/*	$OpenBSD: login_kerberos.c,v 1.1 2000/12/12 02:31:38 millert Exp $	*/

/*-
 * Copyright (c) 1995 Berkeley Software Design, Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Berkeley Software Design,
 *      Inc.
 * 4. The name of Berkeley Software Design, Inc.  may not be used to endorse
 *    or promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN, INC. ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN, INC. BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	BSDI $From: login_kerberos.c,v 1.15 1997/08/08 18:58:22 prb Exp $
 */
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/file.h>
#include <sys/wait.h>

#include <err.h>
#include <errno.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <util.h>

#include <login_cap.h>
#include <bsd_auth.h>

#ifdef	KERBEROS
#include <kerberosIV/krb.h>
#endif

int	klogin __P((struct passwd *, char *, char *, char *));
int	krb_configured __P((void));
int	koktologin __P((char *, char *, char *));

int	always_use_klogin;
int	notickets = 1;
char	*krbtkfile_env;
int	authok;

int
main(argc, argv)
	int argc;
	char *argv[];
{
	FILE *back;
	struct passwd *pwd;
	char *p, *class, *username, *instance, *wheel;
	char localhost[MAXHOSTNAMELEN], response[1024];
	int c, krb_configed = 0, mode, rval, lastchance;
	struct rlimit rl;
	login_cap_t *lc;

	rl.rlim_cur = 0;
	rl.rlim_max = 0;
	(void)setrlimit(RLIMIT_CORE, &rl);

	(void)signal(SIGQUIT, SIG_IGN);
	(void)signal(SIGINT, SIG_IGN);
	(void)setpriority(PRIO_PROCESS, 0, 0);

	openlog(NULL, LOG_ODELAY, LOG_AUTH);

	if (gethostname(localhost, sizeof(localhost)) < 0)
		syslog(LOG_ERR, "couldn't get local hostname: %m");

	class = NULL;
	username = NULL;
	instance = NULL;
	wheel = NULL;
	mode = 0;
	rval = 1;
	back = NULL;
	p = NULL;
	lastchance = 0;
	
	while ((c = getopt(argc, argv, "dv:s:")) != -1)
		switch(c) {
		case 'd':
			back = stdout;
			break;

		case 'v':
			if (strncmp(optarg, "wheel=", 6) == 0)
				wheel = optarg + 6;
			else if (strncmp(optarg, "lastchance=", 10) == 0)
				lastchance = (strcmp(optarg + 10, "yes") == 0);
			break;
		case 's':	/* service */
			if (strcmp(optarg, "login") == 0)
				mode = 0;
			else if (strcmp(optarg, "challenge") == 0)
				mode = 1;
			else if (strcmp(optarg, "response") == 0)
				mode = 2;
			else {
				syslog(LOG_ERR, "invalid service: %s", optarg);
				exit(1);
			}
			break;
		default:
			syslog(LOG_ERR, "usage error");
			exit(1);
		}

	switch(argc - optind) {
	case 2:
		class = argv[optind + 1];
	case 1:
		username = argv[optind];
		break;
	default:
		syslog(LOG_ERR, "usage error");
		exit(1);
	}

	instance = strchr(username, '.');
	if (instance)
		*instance++ = '\0';
	else
		instance = "";

	if (back == NULL && (back = fdopen(3, "r+")) == NULL)  {
		syslog(LOG_ERR, "reopening back channel: %m");
		exit(1);
	}

	pwd = getpwnam(username);
	if (pwd)
		pwd = pw_dup(pwd);
	if (class && pwd)
		pwd->pw_class = class;

	if (pwd == NULL || (lc = login_getclass(pwd->pw_class)) == NULL)
		always_use_klogin = 1;
	else
		always_use_klogin = login_getcapbool(lc, "alwaysuseklogin", 0);

#if defined(KERBEROS)
	krb_configed = (krb_configured() != KFAILURE);
#endif

#if defined(PASSWD)
	if (wheel != NULL && strcmp(wheel, "yes") != 0 &&
	    (!krb_configed || pwd == NULL ||
	    koktologin(pwd->pw_name, instance,
	    strcmp(instance, "root") == 0 ? instance : pwd->pw_name))) {
		fprintf(back, BI_VALUE " errormsg %s\n",
		    auth_mkvalue("you are not in group wheel"));
		fprintf(back, BI_REJECT "\n");
		exit(1);
	}

	if (*instance == '\0' && pwd && *pwd->pw_passwd == '\0') {
		fprintf(back, BI_AUTH "\n");
		exit(0);
	}
#else
	if (!krb_configed) {
		syslog(LOG_ERR, "Kerberos not configured");
		exit(1);
	}
	if (koktologin(pwd->pw_name, instance, strcmp(instance, "root") == 0 ?
	    instance : pwd->pw_name)) {
		fprintf(back, BI_REJECT "\n");
		exit(1);
	}
#endif

	if (mode == 1) {
		fprintf(back, BI_SILENT "\n");
		exit(0);
	}

	(void)setpriority(PRIO_PROCESS, 0, -4);

	if (mode == 2) {
		mode = 0;
		c = -1;
		while (++c < sizeof(response) &&
		    read(3, &response[c], 1) == 1) {
			if (response[c] == '\0' && ++mode == 2)
				break;
			if (response[c] == '\0' && mode == 1)
				p = response + c + 1;
		}
		if (mode < 2) {
			syslog(LOG_ERR, "protocol error on back channel");
			exit(1);
		}
	} else
#if defined(PASSWD)
		p = getpass("Password:");
#else
		p = getpass("Kerberos Password:");
#endif

	if (pwd) {
#if defined(KERBEROS)
		rval = krb_configed ? klogin(pwd, instance, localhost, p) : 1;
		if (rval == 0)
			if (*instance && strcmp(instance, "root") == 0)
				fprintf(back, BI_ROOTOKAY "\n");
			else
				fprintf(back, BI_AUTH "\n");
		else if (rval == 1)
#endif
#if defined(PASSWD)
		{
			if (wheel != NULL && strcmp(wheel, "yes") != 0)
				exit(1);
			if (*instance &&
			    (strcmp(instance, "root") != 0 ||
			    (pwd = getpwnam(instance)) == NULL)) {
				crypt(p, "xx");
				memset(p, 0, strlen(p));
				exit(1);
			}
			rval = strcmp(crypt(p, pwd->pw_passwd), pwd->pw_passwd);
			if (rval == 0)
				rval = login_check_expire(back, pwd, class,
				    lastchance);
		}
#else
		{ ; }
#endif
	}
#if defined(PASSWD)
	else
		crypt(p, "xx");
#endif
	memset(p, 0, strlen(p));

	if (!pwd || rval)
		exit(1);
	fprintf(back, BI_AUTH "\n");

	if (krbtkfile_env) {
		fprintf(back, BI_REMOVE " %s\n", krbtkfile_env);
		fprintf(back, BI_SETENV " KRBTKFILE %s\n", krbtkfile_env);
	}
	return(0);
}

#if !defined(KERBEROS)
int
koktologin(name, instance, user)
        char *name, *instance, *user;
{

	return(1);
}
#endif