NAME

       dns2tcpc - A tunneling tool that encapsulate TCP traffic over DNS.

SYNOPSIS

       dns2tcpc  [ -h ] [ -c ] [ -z domain zone ] [ -d debug_level ] [ -r resource ] [ -k key ] [
       -f config_file ] [ -e command ] [ -T request type ] [ -l local_port ] [ server ]

DESCRIPTION

       dns2tcpc is a network tool used to encapsulate TCP communications in DNS. When connections
       are  received on a specific port all TCP traffic is sent to the remote dns2tcpd server and
       forwarded to a specific host and port. Multiple connections are supported.

       dns2tcpc was written for demonstration purposes.

OPTIONS

       -h     Help Menu

       -c     Enable DNS compression. When used, be sure that all relay and  DNS  server  support
              compression and really use it.

       -z domain zone
              Use this domain as endpoint.

       -d debug level
              Change debug level. Levels available are 1, 2 or 3.

       -r resource
              Remote resource to access.

       -k key Pre shared key used for authentication (identification).

       -f config file
              Configuration file to use.

       -T request type
              Request type to use. Actually only KEY and TXT requests are supported.

       -e command
              Command to execute, I/O are redirected in the tunnel.

       -l local_port
              Local port accepting incoming connections (or - for stdin on UNIX systems).

       -t connection timeout
              Maximum  DNS  server's  answer delay in seconds. A valid delay is between 1 and 240
              seconds. Default is 3.

       server DNS server to use. The first entry in resolv.conf file will be chosen if the server
              is not specified.

CONFIGURATION FILES

       By  default  ${HOME}/.dns2tcprc  is used if no configuration file is specified. Here is an
       example :

              domain = dns2tcp.hsc.fr
              resource = ssltunnel
              local_port = 4430
              enable_compression = 0
              debug_level = 1
              key = mykey
              # DNS to use
              server = ns.hsc.fr

EXAMPLES

       dns2tcpc -k mykey -z dns2tcp.hsc.fr mydns

              Ask the dns2tcp server to list available resources.

       ssh -o 'ProxyCommand dns2tcpc -r ssh -l - -z dns2tcp.hsc.fr -k mykey mydns' myserver

              Use dns2tcp as a proxy command with ssh. We try to connect to the ssh resource with
              the key 'mykey' and the DNS mydns.

       dns2tcpc -r socat-resource -e '/bin/bash -i' -k mykey -z dns2tcp.hsc.fr mydns

              Use dns2tcp as a reverse shell, the remote shell will appear on the socat-resource.

       dns2tcpc -d 1 -f /dev/null -r ssl-tunnel -l 2000 -k mykey  -T KEY -z dns2tcp.hsc.fr mydns

              Do not use the default configuration file, bind local port 2000 and forward all the
              traffic on the remote ssl-tunnel resource, use the first debug level. Use KEY  type
              DNS requests.

AUTHORS

       Olivier Dembour <olivier.dembour@hsc.fr>

SEE ALSO

       ssltunnel

                                                                                      dns2tcpc(1)