Re: [Nss-mysql-users] command line password changer tool

[Guillaume Morin]

Dans un message du 28 jan à 15:55, Daniel Drotos écrivait :
> If somebody interested, I wrote a simple command line tool to change
> passwords handled by nss-mysql:
> 
> http://mazsola.iit.uni-miskolc.hu/~drdani/prj/mysqlpasswd
 
I had a quick look of your code. I have some remarks

Compile: cc -DUSE_SHADOW -DUSE_GROUP -I$$HOME/nss-mysql-0.35 -ggdb \
            -o mysqlpasswd mysqlpasswd.c -lcrypt -lmysqlclient
            -lnss_mysql

I think you should not link your binary against nss-mysql but compile
some nss-mysql objects (like parser.o and lib.o)

  euid= geteuid();
  ruid= getuid();
  if (euid != 0)
    {
      fprintf(stderr, "Insufficient permissions\n");
      return(30);
    }
  if (debug) printf("real uid=%d effective uid=%d\n",ruid,euid);

  _nss_mysql_read_conf_file("users",
                            &nss_options, NULL, NULL);
  /*_nss_mysql_read_conf_file("groups",
  &nss_options, &nss_goptions, &nss_soptions);*/
  _nss_mysql_read_conf_file("shadow",
                            /*&nss_options*/NULL,
                            /*&nss_goptions*/NULL,
                            &nss_soptions);


Do not trust geteuid or getuid. e.g

address@hidden:~$ cat te.c
#include <unistd.h>
#include <sys/types.h>
#include <stdio.h>
#include <errno.h>

int main(void) {
        printf("%d %d\n",geteuid(),getuid());
        if (! fopen("/etc/shadow","r"))
                perror("fopen");
        return 0;
}
address@hidden:~$ ./te
1000 1000
fopen: Permission denied
address@hidden:~$ fakeroot ./te
0 0
fopen: Permission denied
address@hidden:~$ su
Password:
siri:/home/guillaum# ./te
0 0
siri:/home/guillaum# exit
address@hidden:~$

It is easy to work around gete?uid... Test the return value of
_nss_mysql_read_conf_file, it is much better and should have done it
anyway :-)

You might want to use readline to read the password. It would ease your
task..

-- 
Guillaume Morin <address@hidden>

   I'm unclean, a libertine, every time you vent your spleen, I seem to lose
    the power of speech, you're slipping slowly from my reach, you grow me
        like an evergreen, you've never seen me lonely at all. (Placebo)