| NETCONF Working Group | K. Watsen |
| Internet-Draft | Watsen Networks |
| Intended status: Standards Track | November 2, 2019 |
| Expires: May 5, 2020 |
YANG Groupings for HTTP Clients and HTTP Servers
draft-kwatsen-netconf-http-client-server-05
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.
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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.
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.
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-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
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>
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
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
"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;
}
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>
This section provides a tree diagram [RFC8340] for the "ietf-http-server" module.
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
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>
This YANG module has normative references to [RFC6991].
<CODE BEGINS> file "ietf-http-server@2019-11-02.yang"
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
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.";
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 {
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
"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>
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, 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:
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 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:
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:
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.
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
| [RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997. |
| [RFC6020] | Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010. |
| [RFC6991] | Schoenwaelder, J., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013. |
| [RFC7950] | Bjorklund, M., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016. |
| [RFC8174] | Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017. |
| [RFC8341] | Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018. |
| [RFC3688] | Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004. |
| [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. |
| [RFC8340] | Bjorklund, M. and L. Berger, "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018. |