pam_usb/src/pam.c

/*
 * Copyright (c) 2003-2007 Andrea Luzzardi <scox@sig11.org>
 *
 * This file is part of the pam_usb project. pam_usb is free software;
 * you can redistribute it and/or modify it under the terms of the GNU General
 * Public License version 2, as published by the Free Software Foundation.
 *
 * pam_usb is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51 Franklin
 * Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#define PAM_SM_AUTH
#include <security/pam_modules.h>
#include <security/_pam_macros.h>

#include "version.h"
#include "conf.h"
#include "log.h"
#include "local.h"
#include "device.h"

PAM_EXTERN
int pam_sm_authenticate(pam_handle_t *pamh, int flags,
		int argc, const char **argv)
{
	t_pusb_options	opts;
	const char		*service;
	const char		*user;
	const char		*tty;
	char			*conf_file = PUSB_CONF_FILE;
	int				retval;

	pusb_log_init(&opts);
	retval = pam_get_item(pamh, PAM_SERVICE,
			(const void **)(const void *)&service);
	if (retval != PAM_SUCCESS)
	{
		log_error("Unable to retrieve the PAM service name.\n");
		return (PAM_AUTH_ERR);
	}

	if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS || !user || !*user)
	{
		log_error("Unable to retrieve the PAM user name.\n");
		return (PAM_AUTH_ERR);
	}

	if (argc > 1)
		if (!strcmp(argv[0], "-c"))
			conf_file = (char *)argv[1];
	if (!pusb_conf_init(&opts))
		return (PAM_AUTH_ERR);
	if (!pusb_conf_parse(conf_file, &opts, user, service))
		return (PAM_AUTH_ERR);

	if (!opts.enable)
	{
		log_debug("Not enabled, exiting...\n");
		return (PAM_IGNORE);
	}

	log_info("pam_usb v%s\n", PUSB_VERSION);
	log_info("Authentication request for user \"%s\" (%s)\n",
			user, service);

	if (pam_get_item(pamh, PAM_TTY,
				(const void **)(const void *)&tty) == PAM_SUCCESS)
	{
		if (tty && !strcmp(tty, "ssh"))
		{
			log_debug("SSH Authentication, aborting.\n");
			return (PAM_AUTH_ERR);
		}
	}
	if (!pusb_local_login(&opts, user))
	{
		log_error("Access denied.\n");
		return (PAM_AUTH_ERR);
	}
	if (pusb_device_check(&opts, user))
	{
		log_info("Access granted.\n");
		return (PAM_SUCCESS);
	}
	log_error("Access denied.\n");
	return (PAM_AUTH_ERR);
}

PAM_EXTERN
int pam_sm_setcred(pam_handle_t *pamh,int flags,int argc,
		const char **argv)
{
	return (PAM_SUCCESS);
}

#ifdef PAM_STATIC

struct pam_module _pam_usb_modstruct = {
	"pam_usb",
	pam_sm_authenticate,
	pam_sm_setcred,
	NULL,
	NULL,
	NULL,
	NULL
};

#endif