[techtalk] Security techniques ( Redhat 6.2 question)

Beverly Guillermo mezanin at home.com
Tue May 23 21:34:55 EST 2000


On Tue, 23 May 2000, Alex Yan wrote:

> I think that the hosts.allow and hosts.deny files are both used by
> tcpd, and if she's not running inetd, then she's probably not running
> anything with the tcpd wrapper, in which case, whatever remaining
> services she has won't use those files for keeping out intruders.
> 
> This is the way I think it works:
> 
>  inetd: looks up all the services in inetd.conf and connects them to
> 	their respective ports
> 
>  tcpd:  a wrapper for running those services, which reads hosts.allow
> 	and hosts.deny to determine whether a client has permissions
> 	to connect to that service.  tcpd is usually invoked in
> 	inetd.conf:
> 
> 	telnet  stream  tcp     nowait  root    /usr/sbin/tcpd in.telnetd
> 
>  in.telnetd: one of the services that is run, wrapped by tcpd, managed
> 	by inetd.
> 
> So theoretically, one could run those services with the tcpd wrapper
> directly, which would still give you that nice security layer.  But I
> don't know how to do that.  :)

True.  I did forget to mention that part, didn't I?  Most integral
services can use the tcpwrapper, and I recommend using them if you're
going to use services like telnetd, fingerd, ftpd, etc..

That's another thing, I recommend using secure alternatives to those
services.  The only thing I can think of right now is ssh instead of
telnet or rlogin... =)


> I hope I didn't confuse anyone.

Not here. =)

Beverly






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