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Securing Zeroconf Networks draft-williams-zeroconf-security-00.txt. Aidan Williams Motorola Australian Research Centre Aidan.Williams@motorola.com Steve Hanna Sun Microsystems Steve.Hanna@east.sun.com. Presentation Outline. Background Characteristics Evaluate two approaches: Use IPSec
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Securing Zeroconf Networksdraft-williams-zeroconf-security-00.txt Aidan Williams Motorola Australian Research Centre Aidan.Williams@motorola.com Steve Hanna Sun Microsystems Steve.Hanna@east.sun.com
Presentation Outline • Background • Characteristics • Evaluate two approaches: • Use IPSec • Secure various protocols • Conclusion
Background • Security requires configuration • Is not pure zeroconf • Can be done within the spirit of zeroconf? • Motivating scenarios • Adhoc networks • Home networking
Characteristics • Want to form groups of devices which can communicate securely, with ease • Assume that there is some kind of secret sharing scheme available • Zeroconf protocols often check for configuration servers • Security in candidate protocols is usually limited to request/response authentication.Probably not good enough.
Evaluate Two Approaches • Use IPSec to provide network layer security • Secure candidate protocols individually
IPSec for ZC security • Pre-shared secret used to authenticate IKE Phase-1, unicast SAs negotiated as usual • IKE cannot be used to negotiate SAs for multicast and broadcast • Can either: • Configure an SA and SPI on devices “manually” when the secret is shared • Wait for smug/msec to define protocols
Proto: interface configuration • IPv4 link local relies on claim/collide using ARP. ARP as specified cannot be secured. • IPv6 address autoconfiguration uses claim/collide with IP multicast neighbour discovery: • If we secure IP multicast with IPSec,we secure neighbour discovery • Thus we can secure IPv6 interface config
Proto: multicast DNS • DNS is secured using DNSSEC • Resolver starts with a trusted key, builds paths to other zones retrieving and verifying KEY and SIG RRs from the DNS. • Use pre-shared secret for SIGs • DNSSEC does not: • Provide confidentiality • Authenticate requests
Proto: SLPv2 • Optional authentication • No confidentiality • Authentication mandates DSA+SHA-1 digital signature • Could: • Pre-share a DSA key-pair • Add another authentication scheme and ignore the DSA one
Proto: AutoAAP • Claim/collide • Recommends the use of IPSec for security, specifies no additional mechanisms • Uses multicast, therefore needs shared SA/SPI
Conclusions • Bootstrapping IPSec seems promising • The candidate protocols described need significant work, in particular to support confidentiality • Having one scheme which covered all the protocols would be really nice