Multitun – Tunnel arbitrary traffic through an innocuous WebSocket

https://github.com/covertcodes/multitun

by aburan28 • 12 years ago

18 7 12 years ago

github.com

pielud2• 12 years ago

This looks pretty cool, but why not just run sshd on port 80/443 then use corkscrew[1] to tunnel through an http proxy?

[1] http://www.agroman.net/corkscrew/

voltagex_• 12 years ago

Does corkscrew still use HTTP CONNECT? That's often blocked.

pielud2• 12 years ago

Ah yes, looks like it does use CONNECT.

ryan-c2• 12 years ago

The use of SHA-2-224 is kinda weird.

Based on a quick skim:

* no kdf on the password, just SHA-2-224(password)

* uses the same key and iv (which always starts as 0) in both directions

* uses CFB mode without a MAC, which has malleability issues (IIRC you can flip bits in a ciphertext block, and the same bits will be flipped in the plaintext, but the rest of the stream will be garbage).

* the authentication used is pretty sketchy (the key is fixed at 16 bytes and PW_LEN 15, so ljust shouldn't be doing anything):

    if tmp_data[:len(self.key)].ljust(PW_LEN,'0') != self.key.ljust(PW_LEN, '0'):
        log.msg("Remote unauthorized", logLevel=logging.INFO)

Reminds me of this: https://www.cs.auckland.ac.nz/~pgut001/pubs/linux_vpn.txt

rapidally2• 12 years ago

The IV doesn't start as zero; it starts as a random number.

ryan-c2• 12 years ago

Oh, you are correct. It's chosen by the client here:

https://github.com/covertcodes/multitun/blob/master/multitun...

V1• 12 years ago

To bad that networks/proxies usually block websocket connections causing this solution to fail.

Multitun – Tunnel arbitrary traffic through an innocuous WebSocket

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