传递euid和egid给脚本，使脚本具有特殊用户的权限
使脚本实现类似于设置了stick位的效果
shell，python，perl等脚本、程序不能取得suid，因为这些脚本程序需要解释器-/bin/bash，/usr/bin/python等来执行，而这些解释器本身没有suid也不方便设置suid。碰到这种情况可以用c写一个外壳，对这个外壳设置suid，而在c程序里面把自身的uid，gid传递给实际执行任务的脚本。
c程序如下：
/* # ScriptName: transeuid.c
# Author: JH Gao <gaopenghigh@gmail.com>
# Create Date: 2012-06-05
# Function: transmit euid and egid to other scripts
# since shell/python/... scripts can't get suid permission in Linux
# usage: transeuid xxx.sh par1 par2 par3
# xxx.sh will get the euid and egid from transeuid
# ******************************************************************** */ #include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#define BUFFSIZE 1024 /*
* usually euid is the uid who run the program
* but when stick is setted to the program
* euid is the uid or the program's owner
*/
int main(int argc, char *argv[]) {
char *cmd = malloc(BUFFSIZE);
// set uid and gid to euid and egid
setuid(geteuid());
setgid(getegid());
cmd = argv[1];
int i = 0;
for(i = 0;i < argc - 1;i++) {
argv[i] = argv[i+1];
}
argv[argc-1] = NULL
// search $PATH find this cmd and run it with pars:argv
if (execvp(cmd, argv)) {
printf("error");
free(cmd);
exit(1);
}
free(cmd);
} |
编译这个程序，在给这个程序设置希望取得的用户，再设置suid，然后就可以用这个用户的权限执行脚本或命令了：
Shell代码：
$ gcc -t transeuid transeuid.c
$ sudo chown root transeuid
$ sudo chmod +s transeuid
$ ./transeuid ls /root /home
/home:
. .. data .directory gp_old jh jh_old lost+found /root:
. .. .bash_history .bashrc .cache .dbus .profile .pulse .pulse-cookie .viminfo |
