su ,how ?

[Frank Li]

Hi ,

We know when you run "su " , the system will prompt you for passwd , after you type the correct root passwd , you will get the shell for root (The prompt is #) .

Here I want to implement such program named "chsu" so that certain persons need not type the root passwd to get root access when they execte chsu .

I wrote a program in c ( chsu.c) with the "setuid(0)" in it and change the exection file(chsu) persion to 4755 , I can get the root permission , but not the same as execute "su" , for example , when you execute "su" , you get "#" for root . and the command "id" are different after you execte "chsu" and "su" .

chsu.c
#######################
#include
#include

main()
{

// if the user is granted to execute this program
// maybe can control by a file chsu.txt
// ....
setuid(0);
system("sh");

}
#######################################

Any body can give hint to me ? such as how to write such a program,
or how to write a program like "su"
( I am not a C programer , so if you give me the source file , Great!!)

thanks
Frank Li

[Klaus Crusius]

main( argc, argv ) {

setuid(0);
execv( "/usr/bin/su", argv );
}

should do.
Klaus

[Wodisch]

Hello Frank,

get a copy of "sudo", edit the "/etc/sudoers" config file
and live happily ever after ;-)
Do NOT go for your first attempt of your script, as that
is much (MUCH) to dangerous!!!

Be careful,
Wodisch

[linuxfan]

Hi frank,

I completely agree with Wodisch here. You can download sudo either from
ftp://ftp.courtesan.com/sudo/dist/sudo-1.6.3p7.tar.gz
or in swinstall format
http://hpux.cs.utah.edu/hppd/hpux/Sysadmin/sudo-1.6.2b1/

The good thing using sudo, users can execute commands as other users or root, without knowing any other passwords beside their own

-HTH
Ramesh