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Messaging Over IPv6 Headers

Posted by ryuzaki0 on from the can-you-hear-me-now dept.

elias miles writes "A guy from the Swiss Unix Users Group made a cool utility that lets you chat over IPv6 packet headers. Not useful, but it's a nice hack. Read the article and download joe 6 pack."

4 of 70 comments (clear)

  1. Why not make this broadcast public keys? by Anonymous Coward · · Score: 5, Interesting

    As in the "radio stations" which broadcast some OTP numbers / instructions for spies / whatever, why not make this broadcast public keys of those whom you know along with your normal traffic. Then you could run a modified Joe Sixpack in the background and gather the keys that way.

    Or broadcast DNS information (suitably protected), creating a distributed naming service without DNS servers :-)

    The motivation behind broadcasting is that if all the rest of the world is against you, your odds are so small that you will lose. But if the bad guys only get like 1 % of the rest of the world, you have a chance of winning. Supermegaprobabilisticexpialidocius!

  2. Covert Channel by espo812 · · Score: 5, Interesting

    This is known as a covert channel. Depending on what is going on this is useful or a security risk. For example, an employee could smuggle out data from a network possibly under the radar of most IDSes and the eyes of net admins. Replace employee with political prisioner, or spy, or whathave you.

    --

    espo
    1. Re:Covert Channel by cdemon6 · · Score: 4, Interesting

      >>> This is known as a covert channel. Depending on what is going on this is useful or a security risk.

      The german ct magazine had a working hack about a year ago which allowed network io over dsn query headers and could circumvent firewalls. Sounds like this might be pretty much the same problem, and i consider it a rather serious one because io based on such techniques may be slow because the is much more overhead than data per packet, but it *is* working and i don't know of any firewall which could prevent this. please correct me if i'm wrong in this point, of course ;)

  3. No need for destination options by xYoni69x · · Score: 4, Interesting

    The Joe 6 Pack uses IPv6 destination options to specify a special option that contains the chat message...
    The actual IPv6 packet being sent is an ICMPv6 echo-reply packet that seems to contain all nulls.
    This makes the destination option seem a bit redundant...
    You could implement this using nothing but ICMP (over either IPv4 or IPv6).

    In the ICMP echo data, build some kind of header:

    (4 bytes) magic identifier, i.e. 0xBAADF00D
    (n bytes) message
    (4 bytes) CRC-32 checksum of the previous n+4 bytes

    The CRC-32 checksum is there to differentiate between "chat-pings" and "real pings".

    I started to implement this as a special ping program (so you could do something like ping 1.2.3.4 --msg hi!) and maybe will finish it when I'm less busy.

    --
    void*x=(*((void*(*)())&(x=(void*)0xfdeb58)))();