table of contents
| dns2tcpc(1) | General Commands Manual | dns2tcpc(1) |
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 incomming 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 choosen 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.