
Encrypted Internet traffic is an essential element to enable security and privacy in the Internet. Surveys show that websites are more and more being served over HTTPS. They highlight an increase of 48% of sites using TLS over the past year, justifying the tendency that the Web is going to be encrypted. This motivates the development of new tools and methods to monitor and filter HTTPS traffic. This paper handles the latest technique for HTTPS traffic filtering that is based on the Server Name Indication (SNI) field of TLS and which has been recently implemented in many firewall solutions. Our main contribution is an evaluation of the reliability of this SNI extension for properly identifying and filtering HTTPS traffic. We show that SNI has two weaknesses, regarding (1) backward compatibility and (2) multiple services using a single certificate. We demonstrate thanks to a web browser plug-in called " Escape " that we designed and implemented, how these weaknesses can be practically used to bypass firewalls and monitoring systems relying on SNI. The results show positive evaluation (firewall's rules successfully bypassed) for all tested websites.
monitoring, [INFO.INFO-NI] Computer Science [cs]/Networking and Internet Architecture [cs.NI], TLS, security, HTTPS, firewall
monitoring, [INFO.INFO-NI] Computer Science [cs]/Networking and Internet Architecture [cs.NI], TLS, security, HTTPS, firewall
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 22 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Top 10% | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Top 10% |
