/*
  This program was contributed by Shane Watts
  [modifications by AGM]

  You need to add the following (or equivalent) to the /etc/pam.conf file.
  # check authorization
  check_user   auth       required     /usr/lib/security/pam_unix_auth.so
  check_user   account    required     /usr/lib/security/pam_unix_acct.so
 */

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

/* declare functions */
void dump(int retval);

int my_conv(int num_msg, const struct pam_message **msg,
	    struct pam_response **resp,
	    void *appdata_ptr);


static struct pam_conv conv = {
    misc_conv,
    /*my_conv,*/
    NULL
};



/*****************************************'
 * functions
 */

void dump(int retval) {
	printf("Retval=%i\n",retval);
}

int my_conv(int num_msg, const struct pam_message **msg,
	    struct pam_response **resp,
	    void *appdata_ptr)
{

//	struct pam_message my_msg;

	return PAM_SUCCESS;
}

int main(int argc, char *argv[])
{
    pam_handle_t *pamh=NULL;
    int retval;
    const char *user,*service;

    if(argc != 3 ) {
        fprintf(stderr, "Usage: check_user <service> <username>\n");
        exit(1);
    }

    service = argv[1];
    user = argv[2];

    retval = pam_start(service, user, &conv, &pamh);
    dump(retval);
    if (retval == PAM_SUCCESS)
        retval = pam_authenticate(pamh, 0);    /* is user really user? */
    dump(retval);

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

    /* 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 */
}