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Versions: (draft-kim-i2nsf-consumer-facing-interface-dm) 00 01 02 03 04 05 06

I2NSF Working Group                                             J. Jeong
Internet-Draft                                                    E. Kim
Intended status: Standards Track                 Sungkyunkwan University
Expires: December 14, 2019                                        T. Ahn
                                                           Korea Telecom
                                                                R. Kumar
                                                        Juniper Networks
                                                                S. Hares
                                                                  Huawei
                                                           June 12, 2019


            I2NSF Consumer-Facing Interface YANG Data Model
            draft-ietf-i2nsf-consumer-facing-interface-dm-05

Abstract

   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.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on December 14, 2019.





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Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   5
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   5
   4.  Information Model for Policy  . . . . . . . . . . . . . . . .   5
     4.1.  Event Sub-model . . . . . . . . . . . . . . . . . . . . .   7
     4.2.  Condition Sub-model . . . . . . . . . . . . . . . . . . .   7
     4.3.  Action Sub-model  . . . . . . . . . . . . . . . . . . . .   9
   5.  Information Model for Multi-Tenancy . . . . . . . . . . . . .  10
     5.1.  Policy Domain . . . . . . . . . . . . . . . . . . . . . .  10
     5.2.  Policy Tenant . . . . . . . . . . . . . . . . . . . . . .  11
     5.3.  Policy Role . . . . . . . . . . . . . . . . . . . . . . .  12
     5.4.  Policy User . . . . . . . . . . . . . . . . . . . . . . .  13
     5.5.  Policy Management Authentication Method . . . . . . . . .  13
   6.  Information Model for Policy Endpoint Groups  . . . . . . . .  15
     6.1.  User Group  . . . . . . . . . . . . . . . . . . . . . . .  15
     6.2.  Device Group  . . . . . . . . . . . . . . . . . . . . . .  16
     6.3.  Location Group  . . . . . . . . . . . . . . . . . . . . .  17
   7.  Information Model for Threat Prevention . . . . . . . . . . .  17
     7.1.  Threat Feed . . . . . . . . . . . . . . . . . . . . . . .  18
     7.2.  Payload Content . . . . . . . . . . . . . . . . . . . . .  19
   8.  Role-based Acess Control (RBAC) . . . . . . . . . . . . . . .  19
   9.  YANG Data Model for Security Policies for Consumer-Facing
       Interface . . . . . . . . . . . . . . . . . . . . . . . . . .  20
   10. Example XML Output for Various Scenarios  . . . . . . . . . .  38
     10.1.  DB Registration: Information of Positions and Devices
            (Endpoint Group) . . . . . . . . . . . . . . . . . . . .  39
     10.2.  Scenario 1: Block SNS Access during Business Hours . . .  39
     10.3.  Scenario 2: Block Malicious VoIP/VoLTE Packets Coming to
            a Company  . . . . . . . . . . . . . . . . . . . . . . .  41
     10.4.  Scenario 3: Mitigate HTTP and HTTPS Flood Attacks on a
            Company Web Server . . . . . . . . . . . . . . . . . . .  42



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   11. Security Considerations . . . . . . . . . . . . . . . . . . .  44
   12. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  44
   13. References  . . . . . . . . . . . . . . . . . . . . . . . . .  44
     13.1.  Normative References . . . . . . . . . . . . . . . . . .  44
     13.2.  Informative References . . . . . . . . . . . . . . . . .  45
   Appendix A.  Changes from draft-ietf-i2nsf-consumer-facing-
                interface-dm-04  . . . . . . . . . . . . . . . . . .  47
   Appendix B.  Acknowledgments  . . . . . . . . . . . . . . . . . .  47
   Appendix C.  Contributors . . . . . . . . . . . . . . . . . . . .  47
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  49

1.  Introduction

   In an I2NSF framework, 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



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   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   |
                       +--------+--------+    +-----------------+
                                ^
                                |
                  +-------------+-------------+------------+
                  |             |             |            |
             +----+----+  +-----+----+  +-----+----+  +----+----+
             |  Multi  |  |  Policy  |  | Endpoint |  | Threat  |
             | Tenancy |  |          |  |  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



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   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.

2.  Requirements Language

   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].

3.  Terminology

   This document uses the terminology described in
   [i2nsf-terminology][client-facing-inf-req].

   This document follows the guidelines of [RFC6087], 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].

4.  Information Model for Policy

   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 XML instance of the Policy object.  The
   Policy object SHALL have the following information:

      Name:  This field identifies the name of this object.

      Date:  Date when this object was created or last modified.

      Rules: This field contains a list of rules.  If the rule does not
             have a user-defined precedence, then any conflict must be
             manually resolved.

            +--rw policy
               +--rw policy-name?               string
               +--rw rule* [rule-name]
               |   +--rw event
               |   +--rw condition
               |   +--rw action
                   ...


                      Figure 2: Policy YANG Data Tree




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   A policy is a container of Rules.  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 XML instance of the
   Rule object.  The rule object SHALL have the following information:

      Name:  This field identifies the name of this object.

      Date:  This field indicates the date when this object was created
             or last modified.

      Event: This field includes the information to determine whether
             the Rule Condition can be evaluated or not.  See details in
             Section 3.1.

      Condition:  This field contains all the checking conditions to
             apply to the objective traffic.  See details in
             Section 4.2.

      Action:  This field identifies the action taken when a rule is
             matched.  There is always an implicit action to drop
             traffic if no rule is matched for a traffic type.  See
             details in Section 4.3.

      IPsec-Method:  This field contains the information about IPsec
             method type.  There are two types such as IPsec-IKE and
             IPsec-IKEless.  [i2nsf-ipsec].

      Owner: This field contains the onwer of the rule.  For example,
             the person who created it, and eligible for modifying it.

           +--rw rule* [rule-name]
              +--rw rule-name    string
              +--rw date?        yang:date-and-time
              +--rw event* [name]
              +--rw condition
              +--rw action
              +--rw ipsec-method
              +--rw owner?       string


                     Figure 3: YANG Data Tree for Rule






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4.1.  Event Sub-model

   The Event Object contains information related to scheduling a Rule.
   The Rule could be activated based on a time calendar or security
   event including threat level changes.  Figure 4 shows the XML
   instance of the Event object.  Event object SHALL have following
   information:

      Name:  This field identifies the name of this object.

      Date:  This field indicates the date when this object was created
             or last modified.

      Event-Type:  This field identifies whether the event of triggering
             policy enforcement is "ADMIN-ENFORCED", "TIME-ENFORCED" or
             "EVENT-ENFORCED".

      Time-Information:  This field contains a time calendar such as
             "BEGIN-TIME" and "END-TIME" for one time enforcement or
             recurring time calendar for periodic enforcement.

               +--rw event
                  +--rw name?                     string
                  +--rw date?                     yang:date-and-time
                  +--rw event-type                enumeration
                  +--rw time-information
                     +--rw time
                     |  +--rw begin-time          begin-time-type
                     |  +--rw end-time            end-time-type
                     +--rw recursive
                        +--rw recur               boolean
                        +--rw recursive-type?     enumeration


                 Figure 4: Event Sub-model YANG Data Tree

4.2.  Condition Sub-model

   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-target and
   destination-target to represent the source and destination for each
   case.  Figure 5 shows the XML instance of the Condition object.  The
   Condition Sub-model SHALL have following information:



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      Firewall-condition:  This field represents the general firewall
             case, where a security admin can set up firewall conditions
             using the information present in this field.  The source
             and destination is represented as source-target and
             destination-target, each referring to the IP-address-based
             groups defined in the endpoint-group.

      DDoS-condition:  This field represents the condition for DDoS
             mitigation, where a security admin can set up DDoS
             mitigation conditions using the information present in this
             field.  The source and destination is represented as
             source-target and destination-target, each referring to the
             device-groups defined and registered in the endpoint-group.

      Custom-condition:  This field contains the payload string
             information.  This information is useful when security rule
             condition is based on the string contents of incoming or
             outgoing packets.  The source and destination is
             represented as source-target and destination-target, each
             referring to the payload-groups defined and registered in
             the endpoint-group.

           +--rw condition
             +--rw firewall-condition
              |  +--rw source-target
              |  |  +--rw src-target?   -> /policy
              |  |                         /endpoint-group
              |  |                         /user-group
              |  |                         /name
              |  +--rw destination-target
              |  |  +--rw dest-target*  -> /policy
              |  |                         /endpoint-group
              |  |                         /user-group
              |  |                         /name
              +--rw ddos-condition
              |  +--rw source-target
              |  |  +--rw src-target*   -> /policy
              |  |                         /endpoint-group
              |  |                         /device-group
              |  |                         /name
              |  +--rw destination-target
              |  |  +--rw dest-target*  -> /policy
              |  |                         /endpoint-group
              |  |                         /device-group
              |  |                         /name
              |  +--rw rate-limit
              |     +--rw packet-per-second?   uint8
              +--rw custom-condition



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              |  +--rw source-target
              |  |  +--rw src-target*   -> /policy
              |  |                         /threat-prevention
              |  |                         /payload-content
              |  |                         /name
              |  +--rw destination-target
              |  |  +--rw dest-target?  -> /policy
              |  |                         /threat-prevention
              |  |                         /payload-content
              |  |                         /name
              +--rw threat-feed-condition
                 +--rw source-target
                 |  +--rw src-target*   -> /policy
                 |                         /threat-prevention
                 |                         /threat-feed-list
                 |                         /name
                 +--rw destination-target
                    +--rw dest-target?  -> /policy
                                           /threat-prevention
                                           /threat-feed-list
                                           /name


               Figure 5: Condition Sub-model YANG Data Tree

4.3.  Action Sub-model

   This object represents actions that Security Admin wants to perform
   based on certain traffic class.  Figure 6 shows the XML instance of
   the Action object.  The Action object SHALL have following
   information:

      Name:  This field identifies the name of this object.

      Date:  This field indicates the date when this object was created
             or last modified.

      Action:  This field identifies the action when a rule is matched
             by an NSF.  The action could be one of "PASS", "DROP",
             "ALERT", "MIRROR", and "LOG".

           +--rw action
              +--rw name            string
              +--rw date            yang:date-and-time
              +--rw action          string


                 Figure 6: Action Sub-model YANG Data Tree



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5.  Information Model for Multi-Tenancy

   Multi-tenancy is an important aspect of any application that enables
   multiple administrative domains in order to manage application
   resources.  An Enterprise organization may have multiple tenants or
   departments such as Human Resources (HR), Finance, and Legal, with
   each tenant having a need to manage their own Security Policies.  In
   a Service Provider, a tenant could represent a Customer that wants to
   manage its own Security Policies.  There are multiple managed objects
   that constitute multi-tenancy aspects as shown in Figure 7.  This
   section lists these objects and the relationship among these objects.
   Below diagram shows an example of multi-tenancy in an Enterprise
   domain.

                             +-------------------+
       (Multi-Tenancy)       |       Domain      |
                             |(e.g., Enterprise) |
                             +---------+---------+
                                       ^
                                       |
                  +--------------------+--------------------+
                  |                    |                    |
         +--------+-------+  +---------+--------+  +--------+--------+
         |  Department 1  |  |   Department 2   |  |  Department n   |
         +--------+-------+  +---------+--------+  +--------+--------+
                  ^                    ^                    ^
                  |                    |                    |
         +--------+--------+  +-----------------+  +--------+--------+
         | Sub-domain 1..n |  | Sub-domain 1..n |  | Sub-domain 1..n |
         +--------+--------+  +--------+--------+  +--------+--------+
                  ^                    ^                    ^
                  |                    |                    |
         +--------+--------+  +--------+--------+  +--------+--------+
         |   Tenant 1..n   |  |   Tenant 1..n   |  |   Tenant 1..n   |
         +-----------------+  +-----------------+  +-----------------+


                      Figure 7: Multi-tenancy Diagram

5.1.  Policy Domain

   This object defines a boundary for the purpose of policy management
   within a Security Controller.  This may vary based on how the
   Security Controller is deployed and hosted.  For example, if an
   Enterprise hosts a Security Controller in their network; the domain
   in this case could just be the one that represents that Enterprise.
   But if a Cloud Service Provider hosts managed services, then a domain
   could represent a single customer of that Provider.  Figure 8 shows



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   the XML instance of the Policy-Domain object.  Multi-tenancy model
   should be able to work in all such environments.  The Policy-Domain
   object SHALL have the following information:

      Name:  Name of the organization or customer representing this
             domain.

      Address:  Address of the organization or customer.

      Contact:  Contact information of the organization or customer.

      Date:  Date when this account was created or last modified.

      Authentication-Method:  Authentication method to be used for this
             domain.  It should be a reference to a "Policy-Management-
             Authentication-Method" object.

         +--rw policy-domain* [name]
            +--rw name                     string
            +--rw date?                    yang:date-and-time
            +--rw address?                 string
            +--rw contact?                 string
            +--rw policy-tenant* [name]
            +--rw authentication-method?   -> /policy
                                              /multi-tenancy
                                              /policy-mgnt-auth-method
                                              /name
               ...
               ...


                  Figure 8: Policy Domain YANG Data Tree

5.2.  Policy Tenant

   This object defines an entity within an organization.  The entity
   could be a department or business unit within an Enterprise
   organization that would like to manage its own Policies due to
   regulatory compliance or business reasons.  Figure 9 shows the XML
   instance of the Policy-Tenant object.  The Policy-Tenant object SHALL
   have the following information:

      Name:  Name of the Department or Division within an organization.

      Date:  Date when this account was created or last modified.






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      Domain:  This field identifies the domain to which this tenant
             belongs.  This should be a reference to a Policy-Domain
             object.

           +--rw policy-tenant* [name]
              +--rw name      string
              +--rw date?     yang:date-and-time
              +--rw domain?   -> /policy
                                 /multi-tenancy
                                 /policy-domain
                                 /name


                  Figure 9: Policy Tenant YANG Data Tree

5.3.  Policy Role

   This object defines a set of permissions assigned to a user in an
   organization that wants to manage its own Security Policies.  It
   provides a convenient way to assign policy users to a job function or
   a set of permissions within the organization.  Figure 10 shows the
   XML instance of the Policy-Role object.  The Policy-Role object SHALL
   have the following information:

      Name:  This field identifies the name of the role.

      Date:  Date when this role was created or last modified.

      Access-Profile:  This field identifies the access profile for the
             role.  The profile grants or denies the permissions to
             access Endpoint Groups for the purpose of policy management
             or may restrict certain operations related to policy
             managements.  There are two permission types, read-only and
             read-and-write, to choose from for each access-profile.

             +--rw policy-role
             |  +--rw name?             string
             |  +--rw date?             yang:date-and-time
             |  +--rw access-profile* [name]
             |     +--rw name               string
             |     +--rw date?              yang:date-and-time
             |     +--rw permission-type?   identityref


                   Figure 10: Policy Role YANG Data Tree






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5.4.  Policy User

   This object represents a unique identity of a user within an
   organization.  The identity authenticates with Security Controller
   using credentials such as a password or token in order to perform
   policy management.  A user may be an individual, system, or
   application requiring access to Security Controller.  Figure 11 shows
   the XML instance of the Policy-User object.  The Policy-User object
   SHALL have the following information:

      Name:  Name of a user.

      Date:  Date when this user was created or last modified.

      Password:  User password for basic authentication.

      Email: E-mail address of the user.

      Scope-Type:  This field identifies whether the user has domain-
             wide or tenant-wide privileges.

      Role:  This field should be a reference to a Policy-Role object
             that defines the specific permissions.

         +--rw policy-user* [name]
         |  +--rw name          string
         |  +--rw date?         yang:date-and-time
         |  +--rw password?     string
         |  +--rw email?        string
         |  +--rw scope-type?   identityref
         |  +--rw role?         -> /policy
                                   /multi-tenancy
                                   /policy-role
                                   /access-profile
                                   /name


                   Figure 11: Policy User YANG Data Tree

5.5.  Policy Management Authentication Method

   This object represents authentication schemes supported by Security
   Controller.  Figure 12 shows the XML instance of the Policy
   Management Authentication Method onject.  This Policy-Management-
   Authentication-Method object SHALL have the following information:

      Name:  This field identifies name of this object.




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      Date:  Date when this object was created or last modified.

      Authentication-Method:  This field identifies the authentication
             methods.  It could be a password-based, token-based,
             certificate-based or single sign-on authentication.

      Mutual-Authentication:  This field indicates whether mutual
             authentication is mandatory or not.

      Token-Server:  This field stores the information about server that
             validates the token submitted as credentials.

      Certificate-Server:  This field stores the information about
             server that validates certificates submitted as
             credentials.

      IPsec-Method:  This list has IPsec method types based on the
             identities defined.  There are two types such as IPsec-IKE
             and IPsec-IKEless.

      Single Sign-on-Server:  This field stores the information about
             server that validates user credentials.

         +--rw policy-mgnt-auth-method* [name]
            +--rw name                     string
            +--rw date?                    yang:date-and-time
            +--rw mutual-authentication?   boolean
            +--rw password
            |  +--rw password?             password-type
            +--rw token
            |  +--rw token?                string
            |  +--rw token-server?         inet:ipv4-address
            +--rw certificate
            |  +--rw certificate?          certificate-type
            |  +--rw certificate-server?   inet:ipv4-address
            +--rw ipsec-method* [method]
            |  +--rw method                identityref
            +--rw single-sign-on
               +--rw credential?           certificate-type
               +--rw certificate-server?   inet:ipv4-address


     Figure 12: Policy Management Authentication Method YANG Data Tree








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6.  Information Model for Policy Endpoint Groups

   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 13.  Figure 14 shows the XML instance of the
   Endpoint-Group object.  This section lists these objects and
   relationship among them.

                      +-------------------+
                      |  Endpoint Group   |
                      +---------+---------+
                                ^
                                |
                 +--------------+----------------+
          1..n   |      1..n    |       1..n     |
           +-----+----+  +------+-----+  +-------+------+
           |User-group|  |Device-group|  |Location-group|
           +----------+  +------------+  +--------------+


                     Figure 13: Endpoint Group Diagram

           +--rw endpoint-group
              +--rw user-group* [name]
              |  ...
              +--rw device-group* [name]
              |  ...
              +--rw location-group* [name]
                 ...


                 Figure 14: Endpoint Group YANG Data Tree

6.1.  User Group

   This object represents a User-Group.  Figure 15 shows the XML
   instance of the User-Group object.  The User-Group object SHALL have
   the following information:

      Name:  This field identifies the name of this object.

      Date:  Date when this object was created or last modified.

      IP-Address:  This field identifies the IP address of a user.




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      Range-IP-Address:  This field is a range of IP addresses of users.

      +--rw user-group* [name]
         +--rw name                         string
         +--rw date?                        yang:date-and-time
         +--rw (match-type)?
            +--:(exact-match)
            |  +--rw ip-address*            inet:ipv4-address
            +--:(range-match)
               +--rw range-ip-address* [start-ip-address end-ip-address]
                  +--rw start-ip-address    inet:ipv4-address
                  +--rw end-ip-address      inet:ip-address


                   Figure 15: User Group YANG Data Tree

6.2.  Device Group

   This object represents a Device-Group.  Figure 16 shows the XML
   instance of the Device-group object.The Device-Group object SHALL
   have the following information:

      Name:  This field identifies the name of this object.

      Date:  Date when this object was created or last modified.

      IP-Address:  This field identifies the IP address of a device.

      Range-IP-Address:  This field is a range of IP addresses of
             devices.

       +--rw device-group* [name]
          +--rw name                        string
          +--rw date?                       yang:date-and-time
          +--rw (match-type)?
            +--:(exact-match)
            |  +--rw ip-address*            inet:ipv4-address
            +--:(range-match)
               +--rw range-ip-address* [start-ip-address end-ip-address]
                  +--rw start-ip-address    inet:ipv4-address
                  +--rw end-ip-address      inet:ip-address


                  Figure 16: Device Group YANG Data Tree







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6.3.  Location Group

   This object represents a location group based on either tag or other
   information.  Figure 17 shows the XML instance of the Location-Group
   object.  The Location-Group object SHALL have the following
   information:

      Name:  This field identifies the name of this object.

      Date:  Date when this object was created or last modified.

      continent:  to identify which continent the location group member
             is based at.

        +--rw location-group* [name]
           +--rw name         string
           +--rw date?        yang:date-and-time
           +--rw continent?   identityref


                 Figure 17: Location Group YANG Data Tree

7.  Information Model for Threat Prevention

   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), such as EmergingThreats.com or AlienVault.com.  There
   are multiple managed objects that constitute this category.  This
   section lists these objects and relationship among them.  Figure 19
   shows the XML instance of a Threat-Prevention object.

                            +-------------------+
                            | Threat Prevention |
                            +---------+---------+
                                      ^
                                      |
                            +---------+---------+
                    1..n    |         1..n      |
                     +------+------+   +--------+--------+
                     | Threat-feed |   | payload-content |
                     +-------------+   +-----------------+


                   Figure 18: Threat Prevention Diagram






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       +--rw threat-prevention
       |  +--rw threat-feed-list* [name]
       |   ...
       |  +--rw payload-content* [name]
       |   ...


                Figure 19: Threat Prevention YANG Data Tree

7.1.  Threat Feed

   This object represents a threat feed which provides signatures of
   malicious activities.  Figure 20 shows the XML instance of a Threat-
   feed-list.  The Threat-Feed object SHALL have the following
   information:

      Name:  This field identifies the name of this object.

      Date:  Date when this object was created or last modified.

      Threat-feed-Server:  This field identifies the information about
             the feed provider, it may be an external service or local
             server.

      Threat-file-types:  This field identifies the information about
             the file types identified and reported by the threat-feed.

      signatures:  This field contains the signatures of malicious
             programs or activities provided by the threat-feed.

    +--rw threat-feed-list* [name]
       +--rw name                           string
       +--rw date?                          yang:date-and-time
       +--rw threat-feed-server
       |  +--rw (match-type)?
       |  |  +--:(exact-match)
       |  |  |  +--rw ip-address*           inet:ipv4-address
       |  |  +--:(range-match)
       |  |     +--rw range-ip-address* [start-ip-address end-ip-address]
       |  |        +--rw start-ip-address   inet:ipv4-address
       |  |        +--rw end-ip-address     inet:ip-address
       |  +--rw threat-feed-description?    string
       +--rw threat-file-types*             identityref
       +--rw signatures*                    string


                   Figure 20: Threat Feed YANG Data Tree




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7.2.  Payload Content

   This object represents a custom list created for the purpose of
   defining exception to threat feeds.  Figure 21 shows the XML instance
   of a Payload-content list.  The Payload-Content object SHALL have the
   following information:

      Name:  This field identifies the name of this object.

      Date:  Date when this object was created or last modified.

      List-Content:  This field contains contents such as IP addresses
             or URL names.

        +--rw payload-content*  [name]
        |  +--rw name           string
        |  +--rw date?          yang:date-and-time
        |  +--rw content*       string


               Figure 21: Payload Content in YANG Data Tree

8.  Role-based Acess Control (RBAC)

   Role-Based Access Control (RBAC) provides a powerful and centralized
   control within a network.  It is a policy neutral access control
   mechanism defined around roles and privileges.  The components of
   RBAC, such as role-permissions, user-role and role-role
   relationships, make it simple to perform user assignments.

     +--------------+
     |              |
     |    User 1    + (has many)
     |              |\
     +--------------+ \     +---------------+            +-------------+
             .         \    |               | (has many) |             |
             .          --->+ List of roles +----------->+ Permissions |
     +--------------+  /    |               |            |             |
     |              | /     +---------------+            +-------------+
     |    User n    +/
     |              | (has many)
     +--------------+


                Figure 22: Role-based Acess Control Diagram

   As shown in Figure 22, a role represents a collection of permissions
   (e.g., accessing a file server or other particular resources).  A



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   role may be assigned to one or multiple users.  Both roles and
   permissions can be organized in a hirarchy.  A role may consists of
   other roles and permissions.

   Following are the steps required to build RBAC:

     1.      Defining roles and permissions.

     2.      Establishing relations among roles and permissions.

     3.      Defining users.

     4.      Associating rules with roles and permissions.

     5.      assigning roles to users.

9.  YANG Data Model for Security Policies for Consumer-Facing Interface

   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-cfi-policy.yang"
module ietf-i2nsf-cfi-policy {
yang-version 1.1;
  namespace
    "urn:ietf:params:xml:ns:yang:ietf-i2nsf-cfi-policy";
  prefix
    cfi-policy;



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  import ietf-yang-types{
    prefix yang;
    reference
    "Section 3 of RFC 6991";
  }

  import ietf-inet-types{
    prefix inet;
    reference
    "Section 4 of RFC 6991";
  }

  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: Adrian Farrel
     <mailto:Adrain@olddog.co.uk>

     WG Chair: Linda Dunbar
     <mailto:Linda.duhbar@huawei.com>

     Editor: Jaehoon Paul Jeong
     <mailto:pauljeong@skku.edu>";

  description
   "This module is a YANG module for Consumer-Facing Interface.
   Copyright (c) 2018 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 "2019-06-12"{
    description "latest revision";
    reference
      "draft-ietf-consumer-facing-interface-dm-03";
  }



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  identity permission-type {
    description
      "Base identity for the permission types.";
  }

  identity read-only {
    base permission-type;
    description
      "Identity for read-only permission.";
  }
  identity read-and-write {
    base permission-type;
    description
      "Identity for read permission.";
  }

  identity scope-type {
    description
      "Base Identity for scope-type.";
  }
  identity tenant-wide {
    base scope-type;
    description
      "Base Identity for tenant-wide scope type.";
  }
  identity domain-wide {
    base scope-type;
    description
      "Base Identity for domain-wide scope type.";
  }

  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



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      "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 malware-file-type;
    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 ransomeware {
    base malware-file-type;
    description
      "Identity for ransomeware infection event types.";
  }




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  identity i2nsf-ipsec {
    description
      "Base identity for IPsec method types.";
  }

  identity ipsec-ike {
    base i2nsf-ipsec;
    description
      "Identity for ipsec-ike.";
  }

  identity ipsec-ikeless {
    base i2nsf-ipsec;
    description
      "Identity for ipsec-ikeless.";
  }

  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 {



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    base continent;
    description
    "Identity for Oceania";
  }
  typedef certificate-type {

    type enumeration {
      enum cer {
        description
           "The extension type is '.cer'.";
      }
      enum crt {
        description
           "The extension type is '.crt'.";
      }
      enum key {
        description
           "The extension type is '.key'.";
      }
    }
    description
      "CRT certificate extension, which is used for certificates.
      The certificates may be encoded as binary DER or as ASCII PEM.
      The CER and CRT extensions are nearly synonymous.  Most common
      among *nix systems. CER certificate extension, which is an
      alternate form of .crt (Microsoft Convention) You can use MS to
      convert .crt to .cer (.both DER encoded .cer, or base64[PEM]
      encoded .cer). The KEY extension is used both for public and
      private PKCS#8 keys. The keys may be encoded as binary DER or
      as ASCII PEM.";
  }

grouping meta {
  description
    "The purpose of this grouping is to avoid repetition
     of same fields, such as 'name' and 'date'.";
  leaf name {
    type string;
    description "This is the name for an entity.";
  }
  leaf date {
    type yang:date-and-time;
    description "This is the date when the entity is
    created or modified.";
  }
}

grouping ip-address {



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  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 {
        leaf-list ip-address {
          type inet:ipv4-address;
          description
          "Exactly matches the IP address specified.";
        }
      }
      case range-match {
        list range-ip-address {
          key "start-ip-address end-ip-address";
          leaf start-ip-address {
            type inet:ipv4-address;
            description
              "Start IP address for a range match.";
          }
          leaf end-ip-address {
            type inet:ip-address;
            description
              "End IP address for a range match.";
          }
          description
            "Range match for an IP-address.";
        }
      }
    }
}

grouping user-group {
  description
    "This grouping is to remove repetition of
    'name' and 'ip-address' fields.";
  uses meta;
  uses ip-address;
}

grouping device-group {
  description
    "This grouping is to remove repetition of
    'name', 'ip-address', and 'protocol' fields.";
  uses meta;
  uses ip-address;
  leaf-list protocol {



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    type string;
    description
    "This represents the port numbers of devices.";
  }
}

grouping location-group {
  description
    "This grouping is to remove repetition of
    'name' and 'continent' fields.";
  uses meta;
  leaf continent {
    type identityref {
      base continent;
        }
    description
      "location-group-based on geo-ip of
      respective continent.";
  }
}

grouping payload-string {
  description
    "This grouping is to remove repetition of
    'name' and 'content' fields.";
  uses meta;
  leaf-list content {
    type string;
    description
    "This represents the payload string content.";
  }
}

container policy {
    leaf policy-name {
      type string;
      description
        "The name which identifies the policy.";
    }
    description
    "There can be a multiple number of security rules in
    a policy object. This object is a policy instance to
    have complete information such as where and when a
    policy need to be applied.";

    list rule {
      leaf rule-name {
        type string;



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        description
        "This represents the name for rules.";
      }
      key "rule-name";
      description
        "There can be a single or multiple number of rules.";

      leaf date {
       type yang:date-and-time;
        description
         "Date this object was created or last
          modified";
      }
      container event {
        description
         "This represents the event map group name.";
        leaf security-event {
          type identityref {
            base security-event-type;
          }
          description
            "This contains the description of security events.";
        }
        leaf enforce-type {
          type enumeration{
            enum admin-enforced {
              description
                "The enforcement type is admin-enforced.";
            }
            enum time-enforced {
              description
                "The enforcement type is time-enforced.";
            }
            enum event-enforced {
              description
                "The enforcement type is event-enforced.";
            }
          }
          description
            "This field identifies the event of
            policy enforcement trigger type.";
        }
       container time-information {
        description
          "The container for time-information.";
           leaf begin-time {
             type string;
             description



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             "This is start time for time zone";
           }
           leaf end-time {
             type string;
             description
             "This is end time for time zone";
           }
           }
       container recursive {
        description
          "The container to represent the recursiveness
          of the rule.";
         leaf recur {
           type boolean;
           description
           "recursive enforcement";
         }
         leaf recursive-type{
           type enumeration{
             enum daily {
              description
                "The recursive type is daily.";
             }
             enum weekly {
              description
                "The recursive type is weekly.";
             }
             enum monthly {
              description
                "The recursive type is monthly.";
             }
           }
           description
            "This leaf identifies the recursive type.";
         }
       }
      }
      container condition {
        description
          "The conditions for general security policies.";
            container firewall-condition {
              description
                "The general firewall condition.";
              container source-target {
                description
                  "This represents the source.";
                leaf src-target {
                  type leafref {



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                    path "/policy/endpoint-group/user-group/name";
                  }
                  description
                    "This describes the paths to
                    the source reference.";
                }
              }
              container destination-target {
                description
                  "This represents the destination.";
                  leaf-list dest-target {
                    type leafref {
                      path "/policy/endpoint-group/user-group/name";
                    }
                    description
                      "This describes the paths to the
                      destination target reference.";
                  }
                }
            }
            container ddos-condition {
              description
                "The condition for DDoS mitigation.";
              container source-target {
                description
                  "This represents the source.";
                leaf-list src-target {
                    type leafref {
                      path "/policy/endpoint-group/device-group/name";
                    }
                    description
                      "This describes the path to the
                      source target references.";
                }
              }
              container destination-target {
                description
                  "This represents the target.";
                leaf-list dest-target {
                  type leafref {
                    path "/policy/endpoint-group/device-group/name";
                  }
                  description
                    "This describes the path to the
                    destination target references.";
                }
              }
              container rate-limit {



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                description "This describes the rate-limit.";
                leaf packet-per-second {
                  type uint8;
                  description
                  "The rate-limit limits the amount of incoming packets.";
                }
              }
            }
            container custom-condition {
              description
                "The condition based on packet contents.";
              container source-target {
                description
                  "This represents the source.";
                leaf-list src-target {
                  type leafref {
                    path "/policy/threat-prevention/payload-content/name";
                  }
                  description
                    "Describes the payload string
                    content condition source.";
                }
              }
              container destination-target {
                description
                  "This represents the destination.";
                leaf dest-target {
                  type leafref {
                    path "/policy/threat-prevention/payload-content/name";
                  }
                  description
                    "Describes the payload string
                  content condition destination.";
                }
              }
            }
            container threat-feed-condition {
              description
                "The condition based on the threat-feed information.";
              container source-target {
                description
                  "This represents the source.";
                leaf-list src-target {
                  type leafref {
                    path "/policy/threat-prevention/threat-feed-list/name";
                  }
                  description "Describes the threat-feed
                  condition source.";



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                }
              }
              container destination-target {
                description
                  "This represents the destination.";
                leaf dest-target {
                  type leafref {
                    path "/policy/threat-prevention/threat-feed-list/name";
                  }
                  description "Describes the threat-feed
                  condition destination.";
                }
              }
            }
      }
      container action {
        description
          "This is the action container.";
        leaf primary-action {
          type string;
          description
            "This field identifies the action when a rule
            is matched by NSF. The action could be one of
            'PERMIT', 'DENY', 'RATE-LIMIT', 'TRAFFIC-CLASS',
            'AUTHENTICATE-SESSION', 'IPS, 'APP-FIREWALL', etc.";
        }
        leaf secondary-action {
          type string;
          description
            "This field identifies additional actions if
            a rule is matched. This could be one of 'LOG',
            'SYSLOG', 'SESSION-LOG', etc.";
        }
      }
      container ipsec-method {
        description
          "This container represents the IPsec IKE and IKEless cases.";
        leaf method {
          type leafref {
           path "/policy/multi-tenancy/policy-mgnt-auth-method/ipsec-method/method";
          }
          description
            "This references the IPsec method types,
             which includes IPsec IKE and IPsec IKEless cases.";
        }
      }
      leaf owner {
        type string;



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          description
           "This field defines the owner of this
           policy. Only the owner is authorized to
           modify the contents of the policy.";
      }
    }

container multi-tenancy {
    description
      "The multi-tenant environment information
       in which the policy is applied. The Rules
       in the Policy can refer to sub-objects
       (e.g., domain, tenant, role, and user) of it.";

    list policy-domain {
      uses meta;
      key "name";
      leaf address {
        type string;
        description
          "The address details of the organization
          or customer.";
      }
      leaf contact {
        type string;
        description
          "contact information of the organization
           or customer.";
      }
      list policy-tenant {
        uses meta;
        key "name";
        description
        "This represents the list of tenants";
        leaf domain {
          type leafref {
            path "/policy/multi-tenancy/policy-domain/name";
          }
          description
          "This field identifies the domain to which this
          tenant belongs. This should be reference to a
          'Policy-Domain' object.";
        }
      }
      leaf authentication-method {
        type leafref {
          path "/policy/multi-tenancy/policy-mgnt-auth-method/ipsec-method/method";
        }



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        description
        "Authentication method to be used for this domain.
        It should be a reference to a 'policy-mgmt-auth-method'
        object.";
      }
      description
        "This represents the list of policy domains.";
    }
    container policy-role {
      uses meta;
      description
      "This represents the list of policy roles.";
      list access-profile {
        uses meta;
        key "name";
        description
          "This field identifies the access profile for the
          role. The profile grants or denies access to policy
          objects.";
        leaf permission-type {
          type identityref {
            base permission-type;
          }
          default read-only;
          description
            "Permission type for access-profile: read-only
            or read-and-write.";
        }
      }
    }
    list policy-user {
      uses meta;
      key "name";
      description
      "This represents the policy users.";
      leaf password {
        type string;
        description
          "User password for basic authentication";
      }
      leaf email {
        type string;
        description
          "The email account of a user";
      }
      leaf scope-type {
        type identityref {
          base scope-type;



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        }
        default tenant-wide;
        description
          "identifies whether a user has domain-wide
          or tenant-wide privileges";
      }
      leaf role {
        type leafref {
          path "/policy/multi-tenancy/policy-role/access-profile/name";
        }
        description
          "This represents the reference to the
          access-profiles.";
      }
    }
    container policy-mgnt-auth-method {
      description
        "This represents the list of authentication methods.";
      leaf auth-method {
        type string;
        description
          "This represents the authentication method name.";
      }
      leaf mutual-authentication {
        type boolean;
          description
          "To identify whether the authentication
          is mutual.";
      }
      list password-based {
        key "password";
        leaf password {
          type string;
          description
            "This should be defined using the
            regular expression.";
        }
        description
          "This represents the password-based method.";
      }
      list token-based {
        key "token";
        leaf token {
          type string;
          description
            "This should be defined according to
            the token scheme.";
        }



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        leaf token-server {
          type inet:ipv4-address;
          description
            "This represents the token-server
            information if the authentication method
            is token-based.";
        }
        description
          "This represents the token-based method.";
      }
      list certificate-based {
        key "certificate";
        leaf certificate {
          type certificate-type;
          description
            "This represents the certificate-type.";
        }
        leaf certificate-server {
          type inet:ipv4-address;
            description
              "The certificate-server information if
               the authentication method is
               certificate-based";
        }
        description
          "This describes the certificate-based authentication list.";
      }
      list ipsec-method {
        key "method";
        leaf method {
          type identityref {
            base i2nsf-ipsec;
          }
          description
            "This represents IPsec IKE and IPsec IKEless cases.";
        }
        description
          "This represents the list of IPsec method types.";
      }
      list single-sign-on {
        key "credential";
        leaf credential {
          type certificate-type;
          description
            "This represents the authentication
            using user credentials.";
        }
        leaf certificate-server {



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          type inet:ipv4-address;
            description
              "The certificate-server information if
              the authentication method is
              certificate-based";
        }
        description
          "This represents the authentication method
          for single-sing-on.";
      }
  }
}
container endpoint-group {
        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 {
          uses device-group;
          key "name";
          description
            "This represents the device group.";
        }
        list location-group{
          uses location-group;
          key "name";
          description
            "This represents the location group.";
        }
}
container threat-prevention {
      description
      "this describes the list of threat-prevention.";
      list threat-feed-list {
        uses meta;
        key "name";
          description
          "This represents the threat feed list.";
        container threat-feed-server {
          uses ip-address;
          description
            "This describes the threat-feed server.";



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          leaf threat-feed-description {
            type string;
            description
            "This object containes threat-feed
            description.";
          }
        }
        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 string;
          description
            "This contains a list of signatures or hash
            of the threats.";
        }
      }
      list payload-content {
          uses payload-string;
          key "name";
          description
            "This represents the payload-string group.";
      }
    }
  }
}
<CODE ENDS>

               Figure 23: YANG for Consumer-Facing Interface

10.  Example XML Output for Various Scenarios

   This section describes the XML instances for different policies
   examples that are delivered through Consumer-Facing Interface.  The
   considered use cases are: VoIP/VoLTE security service, DDoS-attack
   mitigation, time-based firewall as a web-filter.









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10.1.  DB Registration: Information of Positions and Devices (Endpoint
       Group)

   In order to create a rule of a security policy, it is essential to
   first register data (those which are used to form such rule) to the
   database.  For example, The endpoint group consists of three
   different groups: user-group, device-group, and payload-group.  Each
   of these groups have separate group members with information other
   than meta ("name" or "date"), such as ip-addresses or protocols used
   by devices.  Figure 24 shows an example XML representation of the
   registered information for the user-group and device-group.

         <?xml version="1.0" encoding="UTF-8" ?>
           <ietf-i2nsf-cfi-policy:endpoint-group>
             <user-group>
               <name>employees</name>
               <range-ip-address>
                 <start-ip-address>221.159.112.1</start-ip-address>
                 <end-ip-address>221.159.112.90</end-ip-address>
               </range-ip-address>
             </user-group>
             <device-group>
               <name>webservers</name>
               <range-ip-address>
                 <start-ip-address>221.159.112.91</start-ip-address>
                 <end-ip-address>221.159.112.97</end-ip-address>
               </range-ip-address>
               <protocol>http</protocol>
               <protocol>https</protocol>
             </device-group>
           </ietf-i2nsf-cfi-policy:endpoint-group>

      Figure 24: Registering User-group and Device-group Information

10.2.  Scenario 1: Block SNS Access during Business Hours

   The first example scenario is to "block SNS access during business
   hours" using a time-based firewall policy.  In this scenario, all
   users registered as "employee" in the user-group list are unable to
   access Social Networking Services (SNS) during the office hours.  The
   XML instance is described below:










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   <?xml version="1.0" encoding="UTF-8" ?>
   <ietf-i2nsf-cfi-policy:policy>
     <policy-name>security_policy_for_blocking_sns</policy-name>
     <rule>
       <rule-name>block_access_to_sns_during_office_hours</rule-name>
       <event>
         <time-information>
           <begin-time>09:00</begin-time>
           <end-time>18:00</end-time>
         </time-information>
       </event>
       <condition>
         <firewall-condition>
           <source-target>
             <src-target>employees</src-target>
           </source-target>
         </firewall-condition>
         <custom-condition>
           <destination-target>
             <dest-target>sns-websites</dest-target>
           </destination-target>
         </custom-condition>
       </condition>
       <action>
         <primary-action>drop</primary-action>
       </action>
       <ipsec-method>
         <method>ipsec-ike</method>
       </ipsec-method>
     </rule>
   </ietf-i2nsf-cfi-policy:policy>

             Figure 25: An XML Example for Time-based Firewall

   Time-based-condition Firewall

   1.  The policy name is "security_policy_for_blocking_sns".

   2.  The rule name is "block_access_to_sns_during_office_hours".

   3.  The Source-target is "employees".

   4.  The destination target is "sns-websites". "sns-websites" is the
       key which represents the list containing the information, such as
       URL, about sns-websites.

   5.  The action required is to "drop" any attempt to connect to
       websites related to Social networking.



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   6.  The IPsec method type used for nsf traffic steering is set to
       "ipsec-ike".

10.3.  Scenario 2: Block Malicious VoIP/VoLTE Packets Coming to a
       Company

   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 26 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" ?>
<ietf-i2nsf-cfi-policy:policy>
  <policy-name>security_policy_for_blocking_malicious_voip_packets</policy-name>
  <rule>
    <rule-name>Block_malicious_voip_and_volte_packets</rule-name>
    <condition>
      <custom-condition>
        <source-target>
          <src-target>malicious-id</src-target>
        </source-target>
      </custom-condition>
      <firewall-condition>
        <destination-target>
          <dest-target>employees</dest-target>
        </destination-target>
      </firewall-condition>
    </condition>
    <action>
      <primary-action>drop</primary-action>
    </action>
    <ipsec-method>
      <method>ipsec-ikeless</method>
    </ipsec-method>
  </rule>
</ietf-i2nsf-cfi-policy:policy>

            Figure 26: An XML Example for VoIP Security Service



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   Custom-condition Firewall

   1.  The policy name is
       "security_policy_for_blocking_malicious_voip_packets".

   2.  The rule name is "Block_malicious_voip_and_volte_packets".

   3.  The Source-target is "malicious-id".  This can be a single ID or
       a list of IDs, depending on how the ID are stored in the
       database.  The "malicious-id" is the key so that the security
       admin can read every stored malicious VOIP IDs that are named as
       "malicious-id".

   4.  The destination target is "employees". "employees" is the key
       which represents the list containing information about employees,
       such as IP addresses.

   5.  The action required is "drop" when any incoming packets are from
       "malicious-id".

   6.  The IPsec method used for nsf traffic steering is set to "ipsec-
       ikeless".

10.4.  Scenario 3: Mitigate HTTP and HTTPS Flood Attacks on a Company
       Web Server

   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:













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   <?xml version="1.0" encoding="UTF-8" ?>
   <ietf-i2nsf-cfi-policy:policy>
     <policy-name>security_policy_for_ddos_attacks</policy-name>
     <rule>
       <rule-name>100_packets_per_second</rule-name>
       <condition>
         <ddos-condition>
           <destination-target>
             <dest-target>webservers</dest-target>
           </destination-target>
           <rate-limit>
             <packet-per-second>100</packet-per-second>
           </rate-limit>
         </ddos-condition>
       </condition>
       <action>
         <primary-action>drop</primary-action>
       </action>
       <encrypt>
         <ipsec-method>ipsec-ike</ipsec-method>
       </encrypt>
     </rule>
   </ietf-i2nsf-cfi-policy:policy>

           Figure 27: An XML Example for DDoS-attack Mitigation

   DDoS-condition Firewall

   1.  The policy name is "security_policy_for_ddos_attacks".

   2.  The rule name is "100_packets_per_second".

   3.  The destination target is "webservers". "webservers" is the key
       which represents the list containing information, such as IP
       addresses and ports, about web-servers.

   4.  The rate limit exists to limit the incoming amount of packets per
       second.  In this case the rate limit is "100" packets per second.
       This amount depends on the packet receiving capacity of the
       server devices.

   5.  The Source-target is all sources which send abnormal amount of
       packets.

   6.  The action required is to "drop" packet reception is more than
       100 packets per second.





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   7.  The IPsec method used for nsf traffic steering is set to "ipsec-
       ike".

11.  Security Considerations

   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.

12.  IANA Considerations

   This document requests IANA to register the following URI in the
   "IETF XML Registry" [RFC3688]:

            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.


   This document requests IANA to register the following YANG module in
   the "YANG Module Names" registry [RFC7950].

           name: ietf-i2nsf-cfi-policy
           namespace: urn:ietf:params:xml:ns:yang:ietf-i2nsf-cfi-policy
           prefix: cfi-policy
           reference: RFC 7950


13.  References

13.1.  Normative References

   [RFC3444]  Pras, A. and J. Schoenwaelder, "On the Difference between
              Information Models and Data Models", RFC 3444,
              DOI 10.17487/RFC3444, January 2003,
              <https://www.rfc-editor.org/info/rfc3444>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <https://www.rfc-editor.org/info/rfc6020>.



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   [RFC6087]  Bierman, A., "Guidelines for Authors and Reviewers of YANG
              Data Model Documents", RFC 6087, DOI 10.17487/RFC6087,
              January 2011, <https://www.rfc-editor.org/info/rfc6087>.

   [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
              RFC 6991, DOI 10.17487/RFC6991, July 2013,
              <https://www.rfc-editor.org/info/rfc6991>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [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,
              <https://www.rfc-editor.org/info/rfc8192>.

   [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,
              <https://www.rfc-editor.org/info/rfc8329>.

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.

13.2.  Informative References

   [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", draft-ietf-i2nsf-client-facing-
              interface-req-05 (work in progress), May 2018.

   [i2nsf-capability-im]
              Xia, L., Strassner, J., Basile, C., and D. Lopez,
              "Information Model of NSFs Capabilities", draft-ietf-
              i2nsf-capability-05 (work in progress), April 2019.








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   [i2nsf-ipsec]
              Marin-Lopez, R., Lopez-Millan, G., and F. Pereniguez-
              Garcia, "Software-Defined Networking (SDN)-based IPsec
              Flow Protection", draft-ietf-i2nsf-sdn-ipsec-flow-
              protection-04 (work in progress), March 2019.

   [i2nsf-terminology]
              Hares, S., Strassner, J., Lopez, D., Xia, L., and H.
              Birkholz, "Interface to Network Security Functions (I2NSF)
              Terminology", draft-ietf-i2nsf-terminology-07 (work in
              progress), January 2019.








































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Appendix A.  Changes from draft-ietf-i2nsf-consumer-facing-interface-
             dm-04

   The following changes have been made from draft-ietf-i2nsf-consumer-
   facing-interface-dm-04:

   o  In Section 4 and Section 5.5, a field named "ipsec-method" is
      added to support IPsec method types (i.e., IPsec IKE and IPsec
      IKEless) for the configuration and state data of IPsec management
      in the I2NSF framework, which is specified in [i2nsf-ipsec].

Appendix B.  Acknowledgments

   This work was supported by Institute for Information & communications
   Technology Promotion (IITP) grant funded by the Korea government
   (MSIP)(No.  R-20160222-002755, Cloud based Security Intelligence
   Technology Development for the Customized Security Service
   Provisioning).

Appendix C.  Contributors

   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


   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





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   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



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   101 Software Avenue
   Nanjing, Jiangsu 210012
   China

   EMail: Frank.Xialiang@huawei.com


Authors' Addresses

   Jaehoon Paul Jeong
   Department of Computer Science and Engineering
   Sungkyunkwan University
   2066 Seobu-Ro, Jangan-Gu
   Suwon, Gyeonggi-Do  16419
   Republic of Korea

   Phone: +82 31 299 4957
   Fax:   +82 31 290 7996
   EMail: pauljeong@skku.edu
   URI:   http://iotlab.skku.edu/people-jaehoon-jeong.php


   Eunsoo Kim
   Department of Electronic, Electrical and Computer Engineering
   Sungkyunkwan University
   2066 Seobu-Ro, Jangan-Gu
   Suwon, Gyeonggi-Do  16419
   Republic of Korea

   Phone: +82 31 299 4104
   EMail: eskim86@skku.edu
   URI:   http://seclab.skku.edu/people/eunsoo-kim/


   Tae-Jin Ahn
   Korea Telecom
   70 Yuseong-Ro, Yuseong-Gu
   Daejeon  305-811
   Republic of Korea

   Phone: +82 42 870 8409
   EMail: taejin.ahn@kt.com









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   Rakesh Kumar
   Juniper Networks
   1133 Innovation Way
   Sunnyvale, CA  94089
   USA

   EMail: rkkumar@juniper.net


   Susan Hares
   Huawei
   7453 Hickory Hill
   Saline, MI  48176
   USA

   Phone: +1-734-604-0332
   EMail: shares@ndzh.com


































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