--- 1/draft-ietf-i2nsf-applicability-11.txt 2019-06-18 02:14:44.290348141 -0700 +++ 2/draft-ietf-i2nsf-applicability-12.txt 2019-06-18 02:14:44.342349457 -0700 @@ -1,26 +1,26 @@ I2NSF Working Group J. Jeong Internet-Draft Sungkyunkwan University Intended status: Informational S. Hyun -Expires: November 17, 2019 Chosun University +Expires: December 20, 2019 Chosun University T. Ahn Korea Telecom S. Hares Huawei D. Lopez Telefonica I+D - May 16, 2019 + June 18, 2019 Applicability of Interfaces to Network Security Functions to Network- Based Security Services - draft-ietf-i2nsf-applicability-11 + draft-ietf-i2nsf-applicability-12 Abstract This document describes the applicability of Interface to Network Security Functions (I2NSF) to network-based security services in Network Functions Virtualization (NFV) environments, such as firewall, deep packet inspection, or attack mitigation engines. Status of This Memo @@ -30,21 +30,21 @@ 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 November 17, 2019. + This Internet-Draft will expire on December 20, 2019. 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 @@ -52,76 +52,73 @@ to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. I2NSF Framework . . . . . . . . . . . . . . . . . . . . . . . 5 - 4. Time-dependent Web Access Control Service . . . . . . . . . . 7 - 5. I2NSF Framework with SFC . . . . . . . . . . . . . . . . . . 10 - 6. I2NSF Framework with SDN . . . . . . . . . . . . . . . . . . 12 - 6.1. Firewall: Centralized Firewall System . . . . . . . . . . 15 + 4. Time-dependent Web Access Control Service . . . . . . . . . . 6 + 5. I2NSF Framework with SFC . . . . . . . . . . . . . . . . . . 9 + 6. I2NSF Framework with SDN . . . . . . . . . . . . . . . . . . 11 + 6.1. Firewall: Centralized Firewall System . . . . . . . . . . 13 6.2. Deep Packet Inspection: Centralized VoIP/VoLTE Security - System . . . . . . . . . . . . . . . . . . . . . . . . . 15 + System . . . . . . . . . . . . . . . . . . . . . . . . . 14 6.3. Attack Mitigation: Centralized DDoS-attack Mitigation - System . . . . . . . . . . . . . . . . . . . . . . . . . 15 - 7. I2NSF Framework with NFV . . . . . . . . . . . . . . . . . . 17 - 8. Security Considerations . . . . . . . . . . . . . . . . . . . 19 - 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 19 - 10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 19 - 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 20 - 11.1. Normative References . . . . . . . . . . . . . . . . . . 20 - 11.2. Informative References . . . . . . . . . . . . . . . . . 21 - Appendix A. Changes from draft-ietf-i2nsf-applicability-10 . . . 23 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23 + System . . . . . . . . . . . . . . . . . . . . . . . . . 14 + 7. I2NSF Framework with NFV . . . . . . . . . . . . . . . . . . 15 + 8. Security Considerations . . . . . . . . . . . . . . . . . . . 17 + 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 18 + 10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 18 + 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 19 + 11.1. Normative References . . . . . . . . . . . . . . . . . . 19 + 11.2. Informative References . . . . . . . . . . . . . . . . . 20 + Appendix A. Changes from draft-ietf-i2nsf-applicability-10 . . . 22 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22 1. Introduction Interface to Network Security Functions (I2NSF) defines a framework and interfaces for interacting with Network Security Functions (NSFs). Note that an NSF is defined as software that provides a set of security-related services, such as (i) detecting unwanted activity, (ii) blocking or mitigating the effect of such unwanted activity in order to fulfil service requirements, and (iii) supporting communication stream integrity and confidentiality [i2nsf-terminology]. The I2NSF framework allows heterogeneous NSFs developed by different security solution vendors to be used in the Network Functions Virtualization (NFV) environment [ETSI-NFV] by utilizing the capabilities of such NSFs through I2NSF interfaces such as Customer- Facing Interface [consumer-facing-inf-dm] and NSF-Facing Interface [nsf-facing-inf-dm]. In the I2NSF framework, each NSF initially - registers the profile of its own capabilities into the Security - Controller (i.e., network operator management system [RFC8329]) in - the I2NSF system via Registration Interface [registration-inf-dm] so - that each NSF can be selected and used to enforce a given security - policy from I2NSF User (i.e., network security administrator). Note - that Developer's Management System (DMS) is management software that - provides a vendor's security service software as a Virtual Network - Function (VNF) in an NFV environment (or middlebox in the legacy - network) as an NSF, and registers the capabilities of an NSF into - Security Controller via Registration Interface for a security service - [RFC8329]. + registers the profile of its own capabilities with the Security + Controller (i.e., network operator management system [RFC8329]) of + the I2NSF system via the Registration Interface + [registration-inf-dm]. This registration enables an I2NSF User + (i.e., network security administrator) to select and use the NSF to + enforce a given security policy. Note that Developer's Management + System (DMS) is management software that provides a vendor's security + service software as a Virtual Network Function (VNF) in an NFV + environment (or middlebox in the legacy network) as an NSF, and + registers the capabilities of an NSF into Security Controller via + Registration Interface for a security service [RFC8329]. - Security Controller is defined as a management component that - contains control plane functions to manage NSFs and facilitate - information sharing among other components (e.g., NSFs and I2NSF - User) in an I2NSF system [i2nsf-terminology]. Security Controller - maintains the mapping between a capability and an NSF, so it can - perform to translate a high-level security policy received from I2NSF - User to a low-level security policy configured and enforced in an NSF - [policy-translation]. Security Controller can monitor the states and - security attacks in NSFs through NSF monitoring [nsf-monitoring-dm]. + Security Controller maintains the mapping between a capability and an + NSF, so it can perform to translate a high-level security policy + received from I2NSF User to a low-level security policy configured + and enforced in an NSF [policy-translation]. Security Controller can + monitor the states and security attacks in NSFs through NSF + monitoring [nsf-monitoring-dm]. This document illustrates the applicability of the I2NSF framework with four different scenarios: 1. The enforcement of time-dependent web access control. 2. The application of I2NSF to a Service Function Chaining (SFC) environment [RFC7665]. 3. The integration of the I2NSF framework with Software-Defined @@ -229,83 +225,58 @@ security capabilities, and generates low-level security policies for each of the NSFs so that the high-level security policies are eventually enforced by those NSFs [policy-translation]. Finally, the Security Controller sends the generated low-level security policies to the NSFs via the NSF-Facing Interface [nsf-facing-inf-dm]. As shown in Figure 1, with a Developer's Management System (called DMS), developers (or vendors) inform the Security Controller of the capabilities of the NSFs through the Registration Interface [registration-inf-dm] for registering (or deregistering) the - corresponding NSFs. Note that an inside attacker at the DMS can - seriously weaken the I2NSF system's security. That is, DMS can be - compromised to attack the Security Controller by providing the - Security Controller with malicious NSFs, and controlling those NSFs - in real time. To deal with this type of threat, the role of the DMS - should be restricted to providing an I2NSF system with the software - package/image for NSF execution, and the DMS should never be able to - access NSFs in online/activated status for the I2NSF system's - security. On the other hand, an access to active NSFs should be - allowed only to the Security Controller, not the DMS during the - provisioning time of those NSFs to the I2NSF system. However, note - that an inside attacker can access the active NSFs, which are being - executed as either VNFs or middleboxes in the I2NSF system, through a - back door (i.e., an IP address and a port number that are known to - the DMS to control an NSF). However, the Security Controller can - detect and prevent inside attacks by monitoring the activities of all - the DMSs as well as the NSFs through the I2NSF NSF monitoring - functionality [nsf-monitoring-dm]. Through the NSF monitoring, the - Security Controller can monitor the activities and states of NSFs, - and then can make a diagnosis to see whether the NSFs are working in - normal conditions or in abnormal conditions including the insider - threat. Note that the monitoring of the DMSs is out of scope for - I2NSF. + corresponding NSFs. - The Consumer-Facing Interface can be implemented as an XML file based - on the Consumer-Facing Interface data model [consumer-facing-inf-dm] - along with RESTCONF [RFC8040], which befits a web-based user - interface for an I2NSF User to send a Security Controller a high- - level security policy. Data models specified by YANG [RFC6020] - describe high-level security policies to be specified by an I2NSF - User. The data model defined in [consumer-facing-inf-dm] can be used - for the I2NSF Consumer-Facing Interface. Note that an inside - attacker at the I2NSF User can misuse the I2NSF system so that the - network system under the I2NSF system is vulnerable to security - attacks. To handle this type of threat, the Security Controller - needs to monitor the activities of all the I2NSF Users as well as the - NSFs through the I2NSF NSF monitoring functionality - [nsf-monitoring-dm]. Note that the monitoring of the I2NSF Users is - out of scope for I2NSF. + The Consumer-Facing Interface can be implemented with the Consumer- + Facing Interface YANG data model [consumer-facing-inf-dm] using + RESTCONF [RFC8040] which befits a web-based user interface for an + I2NSF User to send a Security Controller a high-level security + policy. Data models specified by YANG [RFC6020] describe high-level + security policies to be specified by an I2NSF User. The data model + defined in [consumer-facing-inf-dm] can be used for the I2NSF + Consumer-Facing Interface. Note that an inside attacker at the I2NSF + User can misuse the I2NSF system so that the network system under the + I2NSF system is vulnerable to security attacks. To handle this type + of threat, the Security Controller needs to monitor the activities of + all the I2NSF Users as well as the NSFs through the I2NSF NSF + monitoring functionality [nsf-monitoring-dm]. Note that the + monitoring of the I2NSF Users is out of scope of I2NSF. - The NSF-Facing Interface can be implemented as an XML file based on - the NSF-Facing Interface YANG data model [nsf-facing-inf-dm] along - with NETCONF [RFC6241], which befits a command-line-based remote- - procedure call for a Security Controller to configure an NSF with a - low-level security policy. Data models specified by YANG [RFC6020] - describe low-level security policies for the sake of NSFs, which are - translated from the high-level security policies by the Security - Controller. The data model defined in [nsf-facing-inf-dm] can be - used for the I2NSF NSF-Facing Interface. + The NSF-Facing Interface can be implemented with the NSF-Facing + Interface YANG data model [nsf-facing-inf-dm] using NETCONF [RFC6241] + which befits a command-line-based remote-procedure call for a + Security Controller to configure an NSF with a low-level security + policy. Data models specified by YANG [RFC6020] describe low-level + security policies for the sake of NSFs, which are translated from the + high-level security policies by the Security Controller. The data + model defined in [nsf-facing-inf-dm] can be used for the I2NSF NSF- + Facing Interface. - The Registration Interface can be implemented as an XML file based on - the Registration Interface YANG data model [registration-inf-dm] - along with NETCONF [RFC6241], which befits a command-line-based - remote-procedure call for a DMS to send a Security Controller an - NSF's capability information. Data models specified by YANG - [RFC6020] describe the registration of an NSF's capabilities to - enforce security services at the NSF. The data model defined in - [registration-inf-dm] can be used for the I2NSF Registration - Interface. + The Registration Interface can be implemented with the Registration + Interface YANG data model [registration-inf-dm] using NETCONF + [RFC6241] which befits a command-line-based remote-procedure call for + a DMS to send a Security Controller an NSF's capability information. + Data models specified by YANG [RFC6020] describe the registration of + an NSF's capabilities to enforce security services at the NSF. The + data model defined in [registration-inf-dm] can be used for the I2NSF + Registration Interface. - Also, the I2NSF framework can enforce multiple chained NSFs for the - low-level security policies by means of SFC techniques for the I2NSF - architecture [RFC7665]. + The I2NSF framework can chain multiple NSFs to implement low-level + security policies with the SFC architecture [RFC7665]. The following sections describe different security service scenarios illustrating the applicability of the I2NSF framework. 4. Time-dependent Web Access Control Service This service scenario assumes that an enterprise network administrator wants to control the staff members' access to a particular Internet service (e.g., Example.com) during business hours. The following is an example high-level security policy rule @@ -362,21 +333,21 @@ After receiving the high-level security policy, the Security Controller identifies required security capabilities, e.g., IP address and port number inspection capabilities and URL inspection capability. In this scenario, it is assumed that the IP address and port number inspection capabilities are required to check whether a received packet is an HTTP packet from a staff member. The URL inspection capability is required to check whether the target URL of a received packet is in the Example.com domain or not. The Security Controller maintains the security capabilities of each - NSF running in the I2NSF system, which have been reported by the + active NSF in the I2NSF system, which have been reported by the Developer's Management System via the Registration interface. Based on this information, the Security Controller identifies NSFs that can perform the IP address and port number inspection and URL inspection [policy-translation]. In this scenario, it is assumed that a firewall NSF has the IP address and port number inspection capabilities and a web filter NSF has URL inspection capability. The Security Controller generates low-level security rules for the NSFs to perform IP address and port number inspection, URL inspection, and time checking. Specifically, the Security Controller @@ -400,22 +371,22 @@ 1. A staff member tries to access Example.com during business hours, e.g., 10 AM. 2. The packet is forwarded from the staff member's device to the firewall, and the firewall checks the source IP address and port number. Now the firewall identifies the received packet is an HTTP packet from the staff member. 3. The firewall triggers the web filter to further inspect the packet, and the packet is forwarded from the firewall to the web - filter. SFC technology can be utilized to support such packet - forwarding in the I2NSF framework [RFC7665]. + filter. The SFC architecture [RFC7665] can be utilized to + support such packet forwarding in the I2NSF framework. 4. The web filter checks the target URL field of the received packet, and realizes the packet is toward Example.com. The web filter then checks that the current time is in business hours. If so, the web filter drops the packet, and consequently the staff member's access to Example.com during business hours is blocked. +------------+ | I2NSF User | @@ -479,31 +450,31 @@ with the classification rules over NSF-Facing Interface so that relevant traffic packets can follow the SFPs. Also, based on the global view of NSF instances available in the system, the Security Controller constructs forwarding tables, which are required for SFFs to forward a given packet to the next NSF over the SFP, and configures SFFs with those forwarding tables over NSF-Facing Interface. To trigger an advanced security action in the I2NSF architecture, the current NSF appends metadata describing the security capability - required for the advanced action to the suspicious packet to the - network service header (NSH) of the packet [RFC8300]. It then sends - the packet to the classifier. Based on the metadata information, the - classifier searches an SFP which includes an NSF with the required - security capability, changes the SFP-related information (e.g., - service path identifier and service index [RFC8300]) of the packet - with the new SFP that has been found, and then forwards the packet to - the SFF. When receiving the packet, the SFF checks the SFP-related - information such as the service path identifier and service index - contained in the packet and forwards the packet to the next NSF on - the SFP of the packet, according to its forwarding table. + required to the suspicious packet via a network service header (NSH) + [RFC8300]. It then sends the packet to the classifier. Based on the + metadata information, the classifier searches an SFP which includes + an NSF with the required security capability, changes the SFP-related + information (e.g., service path identifier and service index + [RFC8300]) of the packet with the new SFP that has been found, and + then forwards the packet to the SFF. When receiving the packet, the + SFF checks the SFP-related information such as the service path + identifier and service index contained in the packet and forwards the + packet to the next NSF on the SFP of the packet, according to its + forwarding table. +------------+ | I2NSF User | +------------+ ^ | Consumer-Facing Interface v +-------------------+ Registration +-----------------------+ |Security Controller|<-------------------->|Developer's Mgmt System| +-------------------+ Interface +-----------------------+ @@ -549,40 +520,31 @@ both SDN forwarding elements and a firewall NSF is more efficient than a firewall where SDN forwarding elements forward all the packets to a firewall NSF for packet filtering. This is because packets to be filtered out can be early dropped by SDN forwarding elements without consuming further network bandwidth due to the forwarding of the packets to the firewall NSF. Figure 4 shows an I2NSF framework [RFC8329] with SDN networks to support network-based security services. In this system, the enforcement of security policy rules is divided into the SDN - forwarding elements (e.g., switch running as either a hardware middle - box or a software virtual switch) and NSFs (e.g., firewall running in - a form of a virtual network function (VNF) [ETSI-NFV]). Note that - NSFs are created or removed by the NFV Management and Orchestration - (MANO) [ETSI-NFV-MANO], performing the life-cycle management of NSFs - as VNFs. Refer to Section 7 for the detailed discussion of the NSF - life-cycle management in the NFV MANO for I2NSF. SDN forwarding - elements enforce simple packet filtering rules that can be translated - into their packet forwarding rules, whereas NSFs enforce complicated - NSF-related security rules requiring the security capabilities of the - NSFs. Note that SDN packet forwarding rules are for packet - forwarding or filtering by flow table entries at SDN forwarding - elements, and NSF rules are for security enforcement at NSFs (e.g., - firewall). Thus, simple firewall rules can be enforced by SDN packet - forwarding rules at SDN forwarding elements (e.g., switches). For - the tasks for security enforcement (e.g., packet filtering), the - Security Controller instructs the SDN Controller via NSF-Facing - Interface so that SDN forwarding elements can perform the required - security services with flow tables under the supervision of the SDN - Controller. + forwarding elements (e.g., a switch running as either a hardware + middle box or a software virtual switch) and NSFs (e.g., a firewall + running in a form of a VNF [ETSI-NFV]). Note that NSFs are created + or removed by the NFV Management and Orchestration (MANO) + [ETSI-NFV-MANO], performing the lifecycle management of NSFs as VNFs. + Refer to Section 7 for the detailed discussion of the NSF lifecycle + management in the NFV MANO for I2NSF. For security policy + enforcement (e.g., packet filtering), the Security Controller + instructs the SDN Controller via NSF-Facing Interface so that SDN + forwarding elements can perform the required security services with + flow tables under the supervision of the SDN Controller. As an example, let us consider two different types of security rules: Rule A is a simple packet filtering rule that checks only the IP address and port number of a given packet, whereas rule B is a time- consuming packet inspection rule for analyzing whether an attached file being transmitted over a flow of packets contains malware. Rule A can be translated into packet forwarding rules of SDN forwarding elements and thus be enforced by these elements. In contrast, rule B cannot be enforced by forwarding elements, but it has to be enforced by NSFs with anti-malware capability. Specifically, a flow of @@ -598,34 +560,34 @@ rules requires security capabilities that can be provided by SDN forwarding elements, then the Security Controller instructs the SDN Controller via NSF-Facing Interface so that SDN forwarding elements can enforce those security policy rules with flow tables under the supervision of the SDN Controller. Or if some rules require security capabilities that cannot be provided by SDN forwarding elements but by NSFs, then the Security Controller instructs relevant NSFs to enforce those rules. The distinction between software-based SDN forwarding elements and - NSFs, which can both run as virtual network functions (VNFs), may be - necessary for some management purposes in this system. Note that an - SDN forwarding element (i.e., switch) is a specific type of VNF - rather than an NSF because an NSF is for security services rather - than for packet forwarding. For this distinction, we can take - advantage of the NFV MANO where there is a subsystem that maintains - the descriptions of the capabilities each VNF can offer - [ETSI-NFV-MANO]. This subsystem can determine whether a given - software element (VNF instance) is an NSF or a virtualized SDN - switch. For example, if a VNF instance has anti-malware capability - according to the description of the VNF, it could be considered as an - NSF. A VNF onboarding system [VNF-ONBOARDING] can be used as such a - subsystem that maintains the descriptions of each VNF to tell whether - a VNF instance is for an NSF or for a virtualized SDN switch. + NSFs, which can both run as VNFs, may be necessary for some + management purposes in this system. Note that an SDN forwarding + element (i.e., switch) is a specific type of VNF rather than an NSF + because an NSF is for security services rather than for packet + forwarding. For this distinction, we can take advantage of the NFV + MANO where there is a subsystem that maintains the descriptions of + the capabilities each VNF can offer [ETSI-NFV-MANO]. This subsystem + can determine whether a given software element (VNF instance) is an + NSF or a virtualized SDN switch. For example, if a VNF instance has + anti-malware capability according to the description of the VNF, it + could be considered as an NSF. A VNF onboarding system + [VNF-ONBOARDING] can be used as such a subsystem that maintains the + descriptions of each VNF to tell whether a VNF instance is for an NSF + or for a virtualized SDN switch. For the support of SFC in the I2NSF framework with SDN, as shown in Figure 4, network forwarding elements (e.g., switch) can play the role of either SFC Classifier or SFF, which are explained in Section 5. Classifier and SFF have an NSF-Facing Interface with Security Controller. This interface is used to update security service function chaining information for traffic flows. For example, when it needs to update an SFP for a traffic flow in an SDN network, as shown in Figure 4, SFF (denoted as Switch-3) asks Security Controller to update the SFP for the traffic flow (needing @@ -751,36 +713,35 @@ to rapidly and flexibly respond to the amount of service requests by dynamically increasing or decreasing the number of NSF instances. Moreover, NFV technology facilitates flexibly including or excluding NSFs from multiple security solution vendors according to the changes on security requirements. In order to take advantages of the NFV technology, the I2NSF framework can be implemented on top of an NFV infrastructure as show in Figure 5. Figure 5 shows an I2NSF framework implementation based on the NFV reference architecture that the European Telecommunications Standards - Institute (ETSI) defines [ETSI-NFV]. The NSFs are deployed as - virtual network functions (VNFs) in Figure 5. The Developer's - Management System (DMS) in the I2NSF framework is responsible for - registering capability information of NSFs into the Security - Controller. However, those NSFs are created or removed by a virtual - network functions manager (VNFM) in the NFV MANO that performs the - life-cycle management of VNFs. Note that the life-cycle management - of VNFs are out of scope for I2NSF. The Security Controller controls - and monitors the configurations (e.g., function parameters and - security policy rules) of VNFs via NSF-Facing Interface along with - NSF monitoring capability [nsf-facing-inf-dm][nsf-monitoring-dm]. - Both the DMS and Security Controller can be implemented as the - Element Managements (EMs) in the NFV architecture. Finally, the - I2NSF User can be implemented as OSS/BSS (Operational Support - Systems/Business Support Systems) in the NFV architecture that - provides interfaces for users in the NFV system. + Institute (ETSI) defines [ETSI-NFV]. The NSFs are deployed as VNFs + in Figure 5. The Developer's Management System (DMS) in the I2NSF + framework is responsible for registering capability information of + NSFs into the Security Controller. However, those NSFs are created + or removed by a virtual network function manager (VNFM) in the NFV + MANO that performs the lifecycle management of VNFs. Note that the + lifecycle management of VNFs is out of scope of I2NSF. The Security + Controller controls and monitors the configurations (e.g., function + parameters and security policy rules) of VNFs via the NSF-Facing + Interface along with the NSF monitoring capability + [nsf-facing-inf-dm][nsf-monitoring-dm]. Both the DMS and Security + Controller can be implemented as the Element Managements (EMs) in the + NFV architecture. Finally, the I2NSF User can be implemented as OSS/ + BSS (Operational Support Systems/Business Support Systems) in the NFV + architecture that provides interfaces for users in the NFV system. The operation procedure in the I2NSF framework based on the NFV architecture is as follows: 1. The VNFM has a set of virtual machine (VM) images of NSFs, and each VM image can be used to create an NSF instance that provides a set of security capabilities. The DMS initially registers a mapping table of the ID of each VM image and the set of capabilities that can be provided by an NSF instance created from the VM image into the Security Controller. @@ -815,20 +776,56 @@ Ve-Vnfm interface between the DMS and VNFM, as shown in Figure 5. 8. Security Considerations The same security considerations for the I2NSF framework [RFC8329] are applicable to this document. This document shares all the security issues of SDN that are specified in the "Security Considerations" section of [ITU-T.Y.3300]. + Note that an inside attacker (or supply chain attacker) at the DMS + can seriously weaken the I2NSF system's security. Note that a + malicious NSF provider (as a DMS) is relevant to an insider attack, + and a compromised NSF provider is relevant to a supply chain attack. + Also, note that a malicious (or compromised) DMS sending the wrong + NSF may not modify the original code of the NSF but may alter the + sent NSF as an instant. As a result, a malicious (or compromised) + DMS can attack the Security Controller by providing the Security + Controller with malicious (or compromised) NSFs, and controlling + those NSFs in real time. Also, an unwitting DMS vendor could be + compromised and their infrastructure could be coerced into + distributing modified NSFs. To deal with these types of threats, the + role of the DMS should be restricted to providing an I2NSF system + with the software package/image for NSF execution, and the DMS should + never be able to access NSFs in activated status for the I2NSF + system's security. On the other hand, an access to active NSFs + should be allowed only to the Security Controller, not the DMS during + the provisioning time of those NSFs to the I2NSF system. However, + note that an inside attacker (or supply chain attacker) can access + the active NSFs, which are being executed as either VNFs or + middleboxes in the I2NSF system, through a back door (i.e., an IP + address and a port number that are known to the DMS to control an + NSF). However, the Security Controller may detect and prevent those + inside attacks (or supply chain attacks) by monitoring the activities + of all the DMSs as well as the NSFs through the I2NSF NSF Monitoring + Interface [nsf-monitoring-dm] as part of the I2NSF NSF-Facing + Interface. Through the NSF Monitoring Interface, the Security + Controller can monitor the activities and states of NSFs, and then + can make a diagnosis to see whether the NSFs are working in normal + conditions or in abnormal conditions including the insider threats + (or supply chain threats). Note that the monitoring of the DMSs is + out of scope of I2NSF. However, as a general caution, a mitigation + strategy for insider attacks and supply chain attacks is not to use + an NSF without prior testing for an automated security action in the + I2NSF system. + 9. 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). This work has been partially supported by the European Commission under Horizon 2020 grant agreement no. 700199 "Securing against @@ -915,22 +913,22 @@ 11.2. Informative References [AVANT-GUARD] Shin, S., Yegneswaran, V., Porras, P., and G. Gu, "AVANT- GUARD: Scalable and Vigilant Switch Flow Management in Software-Defined Networks", ACM CCS, November 2013. [consumer-facing-inf-dm] Jeong, J., Kim, E., Ahn, T., Kumar, R., and S. Hares, "I2NSF Consumer-Facing Interface YANG Data Model", draft- - ietf-i2nsf-consumer-facing-interface-dm-04 (work in - progress), April 2019. + ietf-i2nsf-consumer-facing-interface-dm-05 (work in + progress), June 2019. [ETSI-NFV-MANO] "Network Functions Virtualisation (NFV); Management and Orchestration", Available: https://www.etsi.org/deliver/etsi_gs/nfv- man/001_099/001/01.01.01_60/gs_nfv-man001v010101p.pdf, December 2014. [i2nsf-terminology] Hares, S., Strassner, J., Lopez, D., Xia, L., and H. @@ -938,22 +936,22 @@ Terminology", draft-ietf-i2nsf-terminology-07 (work in progress), January 2019. [ITU-T.X.800] "Security Architecture for Open Systems Interconnection for CCITT Applications", March 1991. [nsf-facing-inf-dm] Kim, J., Jeong, J., Park, J., Hares, S., and Q. Lin, "I2NSF Network Security Function-Facing Interface YANG - Data Model", draft-ietf-i2nsf-nsf-facing-interface-dm-05 - (work in progress), March 2019. + Data Model", draft-ietf-i2nsf-nsf-facing-interface-dm-06 + (work in progress), June 2019. [nsf-monitoring-dm] Jeong, J., Chung, C., Hares, S., Xia, L., and H. Birkholz, "I2NSF NSF Monitoring YANG Data Model", draft-ietf-i2nsf- nsf-monitoring-data-model-00 (work in progress), March 2019. [opsawg-firewalls] Baker, F. and P. Hoffman, "On Firewalls in Internet Security", draft-ietf-opsawg-firewalls-01 (work in @@ -961,44 +959,46 @@ [policy-translation] Yang, J., Jeong, J., and J. Kim, "Security Policy Translation in Interface to Network Security Functions", draft-yang-i2nsf-security-policy-translation-03 (work in progress), March 2019. [registration-inf-dm] Hyun, S., Jeong, J., Roh, T., Wi, S., and J. Park, "I2NSF Registration Interface YANG Data Model", draft-ietf-i2nsf- - registration-interface-dm-03 (work in progress), March + registration-interface-dm-04 (work in progress), June 2019. [VNF-ONBOARDING] "VNF Onboarding", Available: https://wiki.opnfv.org/display/mano/VNF+Onboarding, November 2016. Appendix A. Changes from draft-ietf-i2nsf-applicability-10 The following changes have been made from draft-ietf-i2nsf- - applicability-10: + applicability-11: - o In Section 1, "Network Security Function (NSF)" is replaced with - "an NSF" because the abbreviation of "Network Security Function" - is defined as "NSF" in the previous sentence. + o This version has reflected further questions and comments from + Roman Danyliw who is a Security Area Director. - o In Section 2, a typo in "funcional block" is corrected as - "functional block". + o The security issues and discussion related to Developer's + Management System (DMS) are moved to Section 8. The monitoring of + DMSs is out of scope of I2NSF. + + o Some typos are corrected. Authors' Addresses Jaehoon Paul Jeong - Department of Software + 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