Re: 'becomes' script

On 10/6/2002 20:55, Will Partain wrote (in an accidentally off-list thread
caused by me):

>> [On the gripping hand, perhaps you could just use Python as the remote
>> interpreter and throw a short script at it that changes gid/uid and then
>> invokes sh with a literal string as input. becomes is so simple that there's
>> no particular need for it to be separate.]
> 
> I like this idea, actually... I think.  We start either
> 
>  ssh remote sudo python
> 
> or just 'ssh remote python', send through all of the
> preliminaries (including user/group setting), then send
> through a last "line" of
> 
>  os.execl('/bin/sh','/bin/sh','-c',"""<the code>""")
> 
> and you'll tell me how to escape <the code> so it doesn't
> ever no-matter-what have """ in it :-)

Aha. My plan here was to use os.popen rather than os.execl then pump in a
literal string as input. So on the sending side you'd build a script
something like:

    pyscript = """import os,sys
    os.setgid( %d )
    os.setuid( %d )
    sh = os.popen( '%s', 'w', 0 )
    sh.write( '''%s''' )
    if sh.close() is not None:
        sys.exit( 1 )
    """ % ( gid, uid, shcmd, shscript )

then you'd throw this at 'ssh remote sudo python'.

The inspiration for this was realising that the whole of your becomes script
would fit in one ssh-compressed eth packet, so the whole shenanigans of
installing it seemed overkill.

Jonathan

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