Embrace RPKI to Secure BGP Routing, Cloudflare Says
22.9.2018 securityweek Safety

BGP (Border Gateway Protocol) routing isn’t secure and organizations should embrace Resource Public Key Infrastructure (RPKI) to improve security, Cloudflare says.

Border Gateway Protocol was designed to control the route of data across the Internet. The state of BGP route validation, the website protection company argues, hasn’t seen improvements, thus leading to route leaks and hijacks.

As part of BGP hijacking, attackers take over IP address groups by corrupting the routing tables that store the path to a network.

RPKI, “a cryptographic method of signing records that associate a BGP route announcement with the correct originating AS number,” can improve BGP routing-security globally, but only if it would enjoy broad adoption, such as being deployed by multiple major network operators, Cloudflare claims.

Around 8.7% of the IPv4 Internet routes are currently signed with RPKI, yet only 0.5% of all the networks apply strict RPKI validation, statistics reveal.

Although there are protections in place to manage which network can announce which route and to allow one network to filter another network’s routes, route leaks and hijacks do happen, with the most recent of them involving a Russian ISP rerouting traffic from major tech firms, and the BGP hijack of payment processors.

Although the Internet Routing Registry (IRR) system provides a method to manage the routes, a network can announce, it doesn’t cryptographically sign its data, and the IRR databases contain plenty of invalid data, Cloudflare says. RPKI can secure the route origin and represents a first step in improving the BGP route security.

“Records exist within IRRs that are both clearly wrong and/or are clearly missing. There’s no cryptographic signing of records. There are multiple suppliers of IRR data; some better than others,” Cloudflare’s Martin J Levy points out.

Both IRR and RPKI use third-party entities to hold the database information, but, with the latter, the same entity that allocated or assigned a numeric resource (like an IP address or ASN) also holds the TA (Trust Anchor – same as Certificate Authority for web certificates) used to validate the ROA’s (Route Origin Authorization) record.

Today, there are five Regional Internet Registries (RIR) (Afrinic for Africa; APNIC for Asia-Pacific; ARIN for North America; LACNIC for Central and South America; and RIPE for Europe, Middle-East and Russia) and they are the TAs for RPKI.

“The present day RPKI systems operate in conjunction with existing RIR login credentials. Once you can login to a portal and control your IP allocations and ASN allocations; then you can also create, edit, modify, and delete RPKI data in the forms of ROAs. This is the basis of how RPKI separates itself from the IRR. You can only sign your own resources. You can’t just randomly create data. If you lose your RIR allocation, then you lose the RPKI data,” Levy explains.

The issues that arise from this setup include the fact that any ISP with an allocation needs to keep its RIR membership up to date and that the international law plays a role in any dispute between the ISP and RIR, as they might be entities based in different countries.

Despite the obvious benefits, RPKI has seen low adoption, even RIRs are supporting RPKI for their members. One issue would be the limited toolset for successfully operating a network with RPKI enabled route filtering.

According to Levy, IXP (Internet Exchange Points) are noticing that filtering using RPKI is a valid option for their route-servers and a handful of networks are signing IP routes and verifying IP routes via RPKI, which represents a step forward, although a small one.

“RPKI is not a bullet-proof solution to securing all routing on the Internet, however it represents the first milestone in moving from trust based to authentication based routing. Our intention is to demonstrate that it can be done simply and cost efficiently. We are inviting operators of critical Internet infrastructure to follow us in a large scale deployment,” Cloudflare’s Jérôme Fleury and Louis Poinsignon note in a blog post.