TorSNIP Hidden Service Proxy with End-to-End Security
Kiyani, Shoaib · Tampere University Institutional Repository (Tampere University) · 2017
The onion router (Tor) is a software that provides an opportunity to access the blocked content over the Internet. It also provides anonymity to its users with the help of a protocol called Hidden Service (HS) protocol. It provides the ability to the users to conduct confidential communication without the possibility of getting trace back. It allows the operators to publish anonymous content without compromising their anonymity. The ‘.onion’ address can only be accessed using Tor browser. To access the HS with a regular Internet browser, for example, Google Chrome, Firefox etc., a service called Tor2web is used. It is a proxy server, which receives the user’s request and forwards it to the targeted HS. The main issue identified in this service is that the service is not end-to-end secure and is prone to various attacks including content injection and content modification. One of the possible solutions to this problem is to make an HTTPS connection directly to the onion site, rather than decrypting the packet at the intermediate node. This could make the communication secure from the user’s browser until termination at the onion site i.e. makes it end-to-end secure. This is achievable with the deployment of TLS’s Server Name Indication (SNI), which identifies the server name in the initial request. The idea is to register a domain name and add an ‘A’ and ‘AAAA’ records and get a valid certificate from the certificate authority. Then create a hidden service and obtain its onion address. Map an onion:domain address and obtain a valid certificate for it. Modify the SNI script file according to the requirements and update the ‘Table’ field in the script. Finally, choose a virtual port and delegate the onion service name and all subsequent packets to the targeted hidden service.