hansis

Es gibt Momente in denen vorherrschenden Netzwerkumgebungen nicht vertraut werden kann bzw. will (z.B. wenn man über einen unverschlüsselten WLAN Hotspot suft, so wie ich gerade ) , in solchen Momenten bietet sich (fast) immer SSH an .

SSH hat einen “eingebauten” SOCKS Proxy der sehr Trivial zu bedienen ist:

$ ssh -N -C -D port user@zielrechner

In meinem Wahlbrowser kann ich nun einfach einen SOCKS Proxy definieren.
Im Firefox kann ich das z.B. so tun:
Edit -> Preferences -> Advanced -> Network -> Settings -> Manual Proxy Configuration

Als SOCKS Proxy trage ich nun “localhost” bzw “127.0.0.1″ und als Port denselben wie oben.

Ich kann euch auch das Firefox Plugin “SwitchProxy” empfehlen dadurch wird das proxywechseln (vor allem wenn wir diese öfters wechseln ) zum Kinderspiel!

Das tolle daran ist, das SSH ersten ein Standardtool ist und somit auf sehr vielen Linuxen/Unixen installiert ist, zweitens lange Konfigurationsorgien entfallen wenn mal fix ein SOCKS Proxy benötigt wird :) .

Legende:

       -D [bind_address:] port
              Specifies  a  local “dynamic” application-level port forwarding.  This works
              by allocating a socket to listen to port on the local side,  optionally  bound
              to  the  specified  bind_address.  Whenever a connection is made to this port,
              the connection is forwarded over the secure channel, and the application
              protocol  is  then used to determine where to connect to from the remote machine.
              Currently the SOCKS4 and SOCKS5 protocols are supported, and ssh will act as a
              SOCKS  server.  Only root can forward privileged ports.  Dynamic port forwardings
              can also be specified in the configuration file.

              IPv6 addresses can be specified with an alternative syntax:
               [bind_address/] port or by enclosing the address in  square  brackets.   Only
              the  superuser  can  forward  privileged ports.  By default, the local port is
              bound in accordance with  the  GatewayPorts  setting.   However,  an  explicit
              bind_address  may  be  used to bind the connection to a specific address.  The
              bind_address of “localhost” indicates that the listening port be  bound  for
              local  use  only, while an empty address or ‘*’ indicates that the port should
              be available from all interfaces.

       -C     Requests  compression  of  all data (including stdin, stdout, stderr, and data
              for forwarded X11 and TCP connections).  The compression algorithm is the same
              used  by  gzip(1), and the "level" can be controlled by the CompressionLevel
              option for protocol version 1.  Compression is desirable on  modem  lines  and
              other  slow connections, but will only slow down things on fast networks.  The
              default value can be set on a host-by-host basis in the  configuration  files;
              see the Compression option.

       -N     Do not execute a remote command.  This is useful  for  just  forwarding  ports
              (protocol version 2 only).

This entry was posted on Monday, July 14th, 2008 at 6:30 pm and is filed under Computer, Computer Frei. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.