NETCONF Working Group K. Watsen Internet-Draft Watsen Networks Intended status: Standards Track November 20, 2019 Expires: May 23, 2020 YANG Groupings for HTTP Clients and HTTP Servers draft-ietf-netconf-http-client-server-01 Abstract This document defines two YANG modules: the first defines a minimal grouping for configuring an HTTP client, and the second defines a minimal grouping for configuring an HTTP server. It is intended that these groupings will be used to help define the configuration for simple HTTP-based protocols (not for complete webservers or browsers). 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 "2019-11-20" --> 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 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." Watsen Expires May 23, 2020 [Page 1] Internet-Draft Groupings for HTTP Clients and Servers November 2019 This Internet-Draft will expire on May 23, 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 . . . . . . . . . . . . . . . . . . . 12 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 6.1. The IETF XML Registry . . . . . . . . . . . . . . . . . . 13 6.2. The YANG Module Names Registry . . . . . . . . . . . . . 13 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 7.1. Normative References . . . . . . . . . . . . . . . . . . 14 7.2. Informative References . . . . . . . . . . . . . . . . . 14 Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 16 A.1. 00 to 01 . . . . . . . . . . . . . . . . . . . . . . . . 16 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 16 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 16 1. Introduction This document defines two YANG 1.1 [RFC7950] modules: the first defines a minimal grouping for configuring an HTTP client, and the second defines a minimal grouping for configuring an HTTP server. It is intended that these groupings will be used to help define the Watsen Expires May 23, 2020 [Page 2] Internet-Draft Groupings for HTTP Clients and Servers November 2019 configuration for simple HTTP-based protocols (not for complete webservers or browsers). 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. Watsen Expires May 23, 2020 [Page 3] Internet-Draft Groupings for HTTP Clients and Servers November 2019 bob secret 3.3. YANG Module This YANG module has normative references to [RFC6991]. file "ietf-http-client@2019-11-20.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: WG List: Author: Kent Watsen "; description "This module defines reusable groupings for HTTP clients that Watsen Expires May 23, 2020 [Page 4] Internet-Draft Groupings for HTTP Clients and Servers November 2019 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 2019-11-20 { 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 Watsen Expires May 23, 2020 [Page 5] Internet-Draft Groupings for HTTP Clients and Servers November 2019 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."; Watsen Expires May 23, 2020 [Page 6] Internet-Draft Groupings for HTTP Clients and Servers November 2019 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 4. The HTTP Server Model 4.1. Tree Diagram This section provides a tree diagram [RFC8340] for the "ietf-http- server" module. Watsen Expires May 23, 2020 [Page 7] Internet-Draft Groupings for HTTP Clients and Servers November 2019 module: ietf-http-server grouping http-server-grouping +-- server-name? string +-- protocol-versions | +-- protocol-version* enumeration +-- client-authentication! {client-auth-config-supported}? +-- users +-- user* [user-id] +-- user-id? string +-- (auth-type)? +--:(basic) +-- basic {basic-auth}? +-- user-id? string +-- password? ianach:crypt-hash 4.2. Example Usage This section presents an example showing the http-server-grouping populated with some data. foo.example.com HTTP/1.1 HTTP/2.0 4.3. YANG Module This YANG module has normative references to [RFC6991]. file "ietf-http-server@2019-11-20.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; Watsen Expires May 23, 2020 [Page 8] Internet-Draft Groupings for HTTP Clients and Servers November 2019 reference "RFC 8341: Network Configuration Access Control Model"; } organization "IETF NETCONF (Network Configuration) Working Group"; contact "WG Web: WG List: Author: Kent Watsen "; 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 2019-11-20 { description "Initial version"; reference "RFC XXXX: YANG Groupings for HTTP Clients and HTTP Servers"; } // Features feature client-auth-config-supported { description Watsen Expires May 23, 2020 [Page 9] Internet-Draft Groupings for HTTP Clients and Servers November 2019 "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 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."; } Watsen Expires May 23, 2020 [Page 10] Internet-Draft Groupings for HTTP Clients and Servers November 2019 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 { if-feature "client-auth-config-supported"; 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 how the HTTP server can authenticate HTTP clients."; 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."; Watsen Expires May 23, 2020 [Page 11] Internet-Draft Groupings for HTTP Clients and Servers November 2019 } 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"; } } } } } // container client-authentication } // grouping http-server-grouping } 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- 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. Watsen Expires May 23, 2020 [Page 12] Internet-Draft Groupings for HTTP Clients and Servers November 2019 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: 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: Watsen Expires May 23, 2020 [Page 13] Internet-Draft Groupings for HTTP Clients and Servers November 2019 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, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . [RFC7950] Bjorklund, M., Ed., "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, . 7.2. Informative References [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . Watsen Expires May 23, 2020 [Page 14] Internet-Draft Groupings for HTTP Clients and Servers November 2019 [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, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . Watsen Expires May 23, 2020 [Page 15] Internet-Draft Groupings for HTTP Clients and Servers November 2019 Appendix A. Change Log A.1. 00 to 01 o Modified Abstract and Intro to be more accurate wrt intended applicability. o In ietf-http-client, removed "protocol-version" and all auth schemes except "basic". o In ietf-http-client, factored out "client-identity-grouping" for proxy connections. o In ietf-http-server, removed "choice required-or-optional" and "choice local-or-external". o In ietf-http-server, moved the basic auth under a "choice auth- type" limited by new "feature basic-auth". Acknowledgements The authors would like to thank for following for lively discussions on list and in the halls (ordered by last name): TBD Author's Address Kent Watsen Watsen Networks EMail: kent+ietf@watsen.net Watsen Expires May 23, 2020 [Page 16]