I2NSF L. Xia Internet Draft Huawei Intended status: Standard Track E. Lopez Fortinet D Zhang Alibaba N. BOUTHORS Qosmos Expires: January 2016 July 1, 2015 Information Model of Interface to Network Security Functions Capability Interface draft-xia-i2nsf-capability-interface-im-02.txt 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), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. 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." 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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. Abstract This draft is focused on the north-bound interface of NSFs (Network Security Functions) and proposes an information model for configuring various kinds NSF security functions, based on the packet-based paradigm. The Yang structure and application examples are also presented to clarify how to use the information model. Table of Contents 1. Introduction ................................................ 2 2. Conventions used in this document ........................... 3 2.1. Terminology ............................................ 3 3. Information Model for Capability Interface .................. 4 3.1. Overview ............................................... 4 3.2. Packet-Based Paradigm .................................. 7 3.3. Rule .................................................. 10 3.4. Match ................................................. 11 3.5. Actions ............................................... 13 4. I2NSF Capability Interface IM Yang Structure ............... 14 5. Use Examples of I2NSF Capability Interface IM .............. 17 6. Security Considerations .................................... 17 7. IANA Considerations ........................................ 17 8. References ................................................. 17 8.1. Normative References .................................. 17 8.2. Informative References ................................ 17 9. Acknowledgments ............................................ 18 1. Introduction Due to the rapid development and deployment of cloud computing services, the demand of cloud-based security services is also rapidly growing. The customers of them can be enterprises [I- D.zarny-i2nsf-data-center-use-cases], User Equipment (UE) of mobile network and Internet of Things (IoT) [I-D.qi-i2nsf-access-network- usecase], residential access users [I-D.pastor-i2nsf-access- usecases], and so on. Xia, et al. Expires January 1, 2016 [Page 2] Internet-Draft I2NSF Capability Interface IM July 2015 Derived from [I-D.dunbar-i2nsf-problem-statement], there could be two types of I2NSF interfaces: o Interface between I2NSF user/client with network/security controller: [I-D.xia-i2nsf-service-interface-DM] describes the information model used by this type of interface. It's a service- oriented interface, the main objective is to unify the communication channel and the security service request information model between various high-level application (e.g., openstack, various BSS/OSS, etc) with various network controllers. The design goal of the service interface is to decouple security service in application layer from various kinds of security devices and their device-level security functions. The intent- based information model approach derived from RBAC model can be a feasible option for it; o North-bound interface provided by NSFs (e.g., FW, AAA, IPS, Anti- DDOS, Anti-Virus, etc), no matter whether the NSFs are performed by Virtual Machines (VMs) or physical appliances. In this document, this type of interface is also referred to as "capability interface". Any network entities (e.g., I2NSF clients, network/security controller, etc) can use this interface to configure the required security functions of NSFs. Nowadays different NSF vendors have different proprietary interfaces and information models for configuring their security functions. This draft is focused on the capability interfaces and proposes an information model for configuring various kinds NSFs. It's used by the NSFs to decouple from the various security services came from the application layer and highlight the security capabilities they can provide. Section 3 defines the information model for capability interface. Section 4 gives its representation by Yang data model. Section 5 includes some using examples to clarify how to use the information model. 2. Conventions used in this document 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 [RFC2119]. 2.1. Terminology AAA -Access control, Authorization, Authentication ACL - Access Control List Xia, et al. Expires January 1, 2016 [Page 3] Internet-Draft I2NSF Capability Interface IM July 2015 AD - Active Directory ANSI - American National Standards Institute DDoS - Distributed Deny of Services FW - Firewall I2NSF - Interface to Network Security Functions INCITS - International Committee for Information Technology Standards IoT - Internet of Things IPS - Intrusion Prevention System LDAP - Lightweight Directory Access Protocol NAT - Network Address Translation NBI - North-bound Interface NIST - National Institute of Standard Technology NSF - Network Security Function RBAC - Role Based Access Control UE - User Equipment URL - Uniform/Universal Resource Locator VM - Virtual Machine 3. Information Model for Capability Interface 3.1. Overview The capability interface cares about the specific security capabilities that NSF can provide rather than the type of device that the NSF belongs. That is, it is assume that the user of the capability interface does not care about whether the NSF that it is communicating with is a firewall or an IPS. Instead, the user cares about the capability that the NSF has, such as, packet filtering, deep packet inspection, and etc. Based on this consideration, the capability interface discussed in this memo is designed based on a Xia, et al. Expires January 1, 2016 [Page 4] Internet-Draft I2NSF Capability Interface IM July 2015 generic IM that is abstracted from the various specific security capabilities. The information model specified for I2NSF capability interface is shown in Figure 1. Xia, et al. Expires January 1, 2016 [Page 5] Internet-Draft I2NSF Capability Interface IM July 2015 +-------------+ +-> User/tenant| | | /VN-id | | +-------------+ | +---------+ | |Address/ | +->address | | |group | | +---------+ | +-----------+ | |Layer 2/3/4| +->header, or | | |payload | +------+ | +-----------+ |Packet| | +---------+ +->based |-+-> Service | | |match | | +---------+ | +------+ | +-----------+ | +->Application| | +-----------+ +----+ +-----+ | | | +->Match|-+ +----------+ +-->Rule| | +-----+ | +-> Session | | | | | | | | state | | +----+ | | +-------+ | +----------+ | | | |context| | +----------+ | * | +->based +-+-> Schedule | | * | |match | | +----------+ | * | +-------+ | +---------+ | | | |Region/ | | | +->region | +------+ +----+ | |group | | | | | | | +---------+ |Policy+--+-->Rule+--+ | | | | | | +-------+ +------+ | +----+ | +->Permit + | | | +-------+ | * | +-------+ | +-------+ | * | +->Basic +-+-> Deny | | * | | |actions| | +-------+ | | | +-------+ | +-------+ | | | +-> Mirror| | | | +-------+ | | | | | | +----------+ | | | +->Antivirus:| | +----+ | | | |profile | Xia, et al. Expires January 1, 2016 [Page 6] Internet-Draft I2NSF Capability Interface IM July 2015 | | | | +-------+ | | +----------+ +-->Rule| +->Actions+-+ | +---------+ | | +-------+ | +-> IPS: | +----+ | |signature| | | +---------+ | | +----------+ | | | URL | | +->Filtering:| | |data base | | | +----------+ | +--------+ | +----------+ +->Advanced+-+ | File | |actions | +->Blocking: | +--------+ | |profile | | +----------+ | +----------+ | | Data | +->Filtering:| | |profile | | +----------+ | +-----------+ | |Application| +-> control | | +-----------+ | * +-> * * Figure 1. The Overall Information Model for I2NSF Capability Interface As illustrated in Figure 1, at the top level, policy is a container including a set of security rules. Each rule represents some specific security requirements or actions. Security policy combines these rules together according to some logic, i.e., their similarity or mutual relations, etc. A Security policy is created and assigned to any NSFs depending on specific requirements and scenarios. For example, a security policy can be responsible for an enterprise branch, or can be used for the access control to one set of services. 3.2. Packet-Based Paradigm It is clarified in [I-D.lopez-i2nsf-packet] that abstractly all NSFs are packet-processing engines that inspect packets traversing networks, either directly or in context to sessions to which the packet is associated. This draft uses this packet-based paradigm for Xia, et al. Expires January 1, 2016 [Page 7] Internet-Draft I2NSF Capability Interface IM July 2015 the design of NSF capability interface IM. This packet-based design approach is very general and easily extensible, and so can avoid any potential constraints which could limit NSFs' functional capabilities. Considering from the perspective of packet-processing, NSFs differ in the depths of packet headers and/or payloads they can inspect, the various session/context states they can maintain, and the actions or specific profiles they can apply. Therefore, the NSF capabilities can be characterized by the level of packet-processing and context that a NSF can support, and the actions and profiles that the NSF can apply. In the other hand, NSF Vendors can register their provided NSF capabilities by using the Subject-Object-Action- Function categories described by [I-D.lopez-i2nsf-packet]. Table 1-4 below lists some examples included in the categories for constructing the NSF capability: +-----------------------------------------------------------+ | Subject (packet) Capability Index | +---------------+-------------------------------------------+ | Layer 2 | Layer 2 header fields: | | Header | Source/Destination/s-VID/c-VID/EtherType/.| | | | |---------------+-------------------------------------------+ | Layer 3 | Layer header fields: | | | protocol | | IPv4 objects | port | | | src port | | | dscp | | | length | | | flags | | | ttl | | | | | IPv6 Object | | | | addr | | | protocol/nh | | | src port | | | length | | | traffic class | | | hop limit | | | flow label | | | | Xia, et al. Expires January 1, 2016 [Page 8] Internet-Draft I2NSF Capability Interface IM July 2015 | TCP | Port | | SCTP | syn | | DCCP | ack | | | fin | | | rst | | | psh | | | urg | | | window | | | sockstress | | UDP | | | | flood abuse | | | fragment abuse | | | Port | | HTTP layer | | | | hash collision | | | http - get flood | | | http - post flood | | | http - random/invalid url | | | http - slowloris | | | http - slow read | | | http - r-u-dead-yet (rudy) | | | http - malformed request | | | http - xss | | | https - ssl session exhaustion | +---------------+-------------------------------------------+ | IETF PCP | Configurable | | | Ports | | | | +---------------+-------------------------------------------+ | IETF TRAM | profile | | | | | | | |---------------+-------------------------------------------+ Table 1. Subject (packet) Capability Index +-----------------------------------------------------------+ | Object (context) Capability Index | +---------------+-------------------------------------------+ | Session | Session state, | | | bidirectional state | | | | Xia, et al. Expires January 1, 2016 [Page 9] Internet-Draft I2NSF Capability Interface IM July 2015 +---------------+-------------------------------------------+ | Time | time span | | | days, minutes, seconds, | | | Events | +---------------+-------------------------------------------+ | Events | Event URL, variables | +---------------+-------------------------------------------+ Table 2. Object (context) Capability Index +-----------------------------------------------------------+ | Actions Capability Index | +---------------+-------------------------------------------+ | Ingress port | SFC header termination , | +---------------+-------------------------------------------+ | | Pass | | Egress | Deny | | | Mirror | | | Functional call | | | Encap various header | +---------------+-------------------------------------------+ Table 3. Actions Capability Index +-----------------------------------------------------------+ | Functional profile (advanced actions) Capability Index | +---------------+-------------------------------------------+ | Profile types | Vendor specific | | | Flexible Profile URL | | | Accept external | | | | +---------------+-------------------------------------------+ Table 4. Functional profile (advanced actions) Capability Index 3.3. Rule Each rule is defined in the classic "match & action" style that already implemented in most NSFs today. The NSF follows the rules one by one to process the passing traffic as follows: Xia, et al. Expires January 1, 2016 [Page 10] Internet-Draft I2NSF Capability Interface IM July 2015 1. The NSF analyzes traffics in a packet-based match fashion or a context-based match fashion, or both. In the packet-based match fashion, the NSF only inspects the packet header and/or payload to retrieve the attributes at the network or the application layers. Such attributes could include address, length of payload, port, protocol, user, and etc. When performing a context-based match, besides retrieving and analyzing the attributes from the packet, the NSF also needs to check some of the attributes against contextual attributes (e.g., session state, schedule and region) in order to decide the ways of processing the packets; 2. The NSF compares the attributes with the match conditions defined in the first rule. If all the conditions are met, the traffic matches the rule. If one or more conditions are not met, the NSF compares the attributes with the conditions of objects defined in the next rule. If all rules are not met, the NSF denies the traffic by default; 3. If the traffic matches a rule, the NSF performs the defined basic actions over the traffic. If the basic action is deny, the NSF blocks the traffic. If the basic action is permit/mirror, the NSF resumes checking whether certain advanced actions are referenced in the rule. If yes, go to step 4. If no, the traffic is permitted; 4. If certain advanced actions (e.g., Antivirus, IPS, etc) are referenced in the rule and the basic action defined in the rule is permit/mirror, the NSF performs integrated checks on the content carried over the traffic. The integrated check inspects the content carried over the traffic based on the conditions defined in the referenced profiles of advanced action and implements appropriate actions based on the check result. If any advanced action determines to block the traffic, the NSF blocks the traffic. If all advanced actions determine to permit the traffic, the NSF allows the traffic through. One rule can be applied multiple times on different places, i.e., links, devices, networks, vpns, etc. It not only guarantees the consistent policy enforcement in the whole network, but also decreases the configuration workload. 3.4. Match Match (aka, Objects) consists of two categories of match condition: packet-based match and context-based match. Each category includes various match conditions representing different kinds of objects. The logic relation among all the conditions is flexible, it can be Xia, et al. Expires January 1, 2016 [Page 11] Internet-Draft I2NSF Capability Interface IM July 2015 "AND", "OR". The former means the traffic must match all the conditions, while the latter means the traffic only needs to match one of the conditions. The general objects for packet-based match are as follows: o User: A user is a person applicaiton who is authorized to access network resources. A user can be an internet access user who accesses Internet resources or intranet resources from inside the intranet through a FW, or a remote access user who connects to a FW in VPN, or PPPoE mode to access intranet resources. The NSFs need to know the IP address or other information (i.e., user's tenant or VN-ID) of the user to identify the user's traffic and perform the pre-defined actions. It can also define a group of users to match and perform actions to them together; o Source and destination address scope; o Layer 2/3/4 header, or payload related attributes: other meaningful and useful attributes in packet except for existing objects; o Service: A service is an application identified by a protocol type and port number. It can be a service or a group of services. NSF matches the service traffics based on the protocol types and port numbers and applies the security actions to them; o Application: An application is a computer program for a specific task or purpose, and multiple applications constitute an application group. It provides a finer granularity than service in matching traffic. Even if different applications have the same service, they still can be distinguished by analyzing the data packets and comparing the signatures of each application. The hierarchy category method is appropriate for identifying applications. For example, the application of Gmail belongs to the category of business systems, and the subcategory of Email. Other key attributes that belongs to and can be used to identify an application are data transmission model (e.g., client-server, browser-based, networking, peer-to-peer, etc), risk level (e.g., Exploitable, Evasive, Data-loss, Bandwidth-consuming, etc). The general objects for context-based match are as follows: o Session state: any one specific state related to the user/operation sessions, such as authentication state, TCP/UDP session state, bidirectional state, etc; Xia, et al. Expires January 1, 2016 [Page 12] Internet-Draft I2NSF Capability Interface IM July 2015 o Schedule: A schedule defines time ranges. A rule can reference a schedule to filter traffic that passes through the NSF within the schedule. A schedule can be a periodic schedule, or a one-time schedule; o Region/region group: the logical definition of users' location which can be pre-defined in the in the location signature database by the geographical information, or be manual defined by the user's IP information. Objects are extensible, new match conditions can be defined and added into them any time according to requirements. 3.5. Actions The action of a security rule is also divided into two categories logically: basic actions and advanced actions. Basic actions are either permit, deny or mirror. Deny simple means to block the matching traffics. Permit and mirror have more meanings by performing the referenced advanced actions. The all advanced actions in one rule can inspect traffic content during one-pass, which greatly improves system performance. Every advanced action includes its own matching conditions to identify specific traffic and perform required actions. The advanced action is defined by specific requirements or for specific scenarios. Some typical advanced actions are Antivirus, IPS, URL filtering, File blocking, Data filtering, Application control, and so on. To deal with the situation of emerging new threats, i.e., zero-day exploits, unknown malwares, APTs, NSF's advanced actions (aka functions) should have the capability of dynamic update. A NSF should be able to load the new advanced action and/or update the signature used by existing functions when an unknown threat is identified. The new advanced actions and signature can be provided by different security vendors after their research on the new threats and sent and stored in a centralized policy repository or stored separately in their local policy repository. Anyway, a standard interface is needed when the NSF negotiates with the policy repository about the new functions/signatures needed. Additionally, I2NSF capability interface should have the unified information model to configure and apply all these functions/signatures. The details will be added in future version. By combining advanced actions and using them appropriately, NSFs can defend against possible attacks and reduce the waste of system resources. Xia, et al. Expires January 1, 2016 [Page 13] Internet-Draft I2NSF Capability Interface IM July 2015 4. I2NSF Capability Interface IM Yang Structure This section specifies the I2NSF capability interface information model in Yang structure [RFC6020]. module: Security Policies +--security-policies +--rw policy-set* [policy-name] +--rw policy-name string +--rw policy-id uint16 +--rw security-rules +--rw rule-set* [rule-name] +--rw rule-name string +--rw rule-id uint16 +--rw Match | +--rw packet-based-match | | +--rw user* [login-name] | | | +--rw login-name string | | | +--rw display-name string | | | +--rw group-name string | | | +--rw description string | | | +--rw parent-group string | | | +--rw password string | | | +--rw expired-date data-and-time | | | +--rw allow-multi-account-login boolean | | | +--rw address-binding Boolean Xia, et al. Expires January 1, 2016 [Page 14] Internet-Draft I2NSF Capability Interface IM July 2015 | | | +--rw tenant? uint32 | | | +--rw VN-id? uint32 | | +--rw address-scope* | | | +--rw src-address inet:ip-prefix | | | +--rw dst-address inet:ip-prefix | | +--rw layer-header-payload* | | | ... | | +--rw service* [name] | | | +--rw name string | | | +--rw description string | | | +--rw protocol enumeration | | | +--rw protocol-num uint8 | | | +--rw src-port-num uint16 | | | +--rw dest-port-num uint16 | | +--rw application* [name] | | | +--rw name string | | | +--rw server-address inet:ip-address | | | +--rw protocol enumeration | | | +--rw dest-port-num uint16 | | | +--rw category enumeration | | | +--rw subcategory enumeration | | | +--rw data-transmission-model enumeration | | | +--rw risk-level enumeration | +--rw context-based-match Xia, et al. Expires January 1, 2016 [Page 15] Internet-Draft I2NSF Capability Interface IM July 2015 | +--rw session-state* | | ... | +--rw schedule* [name] | | +--rw name string | | +--rw type enumeration | | +--rw start-time data-and-time | | +--rw end-time data-and-time | | +--rw weekly-validity-time? data-and-time | +--rw region* | ... +--rw actions +--rw basic-actions enumeration +--rw advanced-actions* [name] +--rw name string +--rw profile-antivirus? | ... +--rw profile-IPS? | ... +--rw profile-url-filtering? | ... +--rw profile-file-blocking? | ... +--rw profile-data-filtering? | ... Xia, et al. Expires January 1, 2016 [Page 16] Internet-Draft I2NSF Capability Interface IM July 2015 +--rw profile-application-control? | ... 5. Use Examples of I2NSF Capability Interface IM TBD 6. Security Considerations TBD 7. IANA Considerations 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2234] Crocker, D. and Overell, P.(Editors), "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, Internet Mail Consortium and Demon Internet Ltd., November 1997. [RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, October 2010. 8.2. Informative References [INCITS359 RBAC] NIST/INCITS, "American National Standard for Information Technology - Role Based Access Control", INCITS 359, April, 2003 [I-D.zarny-i2nsf-data-center-use-cases] Zarny, M., et.al., "I2NSF Data Center Use Cases", Work in Progress, October 2014. [I-D.qi-i2nsf-access-network-usecase] Qi, M., et.al., "Integrated Security with Access Network Use Case", Work in Progress, October, 2014. Xia, et al. Expires January 1, 2016 [Page 17] Internet-Draft I2NSF Capability Interface IM July 2015 [I-D.pastor-i2nsf-access-usecases] Pastor, A., et.al., "Access Use Cases for an Open OAM Interface to Virtualized Security Services", Work in Progress, October, 2014. [I-D.dunbar-i2nsf-problem-statement] Dunbar, L., et.al., "Interface to Network Security Functions Problem Statement", Work in Progress, September, 2014. [I-D.xia-i2nsf-service-interface-DM] Xia, L., et.al., "Data Model of Interface to Network Security Functions Service Interface", February, 2015. [I-D.lopez-i2nsf-packet] Lopez, E., "Packet-Based Paradigm For Interfaces To NSFs", March, 2015. 9. Acknowledgments This document was prepared using 2-Word-v2.0.template.dot. Xia, et al. Expires January 1, 2016 [Page 18] Internet-Draft I2NSF Capability Interface IM July 2015 Authors' Addresses Liang Xia (Frank) Huawei 101 Software Avenue, Yuhuatai District Nanjing, Jiangsu 210012 China Email: Frank.xialiang@huawei.com Edward Lopez Fortinet 899 Kifer Road Sunnyvale, CA 94086 Phone: +1 703 220 0988 EMail: elopez@fortinet.com DaCheng Zhang Alibaba Email: Dacheng.zdc@alibaba-inc.com Nicolas BOUTHORS Qosmos Email: Nicolas.BOUTHORS@qosmos.com Xia, et al. Expires January 1, 2016 [Page 19]