Internet DRAFT - draft-kwatsen-netconf-http-client-server
draft-kwatsen-netconf-http-client-server
NETCONF Working Group K. Watsen
Internet-Draft Watsen Networks
Intended status: Standards Track November 1, 2019
Expires: May 4, 2020
YANG Groupings for HTTP Clients and HTTP Servers
draft-kwatsen-netconf-http-client-server-05
Abstract
This document defines two YANG modules: the first defines a minimal
grouping for configuring a generic HTTP client, and the second
defines a minimal grouping for configuring a generic HTTP server. It
is intended that these groupings will be used by higher-level HTTP-
based protocols.
Editorial Note (To be removed by RFC Editor)
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.
Artwork in this document contains placeholder values for the date of
publication of this draft. Please apply the following replacement:
o "2019-11-02" --> the publication date of this draft
The following Appendix section is to be removed prior to publication:
o Appendix A. Change Log
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
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Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
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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 May 4, 2020.
Copyright Notice
Copyright (c) 2019 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.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. The HTTP Client Model . . . . . . . . . . . . . . . . . . . . 3
3.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 3
3.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 3
3.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 4
4. The HTTP Server Model . . . . . . . . . . . . . . . . . . . . 7
4.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 7
4.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 8
4.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 8
5. Security Considerations . . . . . . . . . . . . . . . . . . . 13
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
6.1. The IETF XML Registry . . . . . . . . . . . . . . . . . . 14
6.2. The YANG Module Names Registry . . . . . . . . . . . . . 15
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
7.1. Normative References . . . . . . . . . . . . . . . . . . 15
7.2. Informative References . . . . . . . . . . . . . . . . . 16
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction
This document defines two YANG 1.1 [RFC7950] modules: the first
defines a grouping for configuring a generic HTTP client, and the
second defines a grouping for configuring a generic HTTP server. It
is intended that these groupings will be used by higher-level HTTP-
based protocols.
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2. Terminology
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.
3. The HTTP Client Model
3.1. Tree Diagram
This section provides a tree diagram [RFC8340] for the "ietf-http-
client" module.
module: ietf-http-client
grouping client-identity-grouping
+-- (auth-type)
+--:(basic)
+-- basic {basic-auth}?
+-- user-id string
+-- password string
grouping http-client-grouping
+-- client-identity
| +---u client-identity-grouping
+-- proxy-server! {proxy-connect}?
+-- tcp-client-parameters
| +---u tcpc:tcp-client-grouping
+-- tls-client-parameters
| +---u tlsc:tls-client-grouping
+-- proxy-client-identity
+---u client-identity-grouping
3.2. Example Usage
This section presents an example showing the http-client-grouping
populated with some data.
<http-client xmlns="urn:ietf:params:xml:ns:yang:ietf-http-client">
<client-identity>
<basic>
<user-id>bob</user-id>
<password>secret</password>
</basic>
</client-identity>
</http-client>
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3.3. YANG Module
This YANG module has normative references to [RFC6991].
<CODE BEGINS> file "ietf-http-client@2019-11-02.yang"
module ietf-http-client {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-http-client";
prefix httpc;
import ietf-tcp-client {
prefix tcpc;
reference
"RFC AAAA: YANG Groupings for TCP Clients and TCP Servers";
}
import ietf-tls-client {
prefix tlsc;
reference
"RFC BBBB: YANG Groupings for TLS Clients and TLS Servers";
}
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>";
description
"This module defines reusable groupings for HTTP clients that
can be used as a basis for specific HTTP 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
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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 2019-11-02 {
description
"Initial version";
reference
"RFC XXXX: YANG Groupings for HTTP Clients and HTTP Servers";
}
// Features
feature proxy-connect {
description
"Proxy connection configuration is configurable for
HTTP clients on the server implementing this feature.";
}
feature basic-auth {
description
"The 'basic-auth' feature indicates that the client
may be configured to use the 'basic' HTTP authentication
scheme.";
reference
"RFC 7617: The 'Basic' HTTP Authentication Scheme";
}
// Groupings
grouping client-identity-grouping {
description
"The credentials used by the client to authenticate to
the HTTP server.";
choice auth-type {
nacm:default-deny-write;
mandatory true;
description
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"The authentication type.";
case basic {
container basic {
if-feature "basic-auth";
leaf user-id {
type string;
mandatory true;
description
"The user-id for the authenticating client.";
}
leaf password {
nacm:default-deny-all;
type string;
mandatory true;
description
"The password for the authenticating client.";
}
description
"The 'basic' HTTP scheme credentials.";
reference
"RFC 7617: The 'Basic' HTTP Authentication Scheme";
}
}
}
} // grouping client-identity-grouping
grouping http-client-grouping {
description
"A reusable grouping for configuring a HTTP client,
including the IP address and port number it initiates
a connections to.
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
'http-client-parameters'). This model purposely does
not do this itself so as to provide maximum flexibility
to consuming models.";
container client-identity {
description
"The identity the HTTP client should use when
authenticating itself to the HTTP server.";
uses client-identity-grouping;
}
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container proxy-server {
nacm:default-deny-write;
if-feature "proxy-connect";
presence true; // only so ex-http-client can pass validation?
container tcp-client-parameters {
description
"A wrapper around the TCP parameters to avoid
name collisions.";
uses "tcpc:tcp-client-grouping";
}
container tls-client-parameters {
description
"A wrapper around the TLS parameters to avoid
name collisions.";
uses "tlsc:tls-client-grouping";
}
container proxy-client-identity {
description
"The identity the HTTP client should use when
authenticating itself to the HTTP server.";
uses client-identity-grouping;
}
description
"Proxy server settings.";
}
} // grouping http-client-grouping
} // module ietf-http-client
<CODE ENDS>
4. The HTTP Server Model
4.1. Tree Diagram
This section provides a tree diagram [RFC8340] for the "ietf-http-
server" module.
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module: ietf-http-server
grouping http-server-grouping
+-- server-name? string
+-- protocol-versions
| +-- protocol-version* enumeration
+-- client-authentication!
+-- (required-or-optional)
| +--:(required)
| | +-- required? empty
| +--:(optional)
| +-- optional? empty
+-- (local-or-external)
+--:(local) {local-client-auth-supported}?
| +-- users
| +-- user* [user-id]
| +-- user-id? string
| +-- (auth-type)?
| +--:(basic)
| +-- basic {basic-auth}?
| +-- user-id? string
| +-- password? ianach:crypt-hash
+--:(external) {external-client-auth-supported}?
+-- client-auth-defined-elsewhere? empty
4.2. Example Usage
This section presents an example showing the http-server-grouping
populated with some data.
<http-server xmlns="urn:ietf:params:xml:ns:yang:ietf-http-server">
<server-name>foo.example.com</server-name>
<protocol-versions>
<protocol-version>HTTP/1.1</protocol-version>
<protocol-version>HTTP/2.0</protocol-version>
</protocol-versions>
<client-authentication>
<required/>
<client-auth-defined-elsewhere/>
</client-authentication>
</http-server>
4.3. YANG Module
This YANG module has normative references to [RFC6991].
<CODE BEGINS> file "ietf-http-server@2019-11-02.yang"
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module ietf-http-server {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-http-server";
prefix https;
import iana-crypt-hash {
prefix ianach;
reference
"RFC 7317: A YANG Data Model for System Management";
}
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>";
description
"This module defines reusable groupings for HTTP servers that
can be used as a basis for specific HTTP 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
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capitals, as shown here.";
revision 2019-11-02 {
description
"Initial version";
reference
"RFC XXXX: YANG Groupings for HTTP Clients and HTTP Servers";
}
// Features
feature local-client-auth-supported {
description
"Indicates that the HTTP server supports local configuration
of client credentials.";
}
feature external-client-auth-supported {
description
"Indicates that the HTTP server supports external configuration
of client credentials.";
}
feature basic-auth {
description
"The 'basic-auth' feature indicates that the server
may be configured authenticate users using the 'basic'
HTTP authentication scheme.";
reference
"RFC 7617: The 'Basic' HTTP Authentication Scheme";
}
// Groupings
grouping http-server-grouping {
description
"A reusable grouping for configuring an HTTP server.
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
'http-server-parameters'). This model purposely does
not do this itself so as to provide maximum flexibility
to consuming models.";
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leaf server-name {
nacm:default-deny-write;
type string;
description
"The value of the 'Server' header field. If not set, then
underlying software's default value is used. Set to the
empty string to disable.";
}
container protocol-versions {
nacm:default-deny-write;
description
"A list of HTTP protocol versions supported by this
server.";
leaf-list protocol-version {
type enumeration {
enum "HTTP/1.0" {
description
"The server supports the 'HTTP/1.0' protocol.";
}
enum "HTTP/1.1" {
description
"The server supports the 'HTTP/1.1' protocol.";
}
enum "HTTP/2.0" {
description
"The server supports the 'HTTP/2.0' protocol.";
}
}
description
"An HTTP protocol version supported by this server.";
}
}
container client-authentication {
nacm:default-deny-write;
presence
"Indicates that HTTP based client authentication is
supported (i.e., the server will request that the
HTTP client send authenticate when needed). This
is needed as some HTTP-based protocols may only
support, e.g., TLS-level client authentication.";
description
"Specifies if HTTP client authentication is required or
optional, and specifies if the credentials needed to
authenticate the HTTP client are configured locally
or externally.";
choice required-or-optional {
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mandatory true; // or default to 'required' ?
description
"Indicates if HTTP-level client authentication is required
or optional. This is necessary for some protocols (e.g.,
RESTCONF) that may optionally authenticate a client via
TLS-level authentication, HTTP-level authentication, or
both simultaneously).";
leaf required {
type empty;
description
"Indicates that HTTP-level client authentication is
required to access protected resources.";
}
leaf optional {
type empty;
description
"Indicates that HTTP-level client authentication is
optional to access protected resources.";
}
}
choice local-or-external {
mandatory true;
description
"Indicates if the client credentials are configured
locally or externally. The need to support external
configuration for client authentication stems from
the desire to support consuming data models that
prefer to place client authentication with client
definitions, rather then in a data model principally
concerned with configuring the transport.";
case local {
if-feature "local-client-auth-supported";
description
"Client credentials are configured locally.";
container users {
description
"A list of locally configured users.";
list user {
key user-id;
description
"The list of local users configured on this device.";
leaf user-id {
type string;
description
"The user-id for the authenticating client.";
}
choice auth-type {
description
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"The authentication type.";
container basic {
if-feature "basic-auth";
leaf user-id {
type string;
description
"The user-id for the authenticating client.";
}
leaf password {
nacm:default-deny-write;
type ianach:crypt-hash;
description
"The password for the authenticating client.";
}
description
"The 'basic' HTTP scheme credentials.";
reference
"RFC 7617:
The 'Basic' HTTP Authentication Scheme";
}
}
}
}
}
case external {
if-feature "external-client-auth-supported";
description
"Client credentials are configured externally.";
leaf client-auth-defined-elsewhere {
type empty;
description
"Indicates that credentials needed to authenticate
clients are configured elsewhere.";
}
}
} // choice local-or-external
} // container client-authentication
}
}
<CODE ENDS>
5. Security Considerations
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-
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implement secure transport layers (e.g., SSH, HTTP) 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 defined 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:
FIXME: (pending - TBD)
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:
FIXME: (pending client auth params?)
Some of the RPC 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:
The modules defined in this document do not define any 'RPC' or
'action' statements.
6. IANA Considerations
6.1. The IETF XML Registry
This document registers two URIs in the "ns" subregistry of the IETF
XML Registry [RFC3688]. Following the format in [RFC3688], the
following registrations are requested:
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URI: urn:ietf:params:xml:ns:yang:ietf-http-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-http-server
Registrant Contact: The NETCONF WG of the IETF.
XML: N/A, the requested URI is an XML namespace.
6.2. The YANG Module Names Registry
This document registers two YANG modules in the YANG Module Names
registry [RFC6020]. Following the format in [RFC6020], the following
registrations are requested:
name: ietf-http-client
namespace: urn:ietf:params:xml:ns:yang:ietf-http-client
prefix: httpc
reference: RFC XXXX
name: ietf-http-server
namespace: urn:ietf:params:xml:ns:yang:ietf-http-server
prefix: https
reference: RFC XXXX
7. References
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/info/rfc6020>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/info/rfc6991>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
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[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/info/rfc8341>.
7.2. Informative References
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
Author's Address
Kent Watsen
Watsen Networks
EMail: kent+ietf@watsen.net
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