| I2NSF Working Group | J. Jeong |
| Internet-Draft | C. Chung |
| Intended status: Standards Track | Sungkyunkwan University |
| Expires: September 12, 2020 | T. Ahn |
| Korea Telecom | |
| R. Kumar | |
| Juniper Networks | |
| S. Hares | |
| Huawei | |
| March 11, 2020 |
I2NSF Consumer-Facing Interface YANG Data Model
draft-ietf-i2nsf-consumer-facing-interface-dm-08
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 organized based on the "Event-Condition-Action" (ECA) policy model defined by a capability information model for I2NSF [i2nsf-capability-im], 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 September 12, 2020.
Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
In a framework of Interface to Network Security Functions (I2NSF), 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 [i2nsf-capability-im] 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 | | Consumer-Facing |
| Interface +--->+ Interface |
|Information Model| | Data Model |
+--------+--------+ +-----------------+
^
|
+-------------+------------+
| | |
+-----+----+ +-----+----+ +----+----+
| 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 RFC 2119 [RFC3444] RFC8174 [RFC8174].
This document uses the terminology described in [i2nsf-terminology] [client-facing-inf-req].
This document follows the guidelines of [RFC8407], uses the common YANG types defined in [RFC6991], 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
| uses owners-ref
| +--rw rules* [rule-name]
+--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
| uses owners-ref
+--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" [i2nsf-capability-im].
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 (enforce-type)?
| +--:(admin)
| | +--rw admin?
| +--:(time)
| +--rw time-information
| +--rw begin-time? date-and-time
| +--rw end-time? date-and-time
+--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 -> /../../nacm:group/nacm:user-name
| +--rw dest-target* -> /../../nacm:group/nacm:user-name
+--:(ddos-condition)
| +--rw source* -> /../../device-group/name
| +--rw dest-target* -> /../../device-group/name
| +--rw rate-limit
+--:(custom-condition)
| +--rw source* -> /../../payload-content/name
| +--rw dest-target -> /../../payload-content/name
+--:(threat-feed-condition)
+--rw source* -> /../../threat-feed-list/name
+--rw dest-target -> /../../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.
+-------------------+
| Endpoint Groups |
+---------+---------+
^
|
+--------------+----------------+
1..n | 1..n | 1..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 -> /../../nacm:group/nacm:user-name
+--rw (match-type)?
+--:(exact-match-ipv4)
| +--rw ipv4-address* inet:ipv4-address
+--:(exact-match-ipv6)
| +--rw ipv6-address* inet:ipv6-address
+--:(range-match-ipv4)
| +--rw range-ipv4-address*
[start-ipv4-address end-ipv4-address]
| +--rw start-ipv4-address inet:ipv4-address
| +--rw end-ipv4-address inet:ipv4-address
+--:(range-match-ipv6)
+--rw range-ipv6-address*
[start-ipv6-vaddress end-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-address* inet:ipv4-address
| +--:(exact-match-ipv6)
| | +--rw ipv6-address* inet:ipv6-address
| +--:(range-match-ipv4)
| | +--rw range-ipv4-address*
[start-ipv4-address end-ipv4-address]
| | +--rw start-ipv4-address inet:ipv4-address
| | +--rw end-ipv4-address inet:ipv4-address
| +--:(range-match-ipv6)
| +--rw range-ipv6-address*
[start-ipv6-vaddress end-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 |
+---------+---------+
^
|
+---------+---------+
1..n | 1..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 signatures of malicious activities. Figure 14 shows the YANG tree of a Threat-feed-list. The Threat-Feed object SHALL have the following information:
+--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 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 high-level overview of the access control with the following features [RFC8341]:
The data model for the I2NSF Consumer-Facing Interface provides NACM mechanisms and concepts to user-group and owners permissions. The NACM with the above features can be used to set up all the management access controls in the I2NSF high-level authorization view, and it may have a high impact on the optimization and performance.
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 was 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. This document suggests a VoIP/VoLTE security service as a use case for policy rule generation.
This section describes a YANG data model for Consumer-Facing Interface, based on the information model of Consumer-Facing Interface to Security Controller.
<CODE BEGINS> file "ietf-i2nsf-cfi-policy@2020-03-11.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;
reference "Section 4 of RFC 6991";
}
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>
WG Chair: Linda Dunbar
<mailto:linda.dunbar@futurewei.com>
WG Chair: Yoav Nir
<mailto:ynir.ietf@gmail.com>
Editor: Jaehoon Paul Jeong
<mailto:pauljeong@skku.edu>
Editor: Chaehong Chung
<mailto:darkhong@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 "2020-03-11"{
description "The latest revision";
reference
"draft-ietf-consumer-facing-interface-dm-07";
}
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 {
description
"Identity for DDoS event types.";
}
identity spyware {
base malware-file-type;
description
"Identity for spyware event types.";
}
identity trojan {
base malware-file-type;
description
"Identity for Trojan infection event types.";
}
identity ransomware {
base malware-file-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-07";
}
identity ipsec-ike {
base i2nsf-ipsec;
description
"Identity for ipsec-ike.";
reference
"draft-ietf-i2nsf-sdn-ipsec-flow-protection-07";
}
identity ipsec-ikeless {
base i2nsf-ipsec;
description
"Identity for ipsec-ikeless.";
reference
"draft-ietf-i2nsf-sdn-ipsec-flow-protection-07";
}
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 enforce-type {
description
"This identity represents the event of
policy enforcement trigger type.";
}
identity admin {
description
"The identity for policy enforcement by admin.";
}
identity time {
description
"The identity for policy enforcement based on time.";
}
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.";
}
identity signature-snort {
base signature-type;
description
"This represents the SNORT signatures.";
}
identity signature-suricata {
base signature-type;
description
"This represents the SURICATA signatures.";
}
identity threat-feed-type {
description
"This represents the base identity for threat-feed.";
}
/*
* Typedefs
*/
typedef date-and-time {
type string {
pattern '\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(\.\d+)?'
+ '(Z|[\+\-]\d{2}:\d{2})';
}
description
"This is the format of date-and-time.";
reference
"RFC 3339: Date and Time on the Internet: Timestamps
RFC 2579: Textual Conventions for SMIv2
XSD-TYPES: XML Schema Part 2: Datatypes Second Edition";
}
/*
* Groupings
*/
grouping ipv4-list {
description
"Grouping for ipv4 based ip-addresses.";
leaf-list ipv4 {
type inet:ipv4-address;
description
"This is the entry for the ipv4 ip-addresses.";
}
}
grouping ipv6-list {
description
"Grouping for ipv6 based ip-addresses.";
leaf-list ipv6 {
type inet:ipv6-address;
description
"This is the entry for the ipv6 ip-addresses.";
}
}
grouping ipv4 {
description
"Grouping for ipv4 based ip-address.";
leaf ipv4 {
type inet:ipv4-address;
description
"This is the entry for the ipv4 ip-address.";
}
}
grouping ipv6 {
description
"Grouping for ipv6 based ip-address.";
leaf ipv6 {
type inet:ipv6-address;
description
"This is the entry for the ipv6 ip-address.";
}
}
grouping ip-address-info {
description
"There are two types to configure a security policy
for 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 type addresses";
}
case exact-match-ipv6 {
uses ipv6;
description
"Exact ip-address match for ipv6 type addresses";
}
case range-match-ipv4 {
list range-ipv4-address {
key "start-ipv4-address end-ipv4-address";
leaf start-ipv4-address {
type inet:ipv4-address;
description
"Start IPv4 address for a range match.";
}
leaf end-ipv4-address {
type inet:ipv4-address;
description
"End IPv4 address for a range match.";
}
description
"Range match for an IP-address.";
}
}
case range-match-ipv6 {
list range-ipv6-address {
key "start-ipv6-address end-ipv6-address";
leaf start-ipv6-address {
type inet:ipv6-address;
description
"Start IPv6 address for a range match.";
}
leaf end-ipv6-address {
type inet:ipv6-address;
description
"End IPv6 address for a range match.";
}
description
"Range match for an IP-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-07";
}
}
}
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.";
}
uses ip-address-info;
}
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.";
}
uses ip-address-info;
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.";
}
leaf geo-ip-ipv4 {
type inet:ipv4-address;
description
"This represents the IPv4 geo-ip of a location.";
}
leaf geo-ip-ipv6 {
type inet:ipv6-address;
description
"This represents the IPv6 geo-ip of a location.";
}
leaf continent {
type identityref {
base continent;
}
default asia;
description
"location-group-based on geo-ip of
respective continent.";
}
}
grouping threat-feed-info {
description
"This is the grouping for the threat-feed-list";
leaf name {
type identityref {
base threat-feed-type;
}
description
"This represents the name of the a threat-feed.";
}
leaf server-ipv4 {
type inet:ipv4-address;
description
"The IPv4 ip-address for the threat-feed server.";
}
leaf server-ipv6 {
type inet:ipv6-address;
description
"The IPv6 ip-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
the type, related threat, method, and file type.";
}
}
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 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 strings";
}
}
grouping owners-ref {
description
"This grouping is for owners reference using
Network Configuration Access Control Model
(NACM).";
leaf-list owners {
type leafref {
path "/nacm:nacm/nacm:groups/nacm:group/nacm:name";
}
description
"This leaf-list names the owner groups of the
list instance it sits on. Only the owners listed
in a NACM group are authorized to get full CRUD
privileges for the contents.
If this is not set, it cannot support who has
the prvilege of the contents";
}
}
list i2nsf-cfi-policy {
key "policy-name";
description
"This is the security policy list. Each policy in
the list contains a list of security rules, and is
a policy instance to have complete information
such as where and when a policy needs to be
applied.";
leaf policy-name {
type string;
mandatory true;
description
"The name which identifies the policy.";
}
uses owners-ref;
container rules{
description
"This container is for rules.";
nacm:default-deny-write;
list rule {
key "rule-name";
ordered-by user;
leaf rule-name {
type string;
mandatory true;
description
"This represents the name for the rule.";
}
description
"There can be a single or multiple number of
rules.";
uses owners-ref;
container event {
description
"This represents the event (e.g., 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 security
events. If this is not set, it cannot
support which security event is enforced";
}
choice enforce-type {
description
"There are two different enforcement types;
admin, and time.
It cannot be allowed to configure
admin=='time' or enforce-time=='admin'.";
case enforce-admin {
leaf admin {
type string;
description
"This represents the enforcement type
based on admin's decision.";
}
}
case time {
container time-information {
description
"The begin-time and end-time information
when the security rule should be applied.";
leaf enforce-time {
type date-and-time;
description
"The enforcement type is time-enforced.";
}
leaf begin-time {
type date-and-time;
description
"This is start time for time zone";
}
leaf end-time {
type date-and-time;
description
"This is end time for time zone";
}
}
}
}
leaf frequency {
type enumeration {
enum only-once {
description
"This represents the rule is enforced
only once immediately and not
repeated.";
}
enum daily {
description
"This represents the rule is enforced
on a daily basis.";
}
enum weekly {
description
"This represents the rule is enforced
on a weekly basis.";
}
enum monthly {
description
"This represents the rule is enforced
on a monthly basis.";
}
}
default only-once;
description
"This represents how frequent the rule
should be enforced.";
}
}
container condition {
description
"The conditions for general security policies.";
container firewall-condition {
description
"The general firewall condition.";
leaf source {
type leafref {
path "/i2nsf-cfi-policy/endpoint-groups/user-group/name";
}
description
"This describes the paths to the source reference.";
}
leaf-list dest-target {
type leafref {
path "/i2nsf-cfi-policy/endpoint-groups/user-group/name";
}
description
"This describes the paths to the destination
target reference.";
}
}
container ddos-condition {
description
"The condition for DDoS mitigation.";
leaf-list source {
type leafref {
path "/i2nsf-cfi-policy/endpoint-groups/device-group/name";
}
description
"This describes the path to the
source target references.";
}
leaf-list dest-target {
type leafref {
path "/i2nsf-cfi-policy/endpoint-groups/device-group/name";
}
description
"This describes the path to the destination target
references.";
}
container rate-limit {
description
"This describes the rate-limit.";
leaf packet-threshold-per-second{
type uint32;
description
"This is a trigger value for the condition.";
}
}
}
container custom-condition {
description
"The condition based on packet contents.";
leaf-list source {
type leafref {
path "/i2nsf-cfi-policy/threat-preventions/payload-content/name";
}
description
"Describes the payload string content condition
source.";
}
leaf dest-target {
type leafref {
path "/i2nsf-cfi-policy/threat-preventions/payload-content/name";
}
description
"Describes the payload string content condition destination.";
}
}
container threat-feed-condition {
description
"The condition based on the threat-feed information.";
leaf-list source {
type leafref {
path "/i2nsf-cfi-policy/threat-preventions/threat-feed-list/name";
}
description
"Describes the threat-feed condition source.";
}
leaf dest-target {
type leafref {
path "/i2nsf-cfi-policy/threat-preventions/threat-feed-list/name";
}
description
"Describes the threat-feed condition destination.";
}
}
}
container actions {
description
"This is the action container.";
leaf primary-action {
type identityref {
base primary-action;
}
description
"This represent the primary actions (e.g.,
PASS, DROP, ALERT, and MIRROR) to be
applied a condition.
If this is not set, it cannot support
the primary actions.";
}
leaf secondary-action {
type identityref {
base secondary-action;
}
description
"This represents the secondary actions
(e.g., log and syslog) to be applied
if needed.
If this is not set, it cannot support
the secondary actions.";
}
}
container ipsec-method {
description
"This container represents the IPsec IKE
and IKEless cases.";
leaf method {
type identityref {
base i2nsf-ipsec;
}
description
"This references the IPsec method types,
which includes 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-07";
}
}
}
}
container endpoint-groups {
description
"A logical entity in their business
environment, where a security policy
is to be applied.";
list user-group{
uses user-group;
key "name";
description
"This represents the user group.";
}
list device-group {
key "name";
uses device-group;
description
"This represents the device group.";
}
list location-group{
key "name";
uses location-group;
description
"This represents the location group.";
}
}
container threat-preventions {
description
"this describes the list of threat-prevention.";
list threat-feed-list {
key "name";
description
"There can be a single or multiple number of
threat-feeds.";
uses threat-feed-info;
leaf-list threat-file-types {
type identityref {
base malware-file-type;
}
default executable-file;
description
"This contains a list of file types needed to
be scanned for the virus.";
}
leaf-list signatures {
type identityref {
base signature-type;
}
default signature-suricata;
description
"This contains a list of signatures or hash
of the threats.";
}
}
list payload-content {
key "name";
leaf name {
type string;
description
"This represents the name of payload-content.
It should give an idea of why specific payload
content is marked as threat. For example, the
name 'backdoor' indicates the payload content
is related to backdoor attack.";
}
description
"This represents the payload-string group.";
uses payload-string;
}
}
}
}
<CODE ENDS>
Figure 16: 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 17 shows an example XML representation of the registered information for the user-group and device-group.
<?xml version="1.0" encoding="UTF-8" ?>
<endpoint-groups xmlns="urn:ietf:params:xml:ns:yang:ietf-i2nsf-cfi-policy">
<user-group>
<name>employees</name>
<range-ipv4-address>
<start-ipv4-address>221.159.112.1</start-ipv4-address>
<end-ipv4-address>221.159.112.90</end-ipv4-address>
</range-ipv4-address>
</user-group>
<device-group>
<name>webservers</name>
<range-ipv4-address>
<start-ipv4-address>221.159.112.91</start-ipv4-address>
<end-ipv4-address>221.159.112.97</end-ipv4-address>
</range-ipv4-address>
<protocol>http</protocol>
<protocol>https</protocol>
</device-group>
</endpoint-groups>
Figure 17: Registering User-group and Device-group Information
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. 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_sns</policy-name>
<rules>
<rule>
<rule-name>block_access_to_sns_during_office_hours</rule-name>
<event>
<time-information>
<begin-time>2020-03-11T09:00:00.00Z</begin-time>
<end-time>2020-03-11T18:00:00.00Z</end-time>
</time-information>
<frequency>only-once</frequency>
</event>
<conditions>
<firewall-condition>
<source>employees</source>
</firewall-condition>
<custom-condition>
<dest-target>sns-websites</dest-target>
</custom-condition>
</conditions>
<actions>
<primary-action>drop</primary-action>
</actions>
<ipsec-method>
<method>ipsec-ike</method>
</ipsec-method>
</rule>
</rules>
</i2nsf-cfi-policy>
Figure 18: 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 19 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>
<conditions>
<custom-condition>
<source>malicious-id</source>
</custom-condition>
<firewall-condition>
<dest-target>employees</dest-target>
</firewall-condition>
</conditions>
<actions>
<primary-action>drop</primary-action>
</actions>
<ipsec-method>
<method>ipsec-ikeless</method>
</ipsec-method>
</rule>
</rules>
</i2nsf-cfi-policy>
Figure 19: 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>
<dest-target>webservers</dest-target>
<rate-limit>
<packet-threshold-per-second>100</packet-threshold-per-second>
</rate-limit>
</ddos-condition>
</conditions>
<actions>
<primary-action>drop</primary-action>
</actions>
<ipsec-method>
<method>ipsec-ikeless</method>
</ipsec-method>
</rule>
</rules>
</i2nsf-cfi-policy>
Figure 20: An XML Example for DDoS-attack Mitigation
DDoS-condition Firewall
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].
URI: urn:ietf:params:xml:ns:yang:ietf-i2nsf-cfi-policy
Registrant Contact: The I2NSF.
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 7950
This document requests IANA to register the following URI in the "IETF XML Registry" [RFC3688]: [RFC7950].
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 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:
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
| [client-facing-inf-req] | Kumar, R., Lohiya, A., Qi, D., Bitar, N., Palislamovic, S. and L. Xia, "Requirements for Client-Facing Interface to Security Controller", Internet-Draft draft-ietf-i2nsf-client-facing-interface-req-05, May 2018. |
| [i2nsf-capability-im] | Xia, L., Strassner, J., Basile, C. and D. Lopez, "Information Model of NSFs Capabilities", Internet-Draft draft-ietf-i2nsf-capability-05, April 2019. |
| [i2nsf-ipsec] | Marin-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-07, August 2019. |
| [i2nsf-terminology] | Hares, S., Strassner, J., Lopez, D., Xia, L. and H. Birkholz, "Interface to Network Security Functions (I2NSF) Terminology", Internet-Draft draft-ietf-i2nsf-terminology-08, July 2019. |
The following changes are made from draft-ietf-i2nsf-consumer-facing-interface-dm-07: