Internet Engineering Task Force Internet Draft J. Palet A. Vives Consulintel Document: draft-palet-v6ops-ipv6security-00.txt G. Martinez A. Gomez Univ. of Murcia Category: Expires: August 2004 February 2004 IPv6 distributed security requirements draft-palet-v6ops-ipv6security-00.txt Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026 [i]. 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". The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. draft-palet-v6ops-ipv6security-00.txt Expires - August 2004 [Page 1] Internet Draft IPv6 distributed security requirements February 2004 Abstract The security policies currently applied in Internet with IPv4, doesnÆt longer apply for end-to-end security models which IPv6 will enable. Today, each network is often secured by a unique device (i.e. security gateway or firewall), that becomes a bottleneck for the end- to-end security model with IPv6. In addition, users and devices start to be nomadic, moving between different networks that could have different security policies. A distributed and dynamic approach is consequently required. draft-palet-v6ops-ipv6security-00.txt Expires - August 2004 [Page 2] Internet Draft IPv6 distributed security requirements February 2004 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 [ii]. draft-palet-v6ops-ipv6security-00.txt Expires - August 2004 [Page 3] Internet Draft IPv6 distributed security requirements February 2004 Table of Contents 1. Introduction...................................................4 2. Distributed security model.....................................5 3. Interior security..............................................6 4. The visiting node..............................................6 5. Default security...............................................6 6. The security policy server and protocol........................7 7. Single versus multiple point of attack.........................8 8. Non-security-capable nodes and security workload distribution..9 9. Location of the security policy server.........................9 10. Virus and spam................................................9 11. Security Considerations......................................10 12. References...................................................10 Acknowledgments..................................................10 Authors' Addresses...............................................10 Intellectual Property Statement..................................11 Full Copyright Statement.........................................11 Acknowledgement..................................................12 1. Introduction The todayÆs Internet paradigms for security need a revision with the deployment of IPv6, offering end-to-end security capabilities. Current security policies based on a centric approach with unique border devices donÆt longer apply. Often they are based in a firewall or security gateway and statically configured rules. draft-palet-v6ops-ipv6security-00.txt Expires - August 2004 [Page 4] Internet Draft IPv6 distributed security requirements February 2004 Users and devices start to be nomadic. They often move from one network to another and this needs to be taken in consideration to keep the security of the complete visited network. Keeping todayÆs static security model is a wrong approach, which disables the end-to-end features and advantages of IPv6. Enforcing the nomadic users and devices to connect to Internet by means of the security device, is almost equivalent to disable the IPsec stack on each node, thus invalidating one of the key IPv6 advantages. On the other hand, is also true and perfectly understandable that there is a need to enforce security in the networks, in such way that the network administrator has always the control over it. 2. Distributed security model The paradigm is to keep or even being able to increase the security in the network as a whole and keep the control of it under the network administrator hands, while the individual nodes can take advantage of end-to-end and secure end-to-end communications. This can be achieved with a distributed model replacing the current central one. The distributed security model implies the use of node or personal firewalls. These node or personal firewalls must respect the security policy of the network where they are attached. The effect is simple to understand: instead of a single firewall, a single point of failure for the complete network, that could be easily attacked or fail, and create a single bottleneck for all the communications, there will be a number of firewalls, configured according a central policy, which increase the reliability, efficiency and performance of the complete network. This is possible in most of the situations because, even if IPsec and encryption are enforced for most of the communications, nodes often have powerful CPUs with unused cycles that will easily accommodate the extra required workload. On the other hand, the central firewalls will be able to dedicate CPU cycles to new functions, or be able to protect bigger networks. draft-palet-v6ops-ipv6security-00.txt Expires - August 2004 [Page 5] Internet Draft IPv6 distributed security requirements February 2004 3. Interior security With this approach, the security of each node is not only towards communications with Internet or other networks, but also with the rest of the nodes in the same network. This means an increase in the overall security and the possibility to isolate individual nodes if required. 4. The visiting node This distributed security model is valid not only for fixed nodes, i.e. desktop computers, but specially interesting and important for those nodes like laptops and PDAs, which keep moving among different networks. Vice versa, this model is of key importance for those networks that receive visits from nodes that are not under the control of the network administrator. Different visited networks have different security requirements. Consequently is required that those nomadic nodes dynamically accommodate their own security policy to the one defined in the visited network. Nodes attaching to a network via VPNs, RAS, directly attached modems or other similar means can also be considered as visiting nodes, as they can also create a path between the visited network and any other network where they are actually connected. They must also be able to dynamically configure their own security to match the one existing in then visited network. The alternative often used today to accomplish this, is by means of manual changes in the configuration of the visiting node, but they are always prone to errors and dangerous to be considered useful and secure enough. 5. Default security Implementing IPsec in the IPv6 stack of the nodes is only a first step for a sophisticated security model. A more complete approach is needed. These nodes can be attached to a network which doesnÆt offer any protection means, not only against external attacks, but also those coming from the same network. This is the common case, for example, in hotspots, public networks, ad-hoc networks or even networks temporarily setup for conferences. draft-palet-v6ops-ipv6security-00.txt Expires - August 2004 [Page 6] Internet Draft IPv6 distributed security requirements February 2004 In order to keep the appropriate security level, each node should incorporate a kind of personal or node firewall. The node firewall must be configured by default with a very restrictive set of rules. At this way, the node is self-defended, in any circumstance. The node firewall must act as a policy enforcer. The node firewall should offer a simple user interface to facilitate to relax the security restrictions, if required by certain applications or services, assuming the lack of expertise of the user. 6. The security policy server and protocol In order to achieve the benefits of the distributed security model, and at the same time provide a mean for an adequate control of the overall network security by the network administrator, a security policy server is required. The policy server(s) could replace the central firewall and complement it. The network administrator will define the security rules required by all the network and/or individual nodes. The different nodes should query to the policy server to learn about the network security policy and adapt themselves in order to match it. When a node is attached to a visited network and receives the visited network security policy, basically there are two possible situations: a) The network security policy is less or same restrictive than the node configuration. In this case, the node will not change its security policy configuration. b) The network security policy is more restrictive than the node configuration. In this case, the node will adapt its security configuration to at least match the one indicated by the security policy. Until the node performs and acknowledge the required security policy configuration update, it will not be allowed to transfer/receive data to/from other nodes either in the network or other connected networks. The security policy server can also dynamically update the security policy for the complete network or specific nodes. This can be done in response to a network administrator decision, or other situations, draft-palet-v6ops-ipv6security-00.txt Expires - August 2004 [Page 7] Internet Draft IPv6 distributed security requirements February 2004 like information received from an external or internal attack, detected by an intrusion detection system, firewall or even by nodes inside the network. The security policy can be setup at a network level or individually for every node, upon decision of the network administrator. A single standard language or protocol for the signaling between the nodes, security policy servers, firewalls (including node firewalls), intrusion detections systems, honey pots, routers, and any other elements implicated in the overall network and nodes security is required. For simplicity, the policy server could be integrated in the border router, firewall, or other network elements (AAA, DHCP, COPS, ...). A possible approach is to align this with the existing COPS [iii] and COPS-PR [iv] standards. According this, the network administrator will use a PMT (Policy Management Tool), to edit the policies, distributed them via PMP (Policy Decision Points), to the PEP (Policy Enforcement Points). For the interaction with IPsec policies, it seems appropriate the existing IPsecCPIM [v]. To guarantee the self-security of this model, the security policy being communicated to the nodes should be digitally signed, in order to provide integrity, origin authentication and non-repudiate authenticity of the source. 7. Single versus multiple point of attack The single security gateway approach is a single point of failure and consequently a bottleneck. At the same time, is easier to attack a single device, so the possibilities of a security threat are higher. On the other hand, the distributed approach reduces the risk of a single point of failure and increases the difficulties for potential attackers to succeed (port scanning is more difficult). The failure of the central firewall could completely disconnect the network from Internet or other networks. In the case of a central policy server fail, the nodes can be configured by the security policy in such way that continue working, keeping the same security restrictions imposed by the policy server. draft-palet-v6ops-ipv6security-00.txt Expires - August 2004 [Page 8] Internet Draft IPv6 distributed security requirements February 2004 8. Non-security-capable nodes and security workload distribution Increase in security often means increase in processing power. Some nodes could not have the required CPU cycles to afford the complete required security policy. The firewalls or even other security-capable nodes with free resources, could act as trusted security gateways for the non- security-capable nodes. This seems only possible if minimum security verification can be done by those nodes, i.e. digital signature verification. It could be even considered a system to provide a kind of security workload-balancing. Some work is still required to define if the security level that can be achieved by those nodes is good enough, and to avoid possible attacks. This section needs to be completed in further revisions of this document. 9. Location of the security policy server Firewalls and security gateways are expensive devices and they are required to sit at the border of the network. They also require qualified personal to manage them. In the case of the distributed security model, the security policy server isnÆt required to be collocated as a border device. This provides the opportunity to have this device not only inside the network, but also at any other point in Internet. This opens the doors to new services and business models that provide very sophisticated security services, especially for SOHO and SMEs. Internet Exchanges, PoPs, ISPs, and other similar central Internet locations seem to be ideal locations for the security policy servers. 10. Virus and spam As part of the services offered by the distributed security model, it should be considered means to alleviate the effects of virus and spam. draft-palet-v6ops-ipv6security-00.txt Expires - August 2004 [Page 9] Internet Draft IPv6 distributed security requirements February 2004 This could mean for example, extensions to protocols as SMTP. To be completed in next versions of the document. 11. Security Considerations To be completed in next versions of the document. 12. References i S. Bradner, "The Internet Standards Process -- Revision 3", BCP 9, RFC 2026, October 1996. ii S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. iii D. Durham, Ed., "The COPS (Common Open Policy Service) Protocol", RFC 2748, January 2000. iv K. Chan et al, "COPS Usage for Policy Provisioning (COPS-PR)", RFC 3084, March 2001. v J. Jason et al, "IPsec Configuration Policy Information Model", RFC 3585, August 2003. Acknowledgments The authors would also like to acknowledge the inputs from Cesar Olvera and the European Commission support in the co-funding of the Euro6IX project, where this work is being developed. Authors' Addresses Jordi Palet Martinez Consulintel San Jose Artesano, 1 28108 - Alcobendas (Madrid - Spain) Phone: +34 91 151 81 99 Fax: +34 91 151 81 98 Email: jordi.palet@consulintel.es Alvaro Vives Consulintel San Jose Artesano, 1 draft-palet-v6ops-ipv6security-00.txt Expires - August 2004 [Page 10] Internet Draft IPv6 distributed security requirements February 2004 28108 - Alcobendas (Madrid - Spain) Phone: +34 91 151 81 99 Fax: +34 91 151 81 98 Email: alvaro.vives@consulintel.es Gregorio Martinez University of Murcia (UMU) Campus de Espinardo s/n 30071 - Murcia (Spain) Phone: +34 Fax: +34 Email: gregorio@dif.um.es Antonio Gomez Skarmeta Consulintel Campus de Espinardo s/n 30071 - Murcia (Madrid - Spain) Phone: +34 Fax: +34 Email: skarmeta@dif.um.es Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. 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All Rights Reserved. draft-palet-v6ops-ipv6security-00.txt Expires - August 2004 [Page 11] Internet Draft IPv6 distributed security requirements February 2004 This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. 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