Advanced Onion Router
Description
Advanced Onion Router, commonly called AdvOR, combines the functionality of three different tools — Tor, Vidalia and Privoxy — into one portable executable for Windows. Rather than installing and configuring each part separately, the user simply extracts the downloaded archive and runs the program directly. AdvOR writes all its settings to its own folder and never touches the Windows registry, which means that it runs just as well from a USB drive as it does from a local hard disk.
The program connects to the Tor anonymity network, which passes outgoing traffic through a series of relay nodes operated by volunteers before it leaves to the open internet. Each relay in the chain only knows the identity of the node immediately before and after it, so no single relay can link the user’s actual IP address to the destination they visit. AdvOR builds on this foundation and adds a control interface and a number of privacy extensions that are not included by default by the standard Tor client.
PROCESS INTERCEPTION
One of AdvOR’s most practical features is its point-and-click process interceptor. Standard Tor usage requires the target application to support SOCKS proxies and have them configured manually. Advanced Onion Router overcomes this limitation completely: the user simply selects any running process from a list, and AdvOR forces all TCP connections from that process through the Tor network, regardless of the application’s own proxy settings. At the same time, AdvOR feeds the intercepted process fabricated information about the local system, so that it cannot leak the real local IP address or hardware identifiers through side channels.
PROXY AND HTTP FEATURES
Advanced Onion Router exposes both the HTTP and the HTTPS proxy protocols on the same port that handles the SOCKS4 and SOCKS5 connections. This means that most browsers and tools that speak the language of the HTTP proxies connect without needing any extra configuration. The header filtering module for the web protocol (HTTP) creates fake headers that are linked to the current identity every time the user switches to a new Tor circuit, making it more difficult for remote servers to track sessions across identity changes. AdvOR also supports NTLM proxy authentication, which allows users to sit behind corporate or institutional proxies and still send their traffic out through Tor. Proxy chains — sequences of intermediate proxies before the Tor entry node — work as well.
CIRCUIT AND ROUTING CONTROL
AdvOR gives the user direct control over the formation of Tor circuits. The software calculates the Autonomous System (AS) path for each circuit and is able to reject circuits where two or more hops have the same AS, which reduces the risk that a single network operator sees both the entry and exit traffic. The user can also limit the construction of circuits so that guard, middle and exit nodes are from different countries, distributing geographic exposure across jurisdictions. Circuit length itself is adjustable beyond Tor’s default of three hops. AdvOR supports .onion addresses natively, so hidden services on the Tor network resolve without any additional configuration.
IDENTITY MANAGEMENT
Advanced Onion Router changes identity on demand or on a configurable schedule. Each new identity requests a new Tor circuit with different entrance and exit nodes. The automatic IP change feature can use an exit selection algorithm to select nodes according to the user’s criteria — country, speed, or AS diversity — instead of taking whatever circuit Tor builds by default. A local banlist allows the user to prevent certain IP addresses or ranges of IP addresses from being used as exit nodes, which is useful to avoid exits with known poor reputations or exits that are part of surveillance infrastructure.
PRIVACY ISOLATION
Private identity isolation prevents different application sessions from sharing circuits. When two separate processes are running through AdvOR simultaneously, the isolation feature ensures that they do not use the same Tor circuit, so a correlation attack against one session does not automatically reveal the other. This is most important when a user is running a browser and a separate messaging client at the same time and wants to make sure that neither session can link back to the other by sharing routing.
UNICODE AND LOCALIZATION
AdvOR deals with Unicode file paths properly throughout the application, which is important for users whose system accounts or working directories contain non-ASCII characters. The interface supports multiple languages and the developer distributes the program with localization files that cover a range of character sets.
ONION ADDRESS GENERATOR
A built-in generator allows users to generate vanity .onion addresses using a desired prefix. Generating a matching address is a brute force key generation, so short prefixes will finish quickly and longer ones will take more time depending on hardware. The tool integrates directly into AdvOR without having to run a separate application.
SYSTEM Requirements and Availability
AdvOR works on Windows XP to Windows 11 in both 32-bit and 64-bit versions. The download is about 5MB in size. There is no installation process, the user extracts the archive and runs the executable. The current release is version 0.3.2.0. The source code is located at github.com/AdvOR under a combination of licenses: the Tor core is under the Tor Project’s BSD-style license, while the graphical interface and extensions that were written by Albu Cristian are under the Creative Commons Attribution-NonCommercial-ShareAlike license.
LIMITATIONS
Because AdvOR sends traffic through the Tor network, the connection speeds are slower than a direct connection. The extent of the slowdown depends on the current state of the Tor network and the exit nodes that AdvOR chooses. The Tor Project recommends not routing BitTorrent traffic through Tor, and this is true of AdvOR. Some websites actively block known Tor exit nodes, which can interrupt access to some services no matter which client the user runs.
