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

int main () 
{
  struct pam_conv pamc;
  pam_handle_t* pamh;

  pamc.conv = &misc_conv;
  pamc.appdata_ptr = NULL;

  pam_start ("login", getenv ("USER"), &pamc, &pamh);

  if (pam_authenticate (pamh, 0) != PAM_SUCCESS) {
    fprintf (stderr, "Authentication failed.\n");
  } else {
    fprintf (stderr, "Authentication OK.\n");
  }

  pam_end (pamh, 0);
  return 0;
}