PAM sample application

[Peter Mikula]

> Hmm, kdyz mi posles ukazku, jak se s PAM dela v C, klidne ti to udelam pro
> Perl. Na CPANu jsem to zase nenasel (hledal jsem ty PAM moduly uz delsi
> dobu). Nasel jsem akorat k PAM HOWTO v Linuxu, ale nechce se mi to cist :(
> Ale uz jsem jednou vyhrozoval, ze chci pres PAM udelat authentizaci proti
> PostgreSQL databazi, takze nakonec tu knihovnu preci jen budu muset udelat
> :)
> 

:)) nie je to nic zlozite ...

----------------# from pam_appl docs...


       #include <security/pam_appl.h>
       #include <security/pam_misc.h>
       #include <stdio.h>

       static struct pam_conv conv = {
           misc_conv,
           NULL
       };

       int main(int argc, char *argv[])
       {
           pam_handle_t *pamh=NULL;
           int retval;
           const char *user="nobody";

           if(argc == 2) {
               user = argv[1];
           }

           if(argc > 2) {
               fprintf(stderr, "Usage: check_user [username]\n");
               exit(1);
           }

           retval = pam_start("check_user", user, &conv, &pamh);

           if (retval == PAM_SUCCESS)
               retval = pam_authenticate(pamh, 0);    /* is user really user? */

           if (retval == PAM_SUCCESS)
               retval = pam_acct_mgmt(pamh, 0);       /* permitted access? */

           /* This is where we have been authorized or not. */

           if (retval == PAM_SUCCESS) {
               fprintf(stdout, "Authenticated\n");
           } else {
               fprintf(stdout, "Not Authenticated\n");
           }

           if (pam_end(pamh,retval) != PAM_SUCCESS) {     /* close Linux-PAM */
               pamh = NULL;
               fprintf(stderr, "check_user: failed to release authenticator\n");
               exit(1);
           }

           return ( retval == PAM_SUCCESS ? 0:1 );       /* indicate success */
       }