with
SHA-256/384 and AES Galois Counter Mode (GCM)";
}
identity ecdhe-ecdsa-with-aes-256-cbc-sha384 {
if-feature "tls-ecc and tls-sha2";
base cipher-suite-base;
description
"Cipher suite TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384.";
reference
"RFC 5289: TLS Elliptic Curve Cipher Suites with
SHA-256/384 and AES Galois Counter Mode (GCM)";
}
identity ecdhe-rsa-with-aes-128-cbc-sha256 {
if-feature "tls-ecc and tls-sha2";
base cipher-suite-base;
description
"Cipher suite TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256.";
reference
"RFC 5289: TLS Elliptic Curve Cipher Suites with
SHA-256/384 and AES Galois Counter Mode (GCM)";
}
identity ecdhe-rsa-with-aes-256-cbc-sha384 {
if-feature "tls-ecc and tls-sha2";
base cipher-suite-base;
description
"Cipher suite TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384.";
reference
"RFC 5289: TLS Elliptic Curve Cipher Suites with
SHA-256/384 and AES Galois Counter Mode (GCM)";
}
identity ecdhe-ecdsa-with-aes-128-gcm-sha256 {
if-feature "tls-ecc and tls-gcm and tls-sha2";
base cipher-suite-base;
description
"Cipher suite TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256.";
reference
"RFC 5289: TLS Elliptic Curve Cipher Suites with
SHA-256/384 and AES Galois Counter Mode (GCM)";
}
identity ecdhe-ecdsa-with-aes-256-gcm-sha384 {
if-feature "tls-ecc and tls-gcm and tls-sha2";
base cipher-suite-base;
description
"Cipher suite TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384.";
reference
"RFC 5289: TLS Elliptic Curve Cipher Suites with
SHA-256/384 and AES Galois Counter Mode (GCM)";
}
identity ecdhe-rsa-with-aes-128-gcm-sha256 {
if-feature "tls-ecc and tls-gcm and tls-sha2";
base cipher-suite-base;
description
"Cipher suite TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256.";
reference
"RFC 5289: TLS Elliptic Curve Cipher Suites with
SHA-256/384 and AES Galois Counter Mode (GCM)";
}
identity ecdhe-rsa-with-aes-256-gcm-sha384 {
if-feature "tls-ecc and tls-gcm and tls-sha2";
base cipher-suite-base;
description
"Cipher suite TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384.";
reference
"RFC 5289: TLS Elliptic Curve Cipher Suites with
SHA-256/384 and AES Galois Counter Mode (GCM)";
}
identity rsa-with-3des-ede-cbc-sha {
if-feature "tls-3des";
base cipher-suite-base;
description
"Cipher suite TLS_RSA_WITH_3DES_EDE_CBC_SHA.";
reference
"RFC 5246: The Transport Layer Security (TLS) Protocol
Version 1.2";
}
identity ecdhe-rsa-with-3des-ede-cbc-sha {
if-feature "tls-ecc and tls-3des";
base cipher-suite-base;
description
"Cipher suite TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA.";
reference
"RFC 8422: Elliptic Curve Cryptography (ECC) Cipher Suites
for Transport Layer Security (TLS)";
}
identity ecdhe-rsa-with-aes-128-cbc-sha {
if-feature "tls-ecc";
base cipher-suite-base;
description
"Cipher suite TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA.";
reference
"RFC 8422: Elliptic Curve Cryptography (ECC) Cipher Suites
for Transport Layer Security (TLS)";
}
identity ecdhe-rsa-with-aes-256-cbc-sha {
if-feature "tls-ecc";
base cipher-suite-base;
description
"Cipher suite TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA.";
reference
"RFC 8422: Elliptic Curve Cryptography (ECC) Cipher Suites
for Transport Layer Security (TLS)";
}
// Groupings
grouping hello-params-grouping {
description
"A reusable grouping for TLS hello message parameters.";
reference
"RFC 5246: The Transport Layer Security (TLS) Protocol
Version 1.2";
container tls-versions {
description
"Parameters regarding TLS versions.";
leaf-list tls-version {
type identityref {
base tls-version-base;
}
description
"Acceptable TLS protocol versions.
If this leaf-list is not configured (has zero elements)
the acceptable TLS protocol versions are implementation-
defined.";
}
}
container cipher-suites {
description
"Parameters regarding cipher suites.";
leaf-list cipher-suite {
type identityref {
base cipher-suite-base;
}
ordered-by user;
description
"Acceptable cipher suites in order of descending
preference. The configured host key algorithms should
be compatible with the algorithm used by the configured
private key. Please see Section 5 of RFC XXXX for
valid combinations.
If this leaf-list is not configured (has zero elements)
the acceptable cipher suites are implementation-
defined.";
reference
"RFC XXXX: YANG Groupings for TLS Clients and TLS Servers";
}
}
}
}
<CODE ENDS>
The YANG modules defined in this document are designed to be accessed via YANG based management protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. Both of these protocols have mandatory-to-implement secure transport layers (e.g., SSH, TLS) with mutual authentication.
The NETCONF access control model (NACM) [RFC8341] provides the means to restrict access for particular users to a pre-configured subset of all available protocol operations and content.
Since the modules in this document only define groupings, these considerations are primarily for the designers of other modules that use these groupings.
There are a number of data nodes defined in the YANG modules that are writable/creatable/deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) to these data nodes without proper protection can have a negative effect on network operations. These are the subtrees and data nodes and their sensitivity/vulnerability:
Some of the readable data nodes in the YANG modules may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability:
Some of the operations in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control access to these operations. These are the operations and their sensitivity/vulnerability:
This document registers three URIs in the "ns" subregistry of the IETF XML Registry [RFC3688]. Following the format in [RFC3688], the following registrations are requested:
URI: urn:ietf:params:xml:ns:yang:ietf-tls-client Registrant Contact: The NETCONF WG of the IETF. XML: N/A, the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-tls-server Registrant Contact: The NETCONF WG of the IETF. XML: N/A, the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-tls-common Registrant Contact: The NETCONF WG of the IETF. XML: N/A, the requested URI is an XML namespace.
This document registers three YANG modules in the YANG Module Names registry [RFC6020]. Following the format in [RFC6020], the following registrations are requested:
name: ietf-tls-client namespace: urn:ietf:params:xml:ns:yang:ietf-tls-client prefix: tlsc reference: RFC XXXX name: ietf-tls-server namespace: urn:ietf:params:xml:ns:yang:ietf-tls-server prefix: tlss reference: RFC XXXX name: ietf-tls-common namespace: urn:ietf:params:xml:ns:yang:ietf-tls-common prefix: tlscmn reference: RFC XXXX
| [RFC2246] | Dierks, T. and C. Allen, "The TLS Protocol Version 1.0", RFC 2246, DOI 10.17487/RFC2246, January 1999. |
| [RFC2818] | Rescorla, E., "HTTP Over TLS", RFC 2818, DOI 10.17487/RFC2818, May 2000. |
| [RFC3688] | Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004. |
| [RFC4346] | Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.1", RFC 4346, DOI 10.17487/RFC4346, April 2006. |
| [RFC5246] | Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10.17487/RFC5246, August 2008. |
| [RFC6241] | Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011. |
| [RFC8040] | Bierman, A., Bjorklund, M. and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017. |
| [RFC8071] | Watsen, K., "NETCONF Call Home and RESTCONF Call Home", RFC 8071, DOI 10.17487/RFC8071, February 2017. |
| [RFC8340] | Bjorklund, M. and L. Berger, "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018. |
The authors would like to thank for following for lively discussions on list and in the halls (ordered by last name): Andy Bierman, Martin Bjorklund, Benoit Claise, Mehmet Ersue, Balázs Kovács, David Lamparter, Alan Luchuk, Ladislav Lhotka, Radek Krejci, Tom Petch, Juergen Schoenwaelder, Phil Shafer, Sean Turner, and Bert Wijnen.