[Twisted-Python] How to switch users in SSH session.

Jean-Paul Calderone exarkun at divmod.com
Fri Sep 28 05:34:22 MDT 2007


On Thu, 27 Sep 2007 15:00:14 -0500, paul_s_johnson at mnb.uscourts.gov wrote:
>After much wrangling and a small miracle I have managed to write an object
>that fetches the output of three commands in the order given through an
>SSH connection. How come I cannot switch users? Some of the information I
>need can only be fetched through a root account and security is such that
>I cannot log in remotely from a root account but must switch once logged
>in from an account with less than root privileges.
>
>Here's the line that instaniates my SSH object (also repeated at the end
>of my code):
>
>myssh = SSH("my.host.com", "myusername", "mypasswd", ["id; su - root;
>myrootpasswd; id", "pwd", "ls -l"])

I suspect the list element which includes "su - root; myrootpasswd;"
won't achieve the desired affect.  Even if su weren't careful to try
to read from a pty, "myrootpasswd" won't be sent to its stdin, it'll
be executed by the shell after "su - root" exits, which it probably
won't since nothing is going to write a password to it.

Instead, you probably need to send the password over the connection
after "su - root" has started and is waiting for the password.  I'm
not exactly sure what the steps to this in detail are, though.

Jean-Paul




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