| I2NSF Working Group | J. Jeong, Ed. |
| Internet-Draft | C. Chung |
| Intended status: Standards Track | Sungkyunkwan University |
| Expires: March 1, 2021 | T. Ahn |
| Korea Telecom | |
| R. Kumar | |
| Juniper Networks | |
| S. Hares | |
| Huawei | |
| August 28, 2020 |
I2NSF Consumer-Facing Interface YANG Data Model
draft-ietf-i2nsf-consumer-facing-interface-dm-10
This document describes an information model and a YANG data model for the Consumer-Facing Interface between an Interface to Network Security Functions (I2NSF) User and Security Controller in an I2NSF system in a Network Functions Virtualization (NFV) environment. The information model defines various types of managed objects and the relationship among them needed to build the interface. The information model is based on the "Event-Condition-Action" (ECA) policy model defined by a capability information model for I2NSF [I-D.ietf-i2nsf-capability], and the data model is defined for enabling different users of a given I2NSF system to define, manage, and monitor security policies for specific flows within an administrative domain.
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 March 1, 2021.
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.
In a framework of Interface to Network Security Functions (I2NSF) [RFC8329], each vendor can register their NSFs using a Developer's Management System (DMS). Assuming that vendors also provide the front-end web applications registered with an I2NSF User, the Consumer-Facing Interface is required because the web applications developed by each vendor need to have a standard interface specifying the data types used when the I2NSF User and Security Controller communicate using this interface. Therefore, this document specifies the required information, their data types, and encoding schemes so that high-level security policies (or configuration information for security policies) can be transferred to the Security Controller through the Consumer-Facing Interface. These policies can easily be translated by the Security Controller into low-level security policies. The Security Controller delivers the translated policies to Network Security Functions (NSFs) according to their respective security capabilities for the required securiy enforcement.
The Consumer-Facing Interface would be built using a set of objects, with each object capturing a unique set of information from Security Administrator (i.e., I2NSF User [RFC8329]) needed to express a Security Policy. An object may have relationship with various other objects to express a complete set of requirements. An information model captures the managed objects and relationship among these objects. The information model proposed in this document is structured in accordance with the "Event-Condition-Action" (ECA) policy model.
An NSF Capability model is proposed in [I-D.ietf-i2nsf-capability] as the basic model for both the NSF-Facing interface and Consumer-Facing Interface security policy model of this document.
[RFC3444] explains differences between an information and data model. This document uses the guidelines in [RFC3444] to define both the information and data model for Consumer-Facing Interface. Figure 1 shows a high-level abstraction of Consumer-Facing Interface. A data model, which represents an implementation of the information model in a specific data representation language, is also defined in this document.
+-----------------+
| Consumer-Facing |
| Interface |
+--------+--------+
^
|
+-------------+------------+
| | |
+-----+----+ +-----+----+ +----+----+
| Policy | | Endpoint | | Threat |
| | | groups | | feed |
+-----+----+ +----------+ +---------+
^
|
+------+------+
| Rule |
+------+------+
^
|
+----------------+----------------+
| | |
+------+------+ +------+------+ +------+------+
| Event | | Condition | | Action |
+-------------+ +-------------+ +-------------+
Figure 1: Diagram for High-level Abstraction of Consumer-Facing Interface
Data models are defined at a lower level of abstraction and provide many details. They provide details about the implementation of a protocol's specification, e.g., rules that explain how to map managed objects onto lower-level protocol constructs. Since conceptual models can be implemented in different ways, multiple data models can be derived from a single information model.
The efficient and flexible provisioning of network functions by a Network Functions Virtualization (NFV) system leads to a rapid advance in the network industry. As practical applications, Network Security Functions (NSFs), such as firewall, Intrusion Detection System (IDS)/Intrusion Prevention System (IPS), and attack mitigation, can also be provided as Virtual Network Functions (VNF) in the NFV system. By the efficient virtualization technology, these VNFs might be automatically provisioned and dynamically migrated based on real-time security requirements. This document presents a YANG data model to implement security functions based on NFV.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119][RFC3444] [RFC8174].
This document uses the terminology described in [RFC8329].
This document follows the guidelines of [RFC8407], uses the common YANG types defined in [I-D.ietf-netmod-rfc6991-bis], and adopts the Network Management Datastore Architecture (NMDA). The meaning of the symbols in tree diagrams is defined in [RFC8340].
A Policy object represents a mechanism to express a Security Policy by Security Administrator (i.e., I2NSF User) using Consumer-Facing Interface toward Security Controller; the policy would be enforced on an NSF. Figure 2 shows the YANG tree of the Policy object. The Policy object SHALL have the following information:
+--rw i2nsf-cfi-policy* [policy-name]
+--rw policy-name string
+--rw rules
+--rw endpoint-groups
+--rw threat-prevention
Figure 2: Policy YANG Data Tree
A policy is a container of Rule(s). In order to express a Rule, a Rule must have complete information such as where and when a policy needs to be applied. This is done by defining a set of managed objects and relationship among them. A Policy Rule may be related segmentation, threat mitigation or telemetry data collection from an NSF in the network, which will be specified as the sub-model of the policy model in the subsequent sections. Figure 3 shows the YANG data tree of the Rule object. The rule object SHALL have the following information:
+--rw rules* [rule-name]
+--rw rule-name string
+--rw event
+--rw (condition)?
+--rw action
+--rw ipsec-method
Figure 3: Rule YANG Data Tree
Note that in the case of policy conflicts, the resolution of the conflicted policies conforms to the guidelines of "Information Model of NSFs Capabilities" [I-D.ietf-i2nsf-capability].
The Event Object contains information related to scheduling a Rule. The Rule could be activated based on a set time or security event. Figure 4 shows the YANG tree of the Event object. Event object SHALL have following information:
+--rw event
+--rw security-event identityref
+--rw time-information
| +--rw start-date-time? yang:date-and-time
| +--rw end-date-time? yang:date-and-time
| +--rw period
| | +--rw start-time? time
| | +--rw stop-time? time
| | +--rw day* identityref
| | +--rw date* int32
| | +--rw month* string
+--rw frequency? enumeration
Figure 4: Event Sub-model YANG Data Tree
This object represents Conditions that Security Administrator wants to apply the checking on the traffic in order to determine whether the set of actions in the Rule can be executed or not. The Condition Sub-model consists of three different types of containers each representing different cases, such as general firewall and DDoS-mitigation cases, and a case when the condition is based on the payload strings of packets. Each containers have source and destination-target to represent the source and destination for each case. Figure 5 shows the YANG tree of the Condition object. The Condition Sub-model SHALL have following information:
+--rw condition
+--:firewall-condition
| +--rw source
| | -> /i2nsf-cfi-policy/endpoint-groups/user-group/name
| +--rw destination*
| | -> /i2nsf-cfi-policy/endpoint-groups/user-group/name
+--:ddos-condition
| +--rw source*
| | -> /i2nsf-cfi-policy/endpoint-groups/device-group/name
| +--rw destination*
| | -> /i2nsf-cfi-policy/endpoint-groups/device-group/name
| +--rw rate-limit
| | +--rw packet-threshold-per-second? uint32
+--:location-condition
| +--rw source*
| | -> /i2nsf-cfi-policy/endpoint-groups/location-group/name
| +--rw destination
| | -> /i2nsf-cfi-policy/endpoint-groups/location-group/name
+--:custom-condition
| +--rw source*
| | -> /i2nsf-cfi-policy/threat-preventions/payload-content/name
| +--rw destination?
| | -> /i2nsf-cfi-policy/threat-preventions/payload-content/name
+--:threat-feed-condition
+--rw source*
| -> /i2nsf-cfi-policy/threat-preventions/threat-feed-list/name
+--rw destination?
| -> /i2nsf-cfi-policy/threat-preventions/threat-feed-list/name
Figure 5: Condition Sub-model YANG Data Tree
This object represents actions that Security Admin wants to perform based on certain traffic class. Figure 6 shows the YANG tree of the Action object. The Action object SHALL have following information:
+--rw action +--rw primary-action identityref +--rw secondary-action? identityref
Figure 6: Action Sub-model YANG Data Tree
The Policy Endpoint Group is a very important part of building User-Construct based policies. A Security Administrator would create and use these objects to represent a logical entity in their business environment, where a Security Policy is to be applied. There are multiple managed objects that constitute a Policy's Endpoint Group, as shown in Figure 7. Figure 8 shows the YANG tree of the Endpoint-Groups object. This section lists these objects and relationship among them.
It is assumed that the information of Endpoint Groups (e.g., User-group, Device-group, and Location-group) such as the IP address(es) of each member in a group are stored in the I2NSF database available to the Security Controller, and that the IP address information of each group in the I2NSF database is synchronized with other systems in the networks under the same administration.
+-------------------+
| Endpoint Groups |
+---------+---------+
^
|
+--------------+----------------+
0..n | 0..n | 0..n |
+-----+----+ +------+-----+ +-------+------+
|User-group| |Device-group| |Location-group|
+----------+ +------------+ +--------------+
Figure 7: Endpoint Group Diagram
+--rw endpoint-groups
| +--rw user-group* [name]
| ...
| +--rw device-group* [name]
| ...
| +--rw location-group* [name]
| ...
Figure 8: Endpoint Group YANG Data Tree
This object represents a User-Group. Figure 9 shows the YANG tree of the User-Group object. The User-Group object SHALL have the following information:
+--rw user-group* [name]
+--rw name string
+--rw (match-type)
+--:(exact-match-ipv4)
| +--rw ipv4? inet:ipv4-address
+--:(exact-match-ipv6)
| +--rw ipv6? inet:ipv6-address
+--:(range-match-ipv4)
| +--rw range-ipv4-address
| +--rw start-ipv4-address inet:ipv4-address
| +--rw end-ipv4-address inet:ipv4-address
+--:(range-match-ipv6)
+--rw range-ipv6-address*
+--rw start-ipv6-address inet:ipv6-address
+--rw end-ipv6-address inet:ipv6-address
Figure 9: User Group YANG Data Tree
This object represents a Device-Group. Figure 10 shows the YANG tree of the Device-group object. The Device-Group object SHALL have the following information:
+--rw device-group* [name]
+--rw name string
+--rw (match-type)
| +--:(exact-match-ipv4)
| | +--rw ipv4? inet:ipv4-address
| +--:(exact-match-ipv6)
| | +--rw ipv6? inet:ipv6-address
| +--:(range-match-ipv4)
| | +--rw range-ipv4-address*
| | | +--rw start-ipv4-address inet:ipv4-address
| | | +--rw end-ipv4-address inet:ipv4-address
| +--:(range-match-ipv6)
| | +--rw range-ipv6-address*
| | | +--rw start-ipv6-address inet:ipv6-address
| | | +--rw end-ipv6-address inet:ipv6-address
+--rw protocol identityref
Figure 10: Device Group YANG Data Tree
This object represents a location group based on either tag or other information. Figure 11 shows the YANG tree of the Location-Group object. The Location-Group object SHALL have the following information:
+--rw location-group* [name]
+--rw name string
+--rw geo-ip-ipv4 inet:ipv4-address
+--rw geo-ip-ipv6 inet:ipv6-address
+--rw continent? identityref
Figure 11: Location Group YANG Data Tree
The threat prevention plays an important part in the overall security posture by reducing the attack surfaces. This information could come from various threat feeds (i.e., sources for obtaining the threat information). There are multiple managed objects that constitute this category. This section lists these objects and relationship among them. Figure 13 shows the YANG tree of a Threat-Prevention object.
+-------------------+ | Threat Prevention | +---------+---------+ ^ | +---------+---------+ 0..n | 0..n | +------+------+ +--------+--------+ | Threat-feed | | payload-content | +-------------+ +-----------------+
Figure 12: Threat Prevention Diagram
+--rw threat-prevention
+--rw threat-feed-list* [name]
...
+--rw payload-content* [name]
...
Figure 13: Threat Prevention YANG Data Tree
This object represents a threat feed which provides the signatures of malicious activities. Figure 14 shows the YANG tree of a Threat-feed-list. The Threat-Feed object SHALL have the following information:
It is assumed that the I2NSF User obtains the threat signatures (i.e., threat content patterns) from a threat-feed server (i.e., feed provider), which is a server providing threat signatures. With the obtained threat signatures, the I2NSF User can deliver them to the Security Controller. The retrieval of the threat signatures by the I2NSF User is out of scope in this document.
+--rw threat-prevention
+--rw threat-feed-list* [name]
+--rw name identityref
+--rw server-ipv4? inet:ipv4-address
+--rw server-ipv6? inet:ipv6-address
+--rw description? string
+--rw threat-file-types* identityref
+--rw signatures* identityref
Figure 14: Threat Feed YANG Data Tree
This object represents a custom list created for the purpose of defining an exception to threat feeds. Figure 15 shows the YANG tree of a Payload-content list. The Payload-Content object SHALL have the following information:
+--rw payload-content* [name]
+--rw name string
+--rw description string
+--rw content* string
Figure 15: Payload Content in YANG Data Tree
Network Configuration Access Control Model (NACM) provides a user group with an access control with the following features [RFC8341]:
The data model of the I2NSF Consumer-Facing Interface utilizes the NACM's mechanisms to manage the access control on the I2NSF Consumer-Facing Interface. The NACM with the above features can be used to set up the access control rules of a user group in the I2NSF Consumer-Facing Interface.
list rule {
key "name";
ordered-by user;
leaf name {
type string {
length "1..max";
}
description
"Arbitrary name assigned to the rule.";
}
leaf module-name {
type union {
type matchall-string-type;
type string;
}
default "*";
description
"Name of the module associated with this rule."
}
leaf access-operations {
type union {
type matchall-string-type;
type access-operations-type;
}
default "*";
description
"Access operations associated with this rule."
}
leaf action {
type action-type;
mandatory true;
description
"The access control action associated with the
rule. If a rule is determined to match a
particular request, then this object is used
to determine whether to permit or deny the
request.";
}
Figure 16: A Part of the NACM YANG Data Model
Figure 16 shows part of the NACM module to enable the access control of a user group for the I2NSF Consumer-Facing Interface. To use the NACM, a user needs to configure either a NETCONF server [RFC6241] or a RESTCONF server [RFC8040] to enable the NACM module. Then, the user can simply use an account of root or admin user for the access control for the module of the I2NSF Consumer-Facing Interface (i.e., ietf-i2nsf-cfi-policy). An XML example to configure the access control a user group for the I2NSF Consumer-Facing Interface can be seen in Section 10.
The main objective of this data model is to provide both an information model and the corresponding YANG data model of I2NSF Consumer-Facing Interface. This interface can be used to deliver control and management messages between an I2NSF User and Security Controller for the I2NSF User's high-level security policies.
The semantics of the data model must be aligned with the information model of the Consumer-Facing Interface. The transformation of the information model is performed so that this YANG data model can facilitate the efficient delivery of the control or management messages.
This data model is designed to support the I2NSF framework that can be extended according to the security needs. In other words, the model design is independent of the content and meaning of specific policies as well as the implementation approach.
With the YANG data model of I2NSF Consumer-Facing Interface, this document suggests use cases for security policy rules such as time-based firewall, VoIP/VoLTE security service, and DDoS-attack mitigation in Section 9.
This section describes a YANG module of Consumer-Facing Interface. This YANG module imports from [RFC6991] and uses the typedef of time in [I-D.ietf-netmod-rfc6991-bis]. It makes references to [RFC0854][RFC0913][RFC0959][RFC1081][RFC1631][RFC2616][RFC2818][RFC4250][RFC5321].
<CODE BEGINS> file "ietf-i2nsf-cfi-policy@2020-08-28.yang"
module ietf-i2nsf-cfi-policy {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-i2nsf-cfi-policy";
prefix cfi-policy;
import ietf-inet-types{
prefix inet;
}
import ietf-yang-types{
prefix yang;
}
import ietf-netconf-acm {
prefix nacm;
}
organization
"IETF I2NSF (Interface to Network Security Functions)
Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/i2nsf>
WG List: <mailto:i2nsf@ietf.org>
Editor: Jaehoon Paul Jeong
<mailto:pauljeong@skku.edu>
Editor: Patrick Lingga
<mailto:patricklink@skku.edu>";
description
"This module is a YANG module for Consumer-Facing Interface.
Copyright (c) 2020 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision "2020-08-28"{
description "Initial revision.";
reference
"RFC XXXX: I2NSF Consumer-Facing Interface YANG Data Model";
}
identity malware-file-type {
description
"Base identity for malware file types.";
}
identity executable-file {
base malware-file-type;
description
"Identity for executable file types.";
}
identity doc-file {
base malware-file-type;
description
"Identity for Microsoft document file types.";
}
identity html-app-file {
base malware-file-type;
description
"Identity for html application file types.";
}
identity javascript-file {
base malware-file-type;
description
"Identity for Javascript file types.";
}
identity pdf-file {
base malware-file-type;
description
"Identity for pdf file types.";
}
identity dll-file {
base malware-file-type;
description
"Identity for dll file types.";
}
identity msi-file {
base malware-file-type;
description
"Identity for Microsoft installer file types.";
}
identity security-event-type {
description
"Base identity for security event types.";
}
identity ddos {
base security-event-type;
description
"Identity for DDoS event types.";
}
identity spyware {
base security-event-type;
description
"Identity for spyware event types.";
}
identity trojan {
base security-event-type;
description
"Identity for Trojan infection event types.";
}
identity ransomware {
base security-event-type;
description
"Identity for ransomware infection event types.";
}
identity i2nsf-ipsec {
description
"Base identity for IPsec method types.";
reference
"draft-ietf-i2nsf-sdn-ipsec-flow-protection-08: Software-Defined
Networking (SDN)-based IPsec Flow Protection - IPsec method
types can be selected.";
}
identity ipsec-ike {
base i2nsf-ipsec;
description
"Identity for ipsec-ike.";
reference
"draft-ietf-i2nsf-sdn-ipsec-flow-protection-08: Software-Defined
Networking (SDN)-based IPsec Flow Protection - IPsec method
type with IKE is selected.";
}
identity ipsec-ikeless {
base i2nsf-ipsec;
description
"Identity for ipsec-ikeless.";
reference
"draft-ietf-i2nsf-sdn-ipsec-flow-protection-08: Software-Defined
Networking (SDN)-based IPsec Flow Protection - IPsec method
type without IKE is selected.";
}
identity continent {
description
"Base Identity for continent types.";
}
identity africa {
base continent;
description
"Identity for Africa.";
}
identity asia {
base continent;
description
"Identity for Asia.";
}
identity europe {
base continent;
description
"Identity for Europe.";
}
identity north-america {
base continent;
description
"Identity for North America.";
}
identity south-america {
base continent;
description
"Identity for South America.";
}
identity oceania {
base continent;
description
"Identity for Oceania";
}
identity protocol-type {
description
"This identity represents the protocol types.";
}
identity ftp {
base protocol-type;
description
"The identity for ftp protocol.";
reference
"RFC 959: File Transfer Protocol (FTP)";
}
identity ssh {
base protocol-type;
description
"The identity for ssh protocol.";
reference
"RFC 4250: The Secure Shell (SSH) Protocol";
}
identity telnet {
base protocol-type;
description
"The identity for telnet.";
reference
"RFC 854: Telnet Protocol";
}
identity smtp {
base protocol-type;
description
"The identity for smtp.";
reference
"RFC 5321: Simple Mail Transfer Protocol (SMTP)";
}
identity sftp {
base protocol-type;
description
"The identity for sftp.";
reference
"RFC 913: Simple File Transfer Protocol (SFTP)";
}
identity http {
base protocol-type;
description
"The identity for http.";
reference
"RFC 2616: Hypertext Transfer Protocol (HTTP)";
}
identity https {
base protocol-type;
description
"The identity for https.";
reference
"RFC 2818: HTTP over TLS (HTTPS)";
}
identity pop3 {
base protocol-type;
description
"The identity for pop3.";
reference
"RFC 1081: Post Office Protocol -Version 3 (POP3)";
}
identity nat {
base protocol-type;
description
"The identity for nat.";
reference
"RFC 1631: The IP Network Address Translator (NAT)";
}
identity primary-action {
description
"This identity represents the primary actions, such as
PASS, DROP, ALERT, RATE-LIMIT, and MIRROR.";
}
identity pass {
base primary-action;
description
"The identity for pass.";
}
identity drop {
base primary-action;
description
"The identity for drop.";
}
identity alert {
base primary-action;
description
"The identity for alert.";
}
identity rate-limit {
base primary-action;
description
"The identity for rate-limit.";
}
identity mirror {
base primary-action;
description
"The identity for mirroring.";
}
identity secondary-action {
description
"This field identifies additional actions if a rule is
matched. This could be one of 'LOG', 'SYSLOG',
'SESSION-LOG', etc.";
}
identity log {
base secondary-action;
description
"The identity for logging.";
}
identity syslog {
base secondary-action;
description
"The identity for system logging.";
}
identity session-log {
base secondary-action;
description
"The identity for session logging.";
}
identity signature-type {
description
"This represents the base identity for signature types.";
}
identity signature-yara {
base signature-type;
description
"This represents the YARA signatures.";
reference
"YARA: YARA signatures are explained.";
}
identity signature-snort {
base signature-type;
description
"This represents the SNORT signatures.";
reference
"SNORT: SNORT signatures are explained.";
}
identity signature-suricata {
base signature-type;
description
"This represents the SURICATA signatures.";
reference
"SURICATA: SURICATA signatures are explained.";
}
identity threat-feed-type {
description
"This represents the base identity for threat-feed.";
}
identity day {
description
"This represents the base for days.";
}
identity monday {
base day;
description
"This represents Monday.";
}
identity tuesday {
base day;
description
"This represents Tuesday.";
}
identity wednesday {
base day;
description
"This represents Wednesday.";
}
identity thursday {
base day;
description
"This represents Thursday.";
}
identity friday {
base day;
description
"This represents Friday.";
}
identity saturday {
base day;
description
"This represents Saturday.";
}
identity sunday {
base day;
description
"This represents Sunday.";
}
/*
* Typedefs
*/
typedef time {
type string {
pattern '(0[0-9]|1[0-9]|2[0-3]):[0-5][0-9]:[0-5][0-9](\.\d+)?'
+ '(Z|[\+\-]((1[0-3]|0[0-9]):([0-5][0-9])|14:00))?';
}
description
"The time type represents an instance of time of zero-duration
that recurs every day.";
reference
"draft-ietf-netmod-rfc6991-bis-04: Common YANG Data Types -
typedef time is used.";
}
/*
* Groupings
*/
grouping ipv4-list {
description
"Grouping for an IPv4 address list.";
leaf-list ipv4 {
type inet:ipv4-address;
description
"This is the entry for an IPv4 address list.";
}
}
grouping ipv6-list {
description
"Grouping for an IPv6 address list.";
leaf-list ipv6 {
type inet:ipv6-address;
description
"This is the entry for an IPv6 address list.";
}
}
grouping ipv4 {
description
"Grouping for an IPv4 address.";
leaf ipv4 {
type inet:ipv4-address;
description
"This is the entry for an IPv4 address.";
}
}
grouping ipv6 {
description
"Grouping for an IPv6 address.";
leaf ipv6 {
type inet:ipv6-address;
description
"This is the entry for an IPv6 address.";
}
}
grouping ip-address-info {
description
"There are two types to configure a security policy
for an IPv4 address, such as exact match and range match.";
choice match-type {
description
"User can choose between 'exact match' and 'range match'.";
case exact-match-ipv4 {
uses ipv4;
description
"Exact ip-address match for IPv4 addresses";
}
case exact-match-ipv6 {
uses ipv6;
description
"Exact ip-address match for IPv6 addresses";
}
case range-match-ipv4 {
container range-ipv4-address {
leaf start-ipv4-address {
type inet:ipv4-address;
mandatory true;
description
"A start IPv4 address for a range match.";
}
leaf end-ipv4-address {
type inet:ipv4-address;
mandatory true;
description
"An end IPv4 address for a range match.";
}
description
"A range match for IPv4 addresses is provided. Note that the
start IPv4 address must be lower than the end IPv4 address.";
}
}
case range-match-ipv6 {
container range-ipv6-address {
leaf start-ipv6-address {
type inet:ipv6-address;
mandatory true;
description
"A start IPv6 address for a range match.";
}
leaf end-ipv6-address {
type inet:ipv6-address;
mandatory true;
description
"An end IPv6 address for a range match.";
}
description
"A range match for IPv6 addresses is provided. Note that the
start IPv6 address must be lower than the end IPv4 address.";
}
}
}
}
grouping ipsec-based-method {
description
"This represents the ipsec-based method.";
list ipsec-method {
key "method";
description
"This represents the list of IPsec method types.";
leaf method {
type identityref {
base i2nsf-ipsec;
}
description
"This represents IPsec IKE and IPsec IKEless cases. If this
is not set, it cannot support IPsec IKE or IPsec IKEless.";
reference
"draft-ietf-i2nsf-sdn-ipsec-flow-protection-08:
Software-Defined Networking (SDN)-based IPsec Flow Protection
- IPsec method types can be selected.";
}
}
}
grouping user-group {
description
"The grouping for user-group entities, and contains information
such as name & ip-address.";
leaf name {
type string;
description
"This represents the name of a user-group. A user-group name
is used to map a user-group's name (e.g., employees) to an IP
address. It is dependent on implementation.";
}
uses ip-address-info{
refine match-type{
mandatory true;
}
description
"This represent the IP addresses of a user-group.";
}
}
grouping device-group {
description
"This group represents device group information such as ip-address
protocol.";
leaf name {
type string;
description
"This represents the name of a device-group.";
}
uses ip-address-info{
refine match-type{
mandatory true;
}
}
leaf-list protocol {
type identityref {
base protocol-type;
}
description
"This represents the communication protocols of devices. If this
is not set, it cannot support the appropriate protocol";
}
}
grouping location-group {
description
"This group represents location-group information such as geo-ip
and continent.";
leaf name {
type string;
description
"This represents the name of a location.";
}
list geo-ip-ipv4 {
key "ipv4-address";
description
"This represents the list of IPv4 addresses based on a location.";
leaf ipv4-address{
type inet:ipv4-address;
description
"This represents an IPv4 geo-ip address of a location.";
}
leaf ipv4-prefix{
type inet:ipv4-prefix;
description
"This represents the prefix for the IPv4 addresses.";
}
}
list geo-ip-ipv6 {
key "ipv6-address";
description
"This represents the list of IPv6 addresses based on a location.";
leaf ipv6-address{
type inet:ipv6-address;
description
"This represents an IPv6 geo-ip address of a location.";
}
leaf ipv6-prefix{
type inet:ipv6-prefix;
description
"This represents the prefix for the IPv6 addresses.";
}
}
leaf continent {
type identityref {
base continent;
}
default asia;
description
"location-group has geo-ip addresses of the corresponding
continent.";
}
}
grouping threat-feed-info {
description
"This is the grouping for the threat-feed-list";
leaf threat-type {
type identityref {
base threat-feed-type;
}
description
"This represents the type of the threat-feed.";
}
leaf server-ipv4 {
type inet:ipv4-address;
description
"The IPv4 address for the threat-feed server.";
}
leaf server-ipv6 {
type inet:ipv6-address;
description
"The IPv6 address for the threat-feed server.";
}
leaf description {
type string;
description
"This represents the descriptions of a threat-feed. The
description should include information, such as type, threat,
method, and file type. Structured Threat Information Expression
(STIX) can be used for description of a threat [STIX].";
}
}
grouping payload-string {
description
"The grouping for payload-string content. It contains information
such as name and string content.";
leaf description {
type string;
description
"This represents the description of a payload. If this is not
set, it cannot support the description of how the payload content
is related to a security attack.";
}
leaf-list content {
type string;
description
"This represents the string of the payload contents. This content
leaf-list contains the payload of a packet to analyze a threat.
Due to the types of threats, the type of the content is defined
as a string to accommodate any kind of a payload type such as
HTTP, HTTPS, and SIP. If this is not set, it cannot support the
payload contents involved in a security attack as a string.";
}
}
list i2nsf-cfi-policy {
key "policy-name";
description
"This is a security policy list. Each policy in the list contains
a list of security policy rules, and is a policy instance to have
the information of where and when a policy needs to be applied.";
leaf policy-name {
type string;
description
"The name which identifies the policy.";
}
container rules{
description
"This container has rules.";
nacm:default-deny-write;
list rule {
key "rule-name";
ordered-by user;
leaf rule-name {
type string;
description
"This represents the name for a rule.";
}
description
"There can be a single or multiple number of rules.";
container event {
description
"This represents an event (i.e., a security event), for which
a security rule is made.";
leaf security-event {
type identityref {
base security-event-type;
}
description
"This contains the description of a security event. If this
is not set, it cannot support what security event will be
enforced.";
}
container time-information {
description
"The time information when a security policy rule should be
applied.";
leaf start-date-time {
type yang:date-and-time;
description
"This is the start date and time for a security policy
rule.";
}
leaf end-date-time {
type yang:date-and-time;
description
"This is the end date and time for a policy rule. The
policy rule will stop working after the specified
end-date-time.";
}
container period{
when
"../../frequency!='only-once'";
description
"This represents the repetition time. In the case where
the frequency is weekly, the days can be set.";
leaf start-time {
type time;
description
"This is a period's start time for an event.";
reference
"RFC 6991-bis: Common YANG Data Types - The time type
represents an instance of time of zero-duration that
recurs every day. When RFC 6991-bis becomes an RFC,
time must be replaced with yang:time.";
}
leaf end-time {
type time;
description
"This is a period's end time for an event.";
reference
"RFC 6991-bis: Common YANG Data Types - The time type
represents an instance of time of zero-duration that
recurs every day. When RFC 6991-bis becomes an RFC,
time must be replaced with yang:time.";
}
leaf-list day {
when
"../../../frequency='weekly'";
type identityref{
base day;
}
min-elements 1;
description
"This represents the repeated day of every week (e.g.,
Monday and Tuesday). More than one day can be
specified.";
}
leaf-list date {
when
"../../../frequency='monthly'";
type int32{
range "1..31";
}
min-elements 1;
description
"This represents the repeated date of every month. More
than one date can be specified.";
}
leaf-list month {
when
"../../../frequency='yearly'";
type string{
pattern '\d{2}-\d{2}';
}
min-elements 1;
description
"This represents the repeated date and month of every
year. More than one can be specified. A pattern used
here is Month and Date (MM-DD).";
}
}
}
leaf frequency {
type enumeration {
enum only-once {
description
"This represents that the rule is immediately enforced
only once and not repeated. The policy will
continuously be active from the start-time to the
end-time.";
}
enum daily {
description
"This represents that the rule is enforced on a daily
basis. The policy will be repeated daily until the
end-date.";
}
enum weekly {
description
"This represents that the rule is enforced on a weekly
basis. The policy will be repeated weekly until the
end-date. The repeated days can be specified.";
}
enum monthly {
description
"This represents that the rule is enforced on a monthly
basis. The policy will be repeated monthly until the
end-date.";
}
enum yearly {
description
"This represents that the rule is enforced on a yearly
basis. The policy will be repeated yearly until the
end-date.";
}
}
default only-once;
description
"This represents how frequently the rule should be enforced.";
}
}
container condition {
description
"Conditions for general security policies.";
container firewall-condition {
description
"A general firewall condition.";
leaf source {
type leafref {
path
"/i2nsf-cfi-policy/endpoint-groups/user-group/name";
}
description
"This describes the path to the source.";
}
leaf-list destination {
type leafref {
path
"/i2nsf-cfi-policy/endpoint-groups/user-group/name";
}
description
"This describes the paths to the destinations.";
}
}
container ddos-condition {
description
"A condition for a DDoS attack.";
leaf-list source {
type leafref {
path
"/i2nsf-cfi-policy/endpoint-groups/device-group/name";
}
description
"This describes the paths to the sources.";
}
leaf-list destination {
type leafref {
path
"/i2nsf-cfi-policy/endpoint-groups/device-group/name";
}
description
"This describes the paths to the destinations.";
}
container rate-limit {
description
"This describes the rate-limit.";
leaf packet-threshold-per-second {
type uint32;
description
"This is a trigger value for a rate limit for a
DDoS-attack mitigation.";
}
}
}
container location-condition {
description
"A condition for a location-based connection";
leaf-list source {
type leafref {
path
"/i2nsf-cfi-policy/endpoint-groups/location-group/name";
}
description
"This describes the paths to a location's sources.";
}
leaf-list destination {
type leafref {
path
"/i2nsf-cfi-policy/endpoint-groups/location-group/name";
}
description
"This describes the paths to a location's destinations.";
}
}
container custom-condition {
description
"A condition based on a packet's content.";
leaf-list source {
type leafref {
path
"/i2nsf-cfi-policy/threat-preventions/payload-content/name";
}
description
"This describes the paths to a packet content's sources.";
}
leaf destination {
type leafref {
path
"/i2nsf-cfi-policy/threat-preventions/payload-content/name";
}
description
"This describes the path to a packet content's
destination.";
}
}
container threat-feed-condition {
description
"A condition based on the threat-feed information.";
leaf-list source {
type leafref {
path
"/i2nsf-cfi-policy/threat-preventions/threat-feed-list/name";
}
description
"This describes the paths to a threat-feed's sources.";
}
leaf destination {
type leafref {
path
"/i2nsf-cfi-policy/threat-preventions/threat-feed-list/name";
}
description
"This describes the path to a threat-feed's destination.";
}
}
}
container actions {
description
"This is the action container.";
leaf primary-action {
type identityref {
base primary-action;
}
description
"This represent primary actions (e.g., PASS, DROP, ALERT,
and MIRROR) to be applied to a condition. If this is not
set, it cannot support the primary actions.";
}
leaf secondary-action {
type identityref {
base secondary-action;
}
description
"This represents secondary actions (e.g., log and syslog)
to be applied if they are needed. If this is not set, it
cannot support the secondary actions.";
}
}
container ipsec-method {
description
"This container represents the IPsec method such as IKE case
and IKEless case.";
leaf method {
type identityref {
base i2nsf-ipsec;
}
description
"This represents the IPsec method type such as IKE case and
IKEless case. If this is not set, it cannot support
either IPsec IKE or IPsec IKEless.";
reference
"draft-ietf-i2nsf-sdn-ipsec-flow-protection-08:
Software-Defined Networking (SDN)-based IPsec Flow
Protection - IPsec method types can be selected.";
}
}
}
}
container endpoint-groups {
description
"A logical entity in a business environment, where a security
policy is to be applied.";
list user-group{
uses user-group;
key "name";
description
"This represents a user group.";
}
list device-group {
key "name";
uses device-group;
description
"This represents a device group.";
}
list location-group{
key "name";
uses location-group;
description
"This represents a location group.";
}
}
container threat-preventions {
description
"This describes the list of threat-preventions.";
list threat-feed-list {
key "name";
description
"There can be a single or multiple number of threat-feeds.";
leaf name {
type string;
description
"This represents the name of the threat-feed.";
}
uses threat-feed-info;
leaf-list threat-file-types {
type identityref {
base malware-file-type;
}
description
"This contains a list of file types needed to be scanned for
a security threat (e.g., virus).";
}
leaf-list signatures {
type identityref {
base signature-type;
}
description
"This contains a list of signatures or hashes of the threats.";
}
}
list payload-content {
key "name";
leaf name {
type string;
description
"This represents the name of a packet's payload-content. It
should give an idea of why a specific payload content is
marked as a threat. For example, the name 'backdoor'
indicates the payload content is related to a backdoor
attack.";
}
description
"This represents a payload-string group.";
uses payload-string;
}
}
}
}
<CODE ENDS>
Figure 17: YANG for Consumer-Facing Interface
This section shows XML configuration examples of high-level security policy rules that are delivered from the I2NSF User to the Security Controller over the Consumer-Facing Interface. The considered use cases are: Database registration, time-based firewall for web filtering, VoIP/VoLTE security service, and DDoS-attack mitigation.
If new endpoints are introduced to the network, it is necessary to first register their data to the database. For example, if new members are newly introduced in either of three different groups (i.e., user-group, device-group, and payload-group), each of them should be registered with information such as ip-addresses or protocols used by devices.
Figure 18 shows an example XML representation of the registered information for the user-group and device-group with IPv4 addresses [RFC5737].
<?xml version="1.0" encoding="UTF-8" ?>
<i2nsf-cfi-policy xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-cfi-policy">
<endpoint-groups>
<user-group>
<name>employees</name>
<range-ipv4-address>
<start-ipv4-address>192.0.2.11</start-ipv4-address>
<end-ipv4-address>192.0.2.90</end-ipv4-address>
</range-ipv4-address>
</user-group>
<device-group>
<name>webservers</name>
<range-ipv4-address>
<start-ipv4-address>198.51.100.11</start-ipv4-address>
<end-ipv4-address>198.51.100.20</end-ipv4-address>
</range-ipv4-address>
<protocol>cfi-policy:http</protocol>
<protocol>cfi-policy:https</protocol>
</device-group>
</endpoint-groups>
</i2nsf-cfi-policy>
Figure 18: Registering User-group and Device-group Information with IPv4 Addresses
Also, Figure 19 shows an example XML representation of the registered information for the user-group and device-group with IPv6 addresses [RFC3849].
<?xml version="1.0" encoding="UTF-8" ?>
<i2nsf-cfi-policy xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-cfi-policy">
<endpoint-groups>
<user-group>
<name>employees</name>
<range-ipv6-address>
<start-ipv6-address>2001:DB8:0:1::11</start-ipv6-address>
<end-ipv6-address>2001:DB8:0:1::90</end-ipv6-address>
</range-ipv6-address>
</user-group>
<device-group>
<name>webservers</name>
<range-ipv6-address>
<start-ipv6-address>2001:DB8:0:2::11</start-ipv6-address>
<end-ipv6-address>2001:DB8:0:2::20</end-ipv6-address>
</range-ipv6-address>
<protocol>cfi-policy:http</protocol>
<protocol>cfi-policy:https</protocol>
</device-group>
</endpoint-groups>
</i2nsf-cfi-policy>
Figure 19: Registering User-group and Device-group Information with IPv6 Addresses
The first example scenario is to "block SNS access during office hours" using a time-based firewall policy. In this scenario, all users registered as "employees" in the user-group list are unable to access Social Networking Services (SNS) during the office hours (weekdays). The XML instance is described below:
<?xml version="1.0" encoding="UTF-8" ?>
<i2nsf-cfi-policy xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-cfi-policy">
<policy-name>security_policy_for_blocking_sns123</policy-name>
<rules>
<rule>
<rule-name>block_access_to_sns_during_office_hours</rule-name>
<event>
<time-information>
<start-date-time>2020-03-11T09:00:00.00Z</start-date-time>
<end-date-time>2020-12-31T18:00:00.00Z</end-date-time>
<period>
<start-time>09:00:00Z</start-time>
<end-time>18:00:00Z</end-time>
<day>cfi-policy:monday</day>
<day>cfi-policy:tuesday</day>
<day>cfi-policy:wednesday</day>
<day>cfi-policy:thursday</day>
<day>cfi-policy:friday</day>
</period>
</time-information>
<frequency>weekly</frequency>
</event>
<condition>
<firewall-condition>
<source>employees</source>
</firewall-condition>
<custom-condition>
<destination>sns-websites</destination>
</custom-condition>
</condition>
<actions>
<primary-action>cfi-policy:drop</primary-action>
</actions>
</rule>
</rules>
</i2nsf-cfi-policy>
Figure 20: An XML Example for Time-based Firewall
Time-based-condition Firewall
The second example scenario is to "block malicious VoIP/VoLTE packets coming to a company" using a VoIP policy. In this scenario, the calls comming from from VOIP and/or VOLTE sources with VOLTE IDs that are classified as malicious are dropped. The IP addresses of the employees and malicious VOIP IDs should be blocked are stored in the database or datastore of the enterprise. Here and the rest of the cases assume that the security administrators or someone responsible for the existing and newly generated policies, are not aware of which and/or how many NSFs are needed to meet the security requirements. Figure 21 represents the XML document generated from YANG discussed in previous sections. Once a high-level seucurity policy is created by a security admin, it is delivered by the Consumer-Facing Interface, through RESTCONF server, to the security controller. The XML instance is described below:
<?xml version="1.0" encoding="UTF-8" ?>
<i2nsf-cfi-policy xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-cfi-policy">
<policy-name>
security_policy_for_blocking_malicious_voip_packets
</policy-name>
<rules>
<rule>
<rule-name>Block_malicious_voip_and_volte_packets</rule-name>
<condition>
<custom-condition>
<source>malicious-id</source>
</custom-condition>
<firewall-condition>
<destination>employees</destination>
</firewall-condition>
</condition>
<actions>
<primary-action>cfi-policy:drop</primary-action>
</actions>
<ipsec-method>
<method>cfi-policy:ipsec-ikeless</method>
</ipsec-method>
</rule>
</rules>
</i2nsf-cfi-policy>
Figure 21: An XML Example for VoIP Security Service
Custom-condition Firewall
The third example scenario is to "Mitigate HTTP and HTTPS flood attacks on a company web server" using a DDoS-attack mitigation policy. Here, the time information is not set because the service provided by the network should be maintained at all times. If the packets sent by any sources are more than the set threshold, then the admin can set the percentage of the packets to be dropped to safely maintain the service. In this scenario, the source is set as "any" to block any sources which send abnormal amount of packets. The destination is set as "web_server01". Once the rule is set and delivered and enforced to the nsfs by the securiy controller, the NSFs will monitor the incoming packet amounts and the destination to act according to the rule set. The XML instance is described below:
<?xml version="1.0" encoding="UTF-8" ?>
<i2nsf-cfi-policy xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-cfi-policy">
<policy-name>security_policy_for_ddos_attacks</policy-name>
<rules>
<rule>
<rule-name>100_packets_per_second</rule-name>
<conditions>
<ddos-condition>
<destination>webservers</destination>
<rate-limit>
<packet-threshold-per-second>100</packet-threshold-per-second>
</rate-limit>
</ddos-condition>
</conditions>
<actions>
<primary-action>cfi-policy:drop</primary-action>
</actions>
<ipsec-method>
<method>cfi-policy:ipsec-ikeless</method>
</ipsec-method>
</rule>
</rules>
</i2nsf-cfi-policy>
Figure 22: An XML Example for DDoS-attack Mitigation
DDoS-condition Firewall
This is an example for creating privileges for a group of users (i.e., a user group) to access and use the I2NSF Consumer-Facing Interface to create security policies via the interface. For the access control of the Consumer-Facing Interface, the NACM module can be used. Figure 23 shows an XML example the access control of a user group (named Example-Group) for I2NSF Consumer-Facing Interface A group called Example-Group can be created and configured with NACM for the Consumer-Facing Interface. For Example-Group, a rule list can created with the name of Example-Group-Rules. Example-Group-Rules has two rules of Example-Group-Rule1 and Example-Group-Rule2 as follows. For Example-Group-Rule1, the privilege of "Read" is allowed to Example-Group for the Consumer-Facing Interface. On the other hand, for Example-Group-Rule2, the privileges of "Create", "Update", and "Delete" are denied against Example-Group for the Consumer-Facing Interface.
<?xml version="1.0" encoding="UTF-8" ?>
<nacm xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-acm">
<enable-nacm>true</enable-nacm>
<groups>
<group>
<name>Example-Group</name>
<user-name>Alice</user-name>
<user-name>Bob</user-name>
<user-name>Eve</user-name>
</group>
</groups>
<rule-list>
<name>Example-Group-Rules</name>
<group>Example-Group</group>
<rule>
<name>Example-Group-Rule1</name>
<access-operations>read</access-operations>
<module-name>ietf-i2nsf-cfi-policy</module-name>
<action>permit</action>
</rule>
<rule>
<name>Example-Group-Rule2</name>
<access-operations>create update delete</access-operations>
<module-name>ietf-i2nsf-cfi-policy</module-name>
<action>deny</action>
</rule>
</rule-list>
</nacm>
Figure 23: An XML Example of a User Group's Access Control for I2NSF Consumer-Facing Interface
The access control for the I2NSF Consumer-Facing Interface is as follows.
URI: urn:ietf:params:xml:ns:yang:ietf-i2nsf-cfi-policy Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace.
name: ietf-i2nsf-cfi-policy namespace: urn:ietf:params:xml:ns:yang:ietf-i2nsf-cfi-policy prefix: cfi-policy reference: RFC XXXX
This document requests IANA to register the following URI in the "IETF XML Registry" [RFC3688]: [RFC7950][RFC8525].
The data model for the I2NSF Consumer-Facing Interface is based on the I2NSF framework [RFC8329], so the same security considerations with the I2NSF framework should be included in this document. The data model needs a secure communication channel to protect the Consumer-Facing Interface between the I2NSF User and Security Controller. Also, the data model's management access control is based on Network Configuration Access Control Model(NACM) mechanisms [RFC8341].
This work was supported by Institute of Information & Communications Technology Planning & Evaluation (IITP) grant funded by the Korea MSIT (Ministry of Science and ICT) (R-20160222-002755, Cloud based Security Intelligence Technology Development for the Customized Security Service Provisioning). This work was supported in part by the IITP (2020-0-00395, Standard Development of Blockchain based Network Management Automation Technology).
This document is made by the group effort of I2NSF working group. Many people actively contributed to this document, such as Mahdi F. Dachmehchi and Daeyoung Hyun. The authors sincerely appreciate their contributions.
The following are co-authors of this document:
Patrick Lingga
Department of Electronic, Electrical and Computer Engineering
Sungkyunkwan University
2066 Seo-ro Jangan-gu
Suwon, Gyeonggi-do 16419
Republic of Korea
EMail: patricklink@skku.edu
Hyoungshick Kim
Department of Computer Science and Engineering
Sungkyunkwan University
2066 Seo-ro Jangan-gu
Suwon, Gyeonggi-do 16419
Republic of Korea
EMail: hyoung@skku.edu
Eunsoo Kim
Department of Electronic, Electrical and Computer Engineering
Sungkyunkwan University
2066 Seo-ro Jangan-gu
Suwon, Gyeonggi-do 16419
Republic of Korea
EMail: eskim86@skku.edu
Seungjin Lee
Department of Electronic, Electrical and Computer Engineering
Sungkyunkwan University
2066 Seo-ro Jangan-gu
Suwon, Gyeonggi-do 16419
Republic of Korea
EMail: jine33@skku.edu
Jinyong Tim Kim
Department of Electronic, Electrical and Computer Engineering
Sungkyunkwan University
2066 Seo-ro Jangan-gu
Suwon, Gyeonggi-do 16419
Republic of Korea
EMail: timkim@skku.edu
Anil Lohiya
Juniper Networks
1133 Innovation Way
Sunnyvale, CA 94089
US
EMail: alohiya@juniper.net
Dave Qi
Bloomberg
731 Lexington Avenue
New York, NY 10022
US
EMail: DQI@bloomberg.net
Nabil Bitar
Nokia
755 Ravendale Drive
Mountain View, CA 94043
US
EMail: nabil.bitar@nokia.com
Senad Palislamovic
Nokia
755 Ravendale Drive
Mountain View, CA 94043
US
EMail: senad.palislamovic@nokia.com
Liang Xia
Huawei
101 Software Avenue
Nanjing, Jiangsu 210012
China
EMail: Frank.Xialiang@huawei.com
| [I-D.ietf-netmod-rfc6991-bis] | Schoenwaelder, J., "Common YANG Data Types", Internet-Draft draft-ietf-netmod-rfc6991-bis-04, July 2020. |
| [RFC0854] | Postel, J. and J. Reynolds, "Telnet Protocol Specification", STD 8, RFC 854, DOI 10.17487/RFC0854, May 1983. |
| [RFC0913] | Lottor, M., "Simple File Transfer Protocol", RFC 913, DOI 10.17487/RFC0913, September 1984. |
| [RFC0959] | Postel, J. and J. Reynolds, "File Transfer Protocol", STD 9, RFC 959, DOI 10.17487/RFC0959, October 1985. |
| [RFC1081] | Rose, M., "Post Office Protocol: Version 3", RFC 1081, DOI 10.17487/RFC1081, November 1988. |
| [RFC1631] | Egevang, K. and P. Francis, "The IP Network Address Translator (NAT)", RFC 1631, DOI 10.17487/RFC1631, May 1994. |
| [RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997. |
| [RFC2616] | Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., Leach, P. and T. Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2616, DOI 10.17487/RFC2616, June 1999. |
| [RFC2818] | Rescorla, E., "HTTP Over TLS", RFC 2818, DOI 10.17487/RFC2818, May 2000. |
| [RFC3444] | Pras, A. and J. Schoenwaelder, "On the Difference between Information Models and Data Models", RFC 3444, DOI 10.17487/RFC3444, January 2003. |
| [RFC3688] | Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004. |
| [RFC3849] | Huston, G., Lord, A. and P. Smith, "IPv6 Address Prefix Reserved for Documentation", RFC 3849, DOI 10.17487/RFC3849, July 2004. |
| [RFC4250] | Lehtinen, S. and C. Lonvick, "The Secure Shell (SSH) Protocol Assigned Numbers", RFC 4250, DOI 10.17487/RFC4250, January 2006. |
| [RFC5321] | Klensin, J., "Simple Mail Transfer Protocol", RFC 5321, DOI 10.17487/RFC5321, October 2008. |
| [RFC5737] | Arkko, J., Cotton, M. and L. Vegoda, "IPv4 Address Blocks Reserved for Documentation", RFC 5737, DOI 10.17487/RFC5737, January 2010. |
| [RFC6020] | Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010. |
| [RFC6241] | Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011. |
| [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. |
| [RFC8040] | Bierman, A., Bjorklund, M. and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017. |
| [RFC8174] | Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017. |
| [RFC8192] | Hares, S., Lopez, D., Zarny, M., Jacquenet, C., Kumar, R. and J. Jeong, "Interface to Network Security Functions (I2NSF): Problem Statement and Use Cases", RFC 8192, DOI 10.17487/RFC8192, July 2017. |
| [RFC8329] | Lopez, D., Lopez, E., Dunbar, L., Strassner, J. and R. Kumar, "Framework for Interface to Network Security Functions", RFC 8329, DOI 10.17487/RFC8329, February 2018. |
| [RFC8340] | Bjorklund, M. and L. Berger, "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018. |
| [RFC8341] | Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018. |
| [RFC8407] | Bierman, A., "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", BCP 216, RFC 8407, DOI 10.17487/RFC8407, October 2018. |
| [RFC8525] | Bierman, A., Bjorklund, M., Schoenwaelder, J., Watsen, K. and R. Wilton, "YANG Library", RFC 8525, DOI 10.17487/RFC8525, March 2019. |
| [RFC8805] | Kline, E., Duleba, K., Szamonek, Z., Moser, S. and W. Kumari, "A Format for Self-Published IP Geolocation Feeds", RFC 8805, DOI 10.17487/RFC8805, August 2020. |
| [I-D.ietf-i2nsf-capability] | Xia, L., Strassner, J., Basile, C. and D. Lopez, "Information Model of NSFs Capabilities", Internet-Draft draft-ietf-i2nsf-capability-05, April 2019. |
| [I-D.ietf-i2nsf-sdn-ipsec-flow-protection] | Lopez, R., Lopez-Millan, G. and F. Pereniguez-Garcia, "Software-Defined Networking (SDN)-based IPsec Flow Protection", Internet-Draft draft-ietf-i2nsf-sdn-ipsec-flow-protection-08, June 2020. |
| [SNORT] | Roesch, M., Green, C. and B. Caswell, "SNORT", SNORT Documents https://www.snort.org/#documents, August 2020. |
| [STIX] | Jordan, B., Piazza, R. and T. Darley, "Structured Threat Information Expression (STIX)", STIX Version 2.1: Committee Specification 01 https://docs.oasis-open.org/cti/stix/v2.1/stix-v2.1.pdf, March 2020. |
| [SURICATA] | Julien, V. and . , "SURICATA", SURICATA Documents https://suricata-ids.org/docs/, August 2020. |
| [YARA] | Alvarez, V., Bengen, H., Metz, J., Buehlmann, S. and W. Shields, "YARA", YARA Documents https://yara.readthedocs.io/en/v3.5.0/, August 2020. |