From: Jeremy Bopp <jeremy@...>
Date: 2010-10-15T05:06:26+09:00
Subject: Re: How do i provide password for su command while using net/telnet in ruby

On 10/14/2010 5:22 AM, Amit Tomar wrote:
> Hii all ,
>           Am using Net/TELNET to connect to remote host trying to run su
> command in order to get root privilage this is how i doing
> 
> 
> require 'net/telnet'
>    localhost = Net::Telnet::new("Host" => "192.147.217.27",
>                                "Timeout" => 50,
>                                "Prompt" => /[$%#>] \z/n)
>    localhost.login("dvsdkrp", "dvsdkvrp") { |c| print c }
>    localhost.cmd("cd /home/dvsdkrp/workdir/smruti") { |c| print c }
>    localhost.cmd("su") { |c| print c }
>    localhost.puts("passwd"){ |c| print c }
> 
>   But am getting this error
> 
> Password: C:/Ruby/lib/ruby/1.8/net/telnet.rb:552:in `waitfor': timed out
> while waiting for more data (Timeout::Error)
>         from C:/Ruby/lib/ruby/1.8/net/telnet.rb:679:in `cmd'
>         from tel.rb:7
> 
> What should i do??

I want to think that the problem here is that the su program expects to
have a terminal so that it can disable echoing what you type for your
password and then directly read that password.  Driving a telnet session
like this does not emulate a terminal and could cause problems for su.
I would expect su to error out rather than cause a timeout though.

Are you able to configure sudo on that host?  If so you can configure it
to allow your account to run the desired command(s) without a password
and then invoke sudo instead of su.

-Jeremy