view debian/README.Debian @ 1715:3974f087d9c0

Disallow leading lines before the ident for server (#102) Per RFC4253 4.2 clients must be able to process other lines of data before the version string, server behavior is not defined neither with MUST/SHOULD nor with MAY. If server process up to 50 lines too - it may cause too long hanging session with invalid/evil client that consume host resources and potentially may lead to DDoS on poor embedded boxes. Let's require first line from client to be version string and fail early if it's not - matches both RFC and real OpenSSH behavior.
author Vladislav Grishenko <themiron@users.noreply.github.com>
date Mon, 15 Jun 2020 18:22:18 +0500
parents fe6bca95afa7
children
line wrap: on
line source

Dropbear for Debian
-------------------

This package will attempt to listen on port 22. If the OpenSSH 
package ("ssh") is installed, the file /etc/default/dropbear 
will be set up so that the server does not start by default.

You can run Dropbear concurrently with OpenSSH 'sshd' by 
modifying /etc/default/dropbear so that "NO_START" is set to 
"0" and changing the port number that Dropbear runs on. Follow 
the instructions in the file.

This package suggests you install the "ssh" package. This package 
provides the "ssh" client program, as well as the "/usr/bin/scp" 
binary you will need to be able to retrieve files from a server 
running Dropbear via SCP.

Replacing OpenSSH "sshd" with Dropbear
--------------------------------------

You will still want to have the "ssh" package installed, as it 
provides the "ssh" and "scp" binaries. When you install this 
package, it checks for existing OpenSSH host keys and if found, 
converts them to the Dropbear format.

If this appears to have worked, you should be able to change over 
by following these steps:

1. Stop the OpenSSH server
   % /etc/init.d/ssh stop
2. Prevent the OpenSSH server from starting in the future
   % touch /etc/ssh/sshd_not_to_be_run
3. Modify the Dropbear defaults file, set NO_START to 0 and 
   ensure DROPBEAR_PORT is set to 22.
   % editor /etc/default/dropbear
4. Restart the Dropbear server.
   % /etc/init.d/dropbear restart

See the Dropbear homepage for more information:
  http://matt.ucc.asn.au/dropbear/dropbear.html