topic Re: ksh & rksh in Operating System - HP-UX

ksh & rksh

Indrajit_1 — Sun, 12 Feb 2006 12:24:41 GMT

Hi All;

What is major diffrence between ksh & rksh. If i chage the shell from rksh to ksh, what will be the security thread??

Cheers
Indrajit

Re: ksh & rksh

Steven E. Protter — Sun, 12 Feb 2006 13:15:04 GMT

Shalom Indrajit,

Congrats on your new ITRC hat. !!!!

Answers with better discussion than I can type at this hour.

http://www.in-ulm.de/~mascheck/various/shells/

http://www.scit.wlv.ac.uk/cgi-bin/mansec?1+ksh

http://bama.ua.edu/cgi-bin/man-cgi?ksh+1

The r stands for restricted, which severely limits what a user can do.

SEP

Re: ksh & rksh

Shivam Tiwari — Sun, 12 Feb 2006 14:44:37 GMT

Indrajit,

One more for better understanding

http://docs.sun.com/app/docs/doc/802-1930-01/6i5u959p8?a=view

HTH,

Shivam Tiwari

Re: ksh & rksh

Shivam Tiwari — Sun, 12 Feb 2006 14:46:02 GMT

/usr/xpg4/bin/sh is identical to /usr/bin/ksh, a command and programming language that executes commands read from a terminal or a file. rksh is a restricted version of the command interpreter ksh; it is used to set up login names and execution environments whose capabilities are more controlled than those of the standard shell.

HTH,

Shivam Tiwari

Re: ksh & rksh

Bill Hassell — Sun, 12 Feb 2006 19:57:03 GMT

If a user currently has rksh as their shell, it was done as a conscious decision to severely restrict what that user can do. I assume that you don't know the reason that rksh was given to certain users, but changing it to ksh can be a security risk (the users are obviously not senior Unix users) but it can also increase mistakes that can be made with the the full ksh shell. I would not change to ksh until the reason for the restriction is well understood. Naturally, the system administrator cannot use rksh (or any other restricted shell).

Re: ksh & rksh

Arunvijai_4 — Sun, 12 Feb 2006 23:14:29 GMT

Hi Indrajit,

"rksh" is a restricted shell. It differs from ksh in the following ways,

The following actions cannot be performed:

* Changing directories
* Setting the SHELL and PATH variables to new values
* Using command names or paths containing a /
* Redirecting output (> and >>)

You can refer, http://duplex.hypermart.net/books/bsd/283-285.html
for more information .

-Arun

Re: ksh & rksh

Muthukumar_5 — Mon, 13 Feb 2006 01:36:19 GMT

See man ksh page. It is having an answer to your question as,

The actions of rksh are identical to those of ksh, except that the
following are forbidden:

+ Changing directory (see cd(1))
+ Setting the value of SHELL, ENV, or PATH
+ Specifying path or command names containing /
+ Redirecting output (>, >|, <>, and >>)

The restrictions above are enforced after the .profile and ENV files
are interpreted.

--
Muthu

Re: ksh & rksh

Indrajit_1 — Mon, 13 Feb 2006 12:30:27 GMT

Thanks to all

Cheers
indrajit