---
name: "obfsproxy"
section: "1"
platform: "linux"
package: "obfsproxy"
version: "0.2.13-3"
release: "Debian 10 (Buster)"
platforms: ["linux"]
url: "https://new.carta.tech/obfsproxy"
---

# obfsproxy(1)

a pluggable transports proxy

## NAME

obfsproxy - a pluggable transports proxy

## SYNOPSIS

obfsproxy \[--log-file *log\_file*\] \[--log-min-severity *severity*\] \[--no-log\] \[--no-safe-logging\] managed obfsproxy \[--log-file *log\_file*\] \[--log-min-severity *severity*\] \[--no-log\] \[--no-safe-logging\] *transport* \[-h\] \[--dest *dest*\] \[--ext-cookie-file *ext\_cookie\_file*\] ... *mode* *listen\_addr* obfsproxy --help

## DESCRIPTION

**obfsproxy** is a tool that attempts to circumvent censorship, by transforming the Tor traffic between the client and the bridge. This way, censors, who usually monitor traffic between the client and the bridge, will see innocent-looking transformed traffic instead of the actual Tor traffic.

## OPTIONS

- **--log-file** *log\_file*

  Set logfile location.

- **--log-min-severity** *severity*

  Set minimum logging severity (default: no logging). *severity* must be one of **error**, **warning**, **info**, **debug**.

- **--no-log**

  Disable logging.

- **--no-safe-logging**

  Disable safe (scrubbed address) logging.

- **-h, --help**

  Show help message and exit.

## MANAGED TRANSPORT

Using **managed** as *TRANSPORT* allows Tor to start and control obfsproxy by itself. Add a line like the following to torrc to use it when acting as a bridge:

```
ServerTransportPlugin obfs3,scramblesuit exec /usr/bin/obfsproxy managed
```

When connecting to an obfuscated bridge, adapt the following:

```
ClientTransportPlugin obfs3,scramblesuit exec /usr/bin/obfsproxy managed
```

## DUMMY TRANSPORT

Use a protocol that simply proxies data without obfuscating them. For tests only.

No extra options.

## B64 TRANSPORT

Use a protocol that encodes data with **base64** before pushing them to the network.

No extra options.

## OBFS2 TRANSPORT

Use the **obfs2** protocol. **obfs2 is known to be fingerprintable and is deprecated.** See https://gitweb.torproject.org/obfsproxy.git/blob/HEAD:/doc/obfs2/protocol-spec.txt for the specification.

No extra options.

## OBFS3 TRANSPORT

Use the **obfs3** protocol. See https://gitweb.torproject.org/pluggable-transports/obfsproxy.git/blob/HEAD:/doc/obfs3/obfs3-protocol-spec.txt for the specification.

No extra options.

## SCRAMBLESUIT TRANSPORT

Use the **scramblesuit** protocol. See https://gitweb.torproject.org/pluggable-transports/obfsproxy.git/blob/HEAD:/doc/scramblesuit/scramblesuit-spec.txt for the specification.

**--password** *password*

Shared secret for UniformDH. In server mode, a secret will be automatically generated if unspecified.

In order to configure a password with Tor on the server side, the following can be added to torrc:

```
ServerTransportOptions scramblesuit password=WFVTIHBLAHNBXWSUD6WYTEST42LPIPRT
```

Tor clients (using a version later than 0.2.5.1-alpha) can then use:

```
Bridge scramblesuit 192.0.2.42:2032 password=WFVTIHBLAHNBXWSUD6WYTEST42LPIPRT
```

## COMMON TRANSPORT OPTIONS

Here’s the common synopsis:

Options common for all transports:

**transport**

One of **managed**, **dummy**, **b64**, **obfs2**, **obfs3** or **scramblesuit**. See above for details.

- **-h**

  Show help message and exit.

- **--dest** *dest*

  Set destination address. Mandatory in all modes except **socks**.

- **--ext-cookie-file** *ext\_cookie\_file*

  Configure the filesystem path where the Extended ORPort authentication cookie is stored.

**mode**

Mode must be one of **server** (old-style ServerTransportPlugin), **ext\_server** (support for Extended ORPort), **client** (bridge client) or **socks** (client using SOCKS to connect to bridges).

**listen\_addr**

Address on which the proxy will listen.

## BUGS

Plenty, probably. **obfsproxy** is still in development. Please report them.

## AUTHORS

George Kadianakis \<asn@torproject.org\>

Philipp Winter \<phw@torproject.org\>

Brandon Wiley \<brandon@blanu.net\>