Privacy Leaks Via SNI and Certificate Parsing

In the current digital era, it is essential to provide secure and confidential communication over the internet. In order to accomplish this, Transport Layer Security (TLS), is essential. To create a secure connection, TLS requires the exchange of sensitive data, such as the Server Name Indication (SNI), which could put user privacy at risk. Our study delves into the privacy implications of SNI by creating modules that analyze SNI in the ClientHello Message and TLS certificates. The SNI Parser navigates TLS handshake payload in ClientHello packet, and extracts Server Name Indication. By examining SNI, we gain insights into potential privacy risks associated with unencrypted domain name, which can help in devising effective privacy protection mechanisms. The paper then elucidates how to extract important data from X.509 certificates by providing the server name to the certificate parser that was developed. This research contributes to the comprehension of SNI-related privacy concerns, with the goal of improving user privacy and ensuring a secure online environment.