“Secure” migration to host identity based networks Kristian Slavov, Patrik Salmela Ericsson Research, NomadicLab NordicHIP

Assumptions Host Identity based network Hosts in the network utilise host identity binding protocols for communications Hosts in the network utilise host identity binding protocols for communications HIP, NodeID HIP, NodeID Legacy host Doesn’t support used communication protocols Doesn’t support used communication protocols Cannot address all hosts due to complex global network Cannot address all hosts due to complex global network Need to authenticates to the network Need to authenticates to the network

Problems Legacy host How to connect to a host not necessarily reachable via legacy techniques? How to connect to a host not necessarily reachable via legacy techniques? Peer host How to identify and authenticate the client? How to identify and authenticate the client? What is required? Security features, network protocol agility, name resolution Security features, network protocol agility, name resolution

HIP Proxy Basically a simple proxy Store-(modify)-forward Store-(modify)-forward Can do name resolution for the client host Can do name resolution for the client host Additional features Can create HIP connections on behalf of the legacy host Can create HIP connections on behalf of the legacy host Creates temporary host identities for legacy hosts Enables a mobile sub-network

Legacy Authentication Service Understands legacy authentication procedures SIM, HTTP-Digest, etc. SIM, HTTP-Digest, etc. Stores (host) identities for subscribed users AuC, AAA, etc. AuC, AAA, etc. Issues binding certificates for temporary and permanent (host) identities.

λ*λ* β β*β* LAS HIP Proxy Legacy host performs network attachment. HIP Proxy generates temporary identity for the legacy proxy. α*α*

λ*λ* β β*β* LAS HIP Proxy Legacy host authenticates itself to the network. A HIP connection is established between HIP proxy and the authentication server. α*α*

λ*λ* β β*β* LAS HIP Proxy As a result LAS creates identity binding certificate for the HIP proxy. α*α* α β

λ*λ* β β*β* LAS HIP Proxy Traffic sent by the legacy host is intercepted at the HIP proxy. New HIP association is created using identity certificate provided by the LAS. α*α* α β

Recap HIP Proxy creates temporary host identity to a legacy host Legacy host authenticates to LAS LAS negotiates with HIP Proxy and issues a certificate binding temporary identity and permanent identity together. Legacy host initiates connection to a peer host HIP Proxy intercepts, runs connection establishment protocol with the peer host using identity certificate Traffic flows between legacy host and peer host

Weaknesses Network access divided into two parts with different (security) properties access network (i.e. legacy host to HIP proxy) access network (i.e. legacy host to HIP proxy) core network (i.e. HIP proxy to peer host) core network (i.e. HIP proxy to peer host) Access network is insecure Security depends on the legacy host Security depends on the legacy host Identification in the access network Identification in the access network

Security problems HIP proxy Uses legacy host’s identity to do bad things Uses legacy host’s identity to do bad things Target for hacking attacks Operators may certify HIP proxies Operators may certify HIP proxies LAS configured to issue identity binding certificates only to trusted HIP proxies Certificate revocation Lifetimes Lifetimes The peer host must explicitly check from the CA The peer host must explicitly check from the CA The peer host could subscribe for revocation info at the LAS of the certificate Name resolution No DNSSEC or alike No DNSSEC or alike HIP proxy needs to tamper the DNS queries/replies

Conclusion Allows legacy hosts to communicate with “full-featured” hosts Allows the peer hosts to associate the legacy host with proper host identity Allows certain type of network mobility for legacy hosts An opportunistic security solution